archie/tk3.6/tkGrab.c
2024-05-27 16:13:40 +02:00

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/*
* tkGrab.c --
*
* This file provides procedures that implement grabs for Tk.
*
* Copyright (c) 1992-1993 The Regents of the University of California.
* All rights reserved.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
* CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
#ifndef lint
static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkGrab.c,v 1.34 93/10/23 16:21:43 ouster Exp $ SPRITE (Berkeley)";
#endif
#include "tkConfig.h"
#include "tkInt.h"
/*
* This module is ridiculously complicated... sorry about that. The
* problem is that the grabs provided by the X server aren't very
* useful, so this module tries to create a more useful form of grab
* using the X server's rudimentary facilities. This requires us to
* suppress some of the events coming from the X server and generate
* many additional events. Managing the events is hard because of the
* asynchronous way that the event queue is processed. The current
* solution uses an extra "grab event queue" for each display, where
* we put the event that we synthesize here. Events in this queue
* are processed before any events in the normal X queue. The grab
* event queue is needed (rather than just pushing events back on the
* X queue) so that we can keep a clear boundary between the events
* we've synthesized and those coming from the server, so that we can
* add new events after all the other synthesized events but before
* those from the server.
*/
/*
* One of the following structures is kept for each event in the
* grab queue maintained by this module.
*/
struct TkGrabEvent {
XEvent event; /* Event to process. */
struct TkGrabEvent *nextPtr; /* Next event in list, or NULL for
* end of list. */
};
/*
* Bit definitions for grabFlags field of TkDisplay structures:
*
* GRAB_GLOBAL 1 means this is a global grab (we grabbed via
* the server so all applications are locked out).
* 0 means this is a local grab that affects
* only this application.
* GRAB_TRIGGER_QUEUED 1 means that there are events in the grab
* queue for this display and a fake event has
* been pushed to cause the events on the grab
* queue to be processed before any events on
* the regular X event queue.
* GRAB_TEMP_GLOBAL 1 means we've temporarily grabbed via the
* server because a button is down and we want
* to make sure that we get the button-up
* event. The grab will be released when the
* last mouse button goes up.
*/
#define GRAB_GLOBAL 1
#define GRAB_TRIGGER_QUEUED 2
#define GRAB_TEMP_GLOBAL 4
/*
* The following magic value is stored in the "send_event" field of
* EnterNotify and LeaveNotify events that are generated in this
* file. This allows us to separate "real" events coming from the
* server from those that we generated.
*/
#define GENERATED_EVENT_MAGIC ((Bool) 0x147321ac)
/*
* The following magic value stored in the "send_event" field of
* an event identifies it as a special dummy event to trigger a
* change in the grabWinPtr field of a display. The "window"
* field of the event actually contains a (TkWindow *) value to
* put in grabWinPtr.
*/
#define GRAB_WINDOW_EVENT_MAGIC ((Bool) 0x347321ab)
/*
* Mask that selects any of the state bits corresponding to buttons,
* plus masks that select individual buttons' bits:
*/
#define ALL_BUTTONS \
(Button1Mask|Button2Mask|Button3Mask|Button4Mask|Button5Mask)
static unsigned int buttonStates[] = {
Button1Mask, Button2Mask, Button3Mask, Button4Mask, Button5Mask
};
/*
* Forward declarations for procedures declared later in this file:
*/
static void ChangeEventWindow _ANSI_ARGS_((XEvent *eventPtr,
TkWindow *winPtr));
static void EatGrabEvents _ANSI_ARGS_((TkDisplay *dispPtr,
unsigned int serial));
static TkWindow * FindCommonAncestor _ANSI_ARGS_((TkWindow *winPtr1,
TkWindow *winPtr2, int *countPtr1,
int *countPtr2));
static void MovePointer _ANSI_ARGS_((XEvent *eventPtr,
TkWindow *sourcePtr, TkWindow *destPtr,
int leaveEvents, int EnterEvents));
static void MovePointer2 _ANSI_ARGS_((TkWindow *sourcePtr,
TkWindow *destPtr, int mode, int leaveEvents,
int EnterEvents));
static void PushTriggerEvent _ANSI_ARGS_((TkDisplay *dispPtr));
static void QueueGrabWindowChange _ANSI_ARGS_((TkDisplay *dispPtr,
TkWindow *grabWinPtr));
static void ReleaseButtonGrab _ANSI_ARGS_((TkDisplay *dispPtr));
/*
*----------------------------------------------------------------------
*
* Tk_GrabCmd --
*
* This procedure is invoked to process the "grab" Tcl command.
* See the user documentation for details on what it does.
*
* Results:
* A standard Tcl result.
*
* Side effects:
* See the user documentation.
