/*
 * tkBind.c --
 *
 *	This file provides functions 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) 1994-1997 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.
 */

#include "tkInt.h"

#ifdef __WIN32__
#include "tkWinInt.h"
#endif

#if !(defined(__WIN32__) || defined(MAC_OSX_TK)) /* UNIX */
#include "tkUnixInt.h"
#endif

/*
 * File structure:
 *
 * Structure definitions and static variables.
 *
 * Init/Free this package.
 *
 * Tcl "bind" command (actually located in tkCmds.c) core implementation, plus
 * helpers.
 *
 * Tcl "event" command implementation, plus 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.
 */

#define EVENT_BUFFER_SIZE 30
typedef struct Tk_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 commands. 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 {
    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 {
    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 {
    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). */
    char *script;		/* Binding script to evaluate when sequence
				 * matches (ckalloc()ed) */
    int flags;			/* Miscellaneous flag values; see below for
				 * definitions. */
    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.
 */

#define PAT_NEARBY		0x1

/*
 * 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 {
    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
 * command can be invoked whenever the display/screen changes (the command does
 * things like point tk::Priv 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 keeps track of all the information local to the
 * binding package on a per interpreter basis.
 */

typedef struct TkBindInfo_ {
    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. */
    int deleted;		/* 1 the application has been deleted but the
				 * structure has been preserved. */
} 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 {
    const char *name;			/* Name of keysym. */
    KeySym value;		/* Numeric identifier for keysym. */
} KeySymInfo;
static const KeySymInfo keyArray[] = {
#ifndef lint
#include "ks_names.h"
#endif
    {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;
TCL_DECLARE_MUTEX(bindMutex)

/*
 * 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 {
    const 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.
 * QUADRUPLE -		Non-zero means quadruple this event,
 *			e.g. for 4-fold-clicks.
 * MULT_CLICKS -	Combination of all of above.
 */

#define DOUBLE		1
#define TRIPLE		2
#define QUADRUPLE	4
#define MULT_CLICKS	7

static const ModInfo modArray[] = {
    {"Control",		ControlMask,	0},
    {"Shift",		ShiftMask,	0},
    {"Lock",		LockMask,	0},
    {"Meta",		META_MASK,	0},
    {"M",		META_MASK,	0},
    {"Alt",		ALT_MASK,	0},
    {"Extended",	EXTENDED_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},
    {"Quadruple",	0,		QUADRUPLE},
    {"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 {
    const 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 const 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},
    {"CirculateRequest", CirculateRequest,	SubstructureRedirectMask},
    {"ConfigureRequest", ConfigureRequest,	SubstructureRedirectMask},
    {"Create",		CreateNotify,		SubstructureNotifyMask},
    {"MapRequest",	MapRequest,		SubstructureRedirectMask},
    {"ResizeRequest",	ResizeRequest,		ResizeRedirectMask},
    {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	MAPREQ			0x80000
#define	CONFIGREQ		0x100000
#define	RESIZEREQ		0x200000
#define CIRCREQ			0x400000

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

static const 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 */		MAPREQ,
   /* ReparentNotify */		REPARENT,
   /* ConfigureNotify */	CONFIG,
   /* ConfigureRequest */	CONFIGREQ,
   /* GravityNotify */		GRAVITY,
   /* ResizeRequest */		RESIZEREQ,
   /* 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 table is used to map between the location where an generated
 * event should be queued and the string used to specify the location.
 */

static const TkStateMap queuePosition[] = {
    {-1,			"now"},
    {TCL_QUEUE_HEAD,		"head"},
    {TCL_QUEUE_MARK,		"mark"},
    {TCL_QUEUE_TAIL,		"tail"},
    {-2,			NULL}
};

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

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

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

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

static const TkStateMap configureRequestDetail[] = {
    {None,		"None"},
    {Above,		"Above"},
    {Below,		"Below"},
    {BottomIf,		"BottomIf"},
    {TopIf,		"TopIf"},
    {Opposite,		"Opposite"},
    {-1, NULL}
};

static const TkStateMap propNotify[] = {
    {PropertyNewValue,	"NewValue"},
    {PropertyDelete,	"Delete"},
    {-1, NULL}
};

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

static void		ChangeScreen(Tcl_Interp *interp, char *dispName,
			    int screenIndex);
static int		CreateVirtualEvent(Tcl_Interp *interp,
			    VirtualEventTable *vetPtr, char *virtString,
			    const char *eventString);
static int		DeleteVirtualEvent(Tcl_Interp *interp,
			    VirtualEventTable *vetPtr, char *virtString,
			    const char *eventString);
static void		DeleteVirtualEventTable(VirtualEventTable *vetPtr);
static void		ExpandPercents(TkWindow *winPtr, const char *before,
			    XEvent *eventPtr,KeySym keySym,Tcl_DString *dsPtr);
static PatSeq *		FindSequence(Tcl_Interp *interp,
			    Tcl_HashTable *patternTablePtr, ClientData object,
			    const char *eventString, int create,
			    int allowVirtual, unsigned long *maskPtr);
static void		GetAllVirtualEvents(Tcl_Interp *interp,
			    VirtualEventTable *vetPtr);
static char *		GetField(char *p, char *copy, int size);
static Tcl_Obj *	GetPatternObj(PatSeq *psPtr);
static int		GetVirtualEvent(Tcl_Interp *interp,
			    VirtualEventTable *vetPtr, Tcl_Obj *virtName);
static Tk_Uid		GetVirtualEventUid(Tcl_Interp *interp,
			    char *virtString);
static int		HandleEventGenerate(Tcl_Interp *interp, Tk_Window main,
			    int objc, Tcl_Obj *const objv[]);
static void		InitVirtualEventTable(VirtualEventTable *vetPtr);
static PatSeq *		MatchPatterns(TkDisplay *dispPtr,
			    BindingTable *bindPtr, PatSeq *psPtr,
			    PatSeq *bestPtr, ClientData *objectPtr,
			    PatSeq **sourcePtrPtr);
static int		NameToWindow(Tcl_Interp *interp, Tk_Window main,
			    Tcl_Obj *objPtr, Tk_Window *tkwinPtr);
static int		ParseEventDescription(Tcl_Interp *interp,
			    const char **eventStringPtr, Pattern *patPtr,
			    unsigned long *eventMaskPtr);
static void		DoWarp(ClientData clientData);

/*
 *---------------------------------------------------------------------------
 *
 * TkBindInit --
 *
 *	This function 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(
    TkMainInfo *mainPtr)	/* The newly created application. */
{
    BindInfo *bindInfoPtr;

    if (sizeof(XEvent) < sizeof(XVirtualEvent)) {
	Tcl_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_MutexLock(&bindMutex);
	if (!initialized) {
	    Tcl_HashEntry *hPtr;
	    const ModInfo *modPtr;
	    const EventInfo *eiPtr;
	    int newEntry;
#ifdef REDO_KEYSYM_LOOKUP
	    const 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, &newEntry);
		Tcl_SetHashValue(hPtr, kPtr->value);
		hPtr = Tcl_CreateHashEntry(&nameTable, (char *) kPtr->value,
			&newEntry);
		if (newEntry) {
		    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, &newEntry);
		Tcl_SetHashValue(hPtr, modPtr);
	    }

	    Tcl_InitHashTable(&eventTable, TCL_STRING_KEYS);
	    for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
		hPtr = Tcl_CreateHashEntry(&eventTable, eiPtr->name, &newEntry);
		Tcl_SetHashValue(hPtr, eiPtr);
	    }
	    initialized = 1;
	}
	Tcl_MutexUnlock(&bindMutex);
    }

