tkgrab.c

linux系统下的音频通信

     * 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) {
		    TkChangeEventWindow(eventPtr, dispPtr->grabWinPtr);
		    Tk_QueueWindowEvent(eventPtr, TCL_QUEUE_HEAD);
		    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) {
	    TkChangeEventWindow(eventPtr, winPtr2);
	    Tk_QueueWindowEvent(eventPtr, TCL_QUEUE_HEAD);
	    return 0;						/* Note 3. */
	}
    }

    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * TkChangeEventWindow --
 *
 *	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.
 *
 *----------------------------------------------------------------------
 */

void
TkChangeEventWindow(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.height + 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;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TkInOutEvents --
 *
 *	This procedure synthesizes EnterNotify and LeaveNotify events
 *	to correctly transfer the pointer from one window to another.
 *	It can also be used to generate FocusIn and FocusOut events
 *	to move the input focus.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Synthesized events may be pushed back onto the event queue.
 *	The event pointed to by eventPtr is modified.
 *
 *----------------------------------------------------------------------
 */

void
TkInOutEvents(eventPtr, sourcePtr, destPtr, leaveType, enterType, position)
    XEvent *eventPtr;		/* A template X event.  Must have all fields
				 * properly set except for type, window,
				 * subwindow, x, y, detail, and same_screen
				 * (Not all of these fields are valid for
				 * FocusIn/FocusOut events;  x_root and y_root
				 * must be valid for Enter/Leave events, even
				 * though x and y needn't be valid). */
    TkWindow *sourcePtr;	/* Window that used to have the pointer or
				 * focus (NULL means it was not in a window
				 * managed by this process). */
    TkWindow *destPtr;		/* Window that is to end up with the pointer
				 * or focus (NULL means it's not one managed
				 * by this process). */
    int leaveType;		/* Type of events to generate for windows
				 * being left (LeaveNotify or FocusOut).  0
				 * means don't generate leave events. */
    int enterType;		/* Type of events to generate for windows
				 * being entered (EnterNotify or FocusIn).  0
				 * means don't generate enter events. */
    Tcl_QueuePosition position;	/* Position at which events are added to
				 * the system event queue. */
{
    register TkWindow *winPtr;
    int upLevels, downLevels, i, j, focus;

    /*
     * 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;
    }
    if ((leaveType == FocusOut) || (enterType == FocusIn)) {
	focus = 1;
    } else {
	focus = 0;
    }
    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;				\
	if (focus) {					\
	    eventPtr->xfocus.window = w->window;	\
	    eventPtr->xfocus.detail = d;		\
	} else {					\
	    eventPtr->xcrossing.detail = d;		\
	    TkChangeEventWindow(eventPtr, w);		\
	}						\
	Tk_QueueWindowEvent(eventPtr, position);	\
    }

    if (downLevels == 0) {
    
	/*
	 * SourcePtr is an inferior of destPtr.
	 */

	if (leaveType != 0) {
	    QUEUE(sourcePtr, leaveType, NotifyAncestor);
	    for (winPtr = sourcePtr->parentPtr, i = upLevels-1; i > 0;
		    winPtr = winPtr->parentPtr, i--) {
		QUEUE(winPtr, leaveType, NotifyVirtual);
	    }
	}
	if ((enterType != 0) && (destPtr != NULL)) {
	    QUEUE(destPtr, enterType, NotifyInferior);
	}
    } else if (upLevels == 0) {

	/*
	 * DestPtr is an inferior of sourcePtr.
	 */

	if ((leaveType != 0) && (sourcePtr != NULL)) {
	    QUEUE(sourcePtr, leaveType, NotifyInferior);
	}
	if (enterType != 0) {
	    for (i = downLevels-1; i > 0; i--) {
		for (winPtr = destPtr->parentPtr, j = 1; j < i;
			winPtr = winPtr->parentPtr, j++) {
		}
		QUEUE(winPtr, enterType, NotifyVirtual);
	    }
	    if (destPtr != NULL) {
		QUEUE(destPtr, enterType, NotifyAncestor);
	    }
	}
    } else {

	/*
	 * Non-linear:  neither window is an inferior of the other.
	 */

	if (leaveType != 0) {
	    QUEUE(sourcePtr, leaveType, NotifyNonlinear);
	    for (winPtr = sourcePtr->parentPtr, i = upLevels-1; i > 0;
		    winPtr = winPtr->parentPtr, i--) {
		QUEUE(winPtr, leaveType, NotifyNonlinearVirtual);
	    }
	}
	if (enterType != 0) {
	    for (i = downLevels-1; i > 0; i--) {
		for (winPtr = destPtr->parentPtr, j = 1; j < i;
			winPtr = winPtr->parentPtr, j++) {
		}
		QUEUE(winPtr, enterType, NotifyNonlinearVirtual);
	    }
	    if (destPtr != NULL) {
		QUEUE(destPtr, enterType, NotifyNonlinear);
	    }
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * MovePointer2 --
 *
 *	This procedure synthesizes  EnterNotify and LeaveNotify events
 *	to correctly transfer the pointer from one window to another.
 *	It is different from TkInOutEvents in that no template X event
 *	needs to be supplied;  this procedure generates the template
 *	event and calls TkInOutEvents.
 *
 * 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;
    TkInOutEvents(&event, sourcePtr, destPtr, (leaveEvents) ? LeaveNotify : 0,
	    (enterEvents) ? EnterNotify : 0, TCL_QUEUE_MARK);
}

/*
 *----------------------------------------------------------------------
 *
 * 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. */
{