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tkBind.c

/* 
 * tkBind.c --
 *
 *    This file provides procedures that associate Tcl commands
 *    with X events or sequences of X events.
 *
 * Copyright (c) 1989-1994 The Regents of the University of California.
 * Copyright (c) 1994-1996 Sun Microsystems, Inc.
 * Copyright (c) 1998 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tkBind.c,v 1.4 1998/10/10 00:30:36 rjohnson Exp $
 */

#include "tkPort.h"
#include "tkInt.h"

/*
 * File structure:
 *
 * Structure definitions and static variables.
 *
 * Init/Free this package.
 *
 * Tcl "bind" command (actually located in tkCmds.c).
 * "bind" command implementation.
 * "bind" implementation helpers.
 *
 * Tcl "event" command.
 * "event" command implementation.
 * "event" implementation helpers.
 *
 * Package-specific common helpers.
 *
 * Non-package-specific helpers.
 */


/*
 * The following union is used to hold the detail information from an
 * XEvent (including Tk's XVirtualEvent extension).
 */
typedef union {
    KeySym  keySym;         /* KeySym that corresponds to xkey.keycode. */
    int           button;         /* Button that was pressed (xbutton.button). */
    Tk_Uid  name;     /* Tk_Uid of virtual event. */
    ClientData    clientData; /* Used when type of Detail is unknown, and to
                       * ensure that all bytes of Detail are initialized
                       * when this structure is used in a hash key. */
} Detail;

/*
 * The structure below represents a binding table.  A binding table
 * represents a domain in which event bindings may occur.  It includes
 * a space of objects relative to which events occur (usually windows,
 * but not always), a history of recent events in the domain, and
 * a set of mappings that associate particular Tcl commands with sequences
 * of events in the domain.  Multiple binding tables may exist at once,
 * either because there are multiple applications open, or because there
 * are multiple domains within an application with separate event
 * bindings for each (for example, each canvas widget has a separate
 * binding table for associating events with the items in the canvas).
 *
 * Note: it is probably a bad idea to reduce EVENT_BUFFER_SIZE much
 * below 30.  To see this, consider a triple mouse button click while
 * the Shift key is down (and auto-repeating).  There may be as many
 * as 3 auto-repeat events after each mouse button press or release
 * (see the first large comment block within Tk_BindEvent for more on
 * this), for a total of 20 events to cover the three button presses
 * and two intervening releases.  If you reduce EVENT_BUFFER_SIZE too
 * much, shift multi-clicks will be lost.
 * 
 */

#ifdef KANJI
/*
 * Increase event buffer for rapid invocation of kinput2.
 */
#define EVENT_BUFFER_SIZE 120
#else
#define EVENT_BUFFER_SIZE 30
#endif /* KANJI */
typedef struct BindingTable {
    XEvent eventRing[EVENT_BUFFER_SIZE];/* Circular queue of recent events
                               * (higher indices are for more recent
                               * events). */
    Detail detailRing[EVENT_BUFFER_SIZE];/* "Detail" information (keySym,
                               * button, Tk_Uid, or 0) for each
                               * entry in eventRing. */
    int curEvent;             /* Index in eventRing of most recent
                               * event.  Newer events have higher
                               * indices. */
    Tcl_HashTable patternTable;           /* Used to map from an event to a
                               * list of patterns that may match that
                               * event.  Keys are PatternTableKey
                               * structs, values are (PatSeq *). */
    Tcl_HashTable objectTable;            /* Used to map from an object to a
                               * list of patterns associated with
                               * that object.  Keys are ClientData,
                               * values are (PatSeq *). */
    Tcl_Interp *interp;             /* Interpreter in which commands are
                               * executed. */
} BindingTable;

/*
 * The following structure represents virtual event table.  A virtual event
 * table provides a way to map from platform-specific physical events such
 * as button clicks or key presses to virtual events such as <<Paste>>,
 * <<Close>>, or <<ScrollWindow>>.
 *
 * A virtual event is usually never part of the event stream, but instead is
 * synthesized inline by matching low-level events.  However, a virtual
 * event may be generated by platform-specific code or by Tcl scripts.  In
 * that case, no lookup of the virtual event will need to be done using
 * this table, because the virtual event is actually in the event stream.
 */

typedef struct VirtualEventTable {
    Tcl_HashTable patternTable;     /* Used to map from a physical event to
                             * a list of patterns that may match that
                             * event.  Keys are PatternTableKey
                             * structs, values are (PatSeq *). */
    Tcl_HashTable nameTable;      /* Used to map a virtual event name to
                             * the array of physical events that can
                             * trigger it.  Keys are the Tk_Uid names
                             * of the virtual events, values are
                             * PhysicalsOwned structs. */
} VirtualEventTable;

/*
 * The following structure is used as a key in a patternTable for both 
 * binding tables and a virtual event tables.
 *
 * In a binding table, the object field corresponds to the binding tag
 * for the widget whose bindings are being accessed.
 *
 * In a virtual event table, the object field is always NULL.  Virtual
 * events are a global definiton and are not tied to a particular
 * binding tag.
 *
 * The same key is used for both types of pattern tables so that the 
 * helper functions that traverse and match patterns will work for both
 * binding tables and virtual event tables.
 */
typedef struct PatternTableKey {
    ClientData object;        /* For binding table, identifies the binding
                         * tag of the object (or class of objects)
                         * relative to which the event occurred.
                         * For virtual event table, always NULL. */
    int type;                 /* Type of event (from X). */
    Detail detail;            /* Additional information, such as keysym,
                         * button, Tk_Uid, or 0 if nothing
                         * additional. */
} PatternTableKey;

/*
 * The following structure defines a pattern, which is matched against X
 * events as part of the process of converting X events into Tcl commands.
 */

typedef struct Pattern {
    int eventType;            /* Type of X event, e.g. ButtonPress. */
    int needMods;       /* Mask of modifiers that must be
                         * present (0 means no modifiers are
                         * required). */
    Detail detail;            /* Additional information that must
                         * match event.  Normally this is 0,
                         * meaning no additional information
                         * must match.  For KeyPress and
                         * KeyRelease events, a keySym may
                         * be specified to select a
                         * particular keystroke (0 means any
                         * keystrokes).  For button events,
                         * specifies a particular button (0
                         * means any buttons are OK).  For virtual
                         * events, specifies the Tk_Uid of the
                         * virtual event name (never 0). */
} Pattern;

/*
 * The following structure defines a pattern sequence, which consists of one
 * or more patterns.  In order to trigger, a pattern sequence must match
 * the most recent X events (first pattern to most recent event, next
 * pattern to next event, and so on).  It is used as the hash value in a
 * patternTable for both binding tables and virtual event tables.
 *
 * In a binding table, it is the sequence of physical events that make up
 * a binding for an object.
 * 
 * In a virtual event table, it is the sequence of physical events that
 * define a virtual event.
 *
 * The same structure is used for both types of pattern tables so that the 
 * helper functions that traverse and match patterns will work for both
 * binding tables and virtual event tables.
 */

typedef struct PatSeq {
    int numPats;        /* Number of patterns in sequence (usually
                         * 1). */
    TkBindEvalProc *eventProc;      /* The procedure that will be invoked on
                         * the clientData when this pattern sequence
                         * matches. */
    TkBindFreeProc *freeProc; /* The procedure that will be invoked to
                         * release the clientData when this pattern
                         * sequence is freed. */
    ClientData clientData;    /* Arbitray data passed to eventProc and
                         * freeProc when sequence matches. */
    int flags;                /* Miscellaneous flag values; see below for
                         * definitions. */
    int refCount;       /* Number of times that this binding is in
                         * the midst of executing.  If greater than 1,
                         * then a recursive invocation is happening.
                         * Only when this is zero can the binding
                         * actually be freed. */
    struct PatSeq *nextSeqPtr;  /* Next in list of all pattern sequences
                         * that have the same initial pattern.  NULL
                         * means end of list. */
    Tcl_HashEntry *hPtr;      /* Pointer to hash table entry for the
                         * initial pattern.  This is the head of the
                         * list of which nextSeqPtr forms a part. */
    struct VirtualOwners *voPtr;/* In a binding table, always NULL.  In a
                         * virtual event table, identifies the array
                         * of virtual events that can be triggered by
                         * this event. */
    struct PatSeq *nextObjPtr;  /* In a binding table, next in list of all
                         * pattern sequences for the same object (NULL
                         * for end of list).  Needed to implement
                         * Tk_DeleteAllBindings.  In a virtual event
                         * table, always NULL. */
    Pattern pats[1];          /* Array of "numPats" patterns.  Only one
                         * element is declared here but in actuality
                         * enough space will be allocated for "numPats"
                         * patterns.  To match, pats[0] must match
                         * event n, pats[1] must match event n-1, etc.
                         */
} PatSeq;

/*
 * Flag values for PatSeq structures:
 *
 * PAT_NEARBY           1 means that all of the events matching
 *                this sequence must occur with nearby X
 *                and Y mouse coordinates and close in time.
 *                This is typically used to restrict multiple
 *                button presses.
 * MARKED_DELETED 1 means that this binding has been marked as deleted
 *                and removed from the binding table, but its memory
 *                could not be released because it was already queued for
 *                execution.  When the binding is actually about to be
 *                executed, this flag will be checked and the binding
 *                skipped if set.
 */

#define PAT_NEARBY            0x1
#define MARKED_DELETED        0x2

/*
 * Constants that define how close together two events must be
 * in milliseconds or pixels to meet the PAT_NEARBY constraint:
 */

#define NEARBY_PIXELS         5
#define NEARBY_MS       500


/*
 * The following structure keeps track of all the virtual events that are
 * associated with a particular physical event.  It is pointed to by the
 * voPtr field in a PatSeq in the patternTable of a  virtual event table.
 */

typedef struct VirtualOwners {
    int numOwners;                /* Number of virtual events to trigger. */
    Tcl_HashEntry *owners[1];     /* Array of pointers to entries in
                             * nameTable.  Enough space will
                             * actually be allocated for numOwners
                             * hash entries. */
} VirtualOwners;

/*
 * The following structure is used in the nameTable of a virtual event
 * table to associate a virtual event with all the physical events that can
 * trigger it.
 */
typedef struct PhysicalsOwned {
    int numOwned;           /* Number of physical events owned. */
    PatSeq *patSeqs[1];           /* Array of pointers to physical event
                             * patterns.  Enough space will actually
                             * be allocated to hold numOwned. */
} PhysicalsOwned;

/*
 * One of the following structures exists for each interpreter.  This
 * structure keeps track of the current display and screen in the
 * interpreter, so that a script can be invoked whenever the display/screen
 * changes (the script does things like point tkPriv at a display-specific
 * structure).
 */

typedef struct {
    TkDisplay *curDispPtr;    /* Display for last binding command invoked
                         * in this application. */
    int curScreenIndex;       /* Index of screen for last binding command. */
    int bindingDepth;         /* Number of active instances of Tk_BindEvent
                         * in this application. */
} ScreenInfo;

/*
 * The following structure is used to keep track of all the C bindings that
 * are awaiting invocation and whether the window they refer to has been
 * destroyed.  If the window is destroyed, then all pending callbacks for
 * that window will be cancelled.  The Tcl bindings will still all be
 * invoked, however.  
 */

typedef struct PendingBinding {
    struct PendingBinding *nextPtr;
                        /* Next in chain of pending bindings, in
                         * case a recursive binding evaluation is in
                         * progress. */
    Tk_Window tkwin;          /* The window that the following bindings
                         * depend upon. */
    int deleted;        /* Set to non-zero by window cleanup code
                         * if tkwin is deleted. */
    PatSeq *matchArray[5];    /* Array of pending C bindings.  The actual
                         * size of this depends on how many C bindings
                         * matched the event passed to Tk_BindEvent.
                         * THIS FIELD MUST BE THE LAST IN THE
                         * STRUCTURE. */
} PendingBinding;

/*
 * The following structure keeps track of all the information local to
 * the binding package on a per interpreter basis.
 */

typedef struct BindInfo {
    VirtualEventTable virtualEventTable;
                        /* The virtual events that exist in this
                         * interpreter. */
    ScreenInfo screenInfo;    /* Keeps track of the current display and
                         * screen, so it can be restored after
                         * a binding has executed. */
    PendingBinding *pendingList;/* The list of pending C bindings, kept in
                         * case a C or Tcl binding causes the target
                         * window to be deleted. */
} BindInfo;
    
/*
 * In X11R4 and earlier versions, XStringToKeysym is ridiculously
 * slow.  The data structure and hash table below, along with the
 * code that uses them, implement a fast mapping from strings to
 * keysyms.  In X11R5 and later releases XStringToKeysym is plenty
 * fast so this stuff isn't needed.  The #define REDO_KEYSYM_LOOKUP
 * is normally undefined, so that XStringToKeysym gets used.  It
 * can be set in the Makefile to enable the use of the hash table
 * below.
 */

#ifdef REDO_KEYSYM_LOOKUP
typedef struct {
    char *name;                     /* Name of keysym. */
    KeySym value;             /* Numeric identifier for keysym. */
} KeySymInfo;
static KeySymInfo keyArray[] = {
#ifndef lint
#include "ks_names.h"
#endif
    {(char *) NULL, 0}
};
static Tcl_HashTable keySymTable;   /* keyArray hashed by keysym value. */
static Tcl_HashTable nameTable;           /* keyArray hashed by keysym name. */
#endif /* REDO_KEYSYM_LOOKUP */

/*
 * Set to non-zero when the package-wide static variables have been
 * initialized.
 */

static int initialized = 0;

/*
 * A hash table is kept to map from the string names of event
 * modifiers to information about those modifiers.  The structure
 * for storing this information, and the hash table built at
 * initialization time, are defined below.
 */

typedef struct {
    char *name;               /* Name of modifier. */
    int mask;                 /* Button/modifier mask value,                                           * such as Button1Mask. */
    int flags;                /* Various flags;  see below for
                         * definitions. */
} ModInfo;

/*
 * Flags for ModInfo structures:
 *
 * DOUBLE -       Non-zero means duplicate this event,
 *                e.g. for double-clicks.
 * TRIPLE -       Non-zero means triplicate this event,
 *                e.g. for triple-clicks.
 */

#define DOUBLE          1
#define TRIPLE          2

/*
 * The following special modifier mask bits are defined, to indicate
 * logical modifiers such as Meta and Alt that may float among the
 * actual modifier bits.
 */

#define META_MASK (AnyModifier<<1)
#define ALT_MASK  (AnyModifier<<2)

static ModInfo modArray[] = {
    {"Control",         ControlMask,      0},
    {"Shift",           ShiftMask,  0},
    {"Lock",            LockMask,   0},
    {"Meta",            META_MASK,  0},
    {"M",         META_MASK,  0},
    {"Alt",       ALT_MASK,   0},
    {"B1",        Button1Mask,      0},
    {"Button1",         Button1Mask,      0},
    {"B2",        Button2Mask,      0},
    {"Button2",         Button2Mask,      0},
    {"B3",        Button3Mask,      0},
    {"Button3",         Button3Mask,      0},
    {"B4",        Button4Mask,      0},
    {"Button4",         Button4Mask,      0},
    {"B5",        Button5Mask,      0},
    {"Button5",         Button5Mask,      0},
    {"Mod1",            Mod1Mask,   0},
    {"M1",        Mod1Mask,   0},
    {"Command",         Mod1Mask,   0},
    {"Mod2",            Mod2Mask,   0},
    {"M2",        Mod2Mask,   0},
    {"Option",          Mod2Mask,   0},
    {"Mod3",            Mod3Mask,   0},
    {"M3",        Mod3Mask,   0},
    {"Mod4",            Mod4Mask,   0},
    {"M4",        Mod4Mask,   0},
    {"Mod5",            Mod5Mask,   0},
    {"M5",        Mod5Mask,   0},
    {"Double",          0,          DOUBLE},
    {"Triple",          0,          TRIPLE},
    {"Any",       0,          0},   /* Ignored: historical relic. */
    {NULL,        0,          0}
};
static Tcl_HashTable modTable;

/*
 * This module also keeps a hash table mapping from event names
 * to information about those events.  The structure, an array
 * to use to initialize the hash table, and the hash table are
 * all defined below.
 */

typedef struct {
    char *name;               /* Name of event. */
    int type;                 /* Event type for X, such as
                         * ButtonPress. */
    int eventMask;            /* Mask bits (for XSelectInput)
                         * for this event type. */
} EventInfo;

