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Diffstat (limited to 'tk8.6/generic/tkGrab.c')
| -rw-r--r-- | tk8.6/generic/tkGrab.c | 1595 |
1 files changed, 1595 insertions, 0 deletions
diff --git a/tk8.6/generic/tkGrab.c b/tk8.6/generic/tkGrab.c new file mode 100644 index 0000000..00d4511 --- /dev/null +++ b/tk8.6/generic/tkGrab.c @@ -0,0 +1,1595 @@ +/* + * tkGrab.c -- + * + * This file provides functions that implement grabs for Tk. + * + * Copyright (c) 1992-1994 The Regents of the University of California. + * Copyright (c) 1994-1997 Sun Microsystems, Inc. + * + * 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" +#elif !defined(MAC_OSX_TK) +#include "tkUnixInt.h" +#endif + +/* + * The grab state machine has four states: ungrabbed, button pressed, grabbed, + * and button pressed while grabbed. In addition, there are three pieces of + * grab state information: the current grab window, the current restrict + * window, and whether the mouse is captured. + * + * The current grab window specifies the point in the Tk window heirarchy + * above which pointer events will not be reported. Any window within the + * subtree below the grab window will continue to receive events as normal. + * Events outside of the grab tree will be reported to the grab window. + * + * If the current restrict window is set, then all pointer events will be + * reported only to the restrict window. The restrict window is normally set + * during an automatic button grab. + * + * The mouse capture state specifies whether the window system will report + * mouse events outside of any Tk toplevels. This is set during a global grab + * or an automatic button grab. + * + * The transitions between different states is given in the following table: + * + * Event\State U B G GB + * ----------- -- -- -- -- + * FirstPress B B GB GB + * Press B B G GB + * Release U B G GB + * LastRelease U U G G + * Grab G G G G + * Ungrab U B U U + * + * Note: U=Ungrabbed, B=Button, G=Grabbed, GB=Grab and Button + * + * In addition, the following conditions are always true: + * + * State\Variable Grab Restrict Capture + * -------------- ---- -------- ------- + * Ungrabbed 0 0 0 + * Button 0 1 1 + * Grabbed 1 0 b/g + * Grab and Button 1 1 1 + * + * Note: 0 means variable is set to NULL, 1 means variable is set to some + * window, b/g means the variable is set to a window if a button is currently + * down or a global grab is in effect. + * + * The final complication to all of this is enter and leave events. In order + * to correctly handle all of the various cases, Tk cannot rely on X + * enter/leave events in all situations. The following describes the correct + * sequence of enter and leave events that should be observed by Tk scripts: + * + * Event(state) Enter/Leave From -> To + * ------------ ---------------------- + * LastRelease(B | GB): restrict window -> anc(grab window, event window) + * Grab(U | B): event window -> anc(grab window, event window) + * Grab(G): anc(old grab window, event window) -> + * anc(new grab window, event window) + * Grab(GB): restrict window -> anc(new grab window, event window) + * Ungrab(G): anc(grab window, event window) -> event window + * Ungrab(GB): restrict window -> event window + * + * Note: anc(x,y) returns the least ancestor of y that is in the tree of x, + * terminating at toplevels. + */ + +/* + * The following structure is used to pass information to GrabRestrictProc + * from EatGrabEvents. + */ + +typedef struct { + Display *display; /* Display from which to discard events. */ + unsigned int serial; /* Serial number with which to compare. */ +} GrabInfo; + +/* + * 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_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_TEMP_GLOBAL 4 + +/* + * The following structure is a Tcl_Event that triggers a change in the + * grabWinPtr field of a display. This event guarantees that the change occurs + * in the proper order relative to enter and leave events. + */ + +typedef struct NewGrabWinEvent { + Tcl_Event header; /* Standard information for all Tcl events. */ + TkDisplay *dispPtr; /* Display whose grab window is to change. */ + Window grabWindow; /* New grab window for display. This is + * recorded instead of a (TkWindow *) because + * it will allow us to detect cases where the + * window is destroyed before this event is + * processed. */ +} NewGrabWinEvent; + +/* + * 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_GRAB_EVENT_MAGIC ((Bool) 0x147321ac) + +/* + * 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 const unsigned int buttonStates[] = { + Button1Mask, Button2Mask, Button3Mask, Button4Mask, Button5Mask +}; + +/* + * Forward declarations for functions declared later in this file: + */ + +static void EatGrabEvents(TkDisplay *dispPtr, unsigned int serial); +static TkWindow * FindCommonAncestor(TkWindow *winPtr1, + TkWindow *winPtr2, int *countPtr1, int *countPtr2); +static Tk_RestrictProc GrabRestrictProc; +static int GrabWinEventProc(Tcl_Event *evPtr, int flags); +static void MovePointer2(TkWindow *sourcePtr, TkWindow *destPtr, + int mode, int leaveEvents, int EnterEvents); +static void QueueGrabWindowChange(TkDisplay *dispPtr, + TkWindow *grabWinPtr); +static void ReleaseButtonGrab(TkDisplay *dispPtr); + +/* + *---------------------------------------------------------------------- + * + * Tk_GrabObjCmd -- + * + * This function 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_GrabObjCmd( + ClientData clientData, /* Main window associated with interpreter. */ + Tcl_Interp *interp, /* Current interpreter. */ + int objc, /* Number of arguments. */ + Tcl_Obj *const objv[]) /* Argument objects. */ +{ + int globalGrab; + Tk_Window tkwin; + TkDisplay *dispPtr; + const char *arg; + int index; + int len; + static const char *const optionStrings[] = { + "current", "release", "set", "status", NULL + }; + static const char *const flagStrings[] = { + "-global", NULL + }; + enum options { + GRABCMD_CURRENT, GRABCMD_RELEASE, GRABCMD_SET, GRABCMD_STATUS + }; + + if (objc < 2) { + /* + * Can't use Tcl_WrongNumArgs here because we want the message to + * read: + * wrong # args: should be "cmd ?-global? window" or "cmd option + * ?arg ...?" + * We can fake it with Tcl_WrongNumArgs if we assume the command name + * is "grab", but if it has been aliased, the message will be + * incorrect. + */ + + Tcl_WrongNumArgs(interp, 1, objv, "?-global? window"); + Tcl_AppendResult(interp, " or \"", Tcl_GetString(objv[0]), + " option ?arg ...?\"", NULL); + /* This API not exposed: + * + ((Interp *) interp)->flags |= INTERP_ALTERNATE_WRONG_ARGS; + Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?"); + */ + return TCL_ERROR; + } + + /* + * First check for a window name or "-global" as the first argument. + */ + + arg = Tcl_GetStringFromObj(objv[1], &len); + if (arg[0] == '.') { + /* [grab window] */ + if (objc != 2) { + Tcl_WrongNumArgs(interp, 1, objv, "?-global? window"); + return TCL_ERROR; + } + tkwin = Tk_NameToWindow(interp, arg, clientData); + if (tkwin == NULL) { + return TCL_ERROR; + } + return Tk_Grab(interp, tkwin, 0); + } else if (arg[0] == '-' && len > 1) { + if (Tcl_GetIndexFromObj(interp, objv[1], flagStrings, "option", 0, + &index) != TCL_OK) { + return TCL_ERROR; + } + + /* [grab -global window] */ + if (objc != 3) { + Tcl_WrongNumArgs(interp, 1, objv, "?-global? window"); + return TCL_ERROR; + } + tkwin = Tk_NameToWindow(interp, Tcl_GetString(objv[2]), clientData); + if (tkwin == NULL) { + return TCL_ERROR; + } + return Tk_Grab(interp, tkwin, 1); + } + + /* + * First argument is not a window name and not "-global", find out which + * option it is. + */ + + if (Tcl_GetIndexFromObj(interp, objv[1], optionStrings, "option", 0, + &index) != TCL_OK) { + return TCL_ERROR; + } + + switch ((enum options) index) { + case GRABCMD_CURRENT: + /* [grab current ?window?] */ + if (objc > 3) { + Tcl_WrongNumArgs(interp, 1, objv, "current ?window?"); + return TCL_ERROR; + } + if (objc == 3) { + tkwin = Tk_NameToWindow(interp, Tcl_GetString(objv[2]), + clientData); + if (tkwin == NULL) { + return TCL_ERROR; + } + dispPtr = ((TkWindow *) tkwin)->dispPtr; + if (dispPtr->eventualGrabWinPtr != NULL) { + Tcl_SetObjResult(interp, TkNewWindowObj((Tk_Window) + dispPtr->eventualGrabWinPtr)); + } + } else { + Tcl_Obj *resultObj = Tcl_NewObj(); + + for (dispPtr = TkGetDisplayList(); dispPtr != NULL; + dispPtr = dispPtr->nextPtr) { + if (dispPtr->eventualGrabWinPtr != NULL) { + Tcl_ListObjAppendElement(NULL, resultObj, TkNewWindowObj( + (Tk_Window) dispPtr->eventualGrabWinPtr)); + } + } + Tcl_SetObjResult(interp, resultObj); + } + return TCL_OK; + + case GRABCMD_RELEASE: + /* [grab release window] */ + if (objc != 3) { + Tcl_WrongNumArgs(interp, 1, objv, "release window"); + return TCL_ERROR; + } + tkwin = Tk_NameToWindow(interp, Tcl_GetString(objv[2]), clientData); + if (tkwin == NULL) { + Tcl_ResetResult(interp); + } else { + Tk_Ungrab(tkwin); + } + break; + + case GRABCMD_SET: + /* [grab set ?-global? window] */ + if ((objc != 3) && (objc != 4)) { + Tcl_WrongNumArgs(interp, 1, objv, "set ?-global? window"); + return TCL_ERROR; + } + if (objc == 3) { + globalGrab = 0; + tkwin = Tk_NameToWindow(interp, Tcl_GetString(objv[2]), + clientData); + } else { + globalGrab = 1; + + /* + * We could just test the argument by hand instead of using + * Tcl_GetIndexFromObj; the benefit of using the function is that + * it sets up the error message for us, so we are certain to be + * consistant with the rest of Tcl. + */ + + if (Tcl_GetIndexFromObj(interp, objv[2], flagStrings, "option", + 0, &index) != TCL_OK) { + return TCL_ERROR; + } + tkwin = Tk_NameToWindow(interp, Tcl_GetString(objv[3]), + clientData); + } + if (tkwin == NULL) { + return TCL_ERROR; + } + return Tk_Grab(interp, tkwin, globalGrab); + + case GRABCMD_STATUS: { + /* [grab status window] */ + TkWindow *winPtr; + const char *statusString; + + if (objc != 3) { + Tcl_WrongNumArgs(interp, 1, objv, "status window"); + return TCL_ERROR; + } + winPtr = (TkWindow *) Tk_NameToWindow(interp, Tcl_GetString(objv[2]), + clientData); + if (winPtr == NULL) { + return TCL_ERROR; + } + dispPtr = winPtr->dispPtr; + if (dispPtr->eventualGrabWinPtr != winPtr) { + statusString = "none"; + } else if (dispPtr->grabFlags & GRAB_GLOBAL) { + statusString = "global"; + } else { + statusString = "local"; + } + Tcl_SetObjResult(interp, Tcl_NewStringObj(statusString, -1)); + break; + } + } + + 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 the + * interp's 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( + 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, numTries; + 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) { + goto alreadyGrabbed; + } + Tk_Ungrab((Tk_Window) dispPtr->eventualGrabWinPtr); + } + + Tk_MakeWindowExist(tkwin); +#ifndef MAC_OSX_TK + if (!grabGlobal) +#else + if (0) +#endif /* MAC_OSX_TK */ + { + 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) { + 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); + + /* + * Another tricky point: there are races with some window managers + * that can cause grabs to fail because the window manager hasn't + * released its grab quickly enough. To work around this problem, + * retry a few times after AlreadyGrabbed errors to give the grab + * release enough time to register with the server. + */ + + grabResult = 0; /* Needed only to prevent gcc compiler + * warnings. */ + for (numTries = 0; numTries < 10; numTries++) { + grabResult = XGrabPointer(dispPtr->display, winPtr->window, + True, ButtonPressMask|ButtonReleaseMask|ButtonMotionMask + |PointerMotionMask, GrabModeAsync, GrabModeAsync, None, + None, CurrentTime); + if (grabResult != AlreadyGrabbed) { + break; + } + Tcl_Sleep(100); + } + if (grabResult != 0) { + goto grabError; + } + 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; + + grabError: + if (grabResult == GrabNotViewable) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "grab failed: window not viewable", -1)); + Tcl_SetErrorCode(interp, "TK", "GRAB", "UNVIEWABLE", NULL); + } else if (grabResult == AlreadyGrabbed) { + alreadyGrabbed: + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "grab failed: another application has grab", -1)); + Tcl_SetErrorCode(interp, "TK", "GRAB", "GRABBED", NULL); + } else if (grabResult == GrabFrozen) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "grab failed: keyboard or pointer frozen", -1)); + Tcl_SetErrorCode(interp, "TK", "GRAB", "FROZEN", NULL); + } else if (grabResult == GrabInvalidTime) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "grab failed: invalid time", -1)); + Tcl_SetErrorCode(interp, "TK", "GRAB", "BAD_TIME", NULL); + } else { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "grab failed for unknown reason (code %d)", grabResult)); + Tcl_SetErrorCode(interp, "TK", "GRAB", "UNKNOWN", NULL); + } + return TCL_ERROR; +} + +/* + *---------------------------------------------------------------------- + * + * 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( + Tk_Window tkwin) /* Window whose grab should be released. */ +{ + TkDisplay *dispPtr; + TkWindow *grabWinPtr, *winPtr; + unsigned int serial; + + grabWinPtr = (TkWindow *) tkwin; + dispPtr = grabWinPtr->dispPtr; + if (grabWinPtr != dispPtr->eventualGrabWinPtr) { + return; + } + ReleaseButtonGrab(dispPtr); + QueueGrabWindowChange(dispPtr, 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 function 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( + 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 function 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 function 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( + 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. */ + + /* + * Collect information about the grab (if any). + */ + + switch (TkGrabState(winPtr)) { + case TK_GRAB_IN_TREE: + appGrabbed = 1; + break; + case TK_GRAB_ANCESTOR: + appGrabbed = 1; + outsideGrabTree = 1; + ancestorOfGrab = 1; + break; + case TK_GRAB_EXCLUDED: + appGrabbed = 1; + outsideGrabTree = 1; + 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_GRAB_EVENT_MAGIC) { + if ((eventPtr->type == LeaveNotify) && + (winPtr->flags & TK_TOP_HIERARCHY)) { + 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) { + TkChangeEventWindow(eventPtr, winPtr2); + Tk_QueueWindowEvent(eventPtr, TCL_QUEUE_HEAD); + 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)) { + 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( + 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_HIERARCHY) { + 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 function 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( + 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++) { + /* empty */ + } + 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 function 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 function generates the template event and calls + * TkInOutEvents. + * + * Results: + * None. + * + * Side effects: + * Synthesized events may be pushed back onto the event queue. + * + *---------------------------------------------------------------------- + */ + +static void +MovePointer2( + 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_GRAB_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 function 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( + 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_HIERARCHY) { + dispPtr->serverWinPtr = NULL; + } else { + dispPtr->serverWinPtr = winPtr->parentPtr; + } + } + if (dispPtr->grabWinPtr == winPtr) { + dispPtr->grabWinPtr = NULL; + } +} + +/* + *---------------------------------------------------------------------- + * + * EatGrabEvents -- + * + * This function 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 and are not generated by the grab module. + * + * Results: + * None. + * + * Side effects: + * DispPtr's display gets sync-ed, and some of the events get removed + * from the Tk event queue. + * + *---------------------------------------------------------------------- + */ + +static void +EatGrabEvents( + TkDisplay *dispPtr, /* Display from which to consume events. */ + unsigned int serial) /* Only discard events that have a serial + * number at least this great. */ +{ + Tk_RestrictProc *prevProc; + GrabInfo info; + ClientData prevArg; + + info.display = dispPtr->display; + info.serial = serial; + TkpSync(info.display); + prevProc = Tk_RestrictEvents(GrabRestrictProc, &info, &prevArg); + while (Tcl_ServiceEvent(TCL_WINDOW_EVENTS)) { + /* EMPTY */ + } + Tk_RestrictEvents(prevProc, prevArg, &prevArg); +} + +/* + *---------------------------------------------------------------------- + * + * GrabRestrictProc -- + * + * A Tk_RestrictProc used by EatGrabEvents to eliminate any Enter, Leave, + * FocusIn, or FocusOut events in the event queue for a display that has + * mode NotifyGrab or NotifyUngrab and have a serial number no less than + * a given value. + * + * Results: + * Returns either TK_DISCARD_EVENT or TK_DEFER_EVENT. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static Tk_RestrictAction +GrabRestrictProc( + ClientData arg, + XEvent *eventPtr) +{ + GrabInfo *info = arg; + int mode, diff; + + /* + * 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 - info->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 ((info->display != eventPtr->xany.display) || (mode == NotifyNormal) + || (diff < 0)) { + return TK_DEFER_EVENT; + } else { + return TK_DISCARD_EVENT; + } +} + +/* + *---------------------------------------------------------------------- + * + * QueueGrabWindowChange -- + * + * This function queues a special event in the Tcl event queue, which + * will cause the "grabWinPtr" field for the display to get modified when + * the event is processed. This 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 GrabWinEventProc) when + * the event is removed from the grab event queue. + * + *---------------------------------------------------------------------- + */ + +static void +QueueGrabWindowChange( + TkDisplay *dispPtr, /* Display on which to change the grab + * window. */ + TkWindow *grabWinPtr) /* Window that is to become the new grab + * window (may be NULL). */ +{ + NewGrabWinEvent *grabEvPtr; + + grabEvPtr = ckalloc(sizeof(NewGrabWinEvent)); + grabEvPtr->header.proc = GrabWinEventProc; + grabEvPtr->dispPtr = dispPtr; + if (grabWinPtr == NULL) { + grabEvPtr->grabWindow = None; + } else { + grabEvPtr->grabWindow = grabWinPtr->window; + } + Tcl_QueueEvent(&grabEvPtr->header, TCL_QUEUE_MARK); + dispPtr->eventualGrabWinPtr = grabWinPtr; +} + +/* + *---------------------------------------------------------------------- + * + * GrabWinEventProc -- + * + * This function is invoked as a handler for Tcl_Events of type + * NewGrabWinEvent. It updates the current grab window field in a + * display. + * + * Results: + * Returns 1 if the event was processed, 0 if it should be deferred for + * processing later. + * + * Side effects: + * The grabWinPtr field is modified in the display associated with the + * event. + * + *---------------------------------------------------------------------- + */ + +static int +GrabWinEventProc( + Tcl_Event *evPtr, /* Event of type NewGrabWinEvent. */ + int flags) /* Flags argument to Tk_DoOneEvent: indicates + * what kinds of events are being processed + * right now. */ +{ + NewGrabWinEvent *grabEvPtr = (NewGrabWinEvent *) evPtr; + + grabEvPtr->dispPtr->grabWinPtr = (TkWindow *) Tk_IdToWindow( + grabEvPtr->dispPtr->display, grabEvPtr->grabWindow); + return 1; +} + +/* + *---------------------------------------------------------------------- + * + * FindCommonAncestor -- + * + * Given two windows, this function 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( + 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 != NULL; winPtr = winPtr->parentPtr) { + winPtr->flags |= TK_GRAB_FLAG; + if (winPtr->flags & TK_TOP_HIERARCHY) { + 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 (; winPtr != NULL; count2++, winPtr = winPtr->parentPtr) { + if (winPtr->flags & TK_GRAB_FLAG) { + ancestorPtr = winPtr; + break; + } + if (winPtr->flags & TK_TOP_HIERARCHY) { + 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; winPtr != NULL; + i++, winPtr = winPtr->parentPtr) { + winPtr->flags &= ~TK_GRAB_FLAG; + if (winPtr == ancestorPtr) { + count1 = i; + } + if (winPtr->flags & TK_TOP_HIERARCHY) { + if (count1 == -1) { + count1 = i+1; + } + break; + } + } + } + + *countPtr1 = count1; + *countPtr2 = count2; + return ancestorPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TkPositionInTree -- + * + * Compute where the given window is relative to a particular subtree of + * the window hierarchy. + * + * Results: + * Returns TK_GRAB_IN_TREE if the window is contained in the subtree. + * Returns TK_GRAB_ANCESTOR if the window is an ancestor of the subtree, + * in the same toplevel. Otherwise it returns TK_GRAB_EXCLUDED. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkPositionInTree( + TkWindow *winPtr, /* Window to be checked. */ + TkWindow *treePtr) /* Root of tree to compare against. */ +{ + TkWindow *winPtr2; + + for (winPtr2 = winPtr; winPtr2 != treePtr; + winPtr2 = winPtr2->parentPtr) { + if (winPtr2 == NULL) { + for (winPtr2 = treePtr; winPtr2 != NULL; + winPtr2 = winPtr2->parentPtr) { + if (winPtr2 == winPtr) { + return TK_GRAB_ANCESTOR; + } + if (winPtr2->flags & TK_TOP_HIERARCHY) { + break; + } + } + return TK_GRAB_EXCLUDED; + } + } + return TK_GRAB_IN_TREE; +} + +/* + *---------------------------------------------------------------------- + * + * TkGrabState -- + * + * Given a window, this function returns a value that indicates the grab + * state of the application relative to the window. + * + * Results: + * The return value is one of three things: + * TK_GRAB_NONE - no grab is in effect. + * TK_GRAB_IN_TREE - there is a grab in effect, and winPtr is in + * the grabbed subtree. + * TK_GRAB_ANCESTOR - there is a grab in effect; winPtr is an + * ancestor of the grabbed window, in the same + * toplevel. + * TK_GRAB_EXCLUDED - there is a grab in effect; winPtr is outside + * the tree of the grab and is not an ancestor of + * the grabbed window in the same toplevel. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkGrabState( + TkWindow *winPtr) /* Window for which grab information is + * needed. */ +{ + TkWindow *grabWinPtr = winPtr->dispPtr->grabWinPtr; + + if (grabWinPtr == NULL) { + return TK_GRAB_NONE; + } + if ((winPtr->mainPtr != grabWinPtr->mainPtr) + && !(winPtr->dispPtr->grabFlags & GRAB_GLOBAL)) { + return TK_GRAB_NONE; + } + + return TkPositionInTree(winPtr, grabWinPtr); +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |