git.zerfleddert.de Git - micropolis/blob - src/tk/tkshare.c

   1 /*
   2  * tkShare.c --
   3  *
   4  *      This module implements a simple mechanism for sharing
   5  *      mouse- and button-related events among collections of
   6  *      windows.  It is used primarily for menus.  For example,
   7  *      if one menu is posted and mouse moves over the menu button
   8  *      for a different menu, then the menubutton needs to see the
   9  *      event so that it can post itself and unpost the first menu.
  10  *
  11  * Copyright 1990-1992 Regents of the University of California
  12  * Permission to use, copy, modify, and distribute this
  13  * software and its documentation for any purpose and without
  14  * fee is hereby granted, provided that the above copyright
  15  * notice appear in all copies.  The University of California
  16  * makes no representations about the suitability of this
  17  * software for any purpose.  It is provided "as is" without
  18  * express or implied warranty.
  19  */
  20
  21 #ifndef lint
  22 static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkShare.c,v 1.10 92/05/31 16:20:12 ouster Exp $ SPRITE (Berkeley)";
  23 #endif /* not lint */
  24
  25 #include "tkconfig.h"
  26 #include "tk.h"
  27
  28 /*
  29  * the global variable below is used to tell TkPointerEvent
  30  * not to do any processing on an event that we're forwarding from one
  31  * window to another.  This is really ugly.  Eventually this file and
  32  * tkGrab.c need to get merged together to produce something cleaner.
  33  */
  34
  35 XEvent *tkShareEventPtr = NULL;
  36
  37 /*
  38  * Sharing is implemented in terms of groups of windows, where events
  39  * are shared among all the windows in a group.  One of the following
  40  * structures exists for each group.
  41  */
  42
  43 typedef struct Group {
  44     Tk_Uid groupId;                     /* Identifies group uniquely among all
  45                                          * share groups. */
  46     Tk_Window *windows;                 /* Pointer to array of windows in
  47                                          * this group.  Malloc'ed. */
  48     int numWindows;                     /* Number of windows currently in
  49                                          * this group. */
  50     Tk_Window lastWindow;               /* Last window found that contained
  51                                          * an event.  Needed in order to
  52                                          * notify window when mouse moves out
  53                                          * of it.  NULL means nobody to
  54                                          * notify. */
  55     XEvent *activeEvent;                /* If non-NULL, means that a recursive
  56                                          * call to Tk_HandleEvent is in
  57                                          * progress for this share group, and
  58                                          * identifies event.  NULL means no
  59                                          * recursive call in progress.  Used
  60                                          * to avoid infinite recursion. */
  61     struct Group *nextPtr;              /* Next in list of all share groups. */
  62 } Group;
  63
  64 static Group *groupList = NULL;         /* First in list of all share groups
  65                                          * currently defined. */
  66
  67 /*
  68  * Forward declarations for procedures defined later in this file:
  69  */
  70
  71 static void             DeleteGroup _ANSI_ARGS_((Group *groupPtr));
  72 static void             ShareEventProc _ANSI_ARGS_((ClientData clientData,
  73                             XEvent *eventPtr));
  74 \f
  75 /*
  76  *----------------------------------------------------------------------
  77  *
  78  * Tk_ShareEvents --
  79  *
  80  *      Add tkwin to a group of windows sharing events.
  81  *
  82  * Results:
  83  *      None.
  84  *
  85  * Side effects:
  86  *      In the future, if a button- or mouse-related event occurs for
  87  *      any window in the same group as tkwin, but the mouse is actually
  88  *      in tkwin (the event went to a different window because of a
  89  *      grab) then a synthetic event will be generated with tkwin as
  90  *      window and adjusted coordinates.
  91  *
  92  *----------------------------------------------------------------------
  93  */
  94
  95 void
  96 Tk_ShareEvents(tkwin, groupId)
  97     Tk_Window tkwin;                    /* Token for window. */
  98     Tk_Uid groupId;                     /* Identifier for group among which
  99                                          * events are to be shared. */
 100 {
 101     register Group *groupPtr;
 102
 103     /*
 104      * See if this group exists.  If so, add the window to the group.