/*
 * Note:  some of the masks below are an OR-ed combination of
 * several masks.  This is necessary because X doesn't report
 * up events unless you also ask for down events.  Also, X
 * doesn't report button state in motion events unless you've
 * asked about button events.
 */

static EventInfo eventArray[] = {
    {"Key",       KeyPress,         KeyPressMask},
    {"KeyPress",  KeyPress,         KeyPressMask},
    {"KeyRelease",      KeyRelease,       KeyPressMask|KeyReleaseMask},
    {"Button",          ButtonPress,            ButtonPressMask},
    {"ButtonPress",     ButtonPress,            ButtonPressMask},
    {"ButtonRelease",   ButtonRelease,
          ButtonPressMask|ButtonReleaseMask},
    {"Motion",          MotionNotify,
          ButtonPressMask|PointerMotionMask},
    {"Enter",           EnterNotify,            EnterWindowMask},
    {"Leave",           LeaveNotify,            LeaveWindowMask},
    {"FocusIn",         FocusIn,          FocusChangeMask},
    {"FocusOut",  FocusOut,         FocusChangeMask},
    {"Expose",          Expose,                 ExposureMask},
    {"Visibility",      VisibilityNotify, VisibilityChangeMask},
    {"Destroy",         DestroyNotify,          StructureNotifyMask},
    {"Unmap",           UnmapNotify,            StructureNotifyMask},
    {"Map",       MapNotify,        StructureNotifyMask},
    {"Reparent",  ReparentNotify,         StructureNotifyMask},
    {"Configure", ConfigureNotify,  StructureNotifyMask},
    {"Gravity",         GravityNotify,          StructureNotifyMask},
    {"Circulate", CirculateNotify,  StructureNotifyMask},
    {"Property",  PropertyNotify,         PropertyChangeMask},
    {"Colormap",  ColormapNotify,         ColormapChangeMask},
    {"Activate",  ActivateNotify,         ActivateMask},
    {"Deactivate",      DeactivateNotify, ActivateMask},
    {"MouseWheel",      MouseWheelEvent,  MouseWheelMask},
    {(char *) NULL,     0,                0}
};
static Tcl_HashTable eventTable;

/*
 * The defines and table below are used to classify events into
 * various groups.  The reason for this is that logically identical
 * fields (e.g. "state") appear at different places in different
 * types of events.  The classification masks can be used to figure
 * out quickly where to extract information from events.
 */

#define KEY             0x1
#define BUTTON                0x2
#define MOTION                0x4
#define CROSSING        0x8
#define FOCUS                 0x10
#define EXPOSE                0x20
#define VISIBILITY            0x40
#define CREATE                0x80
#define DESTROY               0x100
#define UNMAP                 0x200
#define MAP             0x400
#define REPARENT        0x800
#define CONFIG                0x1000
#define GRAVITY               0x2000
#define CIRC                  0x4000
#define PROP                  0x8000
#define COLORMAP        0x10000
#define VIRTUAL               0x20000
#define ACTIVATE        0x40000

#define KEY_BUTTON_MOTION_VIRTUAL   (KEY|BUTTON|MOTION|VIRTUAL)

static int flagArray[TK_LASTEVENT] = {
   /* Not used */       0,
   /* Not used */       0,
   /* KeyPress */       KEY,
   /* KeyRelease */           KEY,
   /* ButtonPress */          BUTTON,
   /* ButtonRelease */        BUTTON,
   /* MotionNotify */         MOTION,
   /* EnterNotify */          CROSSING,
   /* LeaveNotify */          CROSSING,
   /* FocusIn */        FOCUS,
   /* FocusOut */       FOCUS,
   /* KeymapNotify */         0,
   /* Expose */               EXPOSE,
   /* GraphicsExpose */       EXPOSE,
   /* NoExpose */       0,
   /* VisibilityNotify */     VISIBILITY,
   /* CreateNotify */         CREATE,
   /* DestroyNotify */        DESTROY,
   /* UnmapNotify */          UNMAP,
   /* MapNotify */            MAP,
   /* MapRequest */           0,
   /* ReparentNotify */       REPARENT,
   /* ConfigureNotify */      CONFIG,
   /* ConfigureRequest */     0,
   /* GravityNotify */        GRAVITY,
   /* ResizeRequest */        0,
   /* CirculateNotify */      CIRC,
   /* CirculateRequest */     0,
   /* PropertyNotify */       PROP,
   /* SelectionClear */       0,
   /* SelectionRequest */     0,
   /* SelectionNotify */      0,
   /* ColormapNotify */       COLORMAP,
   /* ClientMessage */        0,
   /* MappingNotify */        0,
   /* VirtualEvent */         VIRTUAL,
   /* Activate */       ACTIVATE,       
   /* Deactivate */           ACTIVATE,
   /* MouseWheel */           KEY
};

/*
 * The following tables are used as a two-way map between X's internal
 * numeric values for fields in an XEvent and the strings used in Tcl.  The
 * tables are used both when constructing an XEvent from user input and
 * when providing data from an XEvent to the user.
 */

static TkStateMap notifyMode[] = {
    {NotifyNormal,            "NotifyNormal"},
    {NotifyGrab,        "NotifyGrab"},
    {NotifyUngrab,            "NotifyUngrab"},
    {NotifyWhileGrabbed,      "NotifyWhileGrabbed"},
    {-1, NULL}
};

static TkStateMap notifyDetail[] = {
    {NotifyAncestor,          "NotifyAncestor"},
    {NotifyVirtual,           "NotifyVirtual"},
    {NotifyInferior,          "NotifyInferior"},
    {NotifyNonlinear,         "NotifyNonlinear"},
    {NotifyNonlinearVirtual,  "NotifyNonlinearVirtual"},
    {NotifyPointer,           "NotifyPointer"},
    {NotifyPointerRoot,       "NotifyPointerRoot"},
    {NotifyDetailNone,        "NotifyDetailNone"},
    {-1, NULL}
};

static TkStateMap circPlace[] = {
    {PlaceOnTop,        "PlaceOnTop"},
    {PlaceOnBottom,           "PlaceOnBottom"},
    {-1, NULL}
};

static TkStateMap visNotify[] = {
    {VisibilityUnobscured,        "VisibilityUnobscured"},
    {VisibilityPartiallyObscured,   "VisibilityPartiallyObscured"},
    {VisibilityFullyObscured,     "VisibilityFullyObscured"},
    {-1, NULL}
};

/*
 * Prototypes for local procedures defined in this file:
 */

static void       ChangeScreen _ANSI_ARGS_((Tcl_Interp *interp,
                      char *dispName, int screenIndex));
static int        CreateVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                      VirtualEventTable *vetPtr, char *virtString,
                      char *eventString));
static int        DeleteVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                      VirtualEventTable *vetPtr, char *virtString,
                      char *eventString));
static void       DeleteVirtualEventTable _ANSI_ARGS_((
                      VirtualEventTable *vetPtr));
static void       ExpandPercents _ANSI_ARGS_((TkWindow *winPtr,
                      char *before, XEvent *eventPtr, KeySym keySym,
                      Tcl_DString *dsPtr));
static void       FreeTclBinding _ANSI_ARGS_((ClientData clientData));
static PatSeq *         FindSequence _ANSI_ARGS_((Tcl_Interp *interp,
                      Tcl_HashTable *patternTablePtr, ClientData object,
                      char *eventString, int create, int allowVirtual,
                      unsigned long *maskPtr));
static void       GetAllVirtualEvents _ANSI_ARGS_((Tcl_Interp *interp,
                      VirtualEventTable *vetPtr));
static char *           GetField _ANSI_ARGS_((char *p, char *copy, int size));
static KeySym           GetKeySym _ANSI_ARGS_((TkDisplay *dispPtr,
                      XEvent *eventPtr));
static void       GetPatternString _ANSI_ARGS_((PatSeq *psPtr,
                      Tcl_DString *dsPtr));
static int        GetVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                      VirtualEventTable *vetPtr, char *virtString));
static Tk_Uid           GetVirtualEventUid _ANSI_ARGS_((Tcl_Interp *interp,
                      char *virtString));
static int        HandleEventGenerate _ANSI_ARGS_((Tcl_Interp *interp,
                      Tk_Window main, int argc, char **argv));
static void       InitKeymapInfo _ANSI_ARGS_((TkDisplay *dispPtr));
static void       InitVirtualEventTable _ANSI_ARGS_((
                      VirtualEventTable *vetPtr));
static PatSeq *         MatchPatterns _ANSI_ARGS_((TkDisplay *dispPtr,
                      BindingTable *bindPtr, PatSeq *psPtr,
                      PatSeq *bestPtr, ClientData *objectPtr,
                      PatSeq **sourcePtrPtr));
static int        ParseEventDescription _ANSI_ARGS_((Tcl_Interp *interp,
                      char **eventStringPtr, Pattern *patPtr,
                      unsigned long *eventMaskPtr));

/*
 * The following define is used as a short circuit for the callback
 * procedure to evaluate a TclBinding.  The actual evaluation of the
 * binding is handled inline, because special things have to be done
 * with a Tcl binding before evaluation time.
 */

#define EvalTclBinding  ((TkBindEvalProc *) 1)


/*
 *---------------------------------------------------------------------------
 *
 * TkBindInit --
 *
 *    This procedure is called when an application is created.  It
 *    initializes all the structures used by bindings and virtual
 *    events.  It must be called before any other functions in this
 *    file are called.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory allocated.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindInit(mainPtr)
    TkMainInfo *mainPtr;      /* The newly created application. */
{
    BindInfo *bindInfoPtr;

    if (sizeof(XEvent) < sizeof(XVirtualEvent)) {
      panic("TkBindInit: virtual events can't be supported");
    }

    /*
     * Initialize the static data structures used by the binding package.
     * They are only initialized once, no matter how many interps are
     * created.
     */

    if (!initialized) {
      Tcl_HashEntry *hPtr;
      ModInfo *modPtr;
      EventInfo *eiPtr;
      int dummy;

#ifdef REDO_KEYSYM_LOOKUP
      KeySymInfo *kPtr;

      Tcl_InitHashTable(&keySymTable, TCL_STRING_KEYS);
      Tcl_InitHashTable(&nameTable, TCL_ONE_WORD_KEYS);
      for (kPtr = keyArray; kPtr->name != NULL; kPtr++) {
          hPtr = Tcl_CreateHashEntry(&keySymTable, kPtr->name, &dummy);
          Tcl_SetHashValue(hPtr, kPtr->value);
          hPtr = Tcl_CreateHashEntry(&nameTable, (char *) kPtr->value,
                &dummy);
          Tcl_SetHashValue(hPtr, kPtr->name);
      }
#endif /* REDO_KEYSYM_LOOKUP */

      Tcl_InitHashTable(&modTable, TCL_STRING_KEYS);
      for (modPtr = modArray; modPtr->name != NULL; modPtr++) {
          hPtr = Tcl_CreateHashEntry(&modTable, modPtr->name, &dummy);
          Tcl_SetHashValue(hPtr, modPtr);
      }
    
      Tcl_InitHashTable(&eventTable, TCL_STRING_KEYS);
      for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
          hPtr = Tcl_CreateHashEntry(&eventTable, eiPtr->name, &dummy);
          Tcl_SetHashValue(hPtr, eiPtr);
      }
      initialized = 1;
    }

    mainPtr->bindingTable = Tk_CreateBindingTable(mainPtr->interp);

    bindInfoPtr = (BindInfo *) ckalloc(sizeof(BindInfo));
    InitVirtualEventTable(&bindInfoPtr->virtualEventTable);
    bindInfoPtr->screenInfo.curDispPtr = NULL;
    bindInfoPtr->screenInfo.curScreenIndex = -1;
    bindInfoPtr->screenInfo.bindingDepth = 0;
    bindInfoPtr->pendingList = NULL;
    mainPtr->bindInfo = (TkBindInfo) bindInfoPtr;

    TkpInitializeMenuBindings(mainPtr->interp, mainPtr->bindingTable);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindFree --
 *
 *    This procedure is called when an application is deleted.  It
 *    deletes all the structures used by bindings and virtual events.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory freed.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindFree(mainPtr)
    TkMainInfo *mainPtr;      /* The newly created application. */
{
    BindInfo *bindInfoPtr;
    
    Tk_DeleteBindingTable(mainPtr->bindingTable);
    mainPtr->bindingTable = NULL;

    bindInfoPtr = (BindInfo *) mainPtr->bindInfo;
    DeleteVirtualEventTable(&bindInfoPtr->virtualEventTable);
    mainPtr->bindInfo = NULL;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_CreateBindingTable --
 *
 *    Set up a new domain in which event bindings may be created.
 *
 * Results:
 *    The return value is a token for the new table, which must
 *    be passed to procedures like Tk_CreatBinding.
 *
 * Side effects:
 *    Memory is allocated for the new table.
 *
 *--------------------------------------------------------------
 */

Tk_BindingTable
Tk_CreateBindingTable(interp)
    Tcl_Interp *interp;       /* Interpreter to associate with the binding
                         * table:  commands are executed in this
                         * interpreter. */
{
    BindingTable *bindPtr;
    int i;

    /*
     * Create and initialize a new binding table.
     */

    bindPtr = (BindingTable *) ckalloc(sizeof(BindingTable));
    for (i = 0; i < EVENT_BUFFER_SIZE; i++) {
      bindPtr->eventRing[i].type = -1;
    }
    bindPtr->curEvent = 0;
    Tcl_InitHashTable(&bindPtr->patternTable,
          sizeof(PatternTableKey)/sizeof(int));
    Tcl_InitHashTable(&bindPtr->objectTable, TCL_ONE_WORD_KEYS);
    bindPtr->interp = interp;
    return (Tk_BindingTable) bindPtr;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBindingTable --
 *
 *    Destroy a binding table and free up all its memory.
 *    The caller should not use bindingTable again after
 *    this procedure returns.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory is freed.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteBindingTable(bindingTable)
    Tk_BindingTable bindingTable;   /* Token for the binding table to
                               * destroy. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *nextPtr;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;

    /*
     * Find and delete all of the patterns associated with the binding
     * table.
     */

    for (hPtr = Tcl_FirstHashEntry(&bindPtr->patternTable, &search);
          hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
      for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
            psPtr != NULL; psPtr = nextPtr) {
          nextPtr = psPtr->nextSeqPtr;
          psPtr->flags |= MARKED_DELETED;
          if (psPtr->refCount == 0) {
            if (psPtr->freeProc != NULL) {
                (*psPtr->freeProc)(psPtr->clientData);
            }
            ckfree((char *) psPtr);
          }
      }
    }

    /*
     * Clean up the rest of the information associated with the
     * binding table.
     */

    Tcl_DeleteHashTable(&bindPtr->patternTable);
    Tcl_DeleteHashTable(&bindPtr->objectTable);
    ckfree((char *) bindPtr);
}

/*
 *--------------------------------------------------------------
 *
 * Tk_CreateBinding --
 *
 *    Add a binding to a binding table, so that future calls to
 *    Tk_BindEvent may execute the command in the binding.
 *
 * Results:
 *    The return value is 0 if an error occurred while setting
 *    up the binding.  In this case, an error message will be
 *    left in interp->result.  If all went well then the return
 *    value is a mask of the event types that must be made
 *    available to Tk_BindEvent in order to properly detect when
 *    this binding triggers.  This value can be used to determine
 *    what events to select for in a window, for example.
 *
 * Side effects:
 *    An existing binding on the same event sequence may be
 *    replaced.  
 *    The new binding may cause future calls to Tk_BindEvent to
 *    behave differently than they did previously.
 *
 *--------------------------------------------------------------
 */

unsigned long
Tk_CreateBinding(interp, bindingTable, object, eventString, command, append)
    Tcl_Interp *interp;       /* Used for error reporting. */
    Tk_BindingTable bindingTable;
                        /* Table in which to create binding. */
    ClientData object;        /* Token for object with which binding is
                         * associated. */
    char *eventString;        /* String describing event sequence that
                         * triggers binding. */
    char *command;            /* Contains Tcl command to execute when
                         * binding triggers. */
    int append;               /* 0 means replace any existing binding for
                         * eventString; 1 means append to that
                         * binding.  If the existing binding is for a
                         * callback function and not a Tcl command
                         * string, the existing binding will always be
                         * replaced. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;
    char *new, *old;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
          1, 1, &eventMask);
    if (psPtr == NULL) {
      return 0;
    }
    if (psPtr->eventProc == NULL) {
      int new;
      Tcl_HashEntry *hPtr;
      
      /*
       * This pattern sequence was just created.
       * Link the pattern into the list associated with the object, so
       * that if the object goes away, these bindings will all
       * automatically be deleted.
       */

      hPtr = Tcl_CreateHashEntry(&bindPtr->objectTable, (char *) object,
            &new);
      if (new) {
          psPtr->nextObjPtr = NULL;
      } else {
          psPtr->nextObjPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
      }
      Tcl_SetHashValue(hPtr, psPtr);
    } else if (psPtr->eventProc != EvalTclBinding) {
      /*
       * Free existing procedural binding.
       */

      if (psPtr->freeProc != NULL) {
          (*psPtr->freeProc)(psPtr->clientData);
      }
      psPtr->clientData = NULL;
      append = 0;
    }

    old = (char *) psPtr->clientData;
    if ((append != 0) && (old != NULL)) {
      int length;

      length = strlen(old) + strlen(command) + 2;
      new = (char *) ckalloc((unsigned) length);
      sprintf(new, "%s\n%s", old, command);
    } else {
      new = (char *) ckalloc((unsigned) strlen(command) + 1);
      strcpy(new, command);
    }
    if (old != NULL) {
      ckfree(old);
    }
    psPtr->eventProc = EvalTclBinding;
    psPtr->freeProc = FreeTclBinding;
    psPtr->clientData = (ClientData) new;
    return eventMask;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkCreateBindingProcedure --
 *
 *    Add a C binding to a binding table, so that future calls to
 *    Tk_BindEvent may callback the procedure in the binding.
 *
 * Results:
 *    The return value is 0 if an error occurred while setting
 *    up the binding.  In this case, an error message will be
 *    left in interp->result.  If all went well then the return
 *    value is a mask of the event types that must be made
 *    available to Tk_BindEvent in order to properly detect when
 *    this binding triggers.  This value can be used to determine
 *    what events to select for in a window, for example.
 *
 * Side effects:
 *    Any existing binding on the same event sequence will be
 *    replaced.  
 *
 *---------------------------------------------------------------------------
 */

unsigned long
TkCreateBindingProcedure(interp, bindingTable, object, eventString,
      eventProc, freeProc, clientData)
    Tcl_Interp *interp;       /* Used for error reporting. */
    Tk_BindingTable bindingTable;
                        /* Table in which to create binding. */
    ClientData object;        /* Token for object with which binding is
                         * associated. */
    char *eventString;        /* String describing event sequence that
                         * triggers binding. */
    TkBindEvalProc *eventProc;      /* Procedure to invoke when binding
                         * triggers.  Must not be NULL. */
    TkBindFreeProc *freeProc; /* Procedure to invoke when binding is
                         * freed.  May be NULL for no procedure. */
    ClientData clientData;    /* Arbitrary ClientData to pass to eventProc
                         * and freeProc. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
          1, 1, &eventMask);
    if (psPtr == NULL) {
      return 0;
    }
    if (psPtr->eventProc == NULL) {
      int new;
      Tcl_HashEntry *hPtr;
      
      /*
       * This pattern sequence was just created.
       * Link the pattern into the list associated with the object, so
       * that if the object goes away, these bindings will all
       * automatically be deleted.
       */

      hPtr = Tcl_CreateHashEntry(&bindPtr->objectTable, (char *) object,
            &new);
      if (new) {
          psPtr->nextObjPtr = NULL;
      } else {
          psPtr->nextObjPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
      }
      Tcl_SetHashValue(hPtr, psPtr);
    } else {

      /*
       * Free existing callback.
       */

      if (psPtr->freeProc != NULL) {
          (*psPtr->freeProc)(psPtr->clientData);
      }
    }

    psPtr->eventProc = eventProc;
    psPtr->freeProc = freeProc;
    psPtr->clientData = clientData;
    return eventMask;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBinding --
 *
 *    Remove an event binding from a binding table.
 *
 * Results:
 *    The result is a standard Tcl return value.  If an error
 *    occurs then interp->result will contain an error message.
 *
 * Side effects:
 *    The binding given by object and eventString is removed
 *    from bindingTable.
 *
 *--------------------------------------------------------------
 */

int
Tk_DeleteBinding(interp, bindingTable, object, eventString)
    Tcl_Interp *interp;             /* Used for error reporting. */
    Tk_BindingTable bindingTable;   /* Table in which to delete binding. */
    ClientData object;              /* Token for object with which binding
                               * is associated. */
    char *eventString;              /* String describing event sequence
                               * that triggers binding. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *prevPtr;
    unsigned long eventMask;
    Tcl_HashEntry *hPtr;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
          0, 1, &eventMask);
    if (psPtr == NULL) {
      Tcl_ResetResult(interp);
      return TCL_OK;
    }

    /*
     * Unlink the binding from the list for its object, then from the
     * list for its pattern.
     */

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
      panic("Tk_DeleteBinding couldn't find object table entry");
    }
    prevPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    if (prevPtr == psPtr) {
      Tcl_SetHashValue(hPtr, psPtr->nextObjPtr);
    } else {
      for ( ; ; prevPtr = prevPtr->nextObjPtr) {
          if (prevPtr == NULL) {
            panic("Tk_DeleteBinding couldn't find on object list");
          }
          if (prevPtr->nextObjPtr == psPtr) {
            prevPtr->nextObjPtr = psPtr->nextObjPtr;
            break;
          }
      }
    }
    prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
    if (prevPtr == psPtr) {
      if (psPtr->nextSeqPtr == NULL) {
          Tcl_DeleteHashEntry(psPtr->hPtr);
      } else {
          Tcl_SetHashValue(psPtr->hPtr, psPtr->nextSeqPtr);
      }
    } else {
      for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
          if (prevPtr == NULL) {
            panic("Tk_DeleteBinding couldn't find on hash chain");
          }
          if (prevPtr->nextSeqPtr == psPtr) {
            prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
            break;
          }
      }
    }

    psPtr->flags |= MARKED_DELETED;
    if (psPtr->refCount == 0) {
      if (psPtr->freeProc != NULL) {
          (*psPtr->freeProc)(psPtr->clientData);
      }
      ckfree((char *) psPtr);
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetBinding --
 *
 *    Return the command associated with a given event string.
 *
 * Results:
 *    The return value is a pointer to the command string
 *    associated with eventString for object in the domain
 *    given by bindingTable.  If there is no binding for
 *    eventString, or if eventString is improperly formed,
 *    then NULL is returned and an error message is left in
 *    interp->result.  The return value is semi-static:  it
 *    will persist until the binding is changed or deleted.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

char *
Tk_GetBinding(interp, bindingTable, object, eventString)
    Tcl_Interp *interp;             /* Interpreter for error reporting. */
    Tk_BindingTable bindingTable;   /* Table in which to look for
                               * binding. */
    ClientData object;              /* Token for object with which binding
                               * is associated. */
    char *eventString;              /* String describing event sequence
                               * that triggers binding. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
          0, 1, &eventMask);
    if (psPtr == NULL) {
      return NULL;
    }
    if (psPtr->eventProc == EvalTclBinding) {
      return (char *) psPtr->clientData;
    }
    return "";
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetAllBindings --
 *
 *    Return a list of event strings for all the bindings
 *    associated with a given object.
 *
 * Results:
 *    There is no return value.  Interp->result is modified to
 *    hold a Tcl list with one entry for each binding associated
 *    with object in bindingTable.  Each entry in the list
 *    contains the event string associated with one binding.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

void
Tk_GetAllBindings(interp, bindingTable, object)
    Tcl_Interp *interp;             /* Interpreter returning result or
                               * error. */
    Tk_BindingTable bindingTable;   /* Table in which to look for
                               * bindings. */
    ClientData object;              /* Token for object. */

{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    Tcl_DString ds;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
      return;
    }
    Tcl_DStringInit(&ds);
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
          psPtr = psPtr->nextObjPtr) {
      /* 
       * For each binding, output information about each of the
       * patterns in its sequence.
       */
       
      Tcl_DStringSetLength(&ds, 0);
      GetPatternString(psPtr, &ds);
      Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }
    Tcl_DStringFree(&ds);
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteAllBindings --
 *
 *    Remove all bindings associated with a given object in a
 *    given binding table.
 *
 * Results:
 *    All bindings associated with object are removed from
 *    bindingTable.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteAllBindings(bindingTable, object)
    Tk_BindingTable bindingTable;   /* Table in which to delete
                               * bindings. */
    ClientData object;              /* Token for object. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *prevPtr;
    PatSeq *nextPtr;
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
      return;
    }
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
          psPtr = nextPtr) {
      nextPtr  = psPtr->nextObjPtr;

      /*
       * Be sure to remove each binding from its hash chain in the
       * pattern table.  If this is the last pattern in the chain,
       * then delete the hash entry too.
       */

      prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
      if (prevPtr == psPtr) {
          if (psPtr->nextSeqPtr == NULL) {
            Tcl_DeleteHashEntry(psPtr->hPtr);
          } else {
            Tcl_SetHashValue(psPtr->hPtr, psPtr->nextSeqPtr);
          }
      } else {
          for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
            if (prevPtr == NULL) {
                panic("Tk_DeleteAllBindings couldn't find on hash chain");
            }
            if (prevPtr->nextSeqPtr == psPtr) {
                prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
                break;
            }
          }
      }
      psPtr->flags |= MARKED_DELETED;

      if (psPtr->refCount == 0) {
          if (psPtr->freeProc != NULL) {
            (*psPtr->freeProc)(psPtr->clientData);
          }
          ckfree((char *) psPtr);
      }
    }
    Tcl_DeleteHashEntry(hPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_BindEvent --
 *
 *    This procedure is invoked to process an X event.  The
 *    event is added to those recorded for the binding table.
 *    Then each of the objects at *objectPtr is checked in
 *    order to see if it has a binding that matches the recent
 *    events.  If so, the most specific binding is invoked for
 *    each object.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Depends on the command associated with the matching binding.
 *
 *    All Tcl bindings scripts for each object are accumulated before
 *    the first binding is evaluated.  If the action of a Tcl binding
 *    is to change or delete a binding, or delete the window associated
 *    with the binding, all the original Tcl binding scripts will still
 *    fire.  Contrast this with C binding procedures.  If a pending C
 *    binding (one that hasn't fired yet, but is queued to be fired for
 *    this window) is deleted, it will not be called, and if it is
 *    changed, then the new binding procedure will be called.  If the
 *    window itself is deleted, no further C binding procedures will be
 *    called for this window.  When both Tcl binding scripts and C binding
 *    procedures are interleaved, the above rules still apply. 
 *
 *---------------------------------------------------------------------------
 */

void
Tk_BindEvent(bindingTable, eventPtr, tkwin, numObjects, objectPtr)
    Tk_BindingTable bindingTable;   /* Table in which to look for
                               * bindings. */
    XEvent *eventPtr;               /* What actually happened. */
    Tk_Window tkwin;                /* Window on display where event
                               * occurred (needed in order to
                               * locate display information). */
    int numObjects;                 /* Number of objects at *objectPtr. */
    ClientData *objectPtr;          /* Array of one or more objects
                               * to check for a matching binding. */
{
    BindingTable *bindPtr;
    TkDisplay *dispPtr;
    BindInfo *bindInfoPtr;
    TkDisplay *oldDispPtr;
    ScreenInfo *screenPtr;
    XEvent *ringPtr;
    PatSeq *vMatchDetailList, *vMatchNoDetailList;
    int flags, oldScreen, i, deferModal;
    unsigned int matchCount, matchSpace;
    Tcl_Interp *interp;
    Tcl_DString scripts, savedResult;
    Detail detail;
    char *p, *end;
    PendingBinding *pendingPtr;
    PendingBinding staticPending;
    TkWindow *winPtr = (TkWindow *)tkwin;
    PatternTableKey key;

    /*
     * Ignore events on windows that don't have names: these are windows
     * like wrapper windows that shouldn't be visible to the
     * application.
     */

    if (winPtr->pathName == NULL) {
      return;
    }

    /*
     * Ignore the event completely if it is an Enter, Leave, FocusIn,
     * or FocusOut event with detail NotifyInferior.  The reason for
     * ignoring these events is that we don't want transitions between
     * a window and its children to visible to bindings on the parent:
     * this would cause problems for mega-widgets, since the internal
     * structure of a mega-widget isn't supposed to be visible to
     * people watching the parent.
     */

    if ((eventPtr->type == EnterNotify)  || (eventPtr->type == LeaveNotify)) {
      if (eventPtr->xcrossing.detail == NotifyInferior) {
          return;
      }
    }
    if ((eventPtr->type == FocusIn)  || (eventPtr->type == FocusOut)) {
      if (eventPtr->xfocus.detail == NotifyInferior) {
          return;
      }
    }

    bindPtr = (BindingTable *) bindingTable;
    dispPtr = ((TkWindow *) tkwin)->dispPtr;
    bindInfoPtr = (BindInfo *) winPtr->mainPtr->bindInfo;

#ifdef KANJI
    memset((VOID *)&detail, 0, sizeof(Detail));
#endif

    /*
     * Add the new event to the ring of saved events for the
     * binding table.  Two tricky points:
     *
     * 1. Combine consecutive MotionNotify events.  Do this by putting
     *    the new event *on top* of the previous event.
     * 2. If a modifier key is held down, it auto-repeats to generate
     *    continuous KeyPress and KeyRelease events.  These can flush
     *    the event ring so that valuable information is lost (such
     *    as repeated button clicks).  To handle this, check for the
     *    special case of a modifier KeyPress arriving when the previous
     *    two events are a KeyRelease and KeyPress of the same key.
     *    If this happens, mark the most recent event (the KeyRelease)
     *    invalid and put the new event on top of the event before that
     *    (the KeyPress).
     */

    if ((eventPtr->type == MotionNotify)
          && (bindPtr->eventRing[bindPtr->curEvent].type == MotionNotify)) {
      /*
       * Don't advance the ring pointer.
       */
    } else if (eventPtr->type == KeyPress) {
      int i;
      for (i = 0; ; i++) {
          if (i >= dispPtr->numModKeyCodes) {
            goto advanceRingPointer;
          }
          if (dispPtr->modKeyCodes[i] == eventPtr->xkey.keycode) {
            break;
          }
      }
      ringPtr = &bindPtr->eventRing[bindPtr->curEvent];
      if ((ringPtr->type != KeyRelease)
            || (ringPtr->xkey.keycode != eventPtr->xkey.keycode)) {
          goto advanceRingPointer;
      }
      if (bindPtr->curEvent <= 0) {
          i = EVENT_BUFFER_SIZE - 1;
      } else {
          i = bindPtr->curEvent - 1;
      }
      ringPtr = &bindPtr->eventRing[i];
      if ((ringPtr->type != KeyPress)
            || (ringPtr->xkey.keycode != eventPtr->xkey.keycode)) {
          goto advanceRingPointer;
      }
      bindPtr->eventRing[bindPtr->curEvent].type = -1;
      bindPtr->curEvent = i;
    } else {
      advanceRingPointer:
      bindPtr->curEvent++;
      if (bindPtr->curEvent >= EVENT_BUFFER_SIZE) {
          bindPtr->curEvent = 0;
      }
    }
    ringPtr = &bindPtr->eventRing[bindPtr->curEvent];
    memcpy((VOID *) ringPtr, (VOID *) eventPtr, sizeof(XEvent));
    detail.clientData = 0;
    flags = flagArray[ringPtr->type];
    if (flags & KEY) {
      detail.keySym = GetKeySym(dispPtr, ringPtr);
      if (detail.keySym == NoSymbol) {
          detail.keySym = 0;
      }
    } else if (flags & BUTTON) {
      detail.button = ringPtr->xbutton.button;
    } else if (flags & VIRTUAL) {
      detail.name = ((XVirtualEvent *) ringPtr)->name;
    }
    bindPtr->detailRing[bindPtr->curEvent] = detail;

    /*
     * Find out if there are any virtual events that correspond to this
     * physical event (or sequence of physical events).
     */

    vMatchDetailList = NULL;
    vMatchNoDetailList = NULL;
    memset(&key, 0, sizeof(key));

    if (ringPtr->type != VirtualEvent) {
      Tcl_HashTable *veptPtr;
      Tcl_HashEntry *hPtr;

      veptPtr = &bindInfoPtr->virtualEventTable.patternTable;

        key.object  = NULL;
      key.type    = ringPtr->type;
      key.detail  = detail;

      hPtr = Tcl_FindHashEntry(veptPtr, (char *) &key);
      if (hPtr != NULL) {
          vMatchDetailList = (PatSeq *) Tcl_GetHashValue(hPtr);
      }

      if (key.detail.clientData != 0) {
          key.detail.clientData = 0;
          hPtr = Tcl_FindHashEntry(veptPtr, (char *) &key);
          if (hPtr != NULL) {
              vMatchNoDetailList = (PatSeq *) Tcl_GetHashValue(hPtr);
          }
      }
    }

    /*
     * Loop over all the binding tags, finding the binding script or
     * callback for each one.  Append all of the binding scripts, with
     * %-sequences expanded, to "scripts", with null characters separating
     * the scripts for each object.  Append all the callbacks to the array
     * of pending callbacks.  
     */
             
    pendingPtr = &staticPending;
    matchCount = 0;
    matchSpace = sizeof(staticPending.matchArray) / sizeof(PatSeq *);
    Tcl_DStringInit(&scripts);

    for ( ; numObjects > 0; numObjects--, objectPtr++) {
      PatSeq *matchPtr, *sourcePtr;
      Tcl_HashEntry *hPtr;

      matchPtr = NULL;
      sourcePtr = NULL;

      /*
       * Match the new event against those recorded in the pattern table,
       * saving the longest matching pattern.  For events with details
       * (button and key events), look for a binding for the specific
       * key or button.  First see if the event matches a physical event
       * that the object is interested in, then look for a virtual event.
       */

      key.object = *objectPtr;
      key.type = ringPtr->type;
      key.detail = detail;
      hPtr = Tcl_FindHashEntry(&bindPtr->patternTable, (char *) &key);
      if (hPtr != NULL) {
          matchPtr = MatchPatterns(dispPtr, bindPtr, 
                (PatSeq *) Tcl_GetHashValue(hPtr), matchPtr, NULL,
                &sourcePtr);
      }

      if (vMatchDetailList != NULL) {
          matchPtr = MatchPatterns(dispPtr, bindPtr, vMatchDetailList,
                matchPtr, objectPtr, &sourcePtr);
      }