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

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

    TkpInitializeMenuBindings(mainPtr->interp, mainPtr->bindingTable);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindFree --
 *
 *	This function 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(
    TkMainInfo *mainPtr)	/* The newly created application. */
{
    BindInfo *bindInfoPtr;

    Tk_DeleteBindingTable(mainPtr->bindingTable);
    mainPtr->bindingTable = NULL;

    bindInfoPtr = mainPtr->bindInfo;
    DeleteVirtualEventTable(&bindInfoPtr->virtualEventTable);
    bindInfoPtr->deleted = 1;
    Tcl_EventuallyFree(bindInfoPtr, TCL_DYNAMIC);
    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
 *	functions like Tk_CreateBinding.
 *
 * Side effects:
 *	Memory is allocated for the new table.
 *
 *--------------------------------------------------------------
 */

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

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

    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 bindPtr;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBindingTable --
 *
 *	Destroy a binding table and free up all its memory. The caller should
 *	not use bindingTable again after this function returns.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory is freed.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteBindingTable(
    Tk_BindingTable bindPtr)	/* Token for the binding table to destroy. */
{
    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 = Tcl_GetHashValue(hPtr); psPtr != NULL; psPtr = nextPtr) {
	    nextPtr = psPtr->nextSeqPtr;
	    ckfree(psPtr->script);
	    ckfree(psPtr);
	}
    }

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

    Tcl_DeleteHashTable(&bindPtr->patternTable);
    Tcl_DeleteHashTable(&bindPtr->objectTable);
    ckfree(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 the interp's
 *	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(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tk_BindingTable bindPtr,	/* Table in which to create binding. */
    ClientData object,		/* Token for object with which binding is
				 * associated. */
    const char *eventString,	/* String describing event sequence that
				 * triggers binding. */
    const char *script,		/* Contains Tcl script 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. */
{
    PatSeq *psPtr;
    unsigned long eventMask;
    char *newStr, *oldStr;

    if (!*script) {
	/* Silently ignore empty scripts -- see SF#3006842 */
	return 1;
    }
    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
	    1, 1, &eventMask);
    if (psPtr == NULL) {
	return 0;
    }
    if (psPtr->script == NULL) {
	int isNew;
	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,
		&isNew);
	if (isNew) {
	    psPtr->nextObjPtr = NULL;
	} else {
	    psPtr->nextObjPtr = Tcl_GetHashValue(hPtr);
	}
	Tcl_SetHashValue(hPtr, psPtr);
    }

    oldStr = psPtr->script;
    if ((append != 0) && (oldStr != NULL)) {
	size_t length1 = strlen(oldStr), length2 = strlen(script);

	newStr = ckalloc(length1 + length2 + 2);
	memcpy(newStr, oldStr, length1);
	newStr[length1] = '\n';
	memcpy(newStr+length1+1, script, length2+1);
    } else {
	size_t length = strlen(script);

	newStr = ckalloc(length + 1);
	memcpy(newStr, script, length+1);
    }
    if (oldStr != NULL) {
	ckfree(oldStr);
    }
    psPtr->script = newStr;
    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 the
 *	interp's result will contain an error message.
 *
 * Side effects:
 *	The binding given by object and eventString is removed from
 *	bindingTable.
 *
 *--------------------------------------------------------------
 */

int
Tk_DeleteBinding(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tk_BindingTable bindPtr,	/* Table in which to delete binding. */
    ClientData object,		/* Token for object with which binding is
				 * associated. */
    const char *eventString)	/* String describing event sequence that
				 * triggers binding. */
{
    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) {
	Tcl_Panic("Tk_DeleteBinding couldn't find object table entry");
    }
    prevPtr = Tcl_GetHashValue(hPtr);
    if (prevPtr == psPtr) {
	Tcl_SetHashValue(hPtr, psPtr->nextObjPtr);
    } else {
	for ( ; ; prevPtr = prevPtr->nextObjPtr) {
	    if (prevPtr == NULL) {
		Tcl_Panic("Tk_DeleteBinding couldn't find on object list");
	    }
	    if (prevPtr->nextObjPtr == psPtr) {
		prevPtr->nextObjPtr = psPtr->nextObjPtr;
		break;
	    }
	}
    }
    prevPtr = 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) {
		Tcl_Panic("Tk_DeleteBinding couldn't find on hash chain");
	    }
	    if (prevPtr->nextSeqPtr == psPtr) {
		prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
		break;
	    }
	}
    }

    ckfree(psPtr->script);
    ckfree(psPtr);
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetBinding --
 *
 *	Return the script associated with a given event string.
 *
 * Results:
 *	The return value is a pointer to the script 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 the interp's
 *	result. The return value is semi-static: it will persist until the
 *	binding is changed or deleted.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

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

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
	    0, 1, &eventMask);
    if (psPtr == NULL) {
	return NULL;
    }
    return psPtr->script;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetAllBindings --
 *
 *	Return a list of event strings for all the bindings associated with a
 *	given object.
 *
 * Results:
 *	There is no return value. The interp's 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(
    Tcl_Interp *interp,		/* Interpreter returning result or error. */
    Tk_BindingTable bindPtr,	/* Table in which to look for bindings. */
    ClientData object)		/* Token for object. */
{
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    Tcl_Obj *resultObj;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
	return;
    }

    resultObj = Tcl_NewObj();
    for (psPtr = Tcl_GetHashValue(hPtr); psPtr != NULL;
	    psPtr = psPtr->nextObjPtr) {
	/*
	 * For each binding, output information about each of the patterns in
	 * its sequence.
	 */

	Tcl_ListObjAppendElement(NULL, resultObj, GetPatternObj(psPtr));
    }
    Tcl_SetObjResult(interp, resultObj);
}

/*
 *--------------------------------------------------------------
 *
 * 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(
    Tk_BindingTable bindPtr,	/* Table in which to delete bindings. */
    ClientData object)		/* Token for object. */
{
    PatSeq *psPtr, *prevPtr;
    PatSeq *nextPtr;
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
	return;
    }
    for (psPtr = 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 = 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) {
		    Tcl_Panic("Tk_DeleteAllBindings couldn't find on hash chain");
		}
		if (prevPtr->nextSeqPtr == psPtr) {
		    prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
		    break;
		}
	    }
	}
	ckfree(psPtr->script);
	ckfree(psPtr);
    }
    Tcl_DeleteHashEntry(hPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_BindEvent --
 *
 *	This function 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 script associated with the matching binding.
 *
 *	All Tcl binding 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.
 *
 *---------------------------------------------------------------------------
 */

void
Tk_BindEvent(
    Tk_BindingTable bindPtr,	/* 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. */
{
    TkDisplay *dispPtr;
    ScreenInfo *screenPtr;
    BindInfo *bindInfoPtr;
    TkDisplay *oldDispPtr;
    XEvent *ringPtr;
    PatSeq *vMatchDetailList, *vMatchNoDetailList;
    int flags, oldScreen;
    Tcl_Interp *interp;
    Tcl_DString scripts;
    Tcl_InterpState interpState;
    Detail detail;
    char *p, *end;
    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;
	}
    }

    dispPtr = ((TkWindow *) tkwin)->dispPtr;
    bindInfoPtr = winPtr->mainPtr->bindInfo;

    /*
     * 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(ringPtr, eventPtr, sizeof(XEvent));
    detail.clientData = 0;
    flags = flagArray[ringPtr->type];
    if (flags & KEY) {
	detail.keySym = TkpGetKeySym(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 = &bindInfoPtr->virtualEventTable.patternTable;
	Tcl_HashEntry *hPtr;