 105      */
 106
 107     for (groupPtr = groupList; groupPtr != NULL;
 108             groupPtr = groupPtr->nextPtr) {
 109         Tk_Window *new;
 110
 111         if (groupPtr->groupId != groupId) {
 112             continue;
 113         }
 114         new = (Tk_Window *) ckalloc((unsigned)
 115                 (groupPtr->numWindows+1) * sizeof(Tk_Window *));
 116         memcpy((VOID *) (new+1), (VOID *) groupPtr->windows,
 117                 (groupPtr->numWindows * sizeof(Tk_Window *)));
 118         ckfree((char *) groupPtr->windows);
 119         groupPtr->windows = new;
 120         groupPtr->windows[0] = tkwin;
 121         groupPtr->numWindows++;
 122         break;
 123     }
 124
 125     if (groupPtr == NULL) {
 126         /*
 127          * Group doesn't exist.  Make a new one.
 128          */
 129
 130         groupPtr = (Group *) ckalloc(sizeof(Group));
 131         groupPtr->groupId = groupId;
 132         groupPtr->windows = (Tk_Window *) ckalloc(sizeof (Tk_Window *));
 133         groupPtr->windows[0] = tkwin;
 134         groupPtr->numWindows = 1;
 135         groupPtr->lastWindow = NULL;
 136         groupPtr->activeEvent = NULL;
 137         groupPtr->nextPtr = groupList;
 138         groupList = groupPtr;
 139     }
 140
 141     /*
 142      * Create an event handler so we find out about relevant events
 143      * that are directed to tkwin.
 144      */
 145
 146     Tk_CreateEventHandler(tkwin,
 147             ButtonPressMask|ButtonReleaseMask|PointerMotionMask,
 148             ShareEventProc, (ClientData) groupPtr);
 149 }
 150 \f
 151 /*
 152  *----------------------------------------------------------------------
 153  *
 154  * Tk_UnshareEvents --
 155  *
 156  *      Remove tkwin from a group of windows sharing events.
 157  *
 158  * Results:
 159  *      None.
 160  *
 161  * Side effects:
 162  *      Tkwin will no longer participate in event-sharing for the
 163  *      given group, either as source of events or as destination.
 164  *
 165  *----------------------------------------------------------------------
 166  */
 167
 168 void
 169 Tk_UnshareEvents(tkwin, groupId)
 170     Tk_Window tkwin;                    /* Token for window. */
 171     Tk_Uid groupId;                     /* Identifier for group. */
 172 {
 173     register Group *groupPtr;
 174     int i;
 175
 176     for (groupPtr = groupList; groupPtr != NULL;
 177             groupPtr = groupPtr->nextPtr) {
 178         if (groupPtr->groupId != groupId) {
 179             continue;
 180         }
 181         if (groupPtr->lastWindow == tkwin) {
 182             groupPtr->lastWindow = NULL;
 183         }
 184         for (i = 0; i < groupPtr->numWindows; i++) {
 185             if (groupPtr->windows[i] != tkwin) {
 186                 continue;
 187             }
 188             if ((i+1) < groupPtr->numWindows) {
 189                 memcpy((VOID *) (groupPtr->windows + i),
 190                         (VOID *) (groupPtr->windows + i + 1),
 191                         (groupPtr->numWindows - (i+1))*sizeof(Tk_Window *));
 192             }
 193             groupPtr->numWindows--;
 194             Tk_DeleteEventHandler(tkwin,
 195                     ButtonPressMask|ButtonReleaseMask|PointerMotionMask,
 196                     ShareEventProc, (ClientData) groupPtr);
 197             if (groupPtr->numWindows == 0) {
 198                 DeleteGroup(groupPtr);
 199             }
 200             return;
 201         }
 202     }
 203 }
 204 \f
 205 /*
 206  *----------------------------------------------------------------------
 207  *
 208  * DeleteGroup --
 209  *
 210  *      This procedure is called when a group has no more members.
 211  *      It deletes the group from the list of existing groups.
 212  *
 213  * Results:
 214  *      None.
 215  *
 216  * Side effects:
 217  *      Memory gets freed.
 218  *
 219  *----------------------------------------------------------------------
 220  */
 221
 222 static void
 223 DeleteGroup(groupPtr)
 224     Group *groupPtr;                    /* Group to delete. */
 225 {
 226     if (groupList == groupPtr) {
 227         groupList = groupPtr->nextPtr;
 228     } else {
 229         register Group *prevPtr;
 230
 231         for (prevPtr = groupList; ; prevPtr = prevPtr->nextPtr) {
 232             if (prevPtr == NULL) {
 233                 panic("DeleteGroup couldn't find group on shareList");
 234             }
 235             if (prevPtr->nextPtr == groupPtr) {
 236                 prevPtr->nextPtr = groupPtr->nextPtr;
 237                 break;
 238             }
 239         }
 240     }
 241     ckfree((char *) groupPtr->windows);
 242     ckfree((char *) groupPtr);
 243 }
 244 \f
 245 /*
 246  *----------------------------------------------------------------------
 247  *
 248  * ShareEventProc --
 249  *
 250  *      This procedure is invoked by the Tk dispatcher when an event
 251  *      occurs for which we need to implement sharing.
 252  *
 253  * Results:
 254  *      None.
 255  *
 256  * Side effects:
 257  *      If the mouse is actually in a window other than the one for
 258  *      which the event occurred, generate a new event translated to
 259  *      that window.
 260  *
 261  *----------------------------------------------------------------------
 262  */
 263
 264 static void
 265 ShareEventProc(clientData, eventPtr)
 266     ClientData clientData;              /* Information about share group. */
 267     register XEvent *eventPtr;          /* Event that just occurred. */
 268 {
 269     register Group *groupPtr = (Group *) clientData;
 270     register Tk_Window tkwin;
 271     Window window;
 272     XEvent newEvent, *savedActive, *savedShareEventPtr;
 273     int i, x, y;
 274     Tk_Uid savedId;
 275     register Group *grpPtr;
 276
 277     /*
 278      * If this event was a synthetic one that we generated, then
 279      * don't bother to process it again.
 280      */
 281
 282     if (groupPtr->activeEvent == eventPtr) {
 283         return;
 284     }
 285     savedActive = groupPtr->activeEvent;
 286     groupPtr->activeEvent = &newEvent;
 287     savedId = groupPtr->groupId;
 288
 289     savedShareEventPtr = tkShareEventPtr;
 290     tkShareEventPtr = &newEvent;
 291
 292     /*
 293      * Scan through all of the windows for this group to find the
 294      * first one (if any) that contains the event.
 295      */
 296
 297     tkwin = NULL;               /* Not needed, but stops compiler warning. */
 298     for (i = 0; i < groupPtr->numWindows; i++) {
 299         Tk_Window tkwin2;
 300
 301         tkwin = groupPtr->windows[i];
 302         Tk_GetRootCoords(tkwin, &x, &y);
 303         x = eventPtr->xmotion.x_root - x - Tk_Changes(tkwin)->border_width;
 304         y = eventPtr->xmotion.y_root - y - Tk_Changes(tkwin)->border_width;
 305         if ((x < 0) || (y < 0) || (x >= Tk_Width(tkwin))
 306                 || (y >= Tk_Height(tkwin))) {
 307             continue;
 308         }
 309         for (tkwin2 = tkwin; ; tkwin2 = Tk_Parent(tkwin2)) {
 310             if (tkwin2 == NULL) {
 311                 goto foundWindow;
 312             }
 313             if (!Tk_IsMapped(tkwin2)) {
 314                 break;
 315             }
 316             if (((Tk_FakeWin *) (tkwin2))->flags & TK_TOP_LEVEL) {
 317                 goto foundWindow;
 318             }
 319         }
 320     }
 321
 322     foundWindow:
 323     window = None;      /* Not really needed but stops compiler warning. */
 324     if (i >= groupPtr->numWindows) {
 325         tkwin = NULL;
 326     } else {
 327         window = Tk_WindowId(tkwin);
 328     }
 329
 330     /*
 331      * SPECIAL NOTE:  it is possible that any or all of the information
 332      * in groupPtr could be modified as part of the processing of the
 333      * events that we generate and hand to Tk_HandleEvent below.  For this
 334      * to work smoothly, it is imperative that we extract any information
 335      * we need from groupPtr (and from tkwin's, since they could be
 336      * deleted) before the first call to Tk_HandleEvent below.  The code
 337      * below may potentially pass an X window identifier to Tk_HandleEvent
 338      * after the window has been deleted, but as long as identifiers
 339      * aren't recycled Tk_HandleEvent will simply discard the event if
 340      * this occurs.