*
*----------------------------------------------------------------------
*/
/* ARGSUSED */
int
Tk_GrabCmd(clientData, interp, argc, argv)
ClientData clientData; /* Main window associated with
* interpreter. */
Tcl_Interp *interp; /* Current interpreter. */
int argc; /* Number of arguments. */
char **argv; /* Argument strings. */
{
int globalGrab;
Tk_Window tkwin;
TkDisplay *dispPtr;
int length;
char c;
if (argc < 2) {
badArgs:
Tcl_AppendResult(interp, "wrong # args: should be \"",
argv[0], " ?-global? window\" or \"", argv[0],
" option ?arg arg ...?\"", (char *) NULL);
return TCL_ERROR;
}
c = argv[1][0];
length = strlen(argv[1]);
if (c == '.') {
if (argc != 2) {
goto badArgs;
}
tkwin = Tk_NameToWindow(interp, argv[1], (Tk_Window) clientData);
if (tkwin == NULL) {
return TCL_ERROR;
}
return Tk_Grab(interp, tkwin, 0);
} else if ((c == '-') && (strncmp(argv[1], "-global", length) == 0)
&& (length >= 2)) {
if (argc != 3) {
goto badArgs;
}
tkwin = Tk_NameToWindow(interp, argv[2], (Tk_Window) clientData);
if (tkwin == NULL) {
return TCL_ERROR;
}
return Tk_Grab(interp, tkwin, 1);
} else if ((c == 'c') && (strncmp(argv[1], "current", length) == 0)) {
if (argc > 3) {
Tcl_AppendResult(interp, "wrong # args: should be \"",
argv[0], " current ?window?\"", (char *) NULL);
return TCL_ERROR;
}
if (argc == 3) {
tkwin = Tk_NameToWindow(interp, argv[2], (Tk_Window) clientData);
if (tkwin == NULL) {
return TCL_ERROR;
}
dispPtr = ((TkWindow *) tkwin)->dispPtr;
if (dispPtr->eventualGrabWinPtr != NULL) {
interp->result = dispPtr->eventualGrabWinPtr->pathName;
}
} else {
for (dispPtr = tkDisplayList; dispPtr != NULL;
dispPtr = dispPtr->nextPtr) {
if (dispPtr->eventualGrabWinPtr != NULL) {
Tcl_AppendElement(interp,
dispPtr->eventualGrabWinPtr->pathName);
}
}
}
return TCL_OK;
} else if ((c == 'r') && (strncmp(argv[1], "release", length) == 0)) {
if (argc != 3) {
Tcl_AppendResult(interp, "wrong # args: should be \"",
argv[0], " release window\"", (char *) NULL);
return TCL_ERROR;
}
tkwin = Tk_NameToWindow(interp, argv[2], (Tk_Window) clientData);
if (tkwin == NULL) {
Tcl_ResetResult(interp);
} else {
Tk_Ungrab(tkwin);
}
} else if ((c == 's') && (strncmp(argv[1], "set", length) == 0)
&& (length >= 2)) {
if (argc > 4) {
Tcl_AppendResult(interp, "wrong # args: should be \"",
argv[0], " set ?-global? window\"", (char *) NULL);
return TCL_ERROR;
}
if (argc == 3) {
globalGrab = 0;
tkwin = Tk_NameToWindow(interp, argv[2], (Tk_Window) clientData);
} else {
globalGrab = 1;
length = strlen(argv[2]);
if ((strncmp(argv[2], "-global", length) != 0) || (length < 2)) {
Tcl_AppendResult(interp, "bad argument \"", argv[2],
"\": must be \"", argv[0], " set ?-global? window\"",
(char *) NULL);
return TCL_ERROR;
}
tkwin = Tk_NameToWindow(interp, argv[3], (Tk_Window) clientData);
}
if (tkwin == NULL) {
return TCL_ERROR;
}
return Tk_Grab(interp, tkwin, globalGrab);
} else if ((c == 's') && (strncmp(argv[1], "status", length) == 0)
&& (length >= 2)) {
TkWindow *winPtr;
if (argc != 3) {
Tcl_AppendResult(interp, "wrong # args: should be \"",
argv[0], " status window\"", (char *) NULL);
return TCL_ERROR;
}
winPtr = (TkWindow *) Tk_NameToWindow(interp, argv[2],
(Tk_Window) clientData);
if (winPtr == NULL) {
return TCL_ERROR;
}
dispPtr = winPtr->dispPtr;
if (dispPtr->eventualGrabWinPtr != winPtr) {
interp->result = "none";
} else if (dispPtr->grabFlags & GRAB_GLOBAL) {
interp->result = "global";
} else {
interp->result = "local";
}
} else {
Tcl_AppendResult(interp, "unknown or ambiguous option \"", argv[1],
"\": must be current, release, set, or status",
(char *) NULL);
return TCL_ERROR;
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tk_Grab --
*
* Grabs the pointer and keyboard, so that mouse-related events are
* only reported relative to a given window and its descendants.
*
* Results:
* A standard Tcl result is returned. TCL_OK is the normal return
* value; if the grab could not be set then TCL_ERROR is returned
* and interp->result will hold an error message.
*
* Side effects:
* Once this call completes successfully, no window outside the
* tree rooted at tkwin will receive pointer- or keyboard-related
* events until the next call to Tk_Ungrab. If a previous grab was
* in effect within this application, then it is replaced with a new
* one.
*
*----------------------------------------------------------------------
*/
int
Tk_Grab(interp, tkwin, grabGlobal)
Tcl_Interp *interp; /* Used for error reporting. */
Tk_Window tkwin; /* Window on whose behalf the pointer
* is to be grabbed. */
int grabGlobal; /* Non-zero means issue a grab to the
* server so that no other application
* gets mouse or keyboard events.
* Zero means the grab only applies
* within this application. */
{
int grabResult;
TkWindow *winPtr = (TkWindow *) tkwin;
TkDisplay *dispPtr = winPtr->dispPtr;
TkWindow *winPtr2;
unsigned int serial;
ReleaseButtonGrab(dispPtr);
if (dispPtr->eventualGrabWinPtr != NULL) {
if ((dispPtr->eventualGrabWinPtr == winPtr)
&& (grabGlobal == ((dispPtr->grabFlags & GRAB_GLOBAL) != 0))) {
return TCL_OK;
}
if (dispPtr->eventualGrabWinPtr->mainPtr != winPtr->mainPtr) {
alreadyGrabbed:
interp->result = "grab failed: another application has grab";
return TCL_ERROR;
}
Tk_Ungrab(tkwin);
}
Tk_MakeWindowExist(tkwin);
if (!grabGlobal) {
Window dummy1, dummy2;
int dummy3, dummy4, dummy5, dummy6;
unsigned int state;
/*
* Local grab. However, if any mouse buttons are down, turn
* it into a global grab temporarily, until the last button
* goes up. This does two things: (a) it makes sure that we
* see the button-up event; and (b) it allows us to track mouse
* motion among all of the windows of this application.