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

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

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

    Tcl_DStringInit(&scripts);

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

	/*
	 * 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, 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,
			Tcl_GetHashValue(hPtr), matchPtr, NULL, &sourcePtr);
	    }

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

	if (matchPtr != NULL) {
	    ExpandPercents(winPtr, sourcePtr->script, eventPtr,
		    detail.keySym, &scripts);

	    /*
	     * A "" is added to the scripts string to separate the various
	     * scripts that should be invoked.
	     */

	    Tcl_DStringAppend(&scripts, "", 1);
	}
    }
    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
     *    the interp's 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;

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

    interpState = Tcl_SaveInterpState(interp, TCL_OK);
    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);
    }

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

    /*
     * Be careful when dereferencing screenPtr or bindInfoPtr. If we evaluate
     * something that destroys ".", bindInfoPtr would have been freed, but we
     * can tell that by first checking to see if winPtr->mainPtr == NULL.
     */

    Tcl_Preserve(bindInfoPtr);
    while (p < end) {
	int len = (int) strlen(p);
	int code;

	if (!bindInfoPtr->deleted) {
	    screenPtr->bindingDepth++;
	}
	Tcl_AllowExceptions(interp);

	code = Tcl_EvalEx(interp, p, len, TCL_EVAL_GLOBAL);
	p += len + 1;

	if (!bindInfoPtr->deleted) {
	    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_BackgroundException(interp, code);
		break;
	    }
	}
    }

    if (!bindInfoPtr->deleted && (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);
    }
    (void) Tcl_RestoreInterpState(interp, interpState);
    Tcl_DStringFree(&scripts);

    Tcl_Release(bindInfoPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * 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 function 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 function 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(
    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 function. 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 = &bindPtr->eventRing[bindPtr->curEvent];
	Detail *detailPtr = &bindPtr->detailRing[bindPtr->curEvent];
	Pattern *patPtr = psPtr->pats;
	Window window = eventPtr->xany.window;
	int patCount, ringCount, flags, state, modMask, i;

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

	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)) {
			/*
			 * 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.type == CreateNotify
		    && eventPtr->xcreatewindow.parent != window) {
		goto nextSequence;
	    } else 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) {
		    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 & META_MASK) && (dispPtr->metaModMask != 0)) {
		    state = (state & ~META_MASK) | dispPtr->metaModMask;
		}
		if ((state & ALT_MASK) && (dispPtr->altModMask != 0)) {
		    state = (state & ~ALT_MASK) | dispPtr->altModMask;
		}

		if ((state & modMask) != modMask) {
		    goto nextSequence;
		}
	    }
	    if (psPtr->flags & PAT_NEARBY) {
		XEvent *firstPtr = &bindPtr->eventRing[bindPtr->curEvent];
		int timeDiff;

		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 = Tcl_GetHashValue(hPtr);

		    if ((virtMatchPtr->numPats != 1)
			    || (virtMatchPtr->nextSeqPtr != NULL)) {
			Tcl_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;

	    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(
    TkWindow *winPtr,		/* Window where event occurred: needed to get
				 * input context. */
    const 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;
#define NUM_SIZE 40
    const char *string;
    Tcl_DString buf;
    char numStorage[NUM_SIZE+1];

    Tcl_DStringInit(&buf);

    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, (int) (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':
	    if (flags & CONFIG) {
		TkpPrintWindowId(numStorage, eventPtr->xconfigure.above);
		string = numStorage;
	    }
	    goto doString;
	case 'b':
	    if (flags & BUTTON) {
		number = eventPtr->xbutton.button;
		goto doNumber;
	    }
	    goto doString;
	case 'c':
	    if (flags & EXPOSE) {
		number = eventPtr->xexpose.count;
		goto doNumber;
	    }
	    goto doString;
	case 'd':
	    if (flags & (CROSSING|FOCUS)) {
		if (flags & FOCUS) {
		    number = eventPtr->xfocus.detail;
		} else {
		    number = eventPtr->xcrossing.detail;
		}
		string = TkFindStateString(notifyDetail, number);
	    } else if (flags & CONFIGREQ) {
		if (eventPtr->xconfigurerequest.value_mask & CWStackMode) {
		    string = TkFindStateString(configureRequestDetail,
			    eventPtr->xconfigurerequest.detail);
		} else {
		    string = "";
		}
	    } else if (flags & VIRTUAL) {
		XVirtualEvent *vePtr = (XVirtualEvent *) eventPtr;

		if (vePtr->user_data != NULL) {
		    string = Tcl_GetString(vePtr->user_data);
		} else {
		    string = "";
		}
	    }
	    goto doString;
	case 'f':
	    if (flags & CROSSING) {
		number = eventPtr->xcrossing.focus;
		goto doNumber;
	    }
	    goto doString;
	case 'h':
	    if (flags & EXPOSE) {
		number = eventPtr->xexpose.height;
	    } else if (flags & CONFIG) {
		number = eventPtr->xconfigure.height;
	    } else if (flags & CREATE) {
		number = eventPtr->xcreatewindow.height;
	    } else if (flags & CONFIGREQ) {
		number = eventPtr->xconfigurerequest.height;
	    } else if (flags & RESIZEREQ) {
		number = eventPtr->xresizerequest.height;
	    } else {
		goto doString;
	    }
	    goto doNumber;
	case 'i':
	    if (flags & CREATE) {
		TkpPrintWindowId(numStorage, eventPtr->xcreatewindow.window);
	    } else if (flags & CONFIGREQ) {
		TkpPrintWindowId(numStorage,
			eventPtr->xconfigurerequest.window);
	    } else if (flags & MAPREQ) {
		TkpPrintWindowId(numStorage, eventPtr->xmaprequest.window);
	    } else {
		TkpPrintWindowId(numStorage, eventPtr->xany.window);
	    }
	    string = numStorage;
	    goto doString;
	case 'k':
	    if ((flags & KEY) && (eventPtr->type != MouseWheelEvent)) {
		number = eventPtr->xkey.keycode;
		goto doNumber;
	    }
	    goto doString;
	case 'm':
	    if (flags & CROSSING) {
		number = eventPtr->xcrossing.mode;
		string = TkFindStateString(notifyMode, number);
	    } 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;
	    } else {
		goto doString;
	    }
	    goto doNumber;
	case 'p':
	    if (flags & CIRC) {
		string = TkFindStateString(circPlace,
			eventPtr->xcirculate.place);
	    } else if (flags & CIRCREQ) {
		string = TkFindStateString(circPlace,
			eventPtr->xcirculaterequest.place);
	    }
	    goto doString;
	case 's':
	    if (flags & KEY_BUTTON_MOTION_VIRTUAL) {
		number = eventPtr->xkey.state;
		goto doNumber;
	    } else if (flags & CROSSING) {
		number = eventPtr->xcrossing.state;
		goto doNumber;
	    } else if (flags & PROP) {
		string = TkFindStateString(propNotify,
			eventPtr->xproperty.state);
	    } else if (flags & VISIBILITY) {
		string = TkFindStateString(visNotify,
			eventPtr->xvisibility.state);
	    }
	    goto doString;
	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;
	    } else {
		goto doString;
	    }
	    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;
	    } else if (flags & CREATE) {
		number = eventPtr->xcreatewindow.width;
	    } else if (flags & CONFIGREQ) {
		number = eventPtr->xconfigurerequest.width;
	    } else if (flags & RESIZEREQ) {
		number = eventPtr->xresizerequest.width;
	    } else {
		goto doString;
	    }
	    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;
	    } else if (flags & CREATE) {
		number = eventPtr->xcreatewindow.x;
	    } else if (flags & CONFIGREQ) {
		number = eventPtr->xconfigurerequest.x;
	    } else {
		goto doString;
	    }
	    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;
	    } else if (flags & CREATE) {
		number = eventPtr->xcreatewindow.y;
	    } else if (flags & CONFIGREQ) {
		number = eventPtr->xconfigurerequest.y;
	    } else {
		goto doString;
	    }
	    goto doNumber;
	case 'A':
	    if ((flags & KEY) && (eventPtr->type != MouseWheelEvent)) {
		Tcl_DStringFree(&buf);
		string = TkpGetString(winPtr, eventPtr, &buf);
	    }
	    goto doString;
	case 'B':
	    if (flags & CREATE) {
		number = eventPtr->xcreatewindow.border_width;
	    } else if (flags & CONFIGREQ) {
		number = eventPtr->xconfigurerequest.border_width;
	    } else if (flags & CONFIG) {
		number = eventPtr->xconfigure.border_width;
	    } else {
		goto doString;
	    }
	    goto doNumber;
	case 'D':
	    /*
	     * This is used only by the MouseWheel event.
	     */