 341      */
 342
 343     /*
 344      * If the pointer is in a different window now than the last time
 345      * we were invoked, send a LeaveNotify event to the old window and
 346      * an EnterNotify event to the new window.
 347      */
 348
 349     newEvent = *eventPtr;
 350     newEvent.xany.send_event = True;
 351     if (tkwin != groupPtr->lastWindow) {
 352         newEvent = *eventPtr;
 353         newEvent.xany.send_event = True;
 354         newEvent.xcrossing.mode = TK_NOTIFY_SHARE;
 355         newEvent.xcrossing.detail = NotifyAncestor;
 356         newEvent.xcrossing.same_screen = True;
 357         newEvent.xcrossing.state = eventPtr->xmotion.state;
 358         if (groupPtr->lastWindow != NULL) {
 359             newEvent.xcrossing.type = LeaveNotify;
 360             newEvent.xcrossing.window = Tk_WindowId(groupPtr->lastWindow);
 361             Tk_GetRootCoords(groupPtr->lastWindow, &newEvent.xcrossing.x,
 362                     &newEvent.xcrossing.y);
 363             newEvent.xcrossing.x = eventPtr->xmotion.x_root
 364                     - newEvent.xcrossing.x
 365                     - Tk_Changes(groupPtr->lastWindow)->border_width;
 366             newEvent.xcrossing.y = eventPtr->xmotion.y_root
 367                     - newEvent.xcrossing.y
 368                     - Tk_Changes(groupPtr->lastWindow)->border_width;
 369             Tk_HandleEvent(&newEvent);
 370         }
 371         if (tkwin != NULL) {
 372             newEvent.xcrossing.type = EnterNotify;
 373             newEvent.xcrossing.window = window;
 374             newEvent.xcrossing.x = x;
 375             newEvent.xcrossing.y = y;
 376             Tk_HandleEvent(&newEvent);
 377         }
 378         groupPtr->lastWindow = tkwin;
 379     }
 380
 381     /*
 382      * If the pointer is in the window to which the event was sent,
 383      * then we needn't do any forwarding at all.  Ditto if the pointer
 384      * isn't in any window at all.
 385      */
 386
 387     if ((tkwin != NULL) && (Tk_WindowId(tkwin) != eventPtr->xmotion.window)) {
 388         newEvent = *eventPtr;
 389         newEvent.xmotion.send_event = True;
 390         newEvent.xmotion.window = window;
 391         newEvent.xmotion.x = x;
 392         newEvent.xmotion.y = y;
 393         Tk_HandleEvent(&newEvent);
 394     }
 395
 396     /*
 397      * Only restore the activeEvent if the group still exists.
 398      * (It could be deleted as a side effect of processing the event.)
 399      */
 400
 401     for (grpPtr = groupList; grpPtr != NULL; grpPtr = grpPtr->nextPtr) {
 402         if (grpPtr->groupId == savedId) {
 403             groupPtr->activeEvent = savedActive;
 404             break;
 405         }
 406     }
 407
 408     tkShareEventPtr = savedShareEventPtr;
 409 }