*/
dispPtr->grabFlags &= ~(GRAB_GLOBAL|GRAB_TEMP_GLOBAL);
XQueryPointer(dispPtr->display, winPtr->window, &dummy1,
&dummy2, &dummy3, &dummy4, &dummy5, &dummy6, &state);
if ((state & ALL_BUTTONS) != 0) {
dispPtr->grabFlags |= GRAB_TEMP_GLOBAL;
goto setGlobalGrab;
}
} else {
dispPtr->grabFlags |= GRAB_GLOBAL;
setGlobalGrab:
/*
* Tricky point: must ungrab before grabbing. This is needed
* in case there is a button auto-grab already in effect. If
* there is, and the mouse has moved to a different window, X
* won't generate enter and leave events to move the mouse if
* we grab without ungrabbing.
*/
XUngrabPointer(dispPtr->display, CurrentTime);
serial = NextRequest(dispPtr->display);
grabResult = XGrabPointer(dispPtr->display, winPtr->window,
True, ButtonPressMask|ButtonReleaseMask|ButtonMotionMask,
GrabModeAsync, GrabModeAsync, None, None, CurrentTime);
if (grabResult != 0) {
grabError:
if (grabResult == GrabNotViewable) {
interp->result = "grab failed: window not viewable";
} else if (grabResult == AlreadyGrabbed) {
goto alreadyGrabbed;
} else if (grabResult == GrabFrozen) {
interp->result = "grab failed: keyboard or pointer frozen";
} else if (grabResult == GrabInvalidTime) {
interp->result = "grab failed: invalid time";
} else {
char msg[100];
sprintf(msg, "grab failed for unknown reason (code %d)",
grabResult);
Tcl_AppendResult(interp, msg, (char *) NULL);
}
return TCL_ERROR;
}
grabResult = XGrabKeyboard(dispPtr->display, Tk_WindowId(tkwin),
False, GrabModeAsync, GrabModeAsync, CurrentTime);
if (grabResult != 0) {
XUngrabPointer(dispPtr->display, CurrentTime);
goto grabError;
}
/*
* Eat up any grab-related events generated by the server for the
* grab. There are several reasons for doing this:
*
* 1. We have to synthesize the events for local grabs anyway, since
* the server doesn't participate in them.
* 2. The server doesn't always generate the right events for global
* grabs (e.g. it generates events even if the current window is
* in the grab tree, which we don't want).
* 3. We want all the grab-related events to be processed immediately
* (before other events that are already queued); events coming
* from the server will be in the wrong place, but events we
* synthesize here will go to the front of the queue.
*/
EatGrabEvents(dispPtr, serial);
}
/*
* Synthesize leave events to move the pointer from its current window
* up to the lowest ancestor that it has in common with the grab window.
* However, only do this if the pointer is outside the grab window's
* subtree but inside the grab window's application.
*/
if ((dispPtr->serverWinPtr != NULL)
&& (dispPtr->serverWinPtr->mainPtr == winPtr->mainPtr)) {
for (winPtr2 = dispPtr->serverWinPtr; ; winPtr2 = winPtr2->parentPtr) {
if (winPtr2 == winPtr) {
break;
}
if (winPtr2 == NULL) {
MovePointer2(dispPtr->serverWinPtr, winPtr, NotifyGrab, 1, 0);
break;
}
}
}
QueueGrabWindowChange(dispPtr, winPtr);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tk_Ungrab --
*
* Releases a grab on the mouse pointer and keyboard, if there
* is one set on the specified window.
*
* Results:
* None.
*
* Side effects:
* Pointer and keyboard events will start being delivered to other
* windows again.
*
*----------------------------------------------------------------------
*/
void
Tk_Ungrab(tkwin)
Tk_Window tkwin; /* Window that identifies display
* for grab to be released. */
{
TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr;
TkWindow *grabWinPtr, *winPtr;
unsigned int serial;
grabWinPtr = (TkWindow *) tkwin;
dispPtr = grabWinPtr->dispPtr;
if (grabWinPtr != dispPtr->eventualGrabWinPtr) {
return;
}
ReleaseButtonGrab(dispPtr);
QueueGrabWindowChange(dispPtr, (TkWindow *) NULL);
if (dispPtr->grabFlags & (GRAB_GLOBAL|GRAB_TEMP_GLOBAL)) {
dispPtr->grabFlags &= ~(GRAB_GLOBAL|GRAB_TEMP_GLOBAL);
serial = NextRequest(dispPtr->display);
XUngrabPointer(dispPtr->display, CurrentTime);
XUngrabKeyboard(dispPtr->display, CurrentTime);
EatGrabEvents(dispPtr, serial);
}
/*
* Generate events to move the pointer back to the window where it
* really is. Some notes:
* 1. As with grabs, only do this if the "real" window is not a
* descendant of the grab window, since in this case the pointer
* is already where it's supposed to be.
* 2. If the "real" window is in some other application then don't
* generate any events at all, since everything's already been
* reported correctly.
* 3. Only generate enter events. Don't generate leave events,
* because we never told the lower-level windows that they
* had the pointer in the first place.
*/
for (winPtr = dispPtr->serverWinPtr; ; winPtr = winPtr->parentPtr) {
if (winPtr == grabWinPtr) {
break;
}
if (winPtr == NULL) {
if ((dispPtr->serverWinPtr == NULL) ||
(dispPtr->serverWinPtr->mainPtr == grabWinPtr->mainPtr)) {
MovePointer2(grabWinPtr, dispPtr->serverWinPtr,
NotifyUngrab, 0, 1);
}
break;
}
}
}
/*
*----------------------------------------------------------------------
*
* ReleaseButtonGrab --
*
* This procedure is called to release a simulated button grab, if
* there is one in effect. A button grab is present whenever
* dispPtr->buttonWinPtr is non-NULL or when the GRAB_TEMP_GLOBAL
* flag is set.
