/* * tkGrab.c -- * * This file provides functions that implement grabs for Tk. * * Copyright © 1992-1994 The Regents of the University of California. * Copyright © 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" #else #include "tkMacOSXInt.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 hierarchy * 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) /* * 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. * *---------------------------------------------------------------------- */ 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; Tcl_Size 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, (Tk_Window)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]), (Tk_Window)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]), (Tk_Window)clientData); if (tkwin == NULL) { return TCL_ERROR; } dispPtr = ((TkWindow *) tkwin)->dispPtr; if (dispPtr->eventualGrabWinPtr != NULL) { Tcl_SetObjResult(interp, Tk_NewWindowObj((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, Tk_NewWindowObj( (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]), (Tk_Window)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]), (Tk_Window)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]), (Tk_Window)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]), (Tk_Window)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); 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) { 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( 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. * Also, this function takes care of warping the mouse pointer with * respect to a given window, both when there is a grab in effect and * when there is none. * * 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. * The mouse pointer may be moved. * *---------------------------------------------------------------------- */ int TkPointerEvent( XEvent *eventPtr, /* Pointer to the event. */ TkWindow *winPtr) /* Tk's information for window where event was * reported. */ { 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 ((eventPtr->type == MotionNotify) && !appGrabbed) { /* * Warp the mouse pointer with respect to window dispPtr->warpWindow * if such a window was set in HandleEventGenerate. */ TkDoWarpWrtWin(dispPtr); } if (!appGrabbed) { return 1; } /* * From this point on, there is a grab in effect. */ 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; } /* * Warp the mouse pointer with respect to window dispPtr->warpWindow * if such a window was set in HandleEventGenerate. */ TkDoWarpWrtWin(dispPtr); 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.button != AnyButton && ((eventPtr->xbutton.state & ALL_BUTTONS) == Tk_GetButtonMask(eventPtr->xbutton.button))) { 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( 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; 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. */ { 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( 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 = (GrabInfo *)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 = (NewGrabWinEvent *)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. */ TCL_UNUSED(int)) /* Flags argument to Tcl_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. */ { 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: */