      /*
       * If no match was found, look for a binding for all keys or buttons
       * (detail of 0).  Again, first match on a virtual event.
       */

      if ((detail.clientData != 0) && (matchPtr == NULL)) {
          key.detail.clientData = 0;
          hPtr = Tcl_FindHashEntry(&bindPtr->patternTable, (char *) &key);
          if (hPtr != NULL) {
            matchPtr = MatchPatterns(dispPtr, bindPtr,
                  (PatSeq *) Tcl_GetHashValue(hPtr), matchPtr, NULL,
                  &sourcePtr);
          }

          if (vMatchNoDetailList != NULL) {
              matchPtr = MatchPatterns(dispPtr, bindPtr, vMatchNoDetailList,
                  matchPtr, objectPtr, &sourcePtr);
          }

      }
    
      if (matchPtr != NULL) {
          if (sourcePtr->eventProc == NULL) {
            panic("Tk_BindEvent: missing command");
          }
          if (sourcePtr->eventProc == EvalTclBinding) {
            ExpandPercents(winPtr, (char *) sourcePtr->clientData,
                  eventPtr, detail.keySym, &scripts);
          } else {
            if (matchCount >= matchSpace) {
                PendingBinding *new;
                unsigned int oldSize, newSize;
                
                oldSize = sizeof(staticPending)
                  - sizeof(staticPending.matchArray)
                  + matchSpace * sizeof(PatSeq*);
                matchSpace *= 2;
                newSize = sizeof(staticPending)
                  - sizeof(staticPending.matchArray)
                  + matchSpace * sizeof(PatSeq*);
                new = (PendingBinding *) ckalloc(newSize);
                memcpy((VOID *) new, (VOID *) pendingPtr, oldSize);
                if (pendingPtr != &staticPending) {
                  ckfree((char *) pendingPtr);
                }
                pendingPtr = new;
            }
            sourcePtr->refCount++;
            pendingPtr->matchArray[matchCount] = sourcePtr;
            matchCount++;
          }
          /*
           * A "" is added to the scripts string to separate the
           * various scripts that should be invoked.
           */

          Tcl_DStringAppend(&scripts, "", 1);
#ifdef XIM_DEBUG
          fprintf(stderr, "debugEv: proc '%s'\n", Tcl_DStringValue(&scripts));
#endif /* XIM_DEBUG */
      }
    }
    if (Tcl_DStringLength(&scripts) == 0) {
      return;
    }

    /*
     * Now go back through and evaluate the binding for each object,
     * in order, dealing with "break" and "continue" exceptions
     * appropriately.
     *
     * There are two tricks here:
     * 1. Bindings can be invoked from in the middle of Tcl commands,
     *    where interp->result is significant (for example, a widget
     *    might be deleted because of an error in creating it, so the
     *    result contains an error message that is eventually going to
     *    be returned by the creating command).  To preserve the result,
     *    we save it in a dynamic string.
     * 2. The binding's action can potentially delete the binding,
     *    so bindPtr may not point to anything valid once the action
     *    completes.  Thus we have to save bindPtr->interp in a
     *    local variable in order to restore the result.
     */

    interp = bindPtr->interp;
    Tcl_DStringInit(&savedResult);

    /*
     * Save information about the current screen, then invoke a script
     * if the screen has changed.
     */

    Tcl_DStringGetResult(interp, &savedResult);
    screenPtr = &bindInfoPtr->screenInfo;
    oldDispPtr = screenPtr->curDispPtr;
    oldScreen = screenPtr->curScreenIndex;
    if ((dispPtr != screenPtr->curDispPtr)
          || (Tk_ScreenNumber(tkwin) != screenPtr->curScreenIndex)) {
      screenPtr->curDispPtr = dispPtr;
      screenPtr->curScreenIndex = Tk_ScreenNumber(tkwin);
      ChangeScreen(interp, dispPtr->name, screenPtr->curScreenIndex);
    }

    if (matchCount > 0) {
      pendingPtr->nextPtr = bindInfoPtr->pendingList;
      pendingPtr->tkwin = tkwin;
      pendingPtr->deleted = 0;
      bindInfoPtr->pendingList = pendingPtr;
    }
    
    /*
     * Save the current value of the TK_DEFER_MODAL flag so we can
     * restore it at the end of the loop.  Clear the flag so we can
     * detect any recursive requests for a modal loop.
     */

    flags = winPtr->flags;
    winPtr->flags &= ~TK_DEFER_MODAL;

    p = Tcl_DStringValue(&scripts);
    end = p + Tcl_DStringLength(&scripts);
    i = 0;

    while (p < end) {
      int code;
      
      screenPtr->bindingDepth++;
      Tcl_AllowExceptions(interp);

      if (*p == '\0') {
          PatSeq *psPtr;
          
          psPtr = pendingPtr->matchArray[i];
          i++;
          code = TCL_OK;
          if ((pendingPtr->deleted == 0)
                && ((psPtr->flags & MARKED_DELETED) == 0)) {
            code = (*psPtr->eventProc)(psPtr->clientData, interp, eventPtr,
                  tkwin, detail.keySym);
          }
          psPtr->refCount--;
          if ((psPtr->refCount == 0) && (psPtr->flags & MARKED_DELETED)) {
            if (psPtr->freeProc != NULL) {
                (*psPtr->freeProc)(psPtr->clientData);
            }
            ckfree((char *) psPtr);
          }
      } else {
          code = Tcl_GlobalEval(interp, p);
          p += strlen(p);
      }
      p++;
      screenPtr->bindingDepth--;
      if (code != TCL_OK) {
          if (code == TCL_CONTINUE) {
            /*
             * Do nothing:  just go on to the next command.
             */
          } else if (code == TCL_BREAK) {
            break;
          } else {
            Tcl_AddErrorInfo(interp, "\n    (command bound to event)");
            Tcl_BackgroundError(interp);
            break;
          }
      }
    }

    if (matchCount > 0 && !pendingPtr->deleted) {
      /*
       * Restore the original modal flag value and invoke the modal loop
       * if needed.
       */

      deferModal = winPtr->flags & TK_DEFER_MODAL;
      winPtr->flags = (winPtr->flags & (unsigned int) ~TK_DEFER_MODAL) 
          | (flags & TK_DEFER_MODAL);
      if (deferModal) {
          (*winPtr->classProcsPtr->modalProc)(tkwin, eventPtr);
      }
    }

    if ((screenPtr->bindingDepth != 0) &&
            ((oldDispPtr != screenPtr->curDispPtr)
                    || (oldScreen != screenPtr->curScreenIndex))) {

      /*
       * Some other binding script is currently executing, but its
       * screen is no longer current.  Change the current display
       * back again.
       */

      screenPtr->curDispPtr = oldDispPtr;
      screenPtr->curScreenIndex = oldScreen;
      ChangeScreen(interp, oldDispPtr->name, oldScreen);
    }
    Tcl_DStringResult(interp, &savedResult);
    Tcl_DStringFree(&scripts);

    if (matchCount > 0) {
      PendingBinding **curPtrPtr;

      for (curPtrPtr = &bindInfoPtr->pendingList; ; ) {
          if (*curPtrPtr == pendingPtr) {
            *curPtrPtr = pendingPtr->nextPtr;
            break;
          }
          curPtrPtr = &(*curPtrPtr)->nextPtr;
      }
      if (pendingPtr != &staticPending) {
          ckfree((char *) pendingPtr);
      }
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindDeadWindow --
 *
 *    This procedure is invoked when it is determined that a window is
 *    dead.  It cleans up bind-related information about the window
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Any pending C bindings for this window are cancelled.
 *
 *---------------------------------------------------------------------------
 */
 
void
TkBindDeadWindow(winPtr)
    TkWindow *winPtr;         /* The window that is being deleted. */
{
    BindInfo *bindInfoPtr;
    PendingBinding *curPtr;

    bindInfoPtr = (BindInfo *) winPtr->mainPtr->bindInfo;
    curPtr = bindInfoPtr->pendingList;
    while (curPtr != NULL) {
      if (curPtr->tkwin == (Tk_Window) winPtr) {
          curPtr->deleted = 1;
      }
      curPtr = curPtr->nextPtr;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * MatchPatterns --
 *
 *      Given a list of pattern sequences and a list of recent events,
 *      return the pattern sequence that best matches the event list,
 *    if there is one.
 *
 *    This procedure is used in two different ways.  In the simplest
 *    use, "object" is NULL and psPtr is a list of pattern sequences,
 *    each of which corresponds to a binding.  In this case, the
 *    procedure finds the pattern sequences that match the event list
 *    and returns the most specific of those, if there is more than one.
 *
 *    In the second case, psPtr is a list of pattern sequences, each
 *    of which corresponds to a definition for a virtual binding.
 *    In order for one of these sequences to "match", it must match
 *    the events (as above) but in addition there must be a binding
 *    for its associated virtual event on the current object.  The
 *    "object" argument indicates which object the binding must be for.
 *
 * Results:
 *      The return value is NULL if bestPtr is NULL and no pattern matches
 *    the recent events from bindPtr.  Otherwise the return value is
 *    the most specific pattern sequence among bestPtr and all those
 *    at psPtr that match the event list and object.  If a pattern
 *    sequence other than bestPtr is returned, then *bestCommandPtr
 *    is filled in with a pointer to the command from the best sequence.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
static PatSeq *
MatchPatterns(dispPtr, bindPtr, psPtr, bestPtr, objectPtr, sourcePtrPtr)
    TkDisplay *dispPtr;       /* Display from which the event came. */
    BindingTable *bindPtr;    /* Information about binding table, such as
                         * ring of recent events. */
    PatSeq *psPtr;            /* List of pattern sequences. */
    PatSeq *bestPtr;          /* The best match seen so far, from a
                         * previous call to this procedure.  NULL
                         * means no prior best match. */
    ClientData *objectPtr;    /* If NULL, the sequences at psPtr
                         * correspond to "normal" bindings.  If
                         * non-NULL, the sequences at psPtr correspond
                         * to virtual bindings; in order to match each
                         * sequence must correspond to a virtual
                         * binding for which a binding exists for
                         * object in bindPtr. */
    PatSeq **sourcePtrPtr;    /* Filled with the pattern sequence that
                         * contains the eventProc and clientData
                         * associated with the best match.  If this
                         * differs from the return value, it is the
                         * virtual event that most closely matched the
                         * return value (a physical event).  Not
                         * modified unless a result other than bestPtr
                         * is returned. */
{
    PatSeq *matchPtr, *bestSourcePtr, *sourcePtr;

    bestSourcePtr = *sourcePtrPtr;

    /*
     * Iterate over all the pattern sequences.
     */

    for ( ; psPtr != NULL; psPtr = psPtr->nextSeqPtr) {
      XEvent *eventPtr;
      Pattern *patPtr;
      Window window;
      Detail *detailPtr;
      int patCount, ringCount, flags, state;
      int modMask;

      /*
       * Iterate over all the patterns in a sequence to be
       * sure that they all match.
       */

      eventPtr = &bindPtr->eventRing[bindPtr->curEvent];
      detailPtr = &bindPtr->detailRing[bindPtr->curEvent];
      window = eventPtr->xany.window;
      patPtr = psPtr->pats;
      patCount = psPtr->numPats;
      ringCount = EVENT_BUFFER_SIZE;
      while (patCount > 0) {
          if (ringCount <= 0) {
            goto nextSequence;
          }
          if (eventPtr->xany.type != patPtr->eventType) {
            /*
             * Most of the event types are considered superfluous
             * in that they are ignored if they occur in the middle
             * of a pattern sequence and have mismatching types.  The
             * only ones that cannot be ignored are ButtonPress and
             * ButtonRelease events (if the next event in the pattern
             * is a KeyPress or KeyRelease) and KeyPress and KeyRelease
             * events (if the next pattern event is a ButtonPress or
             * ButtonRelease).  Here are some tricky cases to consider:
             * 1. Double-Button or Double-Key events.
             * 2. Double-ButtonRelease or Double-KeyRelease events.
             * 3. The arrival of various events like Enter and Leave
             *    and FocusIn and GraphicsExpose between two button
             *    presses or key presses.
             * 4. Modifier keys like Shift and Control shouldn't
             *    generate conflicts with button events.
             */

            if ((patPtr->eventType == KeyPress)
                  || (patPtr->eventType == KeyRelease)) {
                if ((eventPtr->xany.type == ButtonPress)
                      || (eventPtr->xany.type == ButtonRelease)) {
                  goto nextSequence;
                }
            } else if ((patPtr->eventType == ButtonPress)
                  || (patPtr->eventType == ButtonRelease)) {
                if ((eventPtr->xany.type == KeyPress)
                      || (eventPtr->xany.type == KeyRelease)) {
                  int i;

                  /*
                   * Ignore key events if they are modifier keys.
                   */

                  for (i = 0; i < dispPtr->numModKeyCodes; i++) {
                      if (dispPtr->modKeyCodes[i]
                            == eventPtr->xkey.keycode) {
                        /*
                         * This key is a modifier key, so ignore it.
                         */
                        goto nextEvent;
                      }
                  }
                  goto nextSequence;
                }
            }
            goto nextEvent;
          }
          if (eventPtr->xany.window != window) {
            goto nextSequence;
          }

          /*
           * Note: it's important for the keysym check to go before
           * the modifier check, so we can ignore unwanted modifier
           * keys before choking on the modifier check.
           */

          if ((patPtr->detail.clientData != 0)
                && (patPtr->detail.clientData != detailPtr->clientData)) {
            /*
             * The detail appears not to match.  However, if the event
             * is a KeyPress for a modifier key then just ignore the
             * event.  Otherwise event sequences like "aD" never match
             * because the shift key goes down between the "a" and the
             * "D".
             */

            if (eventPtr->xany.type == KeyPress) {
                int i;

                for (i = 0; i < dispPtr->numModKeyCodes; i++) {
                  if (dispPtr->modKeyCodes[i] == eventPtr->xkey.keycode) {
                      goto nextEvent;
                  }
                }
            }
            goto nextSequence;
          }
          flags = flagArray[eventPtr->type];
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
            state = eventPtr->xkey.state;
          } else if (flags & CROSSING) {
            state = eventPtr->xcrossing.state;
          } else {
            state = 0;
          }
          if (patPtr->needMods != 0) {
            modMask = patPtr->needMods;
            if ((modMask & META_MASK) && (dispPtr->metaModMask != 0)) {
                modMask = (modMask & ~META_MASK) | dispPtr->metaModMask;
            }
            if ((modMask & ALT_MASK) && (dispPtr->altModMask != 0)) {
                modMask = (modMask & ~ALT_MASK) | dispPtr->altModMask;
            }
            if ((state & modMask) != modMask) {
                goto nextSequence;
            }
          }
          if (psPtr->flags & PAT_NEARBY) {
            XEvent *firstPtr;
            int timeDiff;

            firstPtr = &bindPtr->eventRing[bindPtr->curEvent];
            timeDiff = (Time) firstPtr->xkey.time - eventPtr->xkey.time;
            if ((firstPtr->xkey.x_root
                      < (eventPtr->xkey.x_root - NEARBY_PIXELS))
                  || (firstPtr->xkey.x_root
                      > (eventPtr->xkey.x_root + NEARBY_PIXELS))
                  || (firstPtr->xkey.y_root
                      < (eventPtr->xkey.y_root - NEARBY_PIXELS))
                  || (firstPtr->xkey.y_root
                      > (eventPtr->xkey.y_root + NEARBY_PIXELS))
                  || (timeDiff > NEARBY_MS)) {
                goto nextSequence;
            }
          }
          patPtr++;
          patCount--;
          nextEvent:
          if (eventPtr == bindPtr->eventRing) {
            eventPtr = &bindPtr->eventRing[EVENT_BUFFER_SIZE-1];
            detailPtr = &bindPtr->detailRing[EVENT_BUFFER_SIZE-1];
          } else {
            eventPtr--;
            detailPtr--;
          }
          ringCount--;
      }

      matchPtr = psPtr;
      sourcePtr = psPtr;

      if (objectPtr != NULL) {
          int iVirt;
          VirtualOwners *voPtr;
          PatternTableKey key;

          /*
           * The sequence matches the physical constraints.
           * Is this object interested in any of the virtual events
           * that correspond to this sequence?  
           */

          voPtr = psPtr->voPtr;

          memset(&key, 0, sizeof(key));
          key.object = *objectPtr;
          key.type = VirtualEvent;
          key.detail.clientData = 0;

          for (iVirt = 0; iVirt < voPtr->numOwners; iVirt++) {
              Tcl_HashEntry *hPtr = voPtr->owners[iVirt];

              key.detail.name = (Tk_Uid) Tcl_GetHashKey(hPtr->tablePtr,
                  hPtr);
            hPtr = Tcl_FindHashEntry(&bindPtr->patternTable,
                  (char *) &key);
            if (hPtr != NULL) {

                /*
                 * This tag is interested in this virtual event and its
                 * corresponding physical event is a good match with the
                 * virtual event's definition.
                 */

                PatSeq *virtMatchPtr;

                virtMatchPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
                if ((virtMatchPtr->numPats != 1)
                      || (virtMatchPtr->nextSeqPtr != NULL)) {
                  panic("MatchPattern: badly constructed virtual event");
                }
                sourcePtr = virtMatchPtr;
                goto match;
            }
          }

          /*
           * The physical event matches a virtual event's definition, but
           * the tag isn't interested in it.
           */
          goto nextSequence;
      }
      match:

      /*
       * This sequence matches.  If we've already got another match,
       * pick whichever is most specific.  Detail is most important,
       * then needMods.
       */

      if (bestPtr != NULL) {
          Pattern *patPtr2;
          int i;

          if (matchPtr->numPats != bestPtr->numPats) {
            if (bestPtr->numPats > matchPtr->numPats) {
                goto nextSequence;
            } else {
                goto newBest;
            }
          }
          for (i = 0, patPtr = matchPtr->pats, patPtr2 = bestPtr->pats;
                i < matchPtr->numPats; i++, patPtr++, patPtr2++) {
            if (patPtr->detail.clientData != patPtr2->detail.clientData) {
                if (patPtr->detail.clientData == 0) {
                  goto nextSequence;
                } else {
                  goto newBest;
                }
            }
            if (patPtr->needMods != patPtr2->needMods) {
                if ((patPtr->needMods & patPtr2->needMods)
                      == patPtr->needMods) {
                  goto nextSequence;
                } else if ((patPtr->needMods & patPtr2->needMods)
                      == patPtr2->needMods) {
                  goto newBest;
                }
            }
          }
          /*
           * Tie goes to current best pattern.
           *
           * (1) For virtual vs. virtual, the least recently defined
           * virtual wins, because virtuals are examined in order of
           * definition.  This order is _not_ guaranteed in the
           * documentation.
           *
           * (2) For virtual vs. physical, the physical wins because all
           * the physicals are examined before the virtuals.  This order
           * is guaranteed in the documentation.
           *
           * (3) For physical vs. physical pattern, the most recently
           * defined physical wins, because physicals are examined in
           * reverse order of definition.  This order is guaranteed in
           * the documentation.
           */

          goto nextSequence;  
      }
      newBest:
      bestPtr = matchPtr;
      bestSourcePtr = sourcePtr;

      nextSequence: continue;
    }

    *sourcePtrPtr = bestSourcePtr;
    return bestPtr;
}

/*
 *--------------------------------------------------------------
 *
 * ExpandPercents --
 *
 *    Given a command and an event, produce a new command
 *    by replacing % constructs in the original command
 *    with information from the X event.
 *
 * Results:
 *    The new expanded command is appended to the dynamic string
 *    given by dsPtr.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

static void
ExpandPercents(winPtr, before, eventPtr, keySym, dsPtr)
    TkWindow *winPtr;         /* Window where event occurred:  needed to
                         * get input context. */
    char *before;       /* Command containing percent expressions
                         * to be replaced. */
    XEvent *eventPtr;         /* X event containing information to be
                         * used in % replacements. */
    KeySym keySym;            /* KeySym: only relevant for KeyPress and
                         * KeyRelease events). */
    Tcl_DString *dsPtr;       /* Dynamic string in which to append new
                         * command. */
{
    int spaceNeeded, cvtFlags;      /* Used to substitute string as proper Tcl
                         * list element. */
    int number, flags, length;
#ifdef TK_USE_INPUT_METHODS
#ifdef USE_FIXED_XMBLOOKUPSTR
#define NUM_SIZE 40
#else
    /*
     * Increase buffersize.
     */
#define NUM_SIZE 1024
#endif /* USE_FIXWD_XMBLOOKUPSTR */
#else
#define NUM_SIZE 40
#endif /* TK_USE_INPUT_METHODS */
    char *string;
    char numStorage[NUM_SIZE+1];

#ifdef USE_FIXED_XMBLOOKUPSTR
#ifdef TK_USE_INPUT_METHODS
    /* Must not free! */
    static char *overFlows = NULL;
    static int overFlowLen = NUM_SIZE + 1;

    if (overFlows == NULL) {
      overFlows = (char *)ckalloc(sizeof(char) * (NUM_SIZE + 1));
    }
#endif /* TK_USE_INPUT_METHODS */
#endif /* USE_FIXED_XMBLOOKUPSTR */
    if (eventPtr->type < TK_LASTEVENT) {
      flags = flagArray[eventPtr->type];
    } else {
      flags = 0;
    }
    while (1) {
      /*
       * Find everything up to the next % character and append it
       * to the result string.
       */

      for (string = before; (*string != 0) && (*string != '%'); string++) {
          /* Empty loop body. */
      }
      if (string != before) {
          Tcl_DStringAppend(dsPtr, before, string-before);
          before = string;
      }
      if (*before == 0) {
          break;
      }

      /*
       * There's a percent sequence here.  Process it.
       */

      number = 0;
      string = "??";
      switch (before[1]) {
          case '#':
            number = eventPtr->xany.serial;
            goto doNumber;
          case 'a':
            TkpPrintWindowId(numStorage, eventPtr->xconfigure.above);
            string = numStorage;
            goto doString;
          case 'b':
            number = eventPtr->xbutton.button;
            goto doNumber;
          case 'c':
            if (flags & EXPOSE) {
                number = eventPtr->xexpose.count;
            }
            goto doNumber;
          case 'd':
            if (flags & (CROSSING|FOCUS)) {
                if (flags & FOCUS) {
                  number = eventPtr->xfocus.detail;
                } else {
                  number = eventPtr->xcrossing.detail;
                }
                string = TkFindStateString(notifyDetail, number);
            }
            goto doString;
          case 'f':
            number = eventPtr->xcrossing.focus;
            goto doNumber;
          case 'h':
            if (flags & EXPOSE) {
                number = eventPtr->xexpose.height;
            } else if (flags & (CONFIG)) {
                number = eventPtr->xconfigure.height;
            }
            goto doNumber;
          case 'k':
            number = eventPtr->xkey.keycode;
            goto doNumber;
          case 'm':
            if (flags & CROSSING) {
                number = eventPtr->xcrossing.mode;
            } else if (flags & FOCUS) {
                number = eventPtr->xfocus.mode;
            }
            string = TkFindStateString(notifyMode, number);
            goto doString;
          case 'o':
            if (flags & CREATE) {
                number = eventPtr->xcreatewindow.override_redirect;
            } else if (flags & MAP) {
                number = eventPtr->xmap.override_redirect;
            } else if (flags & REPARENT) {
                number = eventPtr->xreparent.override_redirect;
            } else if (flags & CONFIG) {
                number = eventPtr->xconfigure.override_redirect;
            }
            goto doNumber;
          case 'p':
            string = TkFindStateString(circPlace, eventPtr->xcirculate.place);
            goto doString;
          case 's':
            if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                number = eventPtr->xkey.state;
            } else if (flags & CROSSING) {
                number = eventPtr->xcrossing.state;
            } else if (flags & VISIBILITY) {
                string = TkFindStateString(visNotify,
                      eventPtr->xvisibility.state);
                goto doString;
            }
            goto doNumber;
          case 't':
            if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                number = (int) eventPtr->xkey.time;
            } else if (flags & CROSSING) {
                number = (int) eventPtr->xcrossing.time;
            } else if (flags & PROP) {
                number = (int) eventPtr->xproperty.time;
            }
            goto doNumber;
          case 'v':
            number = eventPtr->xconfigurerequest.value_mask;
            goto doNumber;
          case 'w':
            if (flags & EXPOSE) {
                number = eventPtr->xexpose.width;
            } else if (flags & CONFIG) {
                number = eventPtr->xconfigure.width;
            }
            goto doNumber;
          case 'x':
            if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                number = eventPtr->xkey.x;
            } else if (flags & CROSSING) {
                number = eventPtr->xcrossing.x;
            } else if (flags & EXPOSE) {
                number = eventPtr->xexpose.x;
            } else if (flags & (CREATE|CONFIG|GRAVITY)) {
                number = eventPtr->xcreatewindow.x;
            } else if (flags & REPARENT) {
                number = eventPtr->xreparent.x;
            }
            goto doNumber;
          case 'y':
            if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                number = eventPtr->xkey.y;
            } else if (flags & EXPOSE) {
                number = eventPtr->xexpose.y;
            } else if (flags & (CREATE|CONFIG|GRAVITY)) {
                number = eventPtr->xcreatewindow.y;
            } else if (flags & REPARENT) {
                number = eventPtr->xreparent.y;
            } else if (flags & CROSSING) {
                number = eventPtr->xcrossing.y;

            }
            goto doNumber;
          case 'A':
            if (flags & KEY) {
                int numChars;

                /*
                 * If we're using input methods and this is a keypress
                 * event, invoke XmbTkFindStateString.  Otherwise just use
                 * the older XTkFindStateString.
                 */

#ifdef TK_USE_INPUT_METHODS
                Status status;
                if ((winPtr->inputContext != NULL)
                      && (eventPtr->type == KeyPress)) {
#ifdef USE_FIXED_XMBLOOKUPSTR
                  numChars = XmbLookupString(winPtr->inputContext,
                        &eventPtr->xkey, overFlows, overFlowLen,
                                (KeySym *) NULL, &status);
                  if (status == XBufferOverflow && numChars > 0) {
                      if (numChars > overFlowLen) {
                        overFlowLen = numChars;
                        overFlows = (char *)ckrealloc(overFlows, sizeof(char) * (numChars + 1));
                      }
                      numChars = XmbLookupString(winPtr->inputContext,
                              &eventPtr->xkey, overFlows, numChars, 
                              (KeySym *) NULL, &status);
                  } 
                  if ((status != XLookupChars) &&
                      (status != XLookupBoth)) {
                      numChars = 0;
                  }
                  overFlows[numChars] = '\0';
                  string = overFlows;
                  goto doString;
#endif /* USE_FIXED_XMBLOOKUPSTR */
                        numChars = XmbLookupString(winPtr->inputContext,
                                &eventPtr->xkey, numStorage, NUM_SIZE,
                                (KeySym *) NULL, &status);
                  if ((status != XLookupChars)
                        && (status != XLookupBoth)) {
                      numChars = 0;
                  }
                } else {
                        numChars = XLookupString(&eventPtr->xkey, numStorage,
                                NUM_SIZE, (KeySym *) NULL,
                                (XComposeStatus *) NULL);
                }
#else /* TK_USE_INPUT_METHODS */
                numChars = XLookupString(&eventPtr->xkey, numStorage,
                      NUM_SIZE, (KeySym *) NULL,
                      (XComposeStatus *) NULL);
#endif /* TK_USE_INPUT_METHODS */
                numStorage[numChars] = '\0';
                string = numStorage;
            }
            goto doString;
          case 'B':
            number = eventPtr->xcreatewindow.border_width;
            goto doNumber;
          case 'D':
            /*
             * This is used only by the MouseWheel event.
             */
                
            number = eventPtr->xkey.keycode;
            goto doNumber;
          case 'E':
            number = (int) eventPtr->xany.send_event;
            goto doNumber;
          case 'K':
            if (flags & KEY) {
                char *name;

                name = TkKeysymToString(keySym);
                if (name != NULL) {
                  string = name;
                }
            }
            goto doString;
          case 'N':
            number = (int) keySym;
            goto doNumber;
          case 'R':
            TkpPrintWindowId(numStorage, eventPtr->xkey.root);
            string = numStorage;
            goto doString;
            case 'S':
            TkpPrintWindowId(numStorage, eventPtr->xkey.subwindow);
            string = numStorage;
            goto doString;
          case 'T':
            number = eventPtr->type;
            goto doNumber;
          case 'W': {
            Tk_Window tkwin;

            tkwin = Tk_IdToWindow(eventPtr->xany.display,
                  eventPtr->xany.window);
            if (tkwin != NULL) {
                string = Tk_PathName(tkwin);
            } else {
                string = "??";
            }
            goto doString;
          }
          case 'X': {
            Tk_Window tkwin;
            int x, y;
            int width, height;

            number = eventPtr->xkey.x_root;
            tkwin = Tk_IdToWindow(eventPtr->xany.display,
                  eventPtr->xany.window);
            if (tkwin != NULL) {
                Tk_GetVRootGeometry(tkwin, &x, &y, &width, &height);
                number -= x;
            }
            goto doNumber;
          }
          case 'Y': {
            Tk_Window tkwin;
            int x, y;
            int width, height;

            number = eventPtr->xkey.y_root;
            tkwin = Tk_IdToWindow(eventPtr->xany.display,
                  eventPtr->xany.window);
            if (tkwin != NULL) {
                Tk_GetVRootGeometry(tkwin, &x, &y, &width, &height);
                number -= y;
            }
            goto doNumber;
          }
          default:
            numStorage[0] = before[1];
            numStorage[1] = '\0';
            string = numStorage;
            goto doString;
      }

      doNumber:
      sprintf(numStorage, "%d", number);
      string = numStorage;

      doString:
      spaceNeeded = Tcl_ScanElement(string, &cvtFlags);
      length = Tcl_DStringLength(dsPtr);
      Tcl_DStringSetLength(dsPtr, length + spaceNeeded);
      spaceNeeded = Tcl_ConvertElement(string,
            Tcl_DStringValue(dsPtr) + length,
            cvtFlags | TCL_DONT_USE_BRACES);
      Tcl_DStringSetLength(dsPtr, length + spaceNeeded);
      before += 2;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ChangeScreen --
 *
 *    This procedure is invoked whenever the current screen changes
 *    in an application.  It invokes a Tcl procedure named
 *    "tkScreenChanged", passing it the screen name as argument.
 *    tkScreenChanged does things like making the tkPriv variable
 *    point to an array for the current display.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Depends on what tkScreenChanged does.  If an error occurs
 *    them tkError will be invoked.
 *
 *----------------------------------------------------------------------
 */

static void
ChangeScreen(interp, dispName, screenIndex)
    Tcl_Interp *interp;             /* Interpreter in which to invoke
                               * command. */
    char *dispName;                 /* Name of new display. */
    int screenIndex;                /* Index of new screen. */
{
    Tcl_DString cmd;
    int code;
    char screen[30];

    Tcl_DStringInit(&cmd);
    Tcl_DStringAppend(&cmd, "tkScreenChanged ", 16);
    Tcl_DStringAppend(&cmd, dispName, -1);
    sprintf(screen, ".%d", screenIndex);
    Tcl_DStringAppend(&cmd, screen, -1);
    code = Tcl_GlobalEval(interp, Tcl_DStringValue(&cmd));
    if (code != TCL_OK) {
      Tcl_AddErrorInfo(interp,
            "\n    (changing screen in event binding)");
      Tcl_BackgroundError(interp);
    }
}


/*
 *----------------------------------------------------------------------
 *
 * Tk_EventCmd --
 *
 *    This procedure is invoked to process the "event" Tcl command.
 *    It is used to define and generate events.
 *
 * Results:
 *    A standard Tcl result.
 *
 * Side effects:
 *    See the user documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tk_EventCmd(clientData, interp, argc, argv)
    ClientData clientData;    /* Main window associated with
                         * interpreter. */
    Tcl_Interp *interp;       /* Current interpreter. */
    int argc;                 /* Number of arguments. */
    char **argv;        /* Argument strings. */
{
    int i;
    size_t length;
    char *option;
    Tk_Window tkwin;
    VirtualEventTable *vetPtr;
    TkBindInfo bindInfo;

    if (argc < 2) {
      Tcl_AppendResult(interp, "wrong # args: should be \"",
            argv[0], " option ?arg1?\"", (char *) NULL);
      return TCL_ERROR;
    }

    option = argv[1];
    length = strlen(option);
    if (length == 0) {
      goto badopt;
    }

    tkwin = (Tk_Window) clientData;
    bindInfo = ((TkWindow *) tkwin)->mainPtr->bindInfo;
    vetPtr = &((BindInfo *) bindInfo)->virtualEventTable;

    if (strncmp(option, "add", length) == 0) {
      if (argc < 4) {
          Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
                " add virtual sequence ?sequence ...?\"", (char *) NULL);
          return TCL_ERROR;
      }
      for (i = 3; i < argc; i++) {
          if (CreateVirtualEvent(interp, vetPtr, argv[2], argv[i])
                != TCL_OK) {
            return TCL_ERROR;
          }
      }
    } else if (strncmp(option, "delete", length) == 0) {
      if (argc < 3) {
          Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
                " delete virtual ?sequence sequence ...?\"",
                (char *) NULL);
          return TCL_ERROR;
      }
      if (argc == 3) {
          return DeleteVirtualEvent(interp, vetPtr, argv[2], NULL);
      }
      for (i = 3; i < argc; i++) {
          if (DeleteVirtualEvent(interp, vetPtr, argv[2], argv[i])
                != TCL_OK) {
            return TCL_ERROR;
          }
      }
    } else if (strncmp(option, "generate", length) == 0) {
      if (argc < 4) {
          Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
                " generate window event ?options?\"", (char *) NULL);
          return TCL_ERROR;
      }
      return HandleEventGenerate(interp, tkwin, argc - 2, argv + 2);
    } else if (strncmp(option, "info", length) == 0) {
      if (argc == 2) {
          GetAllVirtualEvents(interp, vetPtr);
          return TCL_OK;
      } else if (argc == 3) { 
          return GetVirtualEvent(interp, vetPtr, argv[2]);
      } else {
          Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
                " info ?virtual?\"", (char *) NULL);
          return TCL_ERROR;
      }
    } else {
      badopt:
      Tcl_AppendResult(interp, "bad option \"", argv[1],
            "\": should be add, delete, generate, info", (char *) NULL);
      return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * InitVirtualEventTable --
 *
 *    Given storage for a virtual event table, set up the fields to
 *    prepare a new domain in which virtual events may be defined.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    *vetPtr is now initialized.
 *
 *---------------------------------------------------------------------------
 */

static void
InitVirtualEventTable(vetPtr)
    VirtualEventTable *vetPtr;      /* Pointer to virtual event table.  Memory
                         * is supplied by the caller. */
{
    Tcl_InitHashTable(&vetPtr->patternTable,
          sizeof(PatternTableKey) / sizeof(int));
    Tcl_InitHashTable(&vetPtr->nameTable, TCL_ONE_WORD_KEYS);
}

/*
 *---------------------------------------------------------------------------
 *
 * DeleteVirtualEventTable --
 *
 *    Delete the contents of a virtual event table.  The caller is
 *    responsible for freeing any memory used by the table itself.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory is freed.
 *
 *---------------------------------------------------------------------------
 */

static void
DeleteVirtualEventTable(vetPtr)
    VirtualEventTable *vetPtr;      /* The virtual event table to delete. */
{
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    PatSeq *psPtr, *nextPtr;

    hPtr = Tcl_FirstHashEntry(&vetPtr->patternTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
      psPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
      for ( ; psPtr != NULL; psPtr = nextPtr) {
          nextPtr = psPtr->nextSeqPtr;
          ckfree((char *) psPtr->voPtr);
          ckfree((char *) psPtr);
      }
    }
    Tcl_DeleteHashTable(&vetPtr->patternTable);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        ckfree((char *) Tcl_GetHashValue(hPtr));
    }
    Tcl_DeleteHashTable(&vetPtr->nameTable);
}

/*
 *----------------------------------------------------------------------
 *
 * CreateVirtualEvent --
 *
 *    Add a new definition for a virtual event.  If the virtual event
 *    is already defined, the new definition augments those that
 *    already exist.
 *
 * Results:
 *    The return value is TCL_ERROR if an error occured while
 *    creating the virtual binding.  In this case, an error message
 *    will be left in interp->result.  If all went well then the return
 *    value is TCL_OK.
 *
 * Side effects:
 *    The virtual event may cause future calls to Tk_BindEvent to
 *    behave differently than they did previously.
 *
 *----------------------------------------------------------------------
 */

static int
CreateVirtualEvent(interp, vetPtr, virtString, eventString)
    Tcl_Interp *interp;       /* Used for error reporting. */
    VirtualEventTable *vetPtr;/* Table in which to augment virtual event. */
    char *virtString;         /* Name of new virtual event. */
    char *eventString;        /* String describing physical event that
                         * triggers virtual event. */
{
    PatSeq *psPtr;
    int dummy;
    Tcl_HashEntry *vhPtr;
    unsigned long eventMask;
    PhysicalsOwned *poPtr;
    VirtualOwners *voPtr;
    Tk_Uid virtUid;
    
    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    /*
     * Find/create physical event
     */

    psPtr = FindSequence(interp, &vetPtr->patternTable, NULL, eventString,
          1, 0, &eventMask);
    if (psPtr == NULL) {
        return TCL_ERROR;
    }

    /*
     * Find/create virtual event.
     */

    vhPtr = Tcl_CreateHashEntry(&vetPtr->nameTable, virtUid, &dummy);

    /*
     * Make virtual event own the physical event.
     */

    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);
    if (poPtr == NULL) {
      poPtr = (PhysicalsOwned *) ckalloc(sizeof(PhysicalsOwned));
      poPtr->numOwned = 0;
    } else {
        /*
       * See if this virtual event is already defined for this physical
       * event and just return if it is.
       */

      int i;
      for (i = 0; i < poPtr->numOwned; i++) {
          if (poPtr->patSeqs[i] == psPtr) {
              return TCL_OK;
          }
      }
      poPtr = (PhysicalsOwned *) ckrealloc((char *) poPtr,
            sizeof(PhysicalsOwned) + poPtr->numOwned * sizeof(PatSeq *));
    } 
    Tcl_SetHashValue(vhPtr, (ClientData) poPtr);
    poPtr->patSeqs[poPtr->numOwned] = psPtr;
    poPtr->numOwned++;

    /*
     * Make physical event so it can trigger the virtual event.
     */

    voPtr = psPtr->voPtr;
    if (voPtr == NULL) {
        voPtr = (VirtualOwners *) ckalloc(sizeof(VirtualOwners));
      voPtr->numOwners = 0;
    } else {
        voPtr = (VirtualOwners *) ckrealloc((char *) voPtr,
            sizeof(VirtualOwners)
            + voPtr->numOwners * sizeof(Tcl_HashEntry *));
    }
    psPtr->voPtr = voPtr;
    voPtr->owners[voPtr->numOwners] = vhPtr;
    voPtr->numOwners++;

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * DeleteVirtualEvent --
 *
 *    Remove the definition of a given virtual event.  If the 
 *    event string is NULL, all definitions of the virtual event
 *    will be removed.  Otherwise, just the specified definition
 *    of the virtual event will be removed.
 *
 * Results:
 *    The result is a standard Tcl return value.  If an error
 *    occurs then interp->result will contain an error message.
 *    It is not an error to attempt to delete a virtual event that
 *    does not exist or a definition that does not exist.
 *
 * Side effects:
 *    The virtual event given by virtString may be removed from the
 *    virtual event table.  
 *
 *--------------------------------------------------------------
 */

static int
DeleteVirtualEvent(interp, vetPtr, virtString, eventString)
    Tcl_Interp *interp;       /* Used for error reporting. */
    VirtualEventTable *vetPtr;/* Table in which to delete event. */
    char *virtString;         /* String describing event sequence that
                         * triggers binding. */
    char *eventString;        /* The event sequence that should be deleted,
                         * or NULL to delete all event sequences for
                         * the entire virtual event. */
{
    int iPhys;
    Tk_Uid virtUid;
    Tcl_HashEntry *vhPtr;
    PhysicalsOwned *poPtr;
    PatSeq *eventPSPtr;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }
    
    vhPtr = Tcl_FindHashEntry(&vetPtr->nameTable, virtUid);
    if (vhPtr == NULL) {
        return TCL_OK;
    }
    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);

    eventPSPtr = NULL;
    if (eventString != NULL) {
      unsigned long eventMask;

      /*
       * Delete only the specific physical event associated with the
       * virtual event.  If the physical event doesn't already exist, or
       * the virtual event doesn't own that physical event, return w/o
       * doing anything.
       */

      eventPSPtr = FindSequence(interp, &vetPtr->patternTable, NULL,
            eventString, 0, 0, &eventMask);
      if (eventPSPtr == NULL) {
          return (interp->result[0] != '\0') ? TCL_ERROR : TCL_OK;
      }
    }

    for (iPhys = poPtr->numOwned; --iPhys >= 0; ) {
      PatSeq *psPtr = poPtr->patSeqs[iPhys];
      if ((eventPSPtr == NULL) || (psPtr == eventPSPtr)) {
          int iVirt;
          VirtualOwners *voPtr;
          
          /*
           * Remove association between this physical event and the given
           * virtual event that it triggers.
           */

          voPtr = psPtr->voPtr;
          for (iVirt = 0; iVirt < voPtr->numOwners; iVirt++) {
            if (voPtr->owners[iVirt] == vhPtr) {
                break;
            }
          }
          if (iVirt == voPtr->numOwners) {
            panic("DeleteVirtualEvent: couldn't find owner");
          }
          voPtr->numOwners--;
          if (voPtr->numOwners == 0) {
            /*
             * Removed last reference to this physical event, so
             * remove it from physical->virtual map.
             */
            PatSeq *prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
            if (prevPtr == psPtr) {
                if (psPtr->nextSeqPtr == NULL) {
                  Tcl_DeleteHashEntry(psPtr->hPtr);
                } else {
                  Tcl_SetHashValue(psPtr->hPtr,
                        psPtr->nextSeqPtr);
                }
            } else {
                for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
                  if (prevPtr == NULL) {
                      panic("Tk_DeleteVirtualEvent couldn't find on hash chain");
                  }
                  if (prevPtr->nextSeqPtr == psPtr) {
                      prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
                      break;
                  }
                }
            }
            ckfree((char *) psPtr->voPtr);
            ckfree((char *) psPtr);
          } else {
            /*
             * This physical event still triggers some other virtual
             * event(s).  Consolidate the list of virtual owners for
             * this physical event so it no longer triggers the
             * given virtual event.
             */
            voPtr->owners[iVirt] = voPtr->owners[voPtr->numOwners];
          }

          /*
           * Now delete the virtual event's reference to the physical
           * event.
           */

          poPtr->numOwned--;
          if (eventPSPtr != NULL && poPtr->numOwned != 0) {
              /*
             * Just deleting this one physical event.  Consolidate list
             * of owned physical events and return.
             */

            poPtr->patSeqs[iPhys] = poPtr->patSeqs[poPtr->numOwned];
            return TCL_OK;
          }
      }
    }

    if (poPtr->numOwned == 0) {
      /*
       * All the physical events for this virtual event were deleted,
       * either because there was only one associated physical event or
       * because the caller was deleting the entire virtual event.  Now
       * the virtual event itself should be deleted.
       */

      ckfree((char *) poPtr);
      Tcl_DeleteHashEntry(vhPtr);
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetVirtualEvent --
 *
 *    Return the list of physical events that can invoke the
 *    given virtual event.
 *
 * Results:
 *    The return value is TCL_OK and interp->result is filled with the
 *    string representation of the physical events associated with the
 *    virtual event; if there are no physical events for the given virtual
 *    event, interp->result is filled with and empty string.  If the
 *    virtual event string is improperly formed, then TCL_ERROR is
 *    returned and an error message is left in interp->result.
 *
 * Side effects:
 *    None.
 *
 *---------------------------------------------------------------------------
 */

static int
GetVirtualEvent(interp, vetPtr, virtString)
    Tcl_Interp *interp;       /* Interpreter for reporting. */
    VirtualEventTable *vetPtr;/* Table in which to look for event. */
    char *virtString;         /* String describing virtual event. */
{
    Tcl_HashEntry *vhPtr;
    Tcl_DString ds;
    int iPhys;
    PhysicalsOwned *poPtr;
    Tk_Uid virtUid;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    vhPtr = Tcl_FindHashEntry(&vetPtr->nameTable, virtUid);
    if (vhPtr == NULL) {
        return TCL_OK;
    }

    Tcl_DStringInit(&ds);

    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);
    for (iPhys = 0; iPhys < poPtr->numOwned; iPhys++) {
      Tcl_DStringSetLength(&ds, 0);
      GetPatternString(poPtr->patSeqs[iPhys], &ds);
      Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }
    Tcl_DStringFree(&ds);

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * GetAllVirtualEvents --
 *
 *    Return a list that contains the names of all the virtual
 *    event defined.
 *
 * Results:
 *    There is no return value.  Interp->result is modified to
 *    hold a Tcl list with one entry for each virtual event in 
 *    nameTable.  
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

static void
GetAllVirtualEvents(interp, vetPtr)
    Tcl_Interp *interp;       /* Interpreter returning result. */
    VirtualEventTable *vetPtr;/* Table containing events. */
{
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    Tcl_DString ds;

    Tcl_DStringInit(&ds);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
      Tcl_DStringSetLength(&ds, 0); 
      Tcl_DStringAppend(&ds, "<<", 2);
      Tcl_DStringAppend(&ds, Tcl_GetHashKey(hPtr->tablePtr, hPtr), -1);
      Tcl_DStringAppend(&ds, ">>", 2);
        Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }

    Tcl_DStringFree(&ds);
}

/*
 *---------------------------------------------------------------------------
 *
 * HandleEventGenerate --
 *
 *    Helper function for the "event generate" command.  Generate and
 *    process an XEvent, constructed from information parsed from the
 *    event description string and its optional arguments.
 *
 *    argv[0] contains name of the target window.
 *    argv[1] contains pattern string for one event (e.g, <Control-v>).
 *    argv[2..argc-1] contains -field/option pairs for specifying
 *                  additional detail in the generated event.
 *
 *    Either virtual or physical events can be generated this way.
 *    The event description string must contain the specification
 *    for only one event.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    When constructing the event, 
 *     event.xany.serial is filled with the current X serial number.
 *     event.xany.window is filled with the target window.
 *     event.xany.display is filled with the target window's display.
 *    Any other fields in eventPtr which are not specified by the pattern
 *    string or the optional arguments, are set to 0.
 *
 *    The event may be handled sychronously or asynchronously, depending
 *    on the value specified by the optional "-when" option.  The
 *    default setting is synchronous.
 *
 *---------------------------------------------------------------------------
 */
static int
HandleEventGenerate(interp, mainwin, argc, argv)
    Tcl_Interp *interp;     /* Interp for error messages and name lookup. */
    Tk_Window mainwin;      /* Main window associated with interp. */
    int argc;               /* Number of arguments. */
    char **argv;      /* Argument strings. */
{
    Pattern pat;
    Tk_Window tkwin;
    char *p;
    unsigned long eventMask;
    int count, i, state, flags, synch;
    Tcl_QueuePosition pos;
    XEvent event;    

    if (argv[0][0] == '.') {
      tkwin = Tk_NameToWindow(interp, argv[0], mainwin);
      if (tkwin == NULL) {
          return TCL_ERROR;
      }
    } else {
      if (TkpScanWindowId(NULL, argv[0], &i) != TCL_OK) {
          Tcl_AppendResult(interp, "bad window name/identifier \"",
                argv[0], "\"", (char *) NULL);
          return TCL_ERROR;
      }
      tkwin = Tk_IdToWindow(Tk_Display(mainwin), (Window) i);
      if ((tkwin == NULL) || (((TkWindow *) mainwin)->mainPtr
            != ((TkWindow *) tkwin)->mainPtr)) {
          Tcl_AppendResult(interp, "window id \"", argv[0],
                "\" doesn't exist in this application", (char *) NULL);
          return TCL_ERROR;
      }
    }

    p = argv[1];
    count = ParseEventDescription(interp, &p, &pat, &eventMask);
    if (count == 0) {
      return TCL_ERROR;
    }
    if (count != 1) {
      interp->result = "Double or Triple modifier not allowed";
      return TCL_ERROR;
    }
    if (*p != '\0') {
      interp->result = "only one event specification allowed";
      return TCL_ERROR;
    }
    if (argc & 1) {
        Tcl_AppendResult(interp, "value for \"", argv[argc - 1],
            "\" missing", (char *) NULL);
      return TCL_ERROR;
    }

    memset((VOID *) &event, 0, sizeof(event));
    event.xany.type = pat.eventType;
    event.xany.serial = NextRequest(Tk_Display(tkwin));
    event.xany.send_event = False;
    event.xany.window = Tk_WindowId(tkwin);
    event.xany.display = Tk_Display(tkwin);

    flags = flagArray[event.xany.type];
    if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
      event.xkey.state = pat.needMods;
      if ((flags & KEY) && (event.xany.type != MouseWheelEvent)) {
          /*
           * When mapping from a keysym to a keycode, need information about
           * the modifier state that should be used so that when they call 
           * XKeycodeToKeysym taking into account the xkey.state, they will
           * get back the original keysym.  
           */

          if (pat.detail.keySym == NoSymbol) {
              event.xkey.keycode = 0;
          } else {
            event.xkey.keycode = XKeysymToKeycode(event.xany.display,
                  pat.detail.keySym);
          }
          if (event.xkey.keycode != 0) {
            for (state = 0; state < 4; state++) {
                if (XKeycodeToKeysym(event.xany.display,
                      event.xkey.keycode, state) == pat.detail.keySym) {
                  if (state & 1) {
                      event.xkey.state |= ShiftMask;
                  }
                  if (state & 2) {
                      TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr; 
                      event.xkey.state |= dispPtr->modeModMask;
                  }
                  break;
                }
            }
          }
      } else if (flags & BUTTON) {
          event.xbutton.button = pat.detail.button;
      } else if (flags & VIRTUAL) {
          ((XVirtualEvent *) &event)->name = pat.detail.name;
      }
    }
    if (flags & (CREATE|DESTROY|UNMAP|MAP|REPARENT|CONFIG|GRAVITY|CIRC)) {
      event.xcreatewindow.window = event.xany.window;
    }

    /*
     * Process the remaining arguments to fill in additional fields
     * of the event.
     */

    synch = 1;
    pos = TCL_QUEUE_TAIL;
    for (i = 2; i < argc; i += 2) {
      char *field, *value;
      Tk_Window tkwin2;
      int number;
      KeySym keysym;
      
      field = argv[i];
      value = argv[i+1];

      if (strcmp(field, "-when") == 0) {
          if (strcmp(value, "now") == 0) {
            synch = 1;
          } else if (strcmp(value, "head") == 0) {
            pos = TCL_QUEUE_HEAD;
            synch = 0;
          } else if (strcmp(value, "mark") == 0) {
            pos = TCL_QUEUE_MARK;
            synch = 0;
          } else if (strcmp(value, "tail") == 0) {
            pos = TCL_QUEUE_TAIL;
            synch = 0;
          } else {
            Tcl_AppendResult(interp, "bad position \"", value,
                  "\": should be now, head, mark, tail", (char *) NULL);
            return TCL_ERROR;
          }
      } else if (strcmp(field, "-above") == 0) {
          if (value[0] == '.') {
            tkwin2 = Tk_NameToWindow(interp, value, mainwin);
            if (tkwin2 == NULL) {
                return TCL_ERROR;
            }
            number = Tk_WindowId(tkwin2);
          } else if (TkpScanWindowId(interp, value, &number)
                != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & CONFIG) {
            event.xconfigure.above = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-borderwidth") == 0) {
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (CREATE|CONFIG)) {
            event.xcreatewindow.border_width = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-button") == 0) {
          if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & BUTTON) {
              event.xbutton.button = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-count") == 0) {
          if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & EXPOSE) {
            event.xexpose.count = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-delta") == 0) {
          if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if ((flags & KEY) && (event.xkey.type == MouseWheelEvent)) {
              event.xkey.keycode = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-detail") == 0) {
          number = TkFindStateNum(interp, field, notifyDetail, value);
          if (number < 0) {
            return TCL_ERROR;
          }
          if (flags & FOCUS) {
            event.xfocus.detail = number;
          } else if (flags & CROSSING) {
            event.xcrossing.detail = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-focus") == 0) {
          if (Tcl_GetBoolean(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & CROSSING) {
            event.xcrossing.focus = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-height") == 0) {
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & EXPOSE) {
             event.xexpose.height = number;
          } else if (flags & CONFIG) {
            event.xconfigure.height = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-keycode") == 0) {
          if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if ((flags & KEY) && (event.xkey.type != MouseWheelEvent)) {
              event.xkey.keycode = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-keysym") == 0) {
          keysym = TkStringToKeysym(value);
          if (keysym == NoSymbol) {
            Tcl_AppendResult(interp, "unknown keysym \"", value,
                  "\"", (char *) NULL);
            return TCL_ERROR;
          }
          /*
           * When mapping from a keysym to a keycode, need information about
           * the modifier state that should be used so that when they call 
           * XKeycodeToKeysym taking into account the xkey.state, they will
           * get back the original keysym.  
           */

          number = XKeysymToKeycode(event.xany.display, keysym);
          if (number == 0) {
            Tcl_AppendResult(interp, "no keycode for keysym \"", value,
                  "\"", (char *) NULL);
            return TCL_ERROR;
          }
          for (state = 0; state < 4; state++) {
            if (XKeycodeToKeysym(event.xany.display, (unsigned) number,
                  state) == keysym) {
                if (state & 1) {
                  event.xkey.state |= ShiftMask;
                }
                if (state & 2) {
                  TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr; 
                  event.xkey.state |= dispPtr->modeModMask;
                }
                break;
            }
          }     
          if ((flags & KEY) && (event.xkey.type != MouseWheelEvent)) {
            event.xkey.keycode = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-mode") == 0) {
          number = TkFindStateNum(interp, field, notifyMode, value);
          if (number < 0) {
            return TCL_ERROR;
          }
          if (flags & CROSSING) {
            event.xcrossing.mode = number;
          } else if (flags & FOCUS) {
            event.xfocus.mode = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-override") == 0) {
          if (Tcl_GetBoolean(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & CREATE) {
            event.xcreatewindow.override_redirect = number;
          } else if (flags & MAP) {
            event.xmap.override_redirect = number;
          } else if (flags & REPARENT) {
            event.xreparent.override_redirect = number;
          } else if (flags & CONFIG) {
            event.xconfigure.override_redirect = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-place") == 0) {
          number = TkFindStateNum(interp, field, circPlace, value);
          if (number < 0) {
            return TCL_ERROR;
          }
          if (flags & CIRC) {
            event.xcirculate.place = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-root") == 0) {
          if (value[0] == '.') {
            tkwin2 = Tk_NameToWindow(interp, value, mainwin);
            if (tkwin2 == NULL) {
                return TCL_ERROR;
            }
            number = Tk_WindowId(tkwin2);
          } else if (TkpScanWindowId(interp, value, &number)
                != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            event.xkey.root = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-rootx") == 0) {
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            event.xkey.x_root = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-rooty") == 0) {
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            event.xkey.y_root = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-sendevent") == 0) {
          if (isdigit(UCHAR(value[0]))) {
            /*
             * Allow arbitrary integer values for the field; they
             * are needed by a few of the tests in the Tk test suite.
             */

            if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
                return TCL_ERROR;
            }
          } else {
            if (Tcl_GetBoolean(interp, value, &number) != TCL_OK) {
                return TCL_ERROR;
            }
          }
          event.xany.send_event = number;
      } else if (strcmp(field, "-serial") == 0) {
          if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          event.xany.serial = number;
      } else if (strcmp(field, "-state") == 0) {
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
                return TCL_ERROR;
            }
            if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
                event.xkey.state = number;
            } else {
                event.xcrossing.state = number;
            }
          } else if (flags & VISIBILITY) {
            number = TkFindStateNum(interp, field, visNotify, value);
            if (number < 0) {
                return TCL_ERROR;
            }
            event.xvisibility.state = number;
          } else {
            goto badopt;
          }     
      } else if (strcmp(field, "-subwindow") == 0) {
          if (value[0] == '.') {
            tkwin2 = Tk_NameToWindow(interp, value, mainwin);
            if (tkwin2 == NULL) {
                return TCL_ERROR;
            }
            number = Tk_WindowId(tkwin2);
          } else if (TkpScanWindowId(interp, value, &number)
                != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            event.xkey.subwindow = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-time") == 0) {
          if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            event.xkey.time = (Time) number;
          } else if (flags & PROP) {
            event.xproperty.time = (Time) number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-width") == 0) {
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & EXPOSE) {
            event.xexpose.width = number;
          } else if (flags & (CREATE|CONFIG)) {
            event.xcreatewindow.width = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-window") == 0) {
          if (value[0] == '.') {
            tkwin2 = Tk_NameToWindow(interp, value, mainwin);
            if (tkwin2 == NULL) {
                return TCL_ERROR;
            }
            number = Tk_WindowId(tkwin2);
          } else if (TkpScanWindowId(interp, value, &number)
                != TCL_OK) {
            return TCL_ERROR;
          }
          if (flags & (CREATE|DESTROY|UNMAP|MAP|REPARENT|CONFIG
                |GRAVITY|CIRC)) {
            event.xcreatewindow.window = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-x") == 0) {
          int rootX, rootY;
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          Tk_GetRootCoords(tkwin, &rootX, &rootY);
          rootX += number;
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {     
            event.xkey.x = number;
            event.xkey.x_root = rootX;
          } else if (flags & EXPOSE) {
            event.xexpose.x = number;
          } else if (flags & (CREATE|CONFIG|GRAVITY)) { 
            event.xcreatewindow.x = number;
          } else if (flags & REPARENT) {        
            event.xreparent.x = number;
          } else {
            goto badopt;
          }
      } else if (strcmp(field, "-y") == 0) {
          int rootX, rootY;
          if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
            return TCL_ERROR;
          }
          Tk_GetRootCoords(tkwin, &rootX, &rootY);
          rootY += number;
          if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
            event.xkey.y = number;
            event.xkey.y_root = rootY;
          } else if (flags & EXPOSE) {
            event.xexpose.y = number;
          } else if (flags & (CREATE|CONFIG|GRAVITY)) {
            event.xcreatewindow.y = number;
          } else if (flags & REPARENT) {
            event.xreparent.y = number;
          } else {
            goto badopt;
          }
      } else {
          badopt:
          Tcl_AppendResult(interp, "bad option to ", argv[1],
                " event: \"", field, "\"", (char *) NULL);
          return TCL_ERROR;
      }
    }

    if (synch != 0) {
      Tk_HandleEvent(&event);
    } else {
      Tk_QueueWindowEvent(&event, pos);
    }
    Tcl_ResetResult(interp);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------------
 *
 * GetVirtualEventUid --
 *
 *    Determine if the given string is in the proper format for a
 *    virtual event.
 *
 * Results:
 *    The return value is NULL if the virtual event string was
 *    not in the proper format.  In this case, an error message
 *    will be left in interp->result.  Otherwise the return
 *    value is a Tk_Uid that represents the virtual event.
 *
 * Side effects:
 *    None.
 *
 *-------------------------------------------------------------------------
 */
static Tk_Uid
GetVirtualEventUid(interp, virtString)
    Tcl_Interp *interp;
    char *virtString;
{
    Tk_Uid uid;
    int length;

    length = strlen(virtString);

    if (length < 5 || virtString[0] != '<' || virtString[1] != '<' ||
          virtString[length - 2] != '>' || virtString[length - 1] != '>') {
        Tcl_AppendResult(interp, "virtual event \"", virtString,
            "\" is badly formed", (char *) NULL);
        return NULL;
    }
    virtString[length - 2] = '\0';
    uid = Tk_GetUid(virtString + 2);
    virtString[length - 2] = '>';

    return uid;
}


/*
 *----------------------------------------------------------------------
 *
 * FindSequence --
 *
 *    Find the entry in the pattern table that corresponds to a
 *    particular pattern string, and return a pointer to that
 *    entry.
 *
 * Results:
 *    The return value is normally a pointer to the PatSeq
 *    in patternTable that corresponds to eventString.  If an error
 *    was found while parsing eventString, or if "create" is 0 and
 *    no pattern sequence previously existed, then NULL is returned
 *    and interp->result contains a message describing the problem.
 *    If no pattern sequence previously existed for eventString, then
 *    a new one is created with a NULL command field.  In a successful
 *    return, *maskPtr is filled in with a mask of the event types
 *    on which the pattern sequence depends.
 *
 * Side effects:
 *    A new pattern sequence may be allocated.
 *
 *----------------------------------------------------------------------
 */

static PatSeq *
FindSequence(interp, patternTablePtr, object, eventString, create,
      allowVirtual, maskPtr)
    Tcl_Interp *interp;       /* Interpreter to use for error
                         * reporting. */
    Tcl_HashTable *patternTablePtr; /* Table to use for lookup. */
    ClientData object;        /* For binding table, token for object with
                         * which binding is associated.
                         * For virtual event table, NULL. */
    char *eventString;        /* String description of pattern to
                         * match on.  See user documentation
                         * for details. */
    int create;               /* 0 means don't create the entry if
                         * it doesn't already exist.   Non-zero
                         * means create. */
    int allowVirtual;         /* 0 means that virtual events are not
                         * allowed in the sequence.  Non-zero
                         * otherwise. */
    unsigned long *maskPtr;   /* *maskPtr is filled in with the event
                         * types on which this pattern sequence
                         * depends. */
{

    Pattern pats[EVENT_BUFFER_SIZE];
    int numPats, virtualFound;
    char *p;
    Pattern *patPtr;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    int flags, count, new;
    size_t sequenceSize;
    unsigned long eventMask;
    PatternTableKey key;

    /*
     *-------------------------------------------------------------
     * Step 1: parse the pattern string to produce an array
     * of Patterns.  The array is generated backwards, so
     * that the lowest-indexed pattern corresponds to the last
     * event that must occur.
     *-------------------------------------------------------------
     */

    p = eventString;
    flags = 0;
    eventMask = 0;
    virtualFound = 0;

    patPtr = &pats[EVENT_BUFFER_SIZE-1];
    for (numPats = 0; numPats < EVENT_BUFFER_SIZE; numPats++, patPtr--) {
      while (isspace(UCHAR(*p))) {
          p++;
      }
      if (*p == '\0') {
          break;
      }

      count = ParseEventDescription(interp, &p, patPtr, &eventMask);
      if (count == 0) {
          return NULL;
      }

      if (eventMask & VirtualEventMask) {
          if (allowVirtual == 0) {
            interp->result =
                  "virtual event not allowed in definition of another virtual event";
            return NULL;
          }
          virtualFound = 1;
      }

      /*
       * Replicate events for DOUBLE and TRIPLE.
       */

      if ((count > 1) && (numPats < EVENT_BUFFER_SIZE-1)) {
          flags |= PAT_NEARBY;
          patPtr[-1] = patPtr[0];
          patPtr--;
          numPats++;
          if ((count == 3) && (numPats < EVENT_BUFFER_SIZE-1)) {
            patPtr[-1] = patPtr[0];
            patPtr--;
            numPats++;
          }
      }
    }

    /*
     *-------------------------------------------------------------
     * Step 2: find the sequence in the binding table if it exists,
     * and add a new sequence to the table if it doesn't.
     *-------------------------------------------------------------
     */

    if (numPats == 0) {
      interp->result = "no events specified in binding";
      return NULL;
    }
    if ((numPats > 1) && (virtualFound != 0)) {
        interp->result = "virtual events may not be composed";
      return NULL;
    }
    
    patPtr = &pats[EVENT_BUFFER_SIZE-numPats];
    memset(&key, 0, sizeof(key));
    key.object = object;
    key.type = patPtr->eventType;
    key.detail = patPtr->detail;
    hPtr = Tcl_CreateHashEntry(patternTablePtr, (char *) &key, &new);
    sequenceSize = numPats*sizeof(Pattern);
    if (!new) {
      for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
            psPtr = psPtr->nextSeqPtr) {
          if ((numPats == psPtr->numPats)
                && ((flags & PAT_NEARBY) == (psPtr->flags & PAT_NEARBY))
                && (memcmp((char *) patPtr, (char *) psPtr->pats,
                sequenceSize) == 0)) {
            goto done;
          }
      }
    }
    if (!create) {
      if (new) {
          Tcl_DeleteHashEntry(hPtr);
      }
      return NULL;
    }
    psPtr = (PatSeq *) ckalloc((unsigned) (sizeof(PatSeq)
          + (numPats-1)*sizeof(Pattern)));
    psPtr->numPats = numPats;
    psPtr->eventProc = NULL;
    psPtr->freeProc = NULL;
    psPtr->clientData = NULL;
    psPtr->flags = flags;
    psPtr->refCount = 0;
    psPtr->nextSeqPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    psPtr->hPtr = hPtr;
    psPtr->voPtr = NULL;
    psPtr->nextObjPtr = NULL;
    Tcl_SetHashValue(hPtr, psPtr);

    memcpy((VOID *) psPtr->pats, (VOID *) patPtr, sequenceSize);

    done:
    *maskPtr = eventMask;
    return psPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * ParseEventDescription --
 *
 *    Fill Pattern buffer with information about event from
 *    event string.
 *
 * Results:
 *    Leaves error message in interp and returns 0 if there was an
 *    error due to a badly formed event string.  Returns 1 if proper
 *    event was specified, 2 if Double modifier was used in event
 *    string, or 3 if Triple was used.
 *
 * Side effects:
 *    On exit, eventStringPtr points to rest of event string (after the
 *    closing '>', so that this procedure can be called repeatedly to
 *    parse all the events in the entire sequence.
 *
 *---------------------------------------------------------------------------
 */

static int
ParseEventDescription(interp, eventStringPtr, patPtr,
      eventMaskPtr)
    Tcl_Interp *interp;       /* For error messages. */
    char **eventStringPtr;    /* On input, holds a pointer to start of
                         * event string.  On exit, gets pointer to
                         * rest of string after parsed event. */
    Pattern *patPtr;          /* Filled with the pattern parsed from the
                         * event string. */
    unsigned long *eventMaskPtr;/* Filled with event mask of matched event. */
                         
{
    char *p;
    unsigned long eventMask;
    int count, eventFlags;
#define FIELD_SIZE 48
    char field[FIELD_SIZE];
    Tcl_HashEntry *hPtr;

    p = *eventStringPtr;

    patPtr->eventType = -1;
    patPtr->needMods = 0;
    patPtr->detail.clientData = 0;

    eventMask = 0;
    count = 1;
    
    /*
     * Handle simple ASCII characters.
     */

    if (*p != '<') {
      char string[2];

      patPtr->eventType = KeyPress;
      eventMask = KeyPressMask;
      string[0] = *p;
      string[1] = 0;
      patPtr->detail.keySym = TkStringToKeysym(string);
      if (patPtr->detail.keySym == NoSymbol) {
          if (isprint(UCHAR(*p))) {
            patPtr->detail.keySym = *p;
          } else {
            sprintf(interp->result,
                  "bad ASCII character 0x%x", (unsigned char) *p);
            return 0;
          }
      }
      p++;
      goto end;
    }

    /*
     * A fancier event description.  This can be either a virtual event
     * or a physical event.
     *
     * A virtual event description consists of:
     *
     * 1. double open angle brackets.
     * 2. virtual event name.
     * 3. double close angle brackets.
     *
     * A physical event description consists of:
     *
     * 1. open angle bracket.
     * 2. any number of modifiers, each followed by spaces
     *    or dashes.
     * 3. an optional event name.
     * 4. an option button or keysym name.  Either this or
     *    item 3 *must* be present;  if both are present
     *    then they are separated by spaces or dashes.
     * 5. a close angle bracket.
     */

    p++;
    if (*p == '<') {
      /*
       * This is a virtual event: soak up all the characters up to
       * the next '>'.
       */

      char *field = p + 1;        
      p = strchr(field, '>');
      if (p == field) {
          interp->result = "virtual event \"<<>>\" is badly formed";
          return 0;
      }         
      if ((p == NULL) || (p[1] != '>')) {
          interp->result = "missing \">\" in virtual binding";
          return 0;
      }
      *p = '\0';
      patPtr->eventType = VirtualEvent;
      eventMask = VirtualEventMask;
      patPtr->detail.name = Tk_GetUid(field);
      *p = '>';

      p += 2;
      goto end;
    }

    while (1) {
      ModInfo *modPtr;
      p = GetField(p, field, FIELD_SIZE);
      if (*p == '>') {
          /*
           * This solves the problem of, e.g., <Control-M> being
           * misinterpreted as Control + Meta + missing keysym
           * instead of Control + KeyPress + M.
           */
           break;
      }
      hPtr = Tcl_FindHashEntry(&modTable, field);
      if (hPtr == NULL) {
          break;
      }
      modPtr = (ModInfo *) Tcl_GetHashValue(hPtr);
      patPtr->needMods |= modPtr->mask;
      if (modPtr->flags & (DOUBLE|TRIPLE)) {
          if (modPtr->flags & DOUBLE) {
            count = 2;
          } else {
            count = 3;
          }
      }
      while ((*p == '-') || isspace(UCHAR(*p))) {
          p++;
      }
    }

    eventFlags = 0;
    hPtr = Tcl_FindHashEntry(&eventTable, field);
    if (hPtr != NULL) {
      EventInfo *eiPtr;
      eiPtr = (EventInfo *) Tcl_GetHashValue(hPtr);

      patPtr->eventType = eiPtr->type;
      eventFlags = flagArray[eiPtr->type];
      eventMask = eiPtr->eventMask;
      while ((*p == '-') || isspace(UCHAR(*p))) {
          p++;
      }
      p = GetField(p, field, FIELD_SIZE);
    }
    if (*field != '\0') {
      if ((*field >= '1') && (*field <= '5') && (field[1] == '\0')) {
          if (eventFlags == 0) {
            patPtr->eventType = ButtonPress;
            eventMask = ButtonPressMask;
          } else if (eventFlags & KEY) {
            goto getKeysym;
          } else if ((eventFlags & BUTTON) == 0) {
            Tcl_AppendResult(interp, "specified button \"", field,
                  "\" for non-button event", (char *) NULL);
            return 0;
          }
          patPtr->detail.button = (*field - '0');
      } else {
          getKeysym:
          patPtr->detail.keySym = TkStringToKeysym(field);
          if (patPtr->detail.keySym == NoSymbol) {
            Tcl_AppendResult(interp, "bad event type or keysym \"",
                  field, "\"", (char *) NULL);
            return 0;
          }
          if (eventFlags == 0) {
            patPtr->eventType = KeyPress;
            eventMask = KeyPressMask;
          } else if ((eventFlags & KEY) == 0) {
            Tcl_AppendResult(interp, "specified keysym \"", field,
                  "\" for non-key event", (char *) NULL);
            return 0;
          }
      }
    } else if (eventFlags == 0) {
      interp->result = "no event type or button # or keysym";
      return 0;
    }

    while ((*p == '-') || isspace(UCHAR(*p))) {
      p++;
    }
    if (*p != '>') {
      while (*p != '\0') {
          p++;
          if (*p == '>') {
            interp->result = "extra characters after detail in binding";
            return 0;
          }
      }
      interp->result = "missing \">\" in binding";
      return 0;
    }
    p++;

end:
    *eventStringPtr = p;
    *eventMaskPtr |= eventMask;
    return count;
}

/*
 *----------------------------------------------------------------------
 *
 * GetField --
 *
 *    Used to parse pattern descriptions.  Copies up to
 *    size characters from p to copy, stopping at end of
 *    string, space, "-", ">", or whenever size is
 *    exceeded.
 *
 * Results:
 *    The return value is a pointer to the character just
 *    after the last one copied (usually "-" or space or
 *    ">", but could be anything if size was exceeded).
 *    Also places NULL-terminated string (up to size
 *    character, including NULL), at copy.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

static char *
GetField(p, copy, size)
    char *p;            /* Pointer to part of pattern. */
    char *copy;   /* Place to copy field. */
    int size;                 /* Maximum number of characters to
                         * copy. */
{
    while ((*p != '\0') && !isspace(UCHAR(*p)) && (*p != '>')
          && (*p != '-') && (size > 1)) {
      *copy = *p;
      p++;
      copy++;
      size--;
    }
    *copy = '\0';
    return p;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetPatternString --
 *
 *    Produce a string version of the given event, for displaying to
 *    the user.  
 *
 * Results:
 *    The string is left in dsPtr.
 *
 * Side effects:
 *    It is the caller's responsibility to initialize the DString before
 *    and to free it after calling this procedure.
 *
 *---------------------------------------------------------------------------
 */
static void
GetPatternString(psPtr, dsPtr)
    PatSeq *psPtr;
    Tcl_DString *dsPtr;
{
    Pattern *patPtr;
    char c, buffer[10];
    int patsLeft, needMods;
    ModInfo *modPtr;
    EventInfo *eiPtr;

    /*
     * The order of the patterns in the sequence is backwards from the order
     * in which they must be output.
     */

    for (patsLeft = psPtr->numPats, patPtr = &psPtr->pats[psPtr->numPats - 1];
          patsLeft > 0; patsLeft--, patPtr--) {

      /*
       * Check for simple case of an ASCII character.
       */

      if ((patPtr->eventType == KeyPress)
            && ((psPtr->flags & PAT_NEARBY) == 0) 
            && (patPtr->needMods == 0)
            && (patPtr->detail.keySym < 128)
            && isprint(UCHAR(patPtr->detail.keySym))
            && (patPtr->detail.keySym != '<')
            && (patPtr->detail.keySym != ' ')) {

          c = (char) patPtr->detail.keySym;
          Tcl_DStringAppend(dsPtr, &c, 1);
          continue;
      }

      /*
       * Check for virtual event.
       */

      if (patPtr->eventType == VirtualEvent) {
          Tcl_DStringAppend(dsPtr, "<<", 2);
          Tcl_DStringAppend(dsPtr, patPtr->detail.name, -1);
          Tcl_DStringAppend(dsPtr, ">>", 2);
          continue;
      }

      /*
       * It's a more general event specification.  First check
       * for "Double" or "Triple", then modifiers, then event type,
       * then keysym or button detail.
       */

      Tcl_DStringAppend(dsPtr, "<", 1);
      if ((psPtr->flags & PAT_NEARBY) && (patsLeft > 1)
            && (memcmp((char *) patPtr, (char *) (patPtr-1),
                  sizeof(Pattern)) == 0)) {
          patsLeft--;
          patPtr--;
          if ((patsLeft > 1) && (memcmp((char *) patPtr,
                (char *) (patPtr-1), sizeof(Pattern)) == 0)) {
            patsLeft--;
            patPtr--;
            Tcl_DStringAppend(dsPtr, "Triple-", 7);
          } else {
            Tcl_DStringAppend(dsPtr, "Double-", 7);
          }
      }
      for (needMods = patPtr->needMods, modPtr = modArray;
            needMods != 0; modPtr++) {
          if (modPtr->mask & needMods) {
            needMods &= ~modPtr->mask;
            Tcl_DStringAppend(dsPtr, modPtr->name, -1);
            Tcl_DStringAppend(dsPtr, "-", 1);
          }
      }
      for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
          if (eiPtr->type == patPtr->eventType) {
            Tcl_DStringAppend(dsPtr, eiPtr->name, -1);
            if (patPtr->detail.clientData != 0) {
                Tcl_DStringAppend(dsPtr, "-", 1);
            }
            break;
          }
      }

      if (patPtr->detail.clientData != 0) {
          if ((patPtr->eventType == KeyPress)
                || (patPtr->eventType == KeyRelease)) {
            char *string;

            string = TkKeysymToString(patPtr->detail.keySym);
            if (string != NULL) {
                Tcl_DStringAppend(dsPtr, string, -1);
            }
          } else {
            sprintf(buffer, "%d", patPtr->detail.button);
            Tcl_DStringAppend(dsPtr, buffer, -1);
          }
      }
      Tcl_DStringAppend(dsPtr, ">", 1);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * GetKeySym --
 *
 *    Given an X KeyPress or KeyRelease event, map the
 *    keycode in the event into a KeySym.
 *
 * Results:
 *    The return value is the KeySym corresponding to
 *    eventPtr, or NoSymbol if no matching Keysym could be
 *    found.
 *
 * Side effects:
 *    In the first call for a given display, keycode-to-
 *    KeySym maps get loaded.
 *
 *----------------------------------------------------------------------
 */

static KeySym
GetKeySym(dispPtr, eventPtr)
    TkDisplay *dispPtr; /* Display in which to
                               * map keycode. */
    XEvent *eventPtr;         /* Description of X event. */
{
    KeySym sym;
    int index;

    /*
     * Refresh the mapping information if it's stale
     */

    if (dispPtr->bindInfoStale) {
      InitKeymapInfo(dispPtr);
    }

    /*
     * Figure out which of the four slots in the keymap vector to
     * use for this key.  Refer to Xlib documentation for more info
     * on how this computation works.
     */

    index = 0;
    if (eventPtr->xkey.state & dispPtr->modeModMask) {
      index = 2;
    }
    if ((eventPtr->xkey.state & ShiftMask)
          || ((dispPtr->lockUsage != LU_IGNORE)
          && (eventPtr->xkey.state & LockMask))) {
      index += 1;
    }
    sym = XKeycodeToKeysym(dispPtr->display, eventPtr->xkey.keycode, index);

    /*
     * Special handling:  if the key was shifted because of Lock, but
     * lock is only caps lock, not shift lock, and the shifted keysym
     * isn't upper-case alphabetic, then switch back to the unshifted
     * keysym.
     */

    if ((index & 1) && !(eventPtr->xkey.state & ShiftMask)
          && (dispPtr->lockUsage == LU_CAPS)) {
      if (!(((sym >= XK_A) && (sym <= XK_Z))
            || ((sym >= XK_Agrave) && (sym <= XK_Odiaeresis))
            || ((sym >= XK_Ooblique) && (sym <= XK_Thorn)))) {
          index &= ~1;
          sym = XKeycodeToKeysym(dispPtr->display, eventPtr->xkey.keycode,
                index);
      }
    }

    /*
     * Another bit of special handling:  if this is a shifted key and there
     * is no keysym defined, then use the keysym for the unshifted key.
     */

    if ((index & 1) && (sym == NoSymbol)) {
      sym = XKeycodeToKeysym(dispPtr->display, eventPtr->xkey.keycode,
                index & ~1);
    }
    return sym;
}

/*
 *--------------------------------------------------------------
 *
 * InitKeymapInfo --
 *
 *    This procedure is invoked to scan keymap information
 *    to recompute stuff that's important for binding, such
 *    as the modifier key (if any) that corresponds to "mode
 *    switch".
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Keymap-related information in dispPtr is updated.
 *
 *--------------------------------------------------------------
 */

static void
InitKeymapInfo(dispPtr)
    TkDisplay *dispPtr;       /* Display for which to recompute keymap
                         * information. */
{
    XModifierKeymap *modMapPtr;
    KeyCode *codePtr;
    KeySym keysym;
    int count, i, j, max, arraySize;
#define KEYCODE_ARRAY_SIZE 20

    dispPtr->bindInfoStale = 0;
    modMapPtr = XGetModifierMapping(dispPtr->display);

    /*
     * Check the keycodes associated with the Lock modifier.  If
     * any of them is associated with the XK_Shift_Lock modifier,
     * then Lock has to be interpreted as Shift Lock, not Caps Lock.
     */

    dispPtr->lockUsage = LU_IGNORE;
    codePtr = modMapPtr->modifiermap + modMapPtr->max_keypermod*LockMapIndex;
    for (count = modMapPtr->max_keypermod; count > 0; count--, codePtr++) {
      if (*codePtr == 0) {
          continue;
      }
      keysym = XKeycodeToKeysym(dispPtr->display, *codePtr, 0);
      if (keysym == XK_Shift_Lock) {
          dispPtr->lockUsage = LU_SHIFT;
          break;
      }
      if (keysym == XK_Caps_Lock) {
          dispPtr->lockUsage = LU_CAPS;
          break;
      }
    }

    /*
     * Look through the keycodes associated with modifiers to see if
     * the the "mode switch", "meta", or "alt" keysyms are associated
     * with any modifiers.  If so, remember their modifier mask bits.
     */

    dispPtr->modeModMask = 0;
    dispPtr->metaModMask = 0;
    dispPtr->altModMask = 0;
    codePtr = modMapPtr->modifiermap;
    max = 8*modMapPtr->max_keypermod;
    for (i = 0; i < max; i++, codePtr++) {
      if (*codePtr == 0) {
          continue;
      }
      keysym = XKeycodeToKeysym(dispPtr->display, *codePtr, 0);
      if (keysym == XK_Mode_switch) {
          dispPtr->modeModMask |= ShiftMask << (i/modMapPtr->max_keypermod);
      }
      if ((keysym == XK_Meta_L) || (keysym == XK_Meta_R)) {
          dispPtr->metaModMask |= ShiftMask << (i/modMapPtr->max_keypermod);
      }
      if ((keysym == XK_Alt_L) || (keysym == XK_Alt_R)) {
          dispPtr->altModMask |= ShiftMask << (i/modMapPtr->max_keypermod);
      }
    }

    /*
     * Create an array of the keycodes for all modifier keys.
     */

    if (dispPtr->modKeyCodes != NULL) {
      ckfree((char *) dispPtr->modKeyCodes);
    }
    dispPtr->numModKeyCodes = 0;
    arraySize = KEYCODE_ARRAY_SIZE;
    dispPtr->modKeyCodes = (KeyCode *) ckalloc((unsigned)
          (KEYCODE_ARRAY_SIZE * sizeof(KeyCode)));
    for (i = 0, codePtr = modMapPtr->modifiermap; i < max; i++, codePtr++) {
      if (*codePtr == 0) {
          continue;
      }

      /*
       * Make sure that the keycode isn't already in the array.
       */

      for (j = 0; j < dispPtr->numModKeyCodes; j++) {
          if (dispPtr->modKeyCodes[j] == *codePtr) {
            goto nextModCode;
          }
      }
      if (dispPtr->numModKeyCodes >= arraySize) {
          KeyCode *new;

          /*
           * Ran out of space in the array;  grow it.
           */

          arraySize *= 2;
          new = (KeyCode *) ckalloc((unsigned)
                (arraySize * sizeof(KeyCode)));
          memcpy((VOID *) new, (VOID *) dispPtr->modKeyCodes,
                (dispPtr->numModKeyCodes * sizeof(KeyCode)));
          ckfree((char *) dispPtr->modKeyCodes);
          dispPtr->modKeyCodes = new;
      }
      dispPtr->modKeyCodes[dispPtr->numModKeyCodes] = *codePtr;
      dispPtr->numModKeyCodes++;
      nextModCode: continue;
    }
    XFreeModifiermap(modMapPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * EvalTclBinding --
 *
 *    The procedure that is invoked by Tk_BindEvent when a Tcl binding
 *    is fired.  
 *
 * Results:
 *    A standard Tcl result code, the result of globally evaluating the
 *    percent-substitued binding string.
 *
 * Side effects:
 *    Normal side effects due to eval.
 *
 *---------------------------------------------------------------------------
 */

static void
FreeTclBinding(clientData)
    ClientData clientData;
{
    ckfree((char *) clientData);
}

/*
 *----------------------------------------------------------------------
 *
 * TkStringToKeysym --
 *
 *    This procedure finds the keysym associated with a given keysym
 *    name.
 *
 * Results:
 *    The return value is the keysym that corresponds to name, or
 *    NoSymbol if there is no such keysym.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

KeySym
TkStringToKeysym(name)
    char *name;               /* Name of a keysym. */
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr;
    KeySym keysym;

    hPtr = Tcl_FindHashEntry(&keySymTable, name);
    if (hPtr != NULL) {
      return (KeySym) Tcl_GetHashValue(hPtr);
    }
    if (strlen(name) == 1) {
      keysym = (KeySym) (unsigned char) name[0];
      if (TkKeysymToString(keysym) != NULL) {
          return keysym;
      }
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XStringToKeysym(name);
}

/*
 *----------------------------------------------------------------------
 *
 * TkKeysymToString --
 *
 *    This procedure finds the keysym name associated with a given
 *    keysym.
 *
 * Results:
 *    The return value is a pointer to a static string containing
 *    the name of the given keysym, or NULL if there is no known name.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

char *
TkKeysymToString(keysym)
    KeySym keysym;
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&nameTable, (char *)keysym);
    if (hPtr != NULL) {
      return (char *) Tcl_GetHashValue(hPtr);
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XKeysymToString(keysym);
}

/*
 *----------------------------------------------------------------------
 *
 * TkCopyAndGlobalEval --
 *
 *    This procedure makes a copy of a script then calls Tcl_GlobalEval
 *    to evaluate it.  It's used in situations where the execution of
 *    a command may cause the original command string to be reallocated.
 *
 * Results:
 *    Returns the result of evaluating script, including both a standard
 *    Tcl completion code and a string in interp->result.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

int
TkCopyAndGlobalEval(interp, script)
    Tcl_Interp *interp;             /* Interpreter in which to evaluate
                               * script. */
    char *script;             /* Script to evaluate. */
{
    Tcl_DString buffer;
    int code;

    Tcl_DStringInit(&buffer);
    Tcl_DStringAppend(&buffer, script, -1);
    code = Tcl_GlobalEval(interp, Tcl_DStringValue(&buffer));
    Tcl_DStringFree(&buffer);
    return code;
}



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