tkbind.c

linux系统下的音频通信

/* 
 * tkBind.c --
 *
 *	This file provides procedures that associate Tcl commands
 *	with X events or sequences of X events.
 *
 * Copyright (c) 1989-1994 The Regents of the University of California.
 * Copyright (c) 1994-1996 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * SCCS: @(#) tkBind.c 1.133 97/07/01 17:59:53
 */

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

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


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

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

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

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

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

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

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

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

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

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

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

#define PAT_NEARBY		0x1
#define MARKED_DELETED		0x2

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

#define NEARBY_PIXELS		5
#define NEARBY_MS		500


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

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

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

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

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

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

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

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

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

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

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

static int initialized = 0;

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

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

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

#define DOUBLE		1
#define TRIPLE		2

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

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

static ModInfo modArray[] = {
    {"Control",		ControlMask,	0},
    {"Shift",		ShiftMask,	0},