	    if ((flags & KEY) && (eventPtr->type == MouseWheelEvent)) {
		number = eventPtr->xkey.keycode;
		goto doNumber;
	    }
	    goto doString;
	case 'E':
	    number = (int) eventPtr->xany.send_event;
	    goto doNumber;
	case 'K':
	    if ((flags & KEY) && (eventPtr->type != MouseWheelEvent)) {
		const char *name = TkKeysymToString(keySym);

		if (name != NULL) {
		    string = name;
		}
	    }
	    goto doString;
	case 'N':
	    if ((flags & KEY) && (eventPtr->type != MouseWheelEvent)) {
		number = (int) keySym;
		goto doNumber;
	    }
	    goto doString;
	case 'P':
	    if (flags & PROP) {
		string = Tk_GetAtomName((Tk_Window) winPtr,
			eventPtr->xproperty.atom);
	    }
	    goto doString;
	case 'R':
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		TkpPrintWindowId(numStorage, eventPtr->xkey.root);
		string = numStorage;
	    }
	    goto doString;
	case 'S':
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		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':
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {

		number = eventPtr->xkey.x_root;
		Tk_IdToWindow(eventPtr->xany.display,
			eventPtr->xany.window);
		goto doNumber;
	    }
	    goto doString;
	case 'Y':
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {

		number = eventPtr->xkey.y_root;
		Tk_IdToWindow(eventPtr->xany.display,
			eventPtr->xany.window);
		goto doNumber;
	    }
	    goto doString;
	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;
    }
    Tcl_DStringFree(&buf);
}

/*
 *----------------------------------------------------------------------
 *
 * ChangeScreen --
 *
 *	This function is invoked whenever the current screen changes in an
 *	application. It invokes a Tcl command named "tk::ScreenChanged",
 *	passing it the screen name as argument. tk::ScreenChanged does things
 *	like making the tk::Priv variable point to an array for the current
 *	display.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Depends on what tk::ScreenChanged does. If an error occurs then
 *	bgerror will be invoked.
 *
 *----------------------------------------------------------------------
 */

static void
ChangeScreen(
    Tcl_Interp *interp,		/* Interpreter in which to invoke command. */
    char *dispName,		/* Name of new display. */
    int screenIndex)		/* Index of new screen. */
{
    Tcl_Obj *cmdObj = Tcl_ObjPrintf("::tk::ScreenChanged %s.%d",
	    dispName, screenIndex);
    int code;

    Tcl_IncrRefCount(cmdObj);
    code = Tcl_EvalObjEx(interp, cmdObj, TCL_EVAL_GLOBAL);
    if (code != TCL_OK) {
	Tcl_AddErrorInfo(interp,
		"\n    (changing screen in event binding)");
	Tcl_BackgroundException(interp, code);
    }
    Tcl_DecrRefCount(cmdObj);
}

/*
 *----------------------------------------------------------------------
 *
 * Tk_EventCmd --
 *
 *	This function 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_EventObjCmd(
    ClientData clientData,	/* Main window associated with interpreter. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    int index, i;
    char *name;
    const char *event;
    Tk_Window tkwin = clientData;
    TkBindInfo bindInfo = ((TkWindow *) tkwin)->mainPtr->bindInfo;
    VirtualEventTable *vetPtr = &bindInfo->virtualEventTable;
    static const char *const optionStrings[] = {
	"add",		"delete",	"generate",	"info",
	NULL
    };
    enum options {
	EVENT_ADD,	EVENT_DELETE,	EVENT_GENERATE,	EVENT_INFO
    };


    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg?");
	return TCL_ERROR;
    }
    if (Tcl_GetIndexFromObj(interp, objv[1], optionStrings, "option", 0,
	    &index) != TCL_OK) {
	return TCL_ERROR;
    }

    switch ((enum options) index) {
    case EVENT_ADD:
	if (objc < 4) {
	    Tcl_WrongNumArgs(interp, 2, objv,
		    "virtual sequence ?sequence ...?");
	    return TCL_ERROR;
	}
	name = Tcl_GetString(objv[2]);
	for (i = 3; i < objc; i++) {
	    event = Tcl_GetString(objv[i]);
	    if (CreateVirtualEvent(interp, vetPtr, name, event) != TCL_OK) {
		return TCL_ERROR;
	    }
	}
	break;
    case EVENT_DELETE:
	if (objc < 3) {
	    Tcl_WrongNumArgs(interp, 2, objv, "virtual ?sequence ...?");
	    return TCL_ERROR;
	}
	name = Tcl_GetString(objv[2]);
	if (objc == 3) {
	    return DeleteVirtualEvent(interp, vetPtr, name, NULL);
	}
	for (i = 3; i < objc; i++) {
	    event = Tcl_GetString(objv[i]);
	    if (DeleteVirtualEvent(interp, vetPtr, name, event) != TCL_OK) {
		return TCL_ERROR;
	    }
	}
	break;
    case EVENT_GENERATE:
	if (objc < 4) {
	    Tcl_WrongNumArgs(interp, 2, objv,
		    "window event ?-option value ...?");
	    return TCL_ERROR;
	}
	return HandleEventGenerate(interp, tkwin, objc - 2, objv + 2);
    case EVENT_INFO:
	if (objc == 2) {
	    GetAllVirtualEvents(interp, vetPtr);
	    return TCL_OK;
	} else if (objc == 3) {
	    return GetVirtualEvent(interp, vetPtr, objv[2]);
	} else {
	    Tcl_WrongNumArgs(interp, 2, objv, "?virtual?");
	    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(
    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(
    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 = Tcl_GetHashValue(hPtr);
	for ( ; psPtr != NULL; psPtr = nextPtr) {
	    nextPtr = psPtr->nextSeqPtr;
	    ckfree(psPtr->voPtr);
	    ckfree(psPtr);
	}
    }
    Tcl_DeleteHashTable(&vetPtr->patternTable);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
	ckfree(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 the
 *	interp's 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(
    Tcl_Interp *interp,		/* Used for error reporting. */
    VirtualEventTable *vetPtr,	/* Table in which to augment virtual event. */
    char *virtString,		/* Name of new virtual event. */
    const 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 = Tcl_GetHashValue(vhPtr);
    if (poPtr == NULL) {
	poPtr = 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 = ckrealloc(poPtr, sizeof(PhysicalsOwned)
		+ poPtr->numOwned * sizeof(PatSeq *));
    }
    Tcl_SetHashValue(vhPtr, 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 = ckalloc(sizeof(VirtualOwners));
	voPtr->numOwners = 0;
    } else {
	voPtr = ckrealloc(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 the
 *	interp's 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(
    Tcl_Interp *interp,		/* Used for error reporting. */
    VirtualEventTable *vetPtr,	/* Table in which to delete event. */
    char *virtString,		/* String describing event sequence that
				 * triggers binding. */
    const 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 = 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) {
	    const char *string = Tcl_GetStringResult(interp);

	    return (string[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) {
		Tcl_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 = 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) {
			    Tcl_Panic("DeleteVirtualEvent couldn't find on hash chain");
			}
			if (prevPtr->nextSeqPtr == psPtr) {
			    prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
			    break;
			}
		    }
		}
		ckfree(psPtr->voPtr);
		ckfree(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(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 the interp's 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, the interp's 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 the interp's result.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

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

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

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

    resultObj = Tcl_NewObj();
    poPtr = Tcl_GetHashValue(vhPtr);
    for (iPhys = 0; iPhys < poPtr->numOwned; iPhys++) {
	Tcl_ListObjAppendElement(NULL, resultObj,
		GetPatternObj(poPtr->patSeqs[iPhys]));
    }
    Tcl_SetObjResult(interp, resultObj);

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

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

    resultObj = Tcl_NewObj();
    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
	Tcl_ListObjAppendElement(NULL, resultObj, Tcl_ObjPrintf(
		"<<%s>>", (char *) Tcl_GetHashKey(hPtr->tablePtr, hPtr)));
    }
    Tcl_SetObjResult(interp, resultObj);
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Interp *interp,		/* Interp for errors return and name lookup. */
    Tk_Window mainWin,		/* Main window associated with interp. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    union {XEvent general; XVirtualEvent virtual;} event;
    const char *p;
    const char *name, *windowName;
    int count, flags, synch, i, number, warp;
    Tcl_QueuePosition pos;
    Pattern pat;
    Tk_Window tkwin, tkwin2;
    TkWindow *mainPtr;
    unsigned long eventMask;
    Tcl_Obj *userDataObj;

    static const char *const fieldStrings[] = {
	"-when",	"-above",	"-borderwidth",	"-button",
	"-count",	"-data",	"-delta",	"-detail",
	"-focus",	"-height",
	"-keycode",	"-keysym",	"-mode",	"-override",
	"-place",	"-root",	"-rootx",	"-rooty",
	"-sendevent",	"-serial",	"-state",	"-subwindow",
	"-time",	"-warp",	"-width",	"-window",
	"-x",		"-y",	NULL
    };
    enum field {
	EVENT_WHEN,	EVENT_ABOVE,	EVENT_BORDER,	EVENT_BUTTON,
	EVENT_COUNT,	EVENT_DATA,	EVENT_DELTA,	EVENT_DETAIL,
	EVENT_FOCUS,	EVENT_HEIGHT,
	EVENT_KEYCODE,	EVENT_KEYSYM,	EVENT_MODE,	EVENT_OVERRIDE,
	EVENT_PLACE,	EVENT_ROOT,	EVENT_ROOTX,	EVENT_ROOTY,
	EVENT_SEND,	EVENT_SERIAL,	EVENT_STATE,	EVENT_SUBWINDOW,
	EVENT_TIME,	EVENT_WARP,	EVENT_WIDTH,	EVENT_WINDOW,
	EVENT_X,	EVENT_Y
    };

    windowName = Tcl_GetString(objv[0]);
    if (!windowName[0]) {
	tkwin = mainWin;
    } else if (NameToWindow(interp, mainWin, objv[0], &tkwin) != TCL_OK) {
	return TCL_ERROR;
    }

    mainPtr = (TkWindow *) mainWin;
    if ((tkwin == NULL)
	    || (mainPtr->mainPtr != ((TkWindow *) tkwin)->mainPtr)) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"window id \"%s\" doesn't exist in this application",
		Tcl_GetString(objv[0])));
	Tcl_SetErrorCode(interp, "TK", "LOOKUP", "WINDOW",
		Tcl_GetString(objv[0]), NULL);
	return TCL_ERROR;
    }

    name = Tcl_GetString(objv[1]);

    p = name;
    eventMask = 0;
    userDataObj = NULL;
    count = ParseEventDescription(interp, &p, &pat, &eventMask);
    if (count == 0) {
	return TCL_ERROR;
    }
    if (count != 1) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"Double or Triple modifier not allowed", -1));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "BAD_MODIFIER", NULL);
	return TCL_ERROR;
    }
    if (*p != '\0') {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"only one event specification allowed", -1));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "MULTIPLE", NULL);
	return TCL_ERROR;
    }

    memset(&event, 0, sizeof(event));
    event.general.xany.type = pat.eventType;
    event.general.xany.serial = NextRequest(Tk_Display(tkwin));
    event.general.xany.send_event = False;
    if (windowName[0]) {
	event.general.xany.window = Tk_WindowId(tkwin);
    } else {
	event.general.xany.window =
		RootWindow(Tk_Display(tkwin), Tk_ScreenNumber(tkwin));
    }
    event.general.xany.display = Tk_Display(tkwin);

    flags = flagArray[event.general.xany.type];
    if (flags & DESTROY) {
	/*
	 * Event DestroyNotify should be generated by destroying the window.
	 */

	Tk_DestroyWindow(tkwin);
	return TCL_OK;
    }
    if (flags & KEY_BUTTON_MOTION_VIRTUAL) {
	event.general.xkey.state = pat.needMods;
	if ((flags & KEY) && (event.general.xany.type != MouseWheelEvent)) {
	    TkpSetKeycodeAndState(tkwin, pat.detail.keySym, &event.general);
	} else if (flags & BUTTON) {
	    event.general.xbutton.button = pat.detail.button;
	} else if (flags & VIRTUAL) {
	    event.virtual.name = pat.detail.name;
	}
    }
    if (flags & (CREATE|UNMAP|MAP|REPARENT|CONFIG|GRAVITY|CIRC)) {
	event.general.xcreatewindow.window = event.general.xany.window;
    }

    if (flags & KEY_BUTTON_MOTION_CROSSING) {
	event.general.xkey.x_root = -1;
	event.general.xkey.y_root = -1;
    }

    if (event.general.xany.type == FocusIn
	    || event.general.xany.type == FocusOut) {
	event.general.xany.send_event = GENERATED_FOCUS_EVENT_MAGIC;
    }

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

    synch = 1;
    warp = 0;
    pos = TCL_QUEUE_TAIL;
    for (i = 2; i < objc; i += 2) {
	Tcl_Obj *optionPtr, *valuePtr;
	int index;

	optionPtr = objv[i];
	valuePtr = objv[i + 1];

	if (Tcl_GetIndexFromObj(interp, optionPtr, fieldStrings, "option",
		TCL_EXACT, &index) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (objc & 1) {
	    /*
	     * This test occurs after Tcl_GetIndexFromObj() so that "event
	     * generate <Button> -xyz" will return the error message that
	     * "-xyz" is a bad option, rather than that the value for "-xyz"
	     * is missing.
	     */

