| 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 | } |