*
* Results:
* None.
*
* Side effects:
* DispPtr->buttonWinPtr is reset to NULL, and enter and leave
* events are generated if necessary to move the pointer from
* the button grab window to its current window.
*
*----------------------------------------------------------------------
*/
static void
ReleaseButtonGrab(dispPtr)
register TkDisplay *dispPtr; /* Display whose button grab is to be
* released. */
{
unsigned int serial;
if (dispPtr->buttonWinPtr != NULL) {
if (dispPtr->buttonWinPtr != dispPtr->serverWinPtr) {
MovePointer2(dispPtr->buttonWinPtr, dispPtr->serverWinPtr,
NotifyUngrab, 1, 1);
}
dispPtr->buttonWinPtr = NULL;
}
if (dispPtr->grabFlags & GRAB_TEMP_GLOBAL) {
dispPtr->grabFlags &= ~GRAB_TEMP_GLOBAL;
serial = NextRequest(dispPtr->display);
XUngrabPointer(dispPtr->display, CurrentTime);
XUngrabKeyboard(dispPtr->display, CurrentTime);
EatGrabEvents(dispPtr, serial);
}
}
/*
*----------------------------------------------------------------------
*
* TkPointerEvent --
*
* This procedure is called for each pointer-related event, before
* the event has been processed. It does various things to make
* grabs work correctly.
*
* Results:
* If the return value is 1 it means the event should be processed
* (event handlers should be invoked). If the return value is 0
* it means the event should be ignored in order to make grabs
* work correctly. In some cases this procedure modifies the event.
*
* Side effects:
* Grab state information may be updated. New events may also be
* pushed back onto the event queue to replace or augment the
* one passed in here.
*
*----------------------------------------------------------------------
*/
int
TkPointerEvent(eventPtr, winPtr)
register XEvent *eventPtr; /* Pointer to the event. */
TkWindow *winPtr; /* Tk's information for window
* where event was reported. */
{
register TkWindow *winPtr2;
TkDisplay *dispPtr = winPtr->dispPtr;
unsigned int serial;
int outsideGrabTree = 0;
int ancestorOfGrab = 0;
int appGrabbed = 0; /* Non-zero means event is being
* reported to an application that is
* affected by the grab. */
/*
* If a grab is in effect, see if the event is being reported to
* a window in the grab tree or to an ancestor of the grab window
* within its same top-level window. Also see if the event is
* being reported to an application that is affected by the grab.
*/
if (dispPtr->grabWinPtr != NULL) {
if ((winPtr->mainPtr == dispPtr->grabWinPtr->mainPtr)
|| (dispPtr->grabFlags & GRAB_GLOBAL)) {
appGrabbed = 1;
}
for (winPtr2 = winPtr; winPtr2 != dispPtr->grabWinPtr;
winPtr2 = winPtr2->parentPtr) {
if (winPtr2 == NULL) {
outsideGrabTree = 1;
for (winPtr2 = dispPtr->grabWinPtr; ;
winPtr2 = winPtr2->parentPtr) {
if (winPtr2 == winPtr) {
ancestorOfGrab = 1;
}
if (winPtr2->flags & TK_TOP_LEVEL) {
break;
}
}
break;
}
}
}
if ((eventPtr->type == EnterNotify) || (eventPtr->type == LeaveNotify)) {
/*
* Keep track of what window the mouse is *really* over.
* Any events that we generate have a special send_event value,
* which is detected below and used to ignore the event for
* purposes of setting serverWinPtr.
*/
if (eventPtr->xcrossing.send_event != GENERATED_EVENT_MAGIC) {
if ((eventPtr->type == LeaveNotify) &&
(winPtr->flags & TK_TOP_LEVEL)) {
dispPtr->serverWinPtr = NULL;
} else {
dispPtr->serverWinPtr = winPtr;
}
}
/*
* When a grab is active, X continues to report enter and leave
* events for windows outside the tree of the grab window:
* 1. Detect these events and ignore them except for
* windows above the grab window.
* 2. Allow Enter and Leave events to pass through the
* windows above the grab window, but never let them
* end up with the pointer *in* one of those windows.
*/
if (dispPtr->grabWinPtr != NULL) {
if (outsideGrabTree && appGrabbed) {
if (!ancestorOfGrab) {
return 0;
}
switch (eventPtr->xcrossing.detail) {
case NotifyInferior:
return 0;
case NotifyAncestor:
eventPtr->xcrossing.detail = NotifyVirtual;
break;
case NotifyNonlinear:
eventPtr->xcrossing.detail = NotifyNonlinearVirtual;
break;
}
}
/*
* Make buttons have the same grab-like behavior inside a grab
* as they do outside a grab: do this by ignoring enter and
* leave events except for the window in which the button was
* pressed.
*/
if ((dispPtr->buttonWinPtr != NULL)
&& (winPtr != dispPtr->buttonWinPtr)) {
return 0;
}
}
return 1;
}
if (!appGrabbed) {
return 1;
}
if (eventPtr->type == MotionNotify) {
/*
* When grabs are active, X reports motion events relative to the
* window under the pointer. Instead, it should report the events
* relative to the window the button went down in, if there is a
* button down. Otherwise, if the pointer window is outside the
* subtree of the grab window, the events should be reported
* relative to the grab window. Otherwise, the event should be
* reported to the pointer window.
*/
winPtr2 = winPtr;
if (dispPtr->buttonWinPtr != NULL) {
winPtr2 = dispPtr->buttonWinPtr;
} else if (outsideGrabTree || (dispPtr->serverWinPtr == NULL)) {
winPtr2 = dispPtr->grabWinPtr;
}
if (winPtr2 != winPtr) {
XEvent newEvent;
newEvent = *eventPtr;
ChangeEventWindow(&newEvent, winPtr2);
XPutBackEvent(winPtr2->display, &newEvent);
return 0;
}
return 1;
}
/*
* Process ButtonPress and ButtonRelease events:
* 1. Keep track of whether a button is down and what window it
* went down in.
* 2. If the first button goes down outside the grab tree, pretend
* it went down in the grab window. Note: it's important to
* redirect events to the grab window like this in order to make
* things like menus work, where button presses outside the
* grabbed menu need to be seen. An application can always
* ignore the events if they occur outside its window.
* 3. If a button press or release occurs outside the window where
* the first button was pressed, retarget the event so it's reported
* to the window where the first button was pressed.
* 4. If the last button is released in a window different than where
* the first button was pressed, generate Enter/Leave events to
* move the mouse from the button window to its current window.
* 5. If the grab is set at a time when a button is already down, or
* if the window where the button was pressed was deleted, then
* dispPtr->buttonWinPtr will stay NULL. Just forget about the
* auto-grab for the button press; events will go to whatever
* window contains the pointer. If this window isn't in the grab
* tree then redirect events to the grab window.
* 6. When a button is pressed during a local grab, the X server sets
* a grab of its own, since it doesn't even know about our local
* grab. This causes enter and leave events no longer to be
* generated in the same way as for global grabs. To eliminate this
* problem, set a temporary global grab when the first button goes
* down and release it when the last button comes up.
*/
if ((eventPtr->type == ButtonPress) || (eventPtr->type == ButtonRelease)) {
winPtr2 = dispPtr->buttonWinPtr;
if (winPtr2 == NULL) {
if (outsideGrabTree) {
winPtr2 = dispPtr->grabWinPtr; /* Note 5. */
} else {
winPtr2 = winPtr; /* Note 5. */
}
}
if (eventPtr->type == ButtonPress) {
if ((eventPtr->xbutton.state & ALL_BUTTONS) == 0) {
if (outsideGrabTree) {
XEvent newEvent;
newEvent = *eventPtr;
ChangeEventWindow(&newEvent, dispPtr->grabWinPtr);
XPutBackEvent(dispPtr->display, &newEvent);
return 0; /* Note 2. */
}
if (!(dispPtr->grabFlags & GRAB_GLOBAL)) { /* Note 6. */
serial = NextRequest(dispPtr->display);
if (XGrabPointer(dispPtr->display,
dispPtr->grabWinPtr->window, True,
ButtonPressMask|ButtonReleaseMask|ButtonMotionMask,
GrabModeAsync, GrabModeAsync, None, None,
CurrentTime) == 0) {
EatGrabEvents(dispPtr, serial);
if (XGrabKeyboard(dispPtr->display, winPtr->window,
False, GrabModeAsync, GrabModeAsync,
CurrentTime) == 0) {
dispPtr->grabFlags |= GRAB_TEMP_GLOBAL;
} else {
XUngrabPointer(dispPtr->display, CurrentTime);
}
}
}
dispPtr->buttonWinPtr = winPtr;
return 1;
}
} else {
if ((eventPtr->xbutton.state & ALL_BUTTONS)
== buttonStates[eventPtr->xbutton.button - Button1]) {
ReleaseButtonGrab(dispPtr); /* Note 4. */
}
}
if (winPtr2 != winPtr) {
XEvent newEvent;
newEvent = *eventPtr;
ChangeEventWindow(&newEvent, winPtr2);
XPutBackEvent(dispPtr->display, &newEvent);
return 0; /* Note 3. */
}
}
return 1;
}
/*
*----------------------------------------------------------------------
*
* ChangeEventWindow --
*
* Given an event and a new window to which the event should be
* retargeted, modify fields of the event so that the event is
* properly retargeted to the new window.
*
* Results:
* The following fields of eventPtr are modified: window,
* subwindow, x, y, same_screen.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
ChangeEventWindow(eventPtr, winPtr)
register XEvent *eventPtr; /* Event to retarget. Must have
* type ButtonPress, ButtonRelease, KeyPress,
* KeyRelease, MotionNotify, EnterNotify,
* or LeaveNotify. */
TkWindow *winPtr; /* New target window for event. */
{
int x, y, sameScreen, bd;
register TkWindow *childPtr;
eventPtr->xmotion.window = Tk_WindowId(winPtr);
if (eventPtr->xmotion.root ==
RootWindow(winPtr->display, winPtr->screenNum)) {
Tk_GetRootCoords((Tk_Window) winPtr, &x, &y);
eventPtr->xmotion.x = eventPtr->xmotion.x_root - x;
eventPtr->xmotion.y = eventPtr->xmotion.y_root - y;
eventPtr->xmotion.subwindow = None;
for (childPtr = winPtr->childList; childPtr != NULL;
childPtr = childPtr->nextPtr) {
if (childPtr->flags & TK_TOP_LEVEL) {
continue;
}
x = eventPtr->xmotion.x - childPtr->changes.x;
y = eventPtr->xmotion.y - childPtr->changes.y;
bd = childPtr->changes.border_width;
if ((x >= -bd) && (y >= -bd)
&& (x < (childPtr->changes.width + bd))
&& (y < (childPtr->changes.width + bd))) {
eventPtr->xmotion.subwindow = childPtr->window;
}
}
sameScreen = 1;
} else {
eventPtr->xmotion.x = 0;
eventPtr->xmotion.y = 0;
eventPtr->xmotion.subwindow = None;
sameScreen = 0;
}
if (eventPtr->type == MotionNotify) {
eventPtr->xmotion.same_screen = sameScreen;
} else {
eventPtr->xbutton.same_screen = sameScreen;
}
}
/*
*----------------------------------------------------------------------
*
* MovePointer --
*
* This procedure synthesizes EnterNotify and LeaveNotify events
* to correctly transfer the pointer from one window to another.
*
* Results:
* None.
*
* Side effects:
* Synthesized events may be pushed back onto the event queue.
* The event pointed to by eventPtr is modified.
*
*----------------------------------------------------------------------
*/
static void
MovePointer(eventPtr, sourcePtr, destPtr, leaveEvents, enterEvents)
XEvent *eventPtr; /* A template X event. Must have all fields
* properly set for EnterNotify and LeaveNotify
* events except window, subwindow, x, y,
* detail, and same_screen. (x_root and y_root
* must be valid, even though x and y needn't
* be valid). */
TkWindow *sourcePtr; /* Window currently containing pointer (NULL
* means it's not one managed by this
* process). */
TkWindow *destPtr; /* Window that is to end up containing the
* pointer (NULL means it's not one managed
* by this process). */
int leaveEvents; /* Non-zero means generate leave events for the
* windows being left. Zero means don't
* generate leave events. */
int enterEvents; /* Non-zero means generate enter events for the
* windows being entered. Zero means don't
* generate enter events. */
{
register TkWindow *winPtr;
int upLevels, downLevels, i, j;
/*
* There are four possible cases to deal with:
*
* 1. SourcePtr and destPtr are the same. There's nothing to do in
* this case.
* 2. SourcePtr is an ancestor of destPtr in the same top-level
* window. Must generate events down the window tree from source
* to dest.
* 3. DestPtr is an ancestor of sourcePtr in the same top-level
* window. Must generate events up the window tree from sourcePtr
* to destPtr.
* 4. All other cases. Must first generate events up the window tree
* from sourcePtr to its top-level, then down from destPtr's
* top-level to destPtr. This form is called "non-linear."
*
* The call to FindCommonAncestor separates these four cases and decides
* how many levels up and down events have to be generated for.
*/
if (sourcePtr == destPtr) {
return;
}
FindCommonAncestor(sourcePtr, destPtr, &upLevels, &downLevels);
/*
* Generate enter/leave events and add them to the grab event queue.
*/
#define QUEUE(w, t, d) \
if (w->window != None) { \
eventPtr->type = t; \
eventPtr->xcrossing.detail = d; \
ChangeEventWindow(eventPtr, w); \
TkQueueEvent(w->dispPtr, eventPtr); \
}
if (downLevels == 0) {
/*
* SourcePtr is an inferior of destPtr.
*/
if (leaveEvents) {
QUEUE(sourcePtr, LeaveNotify, NotifyAncestor);
for (winPtr = sourcePtr->parentPtr, i = upLevels-1; i > 0;
winPtr = winPtr->parentPtr, i--) {
QUEUE(winPtr, LeaveNotify, NotifyVirtual);
}
}
if ((enterEvents) && (destPtr != NULL)) {
QUEUE(destPtr, EnterNotify, NotifyInferior);
}
} else if (upLevels == 0) {
/*
* DestPtr is an inferior of sourcePtr.
*/
if ((leaveEvents) && (sourcePtr != NULL)) {
QUEUE(sourcePtr, LeaveNotify, NotifyInferior);
}
if (enterEvents) {
for (i = downLevels-1; i > 0; i--) {
for (winPtr = destPtr->parentPtr, j = 1; j < i;
winPtr = winPtr->parentPtr, j++) {
}
QUEUE(winPtr, EnterNotify, NotifyVirtual);
}
if (destPtr != NULL) {
QUEUE(destPtr, EnterNotify, NotifyAncestor);
}
}
} else {
/*
* Non-linear: neither window is an inferior of the other.
*/
if (leaveEvents) {
QUEUE(sourcePtr, LeaveNotify, NotifyNonlinear);
for (winPtr = sourcePtr->parentPtr, i = upLevels-1; i > 0;
winPtr = winPtr->parentPtr, i--) {
QUEUE(winPtr, LeaveNotify, NotifyNonlinearVirtual);
}
}
if (enterEvents) {
for (i = downLevels-1; i > 0; i--) {
for (winPtr = destPtr->parentPtr, j = 1; j < i;
winPtr = winPtr->parentPtr, j++) {
}
QUEUE(winPtr, EnterNotify, NotifyNonlinearVirtual);
}
if (destPtr != NULL) {
QUEUE(destPtr, EnterNotify, NotifyNonlinear);
}
}
}
}
/*
*----------------------------------------------------------------------
*
* TkQueueEvent --
*
* This procedure adds an enter or leave event to the end of the
* grab queue for dispPtr.
*
* Results:
* None.
*
* Side effects:
* A copy of *eventPtr is added to the grab queue for dispPtr.
* It will be processed after all other events on the grab queue
* but before any "real" X events (those not coming from the grab
* queue).
*
*----------------------------------------------------------------------
*/
void
TkQueueEvent(dispPtr, eventPtr)
TkDisplay *dispPtr; /* Display for which the event is to be
* queued. */
XEvent *eventPtr; /* Event to queue. */
{
TkGrabEvent *grabEventPtr;
grabEventPtr = (TkGrabEvent *) ckalloc(sizeof(TkGrabEvent));
grabEventPtr->event = *eventPtr;
grabEventPtr->nextPtr = NULL;
if (dispPtr->firstGrabEventPtr == NULL) {
dispPtr->firstGrabEventPtr = grabEventPtr;
} else {
dispPtr->lastGrabEventPtr->nextPtr = grabEventPtr;
}
dispPtr->lastGrabEventPtr = grabEventPtr;
if (!(dispPtr->grabFlags & GRAB_TRIGGER_QUEUED)) {
PushTriggerEvent(dispPtr);
}
}
/*
*----------------------------------------------------------------------
*
* PushTriggerEvent --
*
* This procedure creates a special "trigger" event and pushes it
* onto the front of the event queue for winPtr's display.
* When Tk_HandleEvent sees this event it will call back to this
* module so that we can feed events from the grab queue onto the
* front of the event queue.
*
* Results:
* None.
*
* Side effects:
* Causes TkGrabTriggerProc to be called later on when the event
* is actually handled.
*
*----------------------------------------------------------------------
*/
static void
PushTriggerEvent(dispPtr)
TkDisplay *dispPtr; /* Display on whose display a trigger
* event is to be pushed back. */
{
XEvent event;
event.xany.type = -1;
event.xany.serial = 0;
event.xany.send_event = True;
event.xany.display = (Display *) dispPtr;
event.xany.window = None;
XPutBackEvent(dispPtr->display, &event);
dispPtr->grabFlags |= GRAB_TRIGGER_QUEUED;
}
/*
*----------------------------------------------------------------------
*
* TkGrabTriggerProc --
*
* This procedure is invoked when a trigger event is encountered
* by Tk_HandleEvent.
*
* Results:
* None.
*
* Side effects:
* See code below.
*
*----------------------------------------------------------------------
*/
void
TkGrabTriggerProc(eventPtr)
XEvent *eventPtr; /* Pointer to the trigger event. */
{
TkDisplay *dispPtr = (TkDisplay *) eventPtr->xany.display;
TkGrabEvent *grabEventPtr;
/*
* Remove the first event from the grab queue, if there is one.
* If there are additional events left on the queue, then push
* back a new trigger event so that this procedure will get called
* again to process them.
*/
dispPtr->grabFlags &= ~GRAB_TRIGGER_QUEUED;
grabEventPtr = dispPtr->firstGrabEventPtr;
if (grabEventPtr == NULL) {
return;
}
dispPtr->firstGrabEventPtr = grabEventPtr->nextPtr;
if (dispPtr->firstGrabEventPtr == NULL) {
dispPtr->lastGrabEventPtr = NULL;
} else {
PushTriggerEvent(dispPtr);
}
/*
* If this is a special event to change grabWinPtr, do that; otherwise
* call Tk_HandleEvent recursively to process the grab event. In either
* case, free up the event when done.
*/
if (grabEventPtr->event.xany.send_event == GRAB_WINDOW_EVENT_MAGIC) {
if (XFindContext(grabEventPtr->event.xany.display,
grabEventPtr->event.xany.window,
tkWindowContext, (caddr_t *) &dispPtr->grabWinPtr) != 0) {
dispPtr->grabWinPtr = NULL;
}
} else {
Tk_HandleEvent(&grabEventPtr->event);
}
ckfree((char *) grabEventPtr);
}
/*
*----------------------------------------------------------------------
*
* MovePointer2 --
*
* This procedure synthesizes EnterNotify and LeaveNotify events
* to correctly transfer the pointer from one window to another.
* It is different from MovePointer in that no template X event
* needs to be supplied; this procedure generates the template
* event and calls MovePointer.
*
* Results:
* None.
*
* Side effects:
* Synthesized events may be pushed back onto the event queue.
*
*----------------------------------------------------------------------
*/
static void
MovePointer2(sourcePtr, destPtr, mode, leaveEvents, enterEvents)
TkWindow *sourcePtr; /* Window currently containing pointer (NULL
* means it's not one managed by this
* process). */
TkWindow *destPtr; /* Window that is to end up containing the
* pointer (NULL means it's not one managed
* by this process). */
int mode; /* Mode for enter/leave events, such as
* NotifyNormal or NotifyUngrab. */
int leaveEvents; /* Non-zero means generate leave events for the
* windows being left. Zero means don't
* generate leave events. */
int enterEvents; /* Non-zero means generate enter events for the
* windows being entered. Zero means don't
* generate enter events. */
{
XEvent event;
Window dummy1, dummy2;
int dummy3, dummy4;
TkWindow *winPtr;
winPtr = sourcePtr;
if ((winPtr == NULL) || (winPtr->window == None)) {
winPtr = destPtr;
if ((winPtr == NULL) || (winPtr->window == None)) {
return;
}
}
event.xcrossing.serial = LastKnownRequestProcessed(winPtr->display);
event.xcrossing.send_event = GENERATED_EVENT_MAGIC;
event.xcrossing.display = winPtr->display;
event.xcrossing.root = RootWindow(winPtr->display, winPtr->screenNum);
event.xcrossing.time = TkCurrentTime(winPtr->dispPtr);
XQueryPointer(winPtr->display, winPtr->window, &dummy1, &dummy2,
&event.xcrossing.x_root, &event.xcrossing.y_root,
&dummy3, &dummy4, &event.xcrossing.state);
event.xcrossing.mode = mode;
event.xcrossing.focus = False;
MovePointer(&event, sourcePtr, destPtr, leaveEvents, enterEvents);
}
/*
*----------------------------------------------------------------------
*
* TkGrabDeadWindow --
*
* This procedure is invoked whenever a window is deleted, so that
* grab-related cleanup can be performed.
*
* Results:
* None.
*
* Side effects:
* Various cleanups happen, such as generating events to move the
* pointer back to its "natural" window as if an ungrab had been
* done. See the code.
*
*----------------------------------------------------------------------
*/
void
TkGrabDeadWindow(winPtr)
register TkWindow *winPtr; /* Window that is in the process
* of being deleted. */
{
TkDisplay *dispPtr = winPtr->dispPtr;
if (dispPtr->eventualGrabWinPtr == winPtr) {
/*
* Grab window was deleted. Release the grab.
*/
Tk_Ungrab((Tk_Window) dispPtr->eventualGrabWinPtr);
} else if (dispPtr->buttonWinPtr == winPtr) {
ReleaseButtonGrab(dispPtr);
}
if (dispPtr->serverWinPtr == winPtr) {
if (winPtr->flags && TK_TOP_LEVEL) {
dispPtr->serverWinPtr = NULL;
} else {
dispPtr->serverWinPtr = winPtr->parentPtr;
}
}
if (dispPtr->grabWinPtr == winPtr) {
dispPtr->grabWinPtr = NULL;
}
}
/*
*----------------------------------------------------------------------
*
* EatGrabEvents --
*
* This procedure is called to eliminate any Enter, Leave,
* FocusIn, or FocusOut events in the event queue for a
* display that have mode NotifyGrab or NotifyUngrab and
* have a serial number no less than a given value.
*
* Results:
* None.
*
* Side effects:
* DispPtr's display gets sync-ed, and some of the events get
* removed from its queue. Unaffected events are initially
* removed from the queue but they are eventually put back again
* in the right order.
*
*----------------------------------------------------------------------
*/
static void
EatGrabEvents(dispPtr, serial)
TkDisplay *dispPtr; /* Display from which to consume events. */
unsigned int serial; /* Only discard events that have a serial
* number at least this great. */
{
int numEvents, i, diff, mode;
XEvent *events, *eventPtr;
XSync(dispPtr->display, False);
numEvents = QLength(dispPtr->display);
if (numEvents == 0) {
return;
}
events = (XEvent *) ckalloc((unsigned) (numEvents * sizeof(XEvent)));
for (i = 0; i < numEvents; i++) {
XNextEvent(dispPtr->display, &events[i]);
}
for (i = numEvents-1, eventPtr = &events[i]; i >= 0; i--, eventPtr--) {
/*
* The diff caculation is trickier than it may seem. Don't forget
* that serial numbers can wrap around, so can't compare the two
* serial numbers directly.
*/
diff = eventPtr->xany.serial - serial;
if ((eventPtr->type == EnterNotify)
|| (eventPtr->type == LeaveNotify)) {
mode = eventPtr->xcrossing.mode;
} else if ((eventPtr->type == FocusIn)
|| (eventPtr->type == FocusOut)) {
mode = eventPtr->xfocus.mode;
} else {
mode = NotifyNormal;
}
if ((mode == NotifyNormal) || (diff < 0)) {
XPutBackEvent(dispPtr->display, eventPtr);
}
}
ckfree((char *) events);
}
/*
*----------------------------------------------------------------------
*
* QueueGrabWindowChange --
*
* This procedure queues a special event in the grab event queue
* for dispPtr, which will cause the "grabWinPtr" field for the
* display to get modified when the event is processed. This
* procedure is needed to make sure that the grab window changes
* at the proper time relative to grab-related enter and leave
* events that are also in the queue. In particular, this approach
* works even when multiple grabs and ungrabs happen back-to-back.
*
* Results:
* None.
*
* Side effects:
* DispPtr->grabWinPtr will be modified later (by TkGrabTriggerProc)
* when the event is removed from the grab event queue.
*
*----------------------------------------------------------------------
*/
static void
QueueGrabWindowChange(dispPtr, grabWinPtr)
TkDisplay *dispPtr; /* Display on which to change the grab
* window. */
TkWindow *grabWinPtr; /* Window that is to become the new grab
* window (may be NULL). */
{
XEvent event;
event.xany.display = dispPtr->display;
event.xany.send_event = GRAB_WINDOW_EVENT_MAGIC;
event.xany.window = (grabWinPtr == NULL) ? None : grabWinPtr->window;
TkQueueEvent(dispPtr, &event);
dispPtr->eventualGrabWinPtr = grabWinPtr;
}
/*
*----------------------------------------------------------------------
*
* FindCommonAncestor --
*
* Given two windows, this procedure finds their least common
* ancestor and also computes how many levels up this ancestor
* is from each of the original windows.
*
* Results:
* If the windows are in different applications or top-level
* windows, then NULL is returned and *countPtr1 and *countPtr2
* are set to the depths of the two windows in their respective
* top-level windows (1 means the window is a top-level, 2 means
* its parent is a top-level, and so on). Otherwise, the return
* value is a pointer to the common ancestor and the counts are
* set to the distance of winPtr1 and winPtr2 from this ancestor
* (1 means they're children, 2 means grand-children, etc.).
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static TkWindow *
FindCommonAncestor(winPtr1, winPtr2, countPtr1, countPtr2)
TkWindow *winPtr1; /* First window. May be NULL. */
TkWindow *winPtr2; /* Second window. May be NULL. */
int *countPtr1; /* Store nesting level of winPtr1 within
* common ancestor here. */
int *countPtr2; /* Store nesting level of winPtr2 within
* common ancestor here. */
{
register TkWindow *winPtr;
TkWindow *ancestorPtr;
int count1, count2, i;
/*
* Mark winPtr1 and all of its ancestors with a special flag bit.
*/
if (winPtr1 != NULL) {
for (winPtr = winPtr1; ; winPtr = winPtr->parentPtr) {
winPtr->flags |= TK_GRAB_FLAG;
if (winPtr->flags & TK_TOP_LEVEL) {
break;
}
}
}
/*
* Search upwards from winPtr2 until an ancestor of winPtr1 is
* found or a top-level window is reached.
*/
winPtr = winPtr2;
count2 = 0;
ancestorPtr = NULL;
if (winPtr2 != NULL) {
for (; ; count2++, winPtr = winPtr->parentPtr) {
if (winPtr->flags & TK_GRAB_FLAG) {
ancestorPtr = winPtr;
break;
}
if (winPtr->flags & TK_TOP_LEVEL) {
count2++;
break;
}
}
}
/*
* Search upwards from winPtr1 again, clearing the flag bits and
* remembering how many levels up we had to go.
*/
if (winPtr1 == NULL) {
count1 = 0;
} else {
count1 = -1;
for (i = 0, winPtr = winPtr1; ; i++, winPtr = winPtr->parentPtr) {
winPtr->flags &= ~TK_GRAB_FLAG;
if (winPtr == ancestorPtr) {
count1 = i;
}
if (winPtr->flags & TK_TOP_LEVEL) {
if (count1 == -1) {
count1 = i+1;
}
break;
}
}
}
*countPtr1 = count1;
*countPtr2 = count2;
return ancestorPtr;
}