	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "value for \"%s\" missing", Tcl_GetString(optionPtr)));
	    Tcl_SetErrorCode(interp, "TK", "EVENT", "MISSING_VALUE", NULL);
	    return TCL_ERROR;
	}

	switch ((enum field) index) {
	case EVENT_WARP:
	    if (Tcl_GetBooleanFromObj(interp, valuePtr, &warp) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (!(flags & KEY_BUTTON_MOTION_VIRTUAL)) {
		goto badopt;
	    }
	    break;
	case EVENT_WHEN:
	    pos = (Tcl_QueuePosition) TkFindStateNumObj(interp, optionPtr,
		    queuePosition, valuePtr);
	    if ((int) pos < -1) {
		return TCL_ERROR;
	    }
	    synch = 0;
	    if ((int) pos == -1) {
		synch = 1;
	    }
	    break;
	case EVENT_ABOVE:
	    if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & CONFIG) {
		event.general.xconfigure.above = Tk_WindowId(tkwin2);
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_BORDER:
	    if (Tk_GetPixelsFromObj(interp,tkwin,valuePtr,&number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & (CREATE|CONFIG)) {
		event.general.xcreatewindow.border_width = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_BUTTON:
	    if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & BUTTON) {
		event.general.xbutton.button = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_COUNT:
	    if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & EXPOSE) {
		event.general.xexpose.count = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_DATA:
	    if (flags & VIRTUAL) {
		/*
		 * Do not increment reference count until after parsing
		 * completes and we know that the event generation is really
		 * going to happen.
		 */

		userDataObj = valuePtr;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_DELTA:
	    if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if ((flags & KEY) && (event.general.xkey.type == MouseWheelEvent)) {
		event.general.xkey.keycode = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_DETAIL:
	    number = TkFindStateNumObj(interp, optionPtr, notifyDetail,
		    valuePtr);
	    if (number < 0) {
		return TCL_ERROR;
	    }
	    if (flags & FOCUS) {
		event.general.xfocus.detail = number;
	    } else if (flags & CROSSING) {
		event.general.xcrossing.detail = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_FOCUS:
	    if (Tcl_GetBooleanFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & CROSSING) {
		event.general.xcrossing.focus = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_HEIGHT:
	    if (Tk_GetPixelsFromObj(interp, tkwin, valuePtr,
		    &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & EXPOSE) {
		event.general.xexpose.height = number;
	    } else if (flags & CONFIG) {
		event.general.xconfigure.height = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_KEYCODE:
	    if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if ((flags & KEY) && (event.general.xkey.type != MouseWheelEvent)) {
		event.general.xkey.keycode = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_KEYSYM: {
	    KeySym keysym;
	    const char *value;

	    value = Tcl_GetString(valuePtr);
	    keysym = TkStringToKeysym(value);
	    if (keysym == NoSymbol) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"unknown keysym \"%s\"", value));
		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "KEYSYM", value,
			NULL);
		return TCL_ERROR;
	    }

	    TkpSetKeycodeAndState(tkwin, keysym, &event.general);
	    if (event.general.xkey.keycode == 0) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"no keycode for keysym \"%s\"", value));
		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "KEYCODE", value,
			NULL);
		return TCL_ERROR;
	    }
	    if (!(flags & KEY)
		    || (event.general.xkey.type == MouseWheelEvent)) {
		goto badopt;
	    }
	    break;
	}
	case EVENT_MODE:
	    number = TkFindStateNumObj(interp,optionPtr,notifyMode,valuePtr);
	    if (number < 0) {
		return TCL_ERROR;
	    }
	    if (flags & CROSSING) {
		event.general.xcrossing.mode = number;
	    } else if (flags & FOCUS) {
		event.general.xfocus.mode = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_OVERRIDE:
	    if (Tcl_GetBooleanFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & CREATE) {
		event.general.xcreatewindow.override_redirect = number;
	    } else if (flags & MAP) {
		event.general.xmap.override_redirect = number;
	    } else if (flags & REPARENT) {
		event.general.xreparent.override_redirect = number;
	    } else if (flags & CONFIG) {
		event.general.xconfigure.override_redirect = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_PLACE:
	    number = TkFindStateNumObj(interp, optionPtr, circPlace, valuePtr);
	    if (number < 0) {
		return TCL_ERROR;
	    }
	    if (flags & CIRC) {
		event.general.xcirculate.place = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_ROOT:
	    if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.root = Tk_WindowId(tkwin2);
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_ROOTX:
	    if (Tk_GetPixelsFromObj(interp,tkwin,valuePtr,&number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.x_root = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_ROOTY:
	    if (Tk_GetPixelsFromObj(interp,tkwin,valuePtr,&number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.y_root = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_SEND: {
	    const char *value;

	    value = Tcl_GetString(valuePtr);
	    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_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		    return TCL_ERROR;
		}
	    } else {
		if (Tcl_GetBooleanFromObj(interp,valuePtr,&number) != TCL_OK) {
		    return TCL_ERROR;
		}
	    }
	    event.general.xany.send_event = number;
	    break;
	}
	case EVENT_SERIAL:
	    if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    event.general.xany.serial = number;
	    break;
	case EVENT_STATE:
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		    return TCL_ERROR;
		}
		if (flags & KEY_BUTTON_MOTION_VIRTUAL) {
		    event.general.xkey.state = number;
		} else {
		    event.general.xcrossing.state = number;
		}
	    } else if (flags & VISIBILITY) {
		number = TkFindStateNumObj(interp, optionPtr, visNotify,
			valuePtr);
		if (number < 0) {
		    return TCL_ERROR;
		}
		event.general.xvisibility.state = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_SUBWINDOW:
	    if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.subwindow = Tk_WindowId(tkwin2);
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_TIME:
	    if (Tcl_GetIntFromObj(interp, valuePtr, &number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.time = (Time) number;
	    } else if (flags & PROP) {
		event.general.xproperty.time = (Time) number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_WIDTH:
	    if (Tk_GetPixelsFromObj(interp,tkwin,valuePtr,&number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & EXPOSE) {
		event.general.xexpose.width = number;
	    } else if (flags & (CREATE|CONFIG)) {
		event.general.xcreatewindow.width = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_WINDOW:
	    if (NameToWindow(interp, tkwin, valuePtr, &tkwin2) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & (CREATE|UNMAP|MAP|REPARENT|CONFIG|GRAVITY|CIRC)) {
		event.general.xcreatewindow.window = Tk_WindowId(tkwin2);
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_X:
	    if (Tk_GetPixelsFromObj(interp,tkwin,valuePtr,&number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.x = number;

		/*
		 * Only modify rootx as well if it hasn't been changed.
		 */

		if (event.general.xkey.x_root == -1) {
		    int rootX, rootY;

		    Tk_GetRootCoords(tkwin, &rootX, &rootY);
		    event.general.xkey.x_root = rootX + number;
		}
	    } else if (flags & EXPOSE) {
		event.general.xexpose.x = number;
	    } else if (flags & (CREATE|CONFIG|GRAVITY)) {
		event.general.xcreatewindow.x = number;
	    } else if (flags & REPARENT) {
		event.general.xreparent.x = number;
	    } else {
		goto badopt;
	    }
	    break;
	case EVENT_Y:
	    if (Tk_GetPixelsFromObj(interp,tkwin,valuePtr,&number) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (flags & KEY_BUTTON_MOTION_CROSSING) {
		event.general.xkey.y = number;

		/*
		 * Only modify rooty as well if it hasn't been changed.
		 */

		if (event.general.xkey.y_root == -1) {
		    int rootX, rootY;

		    Tk_GetRootCoords(tkwin, &rootX, &rootY);
		    event.general.xkey.y_root = rootY + number;
		}
	    } else if (flags & EXPOSE) {
		event.general.xexpose.y = number;
	    } else if (flags & (CREATE|CONFIG|GRAVITY)) {
		event.general.xcreatewindow.y = number;
	    } else if (flags & REPARENT) {
		event.general.xreparent.y = number;
	    } else {
		goto badopt;
	    }
	    break;
	}
	continue;

    badopt:
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"%s event doesn't accept \"%s\" option",
		name, Tcl_GetString(optionPtr)));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "BAD_OPTION", NULL);
	return TCL_ERROR;
    }

    /*
     * Don't generate events for windows that don't exist yet.
     */

    if (!event.general.xany.window) {
	goto done;
    }

    if (userDataObj != NULL) {

	/*
	 * Must be virtual event to set that variable to non-NULL. Now we want
	 * to install the object into the event. Note that we must incr the
	 * refcount before firing it into the low-level event subsystem; the
	 * refcount will be decremented once the event has been processed.
	 */

	event.virtual.user_data = userDataObj;
	Tcl_IncrRefCount(userDataObj);
    }

    /*
     * Now we have constructed the event, inject it into the event handling
     * code.
     */

    if (synch != 0) {
	Tk_HandleEvent(&event.general);
    } else {
	Tk_QueueWindowEvent(&event.general, pos);
    }

    /*
     * We only allow warping if the window is mapped.
     */

    if ((warp != 0) && Tk_IsMapped(tkwin)) {
	TkDisplay *dispPtr = TkGetDisplay(event.general.xmotion.display);

	if (!(dispPtr->flags & TK_DISPLAY_IN_WARP)) {
	    Tcl_DoWhenIdle(DoWarp, dispPtr);
	    dispPtr->flags |= TK_DISPLAY_IN_WARP;
	}
	dispPtr->warpWindow = Tk_IdToWindow(Tk_Display(mainWin),
		event.general.xmotion.window);
	dispPtr->warpMainwin = mainWin;
	dispPtr->warpX = event.general.xmotion.x;
	dispPtr->warpY = event.general.xmotion.y;
    }

  done:
    Tcl_ResetResult(interp);
    return TCL_OK;
}

static int
NameToWindow(
    Tcl_Interp *interp,		/* Interp for error return and name lookup. */
    Tk_Window mainWin,		/* Main window of application. */
    Tcl_Obj *objPtr,		/* Contains name or id string of window. */
    Tk_Window *tkwinPtr)	/* Filled with token for window. */
{
    const char *name = Tcl_GetString(objPtr);
    Tk_Window tkwin;

    if (name[0] == '.') {
	tkwin = Tk_NameToWindow(interp, name, mainWin);
	if (tkwin == NULL) {
	    return TCL_ERROR;
	}
    } else {
	Window id;

	/*
	 * Check for the winPtr being valid, even if it looks ok to
	 * TkpScanWindowId. [Bug #411307]
	 */

	if (TkpScanWindowId(NULL, name, &id) != TCL_OK) {
	    goto badWindow;
	}
	tkwin = Tk_IdToWindow(Tk_Display(mainWin), id);
	if (tkwin == NULL) {
	    goto badWindow;
	}
    }
    *tkwinPtr = tkwin;
    return TCL_OK;

  badWindow:
    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
	    "bad window name/identifier \"%s\"", name));
    Tcl_SetErrorCode(interp, "TK", "LOOKUP", "WINDOW_ID", name, NULL);
    return TCL_ERROR;
}

/*
 *-------------------------------------------------------------------------
 *
 * DoWarp --
 *
 *	Perform Warping of X pointer. Executed as an idle handler only.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	X Pointer will move to a new location.
 *
 *-------------------------------------------------------------------------
 */

static void
DoWarp(
    ClientData clientData)
{
    TkDisplay *dispPtr = clientData;

    TkpWarpPointer(dispPtr);
    XForceScreenSaver(dispPtr->display, ScreenSaverReset);
    dispPtr->flags &= ~TK_DISPLAY_IN_WARP;
}

/*
 *-------------------------------------------------------------------------
 *
 * 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 the
 *	interp's result. Otherwise the return value is a Tk_Uid that
 *	represents the virtual event.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static Tk_Uid
GetVirtualEventUid(
    Tcl_Interp *interp,
    char *virtString)
{
    Tk_Uid uid;
    size_t length;

    length = strlen(virtString);

    if (length < 5 || virtString[0] != '<' || virtString[1] != '<' ||
	    virtString[length - 2] != '>' || virtString[length - 1] != '>') {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"virtual event \"%s\" is badly formed", virtString));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "MALFORMED", 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 the interp's 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(
    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. */
    const 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;
    const char *p;
    Pattern *patPtr;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    int flags, count, isNew;
    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) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(
			"virtual event not allowed in definition of another virtual event",
			-1));
		Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "INNER",
			NULL);
		return NULL;
	    }
	    virtualFound = 1;
	}

	/*
	 * Replicate events for DOUBLE, TRIPLE, QUADRUPLE.
	 */

	while ((count-- > 1) && (numPats < EVENT_BUFFER_SIZE-1)) {
	    flags |= PAT_NEARBY;
	    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) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"no events specified in binding", -1));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "NO_EVENTS", NULL);
	return NULL;
    }
    if ((numPats > 1) && (virtualFound != 0)) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"virtual events may not be composed", -1));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "COMPOSITION",
		NULL);
	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, &isNew);
    sequenceSize = numPats*sizeof(Pattern);
    if (!isNew) {
	for (psPtr = Tcl_GetHashValue(hPtr); psPtr != NULL;
		psPtr = psPtr->nextSeqPtr) {
	    if ((numPats == psPtr->numPats)
		    && ((flags & PAT_NEARBY) == (psPtr->flags & PAT_NEARBY))
		    && (memcmp(patPtr, psPtr->pats, sequenceSize) == 0)) {
		goto done;
	    }
	}
    }
    if (!create) {
	if (isNew) {
	    Tcl_DeleteHashEntry(hPtr);
	}

	/*
	 * No binding exists for the sequence, so return an empty error. This
	 * is a special error that the caller will check for in order to
	 * silently ignore this case. This is a hack that maintains backward
	 * compatibility for Tk_GetBinding but the various "bind" commands
	 * silently ignore missing bindings.
	 */

	return NULL;
    }
    psPtr = ckalloc(sizeof(PatSeq) + (numPats-1)*sizeof(Pattern));
    psPtr->numPats = numPats;
    psPtr->script = NULL;
    psPtr->flags = flags;
    psPtr->nextSeqPtr = Tcl_GetHashValue(hPtr);
    psPtr->hPtr = hPtr;
    psPtr->voPtr = NULL;
    psPtr->nextObjPtr = NULL;
    Tcl_SetHashValue(hPtr, psPtr);

    memcpy(psPtr->pats, 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 function can be called repeatedly to parse
 *	all the events in the entire sequence.
 *
 *---------------------------------------------------------------------------
 */

static int
ParseEventDescription(
    Tcl_Interp *interp,		/* For error messages. */
    const 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;
    Tcl_DString copy;

    Tcl_DStringInit(&copy);
    p = Tcl_DStringAppend(&copy, *eventStringPtr, -1);

    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 {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"bad ASCII character 0x%x", UCHAR(*p)));
		Tcl_SetErrorCode(interp, "TK", "EVENT", "BAD_CHAR", NULL);
		count = 0;
		goto done;
	    }
	}
	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) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "virtual event \"<<>>\" is badly formed", -1));
	    Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "MALFORMED",
		    NULL);
	    count = 0;
	    goto done;
	}
	if ((p == NULL) || (p[1] != '>')) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "missing \">\" in virtual binding", -1));
	    Tcl_SetErrorCode(interp, "TK", "EVENT", "VIRTUAL", "MALFORMED",
		    NULL);
	    count = 0;
	    goto done;
	}
	*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 = Tcl_GetHashValue(hPtr);
	patPtr->needMods |= modPtr->mask;
	if (modPtr->flags & MULT_CLICKS) {
	    int i = modPtr->flags & MULT_CLICKS;

	    count = 2;
	    while (i >>= 1) {
		count++;
	    }
	}
	while ((*p == '-') || isspace(UCHAR(*p))) {
	    p++;
	}
    }

    eventFlags = 0;
    hPtr = Tcl_FindHashEntry(&eventTable, field);
    if (hPtr != NULL) {
	const EventInfo *eiPtr = 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)) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"specified button \"%s\" for non-button event",
			field));
		Tcl_SetErrorCode(interp, "TK", "EVENT", "NON_BUTTON", NULL);
		count = 0;
		goto done;
	    }
	    patPtr->detail.button = (*field - '0');
	} else {

	getKeysym:
	    patPtr->detail.keySym = TkStringToKeysym(field);
	    if (patPtr->detail.keySym == NoSymbol) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"bad event type or keysym \"%s\"", field));
		Tcl_SetErrorCode(interp, "TK", "LOOKUP", "KEYSYM", field,
			NULL);
		count = 0;
		goto done;
	    }
	    if (eventFlags == 0) {
		patPtr->eventType = KeyPress;
		eventMask = KeyPressMask;
	    } else if (!(eventFlags & KEY)) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"specified keysym \"%s\" for non-key event", field));
		Tcl_SetErrorCode(interp, "TK", "EVENT", "NON_KEY", NULL);
		count = 0;
		goto done;
	    }
	}
    } else if (eventFlags == 0) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"no event type or button # or keysym", -1));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "UNMODIFIABLE", NULL);
	count = 0;
	goto done;
    }

    while ((*p == '-') || isspace(UCHAR(*p))) {
	p++;
    }
    if (*p != '>') {
	while (*p != '\0') {
	    p++;
	    if (*p == '>') {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(
			"extra characters after detail in binding", -1));
		Tcl_SetErrorCode(interp, "TK", "EVENT", "PAST_DETAIL", NULL);
		count = 0;
		goto done;
	    }
	}
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"missing \">\" in binding", -1));
	Tcl_SetErrorCode(interp, "TK", "EVENT", "MALFORMED", NULL);
	count = 0;
	goto done;
    }
    p++;

  end:
    *eventStringPtr += (p - Tcl_DStringValue(&copy));
    *eventMaskPtr |= eventMask;
  done:
    Tcl_DStringFree(&copy);
    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(
    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;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetPatternObj --
 *
 *	Produce a string version of the given event, for displaying to the
 *	user.
 *
 * Results:
 *	The string is returned as a Tcl_Obj.
 *
 * Side effects:
 *	It is the caller's responsibility to arrange for the object to be
 *	released; it starts with a refCount of zero.
 *
 *---------------------------------------------------------------------------
 */

static Tcl_Obj *
GetPatternObj(
    PatSeq *psPtr)
{
    Pattern *patPtr;
    int patsLeft, needMods;
    const ModInfo *modPtr;
    const EventInfo *eiPtr;
    Tcl_Obj *patternObj = Tcl_NewObj();

    /*
     * 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)
		&& (patPtr->needMods == 0)
		&& (patPtr->detail.keySym < 128)
		&& isprint(UCHAR(patPtr->detail.keySym))
		&& (patPtr->detail.keySym != '<')
		&& (patPtr->detail.keySym != ' ')) {
	    char c = (char) patPtr->detail.keySym;

	    Tcl_AppendToObj(patternObj, &c, 1);
	    continue;
	}

	/*
	 * Check for virtual event.
	 */

	if (patPtr->eventType == VirtualEvent) {
	    Tcl_AppendPrintfToObj(patternObj, "<<%s>>", patPtr->detail.name);
	    continue;
	}

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

	Tcl_AppendToObj(patternObj, "<", 1);

	if ((psPtr->flags & PAT_NEARBY) && (patsLeft > 1)
		&& (memcmp(patPtr, patPtr-1, sizeof(Pattern)) == 0)) {
	    patsLeft--;
	    patPtr--;
	    if ((patsLeft > 1) &&
		    (memcmp(patPtr, patPtr-1, sizeof(Pattern)) == 0)) {
		patsLeft--;
		patPtr--;
		if ((patsLeft > 1) &&
			(memcmp(patPtr, patPtr-1, sizeof(Pattern)) == 0)) {
		    patsLeft--;
		    patPtr--;
		    Tcl_AppendToObj(patternObj, "Quadruple-", 10);
		} else {
		    Tcl_AppendToObj(patternObj, "Triple-", 7);
		}
	    } else {
		Tcl_AppendToObj(patternObj, "Double-", 7);
	    }
	}

	for (needMods = patPtr->needMods, modPtr = modArray;
		needMods != 0; modPtr++) {
	    if (modPtr->mask & needMods) {
		needMods &= ~modPtr->mask;
		Tcl_AppendPrintfToObj(patternObj, "%s-", modPtr->name);
	    }
	}

	for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
	    if (eiPtr->type == patPtr->eventType) {
		Tcl_AppendToObj(patternObj, eiPtr->name, -1);
		if (patPtr->detail.clientData != 0) {
		    Tcl_AppendToObj(patternObj, "-", 1);
		}
		break;
	    }
	}

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

		if (string != NULL) {
		    Tcl_AppendToObj(patternObj, string, -1);
		}
	    } else {
		Tcl_AppendPrintfToObj(patternObj, "%d", patPtr->detail.button);
	    }
	}

	Tcl_AppendToObj(patternObj, ">", 1);
    }

    return patternObj;
}

/*
 *----------------------------------------------------------------------
 *
 * TkStringToKeysym --
 *
 *	This function 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(
    const char *name)		/* Name of a keysym. */
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr = Tcl_FindHashEntry(&keySymTable, name);

    if (hPtr != NULL) {
	return (KeySym) Tcl_GetHashValue(hPtr);
    }
    if (strlen(name) == 1) {
	KeySym keysym = (KeySym) (unsigned char) name[0];

	if (TkKeysymToString(keysym) != NULL) {
	    return keysym;
	}
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XStringToKeysym(name);
}

/*
 *----------------------------------------------------------------------
 *
 * TkKeysymToString --
 *
 *	This function 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.
 *
 *----------------------------------------------------------------------
 */

const char *
TkKeysymToString(
    KeySym keysym)
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr = Tcl_FindHashEntry(&nameTable, (char *)keysym);

    if (hPtr != NULL) {
	return Tcl_GetHashValue(hPtr);
    }
#endif /* REDO_KEYSYM_LOOKUP */

    return XKeysymToString(keysym);
}

/*
 *----------------------------------------------------------------------
 *
 * TkpGetBindingXEvent --
 *
 *	This function returns the XEvent associated with the currently
 *	executing binding. This function can only be invoked while a binding
 *	is executing.
 *
 * Results:
 *	Returns a pointer to the XEvent that caused the current binding code
 *	to be run.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

XEvent *
TkpGetBindingXEvent(
    Tcl_Interp *interp)		/* Interpreter. */
{
   TkWindow *winPtr = (TkWindow *) Tk_MainWindow(interp);
   BindingTable *bindPtr = winPtr->mainPtr->bindingTable;

   return &(bindPtr->eventRing[bindPtr->curEvent]);
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */