path: root/generic/tkPointer.c

/*
 * tkPointer.c --
 *
 *	This file contains functions for emulating the X server pointer and
 *	grab state machine. This file is used by the Mac and Windows platforms
 *	to generate appropriate enter/leave events, and to update the global
 *	grab window information.
 *
 * Copyright © 1996 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tkInt.h"

#ifdef _WIN32
#include "tkWinInt.h"
#endif

#if defined(MAC_OSX_TK)
#include "tkMacOSXInt.h"
#endif

typedef struct {
    TkWindow *grabWinPtr;	/* Window that defines the top of the grab
				 * tree in a global grab. */
    unsigned lastState;		/* Last known state flags. */
    XPoint lastPos;		/* Last reported mouse position. */
    TkWindow *lastWinPtr;	/* Last reported mouse window. */
    TkWindow *restrictWinPtr;	/* Window to which all mouse events will be
				 * reported. */
    TkWindow *cursorWinPtr;	/* Window that is currently controlling the
				 * global cursor. */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;

/*
 * Forward declarations of procedures used in this file.
 */

static int		GenerateEnterLeave(TkWindow *winPtr, int x, int y,
			    int state);
static void		InitializeEvent(XEvent *eventPtr, TkWindow *winPtr,
			    int type, int x, int y, int state, int detail);
static void		UpdateCursor(TkWindow *winPtr);

/*
 *----------------------------------------------------------------------
 *
 * InitializeEvent --
 *
 *	Initializes the common fields for several X events.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Fills in the specified event structure.
 *
 *----------------------------------------------------------------------
 */

static void
InitializeEvent(
    XEvent *eventPtr,		/* Event structure to initialize. */
    TkWindow *winPtr,		/* Window to make event relative to. */
    int type,			/* Message type. */
    int x, int y,		/* Root coords of event. */
    int state,			/* State flags. */
    int detail)			/* Detail value. */
{
    eventPtr->type = type;
    eventPtr->xany.serial = LastKnownRequestProcessed(winPtr->display);
    eventPtr->xany.send_event = False;
    eventPtr->xany.display = winPtr->display;

    eventPtr->xcrossing.root = RootWindow(winPtr->display, winPtr->screenNum);
    eventPtr->xcrossing.time = TkpGetMS();
    eventPtr->xcrossing.x_root = x;
    eventPtr->xcrossing.y_root = y;

    switch (type) {
    case EnterNotify:
    case LeaveNotify:
	eventPtr->xcrossing.mode = NotifyNormal;
	eventPtr->xcrossing.state = state;
	eventPtr->xcrossing.detail = detail;
	eventPtr->xcrossing.focus = False;
	break;
    case MotionNotify:
	eventPtr->xmotion.state = state;
	eventPtr->xmotion.is_hint = detail;
	break;
    case ButtonPress:
    case ButtonRelease:
	eventPtr->xbutton.state = state;
	eventPtr->xbutton.button = detail;
	break;
    }
    TkChangeEventWindow(eventPtr, winPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * GenerateEnterLeave --
 *
 *	Update the current mouse window and position, and generate any
 *	enter/leave events that are needed.
 *
 * Results:
 *	Returns 1 if enter/leave events were generated.
 *
 * Side effects:
 *	May insert events into the Tk event queue.
 *
 *----------------------------------------------------------------------
 */

static int
GenerateEnterLeave(
    TkWindow *winPtr,		/* Current Tk window (or NULL). */
    int x, int y,		/* Current mouse position in root coords. */
    int state)			/* State flags. */
{
    int crossed = 0;		/* 1 if mouse crossed a window boundary */
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    TkWindow *restrictWinPtr = tsdPtr->restrictWinPtr;
    TkWindow *lastWinPtr = tsdPtr->lastWinPtr;

    if (winPtr != tsdPtr->lastWinPtr) {
	if (restrictWinPtr) {
	    int newPos, oldPos;

	    newPos = TkPositionInTree(winPtr, restrictWinPtr);
	    oldPos = TkPositionInTree(lastWinPtr, restrictWinPtr);

	    /*
	     * Check if the mouse crossed into or out of the restrict window.
	     * If so, we need to generate an Enter or Leave event.
	     */

	    if ((newPos != oldPos) && ((newPos == TK_GRAB_IN_TREE)
		    || (oldPos == TK_GRAB_IN_TREE))) {
		XEvent event;
		int type, detail;

		if (newPos == TK_GRAB_IN_TREE) {
		    type = EnterNotify;
		} else {
		    type = LeaveNotify;
		}
		if ((oldPos == TK_GRAB_ANCESTOR)
			|| (newPos == TK_GRAB_ANCESTOR)) {
		    detail = NotifyAncestor;
		} else {
		    detail = NotifyVirtual;
		}
		InitializeEvent(&event, restrictWinPtr, type, x, y,
			state, detail);
		Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
	    }

	} else {
	    TkWindow *targetPtr;

	    if ((lastWinPtr == NULL)
		|| (lastWinPtr->window == None)) {
		targetPtr = winPtr;
	    } else {
		targetPtr = lastWinPtr;
	    }

	    if (targetPtr && (targetPtr->window != None)) {
		XEvent event;

		/*
		 * Generate appropriate Enter/Leave events.
		 */

		InitializeEvent(&event, targetPtr, LeaveNotify, x, y, state,
			NotifyNormal);

		TkInOutEvents(&event, lastWinPtr, winPtr, LeaveNotify,
			EnterNotify, TCL_QUEUE_TAIL);
		crossed = 1;
	    }
	}
	tsdPtr->lastWinPtr = winPtr;
    }

    return crossed;
}

/*
 *----------------------------------------------------------------------
 *
 * Tk_UpdatePointer --
 *
 *	This function updates the pointer state machine given an the current
 *	window, position and modifier state.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May queue new events and update the grab state.
 *
 *----------------------------------------------------------------------
 */

void
Tk_UpdatePointer(
    Tk_Window tkwin,		/* Window to which pointer event is reported.
				 * May be NULL. */
    int x, int y,		/* Pointer location in root coords. */
    int state)			/* Modifier state mask. */
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    TkWindow *winPtr = (TkWindow *)tkwin;
    TkWindow *targetWinPtr;
    XPoint pos;
    XEvent event;
    unsigned changes = (state ^ tsdPtr->lastState) & ALL_BUTTONS;
    int type, b;
    unsigned mask;

    pos.x = x;
    pos.y = y;

    /*
     * Use the current keyboard state, but the old mouse button state since we
     * haven't generated the button events yet.
     */

    tsdPtr->lastState = (state & ~ALL_BUTTONS) | (tsdPtr->lastState
	    & ALL_BUTTONS);

    /*
     * Generate Enter/Leave events. If the pointer has crossed window
     * boundaries, update the current mouse position so we don't generate
     * redundant motion events.
     */

    if (GenerateEnterLeave(winPtr, x, y, tsdPtr->lastState)) {
	tsdPtr->lastPos = pos;
    }

    /*
     * Generate ButtonPress/ButtonRelease events based on the differences
     * between the current button state and the last known button state.
     */

    for (b = Button1; b <= Button9; b++) {
	mask = Tk_GetButtonMask(b);
	if (changes & mask) {
	    if (state & mask) {
		type = ButtonPress;

		/*
		 * ButtonPress - Set restrict window if we aren't grabbed, or
		 * if this is the first button down.
		 */

		if (!tsdPtr->restrictWinPtr) {
		    if (!tsdPtr->grabWinPtr) {
			/*
			 * Mouse is not grabbed, so set a button grab.
			 */

			tsdPtr->restrictWinPtr = winPtr;
			TkpSetCapture(tsdPtr->restrictWinPtr);

		    } else if (!(tsdPtr->lastState & ALL_BUTTONS)) {
			/*
			 * Mouse is in a non-button grab, so ensure the button
			 * grab is inside the grab tree.
			 */

			if (TkPositionInTree(winPtr, tsdPtr->grabWinPtr)
				== TK_GRAB_IN_TREE) {
			    tsdPtr->restrictWinPtr = winPtr;
			} else {
			    tsdPtr->restrictWinPtr = tsdPtr->grabWinPtr;
			}
			TkpSetCapture(tsdPtr->restrictWinPtr);
		    }
		}

	    } else {
		type = ButtonRelease;

		/*
		 * ButtonRelease - Release the mouse capture and clear the
		 * restrict window when the last button is released. If we
		 * are in a global grab, restore the grab window capture.
		 */

		if ((tsdPtr->lastState & ALL_BUTTONS) == mask) {
		    TkpSetCapture(tsdPtr->grabWinPtr);
		}

		/*
		 * If we are releasing a restrict window, then we need to send
		 * the button event followed by mouse motion from the restrict
		 * window to the current mouse position.
		 */

		if (tsdPtr->restrictWinPtr) {
		    InitializeEvent(&event, tsdPtr->restrictWinPtr, type, x, y,
			    tsdPtr->lastState, b);
		    Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
		    tsdPtr->lastState &= ~mask;
		    tsdPtr->lastWinPtr = tsdPtr->restrictWinPtr;
		    tsdPtr->restrictWinPtr = NULL;

		    GenerateEnterLeave(winPtr, x, y, tsdPtr->lastState);
		    tsdPtr->lastPos = pos;
		    continue;
		}
	    }

	    /*
	     * If a restrict window is set, make sure the pointer event is
	     * reported relative to that window. Otherwise, if a global grab
	     * is in effect then events outside of windows managed by Tk
	     * should be reported to the grab window.
	     */

	    if (tsdPtr->restrictWinPtr) {
		targetWinPtr = tsdPtr->restrictWinPtr;
	    } else if (tsdPtr->grabWinPtr && !winPtr) {
		targetWinPtr = tsdPtr->grabWinPtr;
	    } else {
		targetWinPtr = winPtr;
	    }

	    /*
	     * If we still have a target window, send the event.
	     */

	    if (targetWinPtr != NULL) {
		InitializeEvent(&event, targetWinPtr, type, x, y,
			tsdPtr->lastState, b);
		Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
	    }

	    /*
	     * Update the state for the next iteration.
	     */

	    tsdPtr->lastState = (type == ButtonPress)
		    ? (tsdPtr->lastState | mask) : (tsdPtr->lastState & ~mask);
	    tsdPtr->lastPos = pos;
	}
    }

    /*
     * Make sure the cursor window is up to date.
     */

    if (tsdPtr->restrictWinPtr) {
	targetWinPtr = tsdPtr->restrictWinPtr;
    } else if (tsdPtr->grabWinPtr) {
	targetWinPtr = (TkPositionInTree(winPtr, tsdPtr->grabWinPtr)
		== TK_GRAB_IN_TREE) ? winPtr : tsdPtr->grabWinPtr;
    } else {
	targetWinPtr = winPtr;
    }
    UpdateCursor(targetWinPtr);

    /*
     * If no other events caused the position to be updated, generate a motion
     * event.
     */

    if (tsdPtr->lastPos.x != pos.x || tsdPtr->lastPos.y != pos.y) {
	if (tsdPtr->restrictWinPtr) {
	    targetWinPtr = tsdPtr->restrictWinPtr;
	} else if (tsdPtr->grabWinPtr && !winPtr) {
	    targetWinPtr = tsdPtr->grabWinPtr;
	}

	if (targetWinPtr != NULL) {
	    InitializeEvent(&event, targetWinPtr, MotionNotify, x, y,
		    tsdPtr->lastState, NotifyNormal);
	    Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
	}
	tsdPtr->lastPos = pos;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * XGrabPointer --
 *
 *	Capture the mouse so event are reported outside of toplevels. Note
 *	that this is a very limited implementation that only supports
 *	GrabModeAsync and owner_events True.
 *
 * Results:
 *	Always returns GrabSuccess.
 *
 * Side effects:
 *	Turns on mouse capture, sets the global grab pointer, and clears any
 *	window restrictions.
 *
 *----------------------------------------------------------------------
 */

int
XGrabPointer(
    Display *display,
    Window grab_window,
    Bool owner_events,
    unsigned int event_mask,
    int pointer_mode,
    int keyboard_mode,
    Window confine_to,
    Cursor cursor,
    Time time)
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    (void)owner_events;
    (void)event_mask;
    (void)pointer_mode;
    (void)keyboard_mode;
    (void)confine_to;
    (void)cursor;
    (void)time;

    LastKnownRequestProcessed(display)++;
    tsdPtr->grabWinPtr = (TkWindow *) Tk_IdToWindow(display, grab_window);
    tsdPtr->restrictWinPtr = NULL;
    TkpSetCapture(tsdPtr->grabWinPtr);
    if (TkPositionInTree(tsdPtr->lastWinPtr, tsdPtr->grabWinPtr)
	    != TK_GRAB_IN_TREE) {
	UpdateCursor(tsdPtr->grabWinPtr);
    }
    return GrabSuccess;
}

/*
 *----------------------------------------------------------------------
 *
 * XUngrabPointer --
 *
 *	Release the current grab.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Releases the mouse capture.
 *
 *----------------------------------------------------------------------
 */

int
XUngrabPointer(
    Display *display,
    Time time)
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    (void)time;

    LastKnownRequestProcessed(display)++;
    tsdPtr->grabWinPtr = NULL;
    tsdPtr->restrictWinPtr = NULL;
    TkpSetCapture(NULL);
    UpdateCursor(tsdPtr->lastWinPtr);
    return Success;
}

/*
 *----------------------------------------------------------------------
 *
 * TkPointerDeadWindow --
 *
 *	Clean up pointer module state when a window is destroyed.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May release the current capture window.
 *
 *----------------------------------------------------------------------
 */

void
TkPointerDeadWindow(
    TkWindow *winPtr)
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));

    if (winPtr == tsdPtr->lastWinPtr) {
	tsdPtr->lastWinPtr = TkGetContainer(winPtr);
    }
    if (winPtr == tsdPtr->grabWinPtr) {
	tsdPtr->grabWinPtr = NULL;
    }
    if (winPtr == tsdPtr->restrictWinPtr) {
	tsdPtr->restrictWinPtr = NULL;
    }
    if (!(tsdPtr->restrictWinPtr || tsdPtr->grabWinPtr)) {

        /*
         * Release mouse capture only if the dead window is the capturing
         * window.
         */

        if (winPtr == (TkWindow *)TkpGetCapture()) {
	    TkpSetCapture(NULL);
        }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * UpdateCursor --
 *
 *	Set the windows global cursor to the cursor associated with the given
 *	Tk window.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Changes the mouse cursor.
 *
 *----------------------------------------------------------------------
 */

static void
UpdateCursor(
    TkWindow *winPtr)
{
    Cursor cursor = None;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));

    /*
     * A window inherits its cursor from its parent if it doesn't have one of
     * its own. Top level windows inherit the default cursor.
     */

    tsdPtr->cursorWinPtr = winPtr;
    while (winPtr != NULL) {
	if (winPtr->atts.cursor != None) {
	    cursor = winPtr->atts.cursor;
	    break;
	} else if (winPtr->flags & TK_TOP_HIERARCHY) {
	    break;
	}
	winPtr = winPtr->parentPtr;
    }
    TkpSetCursor((TkpCursor) cursor);
}

/*
 *----------------------------------------------------------------------
 *
 * XDefineCursor --
 *
 *	This function is called to update the cursor on a window. Since the
 *	mouse might be in the specified window, we need to check the specified
 *	window against the current mouse position and grab state.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May update the cursor.
 *
 *----------------------------------------------------------------------
 */

int
XDefineCursor(
    Display *display,
    Window w,
    Cursor cursor)
{
    TkWindow *winPtr = (TkWindow *) Tk_IdToWindow(display, w);
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    (void)cursor;

    if (tsdPtr->cursorWinPtr == winPtr) {
	UpdateCursor(winPtr);
    }
    LastKnownRequestProcessed(display)++;
    return Success;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */