Pileus Git - ~andy/gtk/blob - gdk/x11/xsettings-client.c

   1 /*
   2  * Copyright © 2001 Red Hat, Inc.
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation, and that the name of Red Hat not be used in advertising or
   9  * publicity pertaining to distribution of the software without specific,
  10  * written prior permission.  Red Hat makes no representations about the
  11  * suitability of this software for any purpose.  It is provided "as is"
  12  * without express or implied warranty.
  13  *
  14  * RED HAT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL RED HAT
  16  * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  18  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  19  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  20  *
  21  * Author:  Owen Taylor, Red Hat, Inc.
  22  */
  23 #include <limits.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #include <X11/Xlib.h>
  29 #include <X11/Xmd.h>            /* For CARD16 */
  30
  31 #include "xsettings-client.h"
  32
  33 struct _XSettingsClient
  34 {
  35   Display *display;
  36   int screen;
  37   XSettingsNotifyFunc notify;
  38   XSettingsWatchFunc watch;
  39   void *cb_data;
  40
  41   Window manager_window;
  42   Atom manager_atom;
  43   Atom selection_atom;
  44   Atom xsettings_atom;
  45
  46   XSettingsList *settings;
  47 };
  48
  49 static void
  50 notify_changes (XSettingsClient *client,
  51                 XSettingsList   *old_list)
  52 {
  53   XSettingsList *old_iter = old_list;
  54   XSettingsList *new_iter = client->settings;
  55
  56   if (!client->notify)
  57     return;
  58
  59   while (old_iter || new_iter)
  60     {
  61       int cmp;
  62
  63       if (old_iter && new_iter)
  64         cmp = strcmp (old_iter->setting->name, new_iter->setting->name);
  65       else if (old_iter)
  66         cmp = -1;
  67       else
  68         cmp = 1;
  69
  70       if (cmp < 0)
  71         {
  72           client->notify (old_iter->setting->name,
  73                           XSETTINGS_ACTION_DELETED,
  74                           NULL,
  75                           client->cb_data);
  76         }
  77       else if (cmp == 0)
  78         {
  79           if (!xsettings_setting_equal (old_iter->setting,
  80                                         new_iter->setting))
  81             client->notify (old_iter->setting->name,
  82                             XSETTINGS_ACTION_CHANGED,
  83                             new_iter->setting,
  84                             client->cb_data);
  85         }
  86       else
  87         {
  88           client->notify (new_iter->setting->name,
  89                           XSETTINGS_ACTION_NEW,
  90                           new_iter->setting,
  91                           client->cb_data);
  92         }
  93
  94       if (old_iter)
  95         old_iter = old_iter->next;
  96       if (new_iter)
  97         new_iter = new_iter->next;
  98     }
  99 }
 100
 101 static int
 102 ignore_errors (Display *display, XErrorEvent *event)
 103 {
 104   return True;
 105 }
 106
 107 static char local_byte_order = '\0';
 108
 109 #define BYTES_LEFT(buffer) ((buffer)->data + (buffer)->len - (buffer)->pos)
 110
 111 static XSettingsResult
 112 fetch_card16 (XSettingsBuffer *buffer,
 113               CARD16          *result)
 114 {
 115   CARD16 x;
 116
 117   if (BYTES_LEFT (buffer) < 2)
 118     return XSETTINGS_ACCESS;
 119
 120   x = *(CARD16 *)buffer->pos;
 121   buffer->pos += 2;
 122
 123   if (buffer->byte_order == local_byte_order)
 124     *result = x;
 125   else
 126     *result = (x << 8) | (x >> 8);
 127
 128   return XSETTINGS_SUCCESS;
 129 }
 130
 131 static XSettingsResult
 132 fetch_ushort (XSettingsBuffer *buffer,
 133               unsigned short  *result)
 134 {
 135   CARD16 x;
 136   XSettingsResult r;
 137
 138   r = fetch_card16 (buffer, &x);
 139   if (r == XSETTINGS_SUCCESS)
 140     *result = x;
 141
 142   return r;
 143 }
 144
 145 static XSettingsResult
 146 fetch_card32 (XSettingsBuffer *buffer,
 147               CARD32          *result)
 148 {
 149   CARD32 x;
 150
 151   if (BYTES_LEFT (buffer) < 4)
 152     return XSETTINGS_ACCESS;
 153
 154   x = *(CARD32 *)buffer->pos;
 155   buffer->pos += 4;
 156
 157   if (buffer->byte_order == local_byte_order)
 158     *result = x;
 159   else
 160     *result = (x << 24) | ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | (x >> 24);
 161
 162   return XSETTINGS_SUCCESS;
 163 }
 164
 165 static XSettingsResult
 166 fetch_card8 (XSettingsBuffer *buffer,
 167              CARD8           *result)
 168 {
 169   if (BYTES_LEFT (buffer) < 1)
 170     return XSETTINGS_ACCESS;
 171
 172   *result = *(CARD8 *)buffer->pos;
 173   buffer->pos += 1;
 174
 175   return XSETTINGS_SUCCESS;
 176 }
 177
 178 #define XSETTINGS_PAD(n,m) ((n + m - 1) & (~(m-1)))
 179
 180 static XSettingsList *
 181 parse_settings (unsigned char *data,
 182                 size_t         len)
 183 {
 184   XSettingsBuffer buffer;
 185   XSettingsResult result = XSETTINGS_SUCCESS;
 186   XSettingsList *settings = NULL;
 187   CARD32 serial;
 188   CARD32 n_entries;
 189   CARD32 i;
 190   XSettingsSetting *setting = NULL;
 191
 192   local_byte_order = xsettings_byte_order ();
 193
 194   buffer.pos = buffer.data = data;
 195   buffer.len = len;
 196
 197   result = fetch_card8 (&buffer, &buffer.byte_order);
 198   if (buffer.byte_order != MSBFirst &&
 199       buffer.byte_order != LSBFirst)
 200     {
 201       fprintf (stderr, "Invalid byte order in XSETTINGS property\n");
 202       result = XSETTINGS_FAILED;
 203       goto out;
 204     }
 205
 206   buffer.pos += 3;
 207
 208   result = fetch_card32 (&buffer, &serial);
 209   if (result != XSETTINGS_SUCCESS)
 210     goto out;
 211
 212   result = fetch_card32 (&buffer, &n_entries);
 213   if (result != XSETTINGS_SUCCESS)
 214     goto out;
 215
 216   for (i = 0; i < n_entries; i++)
 217     {
 218       CARD8 type;
 219       CARD16 name_len;
 220       CARD32 v_int;
 221       size_t pad_len;
 222
 223       result = fetch_card8 (&buffer, &type);
 224       if (result != XSETTINGS_SUCCESS)
 225         goto out;
 226
 227       buffer.pos += 1;
 228
 229       result = fetch_card16 (&buffer, &name_len);
 230       if (result != XSETTINGS_SUCCESS)
 231         goto out;
 232
 233       pad_len = XSETTINGS_PAD(name_len, 4);
 234       if (BYTES_LEFT (&buffer) < pad_len)
 235         {
 236           result = XSETTINGS_ACCESS;
 237           goto out;
 238         }
 239
 240       setting = malloc (sizeof *setting);
 241       if (!setting)
 242         {
 243           result = XSETTINGS_NO_MEM;
 244           goto out;
 245         }
 246       setting->type = XSETTINGS_TYPE_INT; /* No allocated memory */
 247
 248       setting->name = malloc (name_len + 1);
 249       if (!setting->name)
 250         {
 251           result = XSETTINGS_NO_MEM;
 252           goto out;
 253         }
 254
 255       memcpy (setting->name, buffer.pos, name_len);
 256       setting->name[name_len] = '\0';
 257       buffer.pos += pad_len;
 258
 259       result = fetch_card32 (&buffer, &v_int);
 260       if (result != XSETTINGS_SUCCESS)
 261         goto out;
 262       setting->last_change_serial = v_int;
 263
 264       switch (type)
 265         {
 266         case XSETTINGS_TYPE_INT:
 267           result = fetch_card32 (&buffer, &v_int);
 268           if (result != XSETTINGS_SUCCESS)
 269             goto out;
 270
 271           setting->data.v_int = (INT32)v_int;
 272           break;
 273         case XSETTINGS_TYPE_STRING:
 274           result = fetch_card32 (&buffer, &v_int);
 275           if (result != XSETTINGS_SUCCESS)
 276             goto out;
 277
 278           pad_len = XSETTINGS_PAD (v_int, 4);
 279           if (v_int + 1 == 0 || /* Guard against wrap-around */
 280               BYTES_LEFT (&buffer) < pad_len)
 281             {
 282               result = XSETTINGS_ACCESS;
 283               goto out;
 284             }
 285
 286           setting->data.v_string = malloc (v_int + 1);
 287           if (!setting->data.v_string)
 288             {
 289               result = XSETTINGS_NO_MEM;
 290               goto out;
 291             }
 292
 293           memcpy (setting->data.v_string, buffer.pos, v_int);
 294           setting->data.v_string[v_int] = '\0';
 295           buffer.pos += pad_len;
 296
 297           break;
 298         case XSETTINGS_TYPE_COLOR:
 299           result = fetch_ushort (&buffer, &setting->data.v_color.red);
 300           if (result != XSETTINGS_SUCCESS)
 301             goto out;
 302           result = fetch_ushort (&buffer, &setting->data.v_color.green);
 303           if (result != XSETTINGS_SUCCESS)
 304             goto out;
 305           result = fetch_ushort (&buffer, &setting->data.v_color.blue);
 306           if (result != XSETTINGS_SUCCESS)
 307             goto out;
 308           result = fetch_ushort (&buffer, &setting->data.v_color.alpha);
 309           if (result != XSETTINGS_SUCCESS)
 310             goto out;
 311
 312           break;
 313         default:
 314           /* Quietly ignore unknown types */
 315           break;
 316         }
 317
 318       setting->type = type;
 319
 320       result = xsettings_list_insert (&settings, setting);
 321       if (result != XSETTINGS_SUCCESS)
 322         goto out;
 323
 324       setting = NULL;
 325     }
 326
 327  out:
 328
 329   if (result != XSETTINGS_SUCCESS)
 330     {
 331       switch (result)
 332         {
 333         case XSETTINGS_NO_MEM:
 334           fprintf(stderr, "Out of memory reading XSETTINGS property\n");
 335           break;
 336         case XSETTINGS_ACCESS:
 337           fprintf(stderr, "Invalid XSETTINGS property (read off end)\n");
 338           break;
 339         case XSETTINGS_DUPLICATE_ENTRY:
 340           fprintf (stderr, "Duplicate XSETTINGS entry for '%s'\n", setting->name);
 341         case XSETTINGS_FAILED:
 342         case XSETTINGS_SUCCESS:
 343         case XSETTINGS_NO_ENTRY:
 344           break;
 345         }
 346
 347       if (setting)
 348         xsettings_setting_free (setting);
 349
 350       xsettings_list_free (settings);
 351       settings = NULL;
 352
 353     }
 354
 355   return settings;
 356 }
 357
 358 static void
 359 read_settings (XSettingsClient *client)
 360 {
 361   Atom type;
 362   int format;
 363   unsigned long n_items;
 364   unsigned long bytes_after;
 365   unsigned char *data;
 366   int result;
 367
 368   int (*old_handler) (Display *, XErrorEvent *);
 369
 370   XSettingsList *old_list = client->settings;
 371
 372   client->settings = NULL;
 373
 374   old_handler = XSetErrorHandler (ignore_errors);
 375   result = XGetWindowProperty (client->display, client->manager_window,
 376                                client->xsettings_atom, 0, LONG_MAX,
 377                                False, client->xsettings_atom,
 378                                &type, &format, &n_items, &bytes_after, &data);
 379   XSetErrorHandler (old_handler);
 380
 381   if (result == Success && type == client->xsettings_atom)
 382     {
 383       if (format != 8)
 384         {
 385           fprintf (stderr, "Invalid format for XSETTINGS property %d", format);
 386         }
 387       else
 388         client->settings = parse_settings (data, n_items);
 389
 390       XFree (data);
 391     }
 392
 393   notify_changes (client, old_list);
 394   xsettings_list_free (old_list);
 395 }
 396
 397 static void
 398 add_events (Display *display,
 399             Window   window,
 400             long     mask)
 401 {
 402   XWindowAttributes attr;
 403
 404   XGetWindowAttributes (display, window, &attr);
 405   XSelectInput (display, window, attr.your_event_mask | mask);
 406 }
 407
 408 static void
 409 check_manager_window (XSettingsClient *client)
 410 {
 411   if (client->manager_window && client->watch)
 412     client->watch (client->manager_window, False, 0, client->cb_data);
 413
 414   XGrabServer (client->display);
 415
 416   client->manager_window = XGetSelectionOwner (client->display,
 417                                                client->selection_atom);
 418   if (client->manager_window)
 419     XSelectInput (client->display, client->manager_window,
 420                   PropertyChangeMask | StructureNotifyMask);
 421
 422   XUngrabServer (client->display);
 423   XFlush (client->display);
 424
 425   if (client->manager_window && client->watch)
 426     client->watch (client->manager_window, True,
 427                    PropertyChangeMask | StructureNotifyMask,
 428                    client->cb_data);
 429
 430   read_settings (client);
 431 }
 432
 433 XSettingsClient *
 434 xsettings_client_new (Display             *display,
 435                       int                  screen,
 436                       XSettingsNotifyFunc  notify,
 437                       XSettingsWatchFunc   watch,
 438                       void                *cb_data)
 439 {
 440   XSettingsClient *client;
 441   char buffer[256];
 442
 443   client = malloc (sizeof *client);
 444   if (!client)
 445     return NULL;
 446
 447   client->display = display;
 448   client->screen = screen;
 449   client->notify = notify;
 450   client->watch = watch;
 451   client->cb_data = cb_data;
 452
 453   client->manager_window = None;
 454   client->settings = NULL;
 455
 456   sprintf(buffer, "_XSETTINGS_S%d", screen);
 457   client->selection_atom = XInternAtom (display, buffer, False);
 458   client->xsettings_atom = XInternAtom (display, "_XSETTINGS_SETTINGS", False);
 459   client->manager_atom = XInternAtom (display, "MANAGER", False);
 460
 461   /* Select on StructureNotify so we get MANAGER events
 462    */
 463   add_events (display, RootWindow (display, screen), StructureNotifyMask);
 464
 465   if (client->watch)
 466     client->watch (RootWindow (display, screen), True, StructureNotifyMask,
 467                    client->cb_data);
 468
 469   check_manager_window (client);
 470
 471   return client;
 472 }
 473
 474 void
 475 xsettings_client_destroy (XSettingsClient *client)
 476 {
 477   if (client->watch)
 478     client->watch (RootWindow (client->display, client->screen),
 479                    False, 0, client->cb_data);
 480   if (client->manager_window && client->watch)
 481     client->watch (client->manager_window, False, 0, client->cb_data);
 482
 483   xsettings_list_free (client->settings);
 484   free (client);
 485 }
 486
 487 XSettingsResult
 488 xsettings_client_get_setting (XSettingsClient   *client,
 489                               const char        *name,
 490                               XSettingsSetting **setting)
 491 {
 492   XSettingsSetting *search = xsettings_list_lookup (client->settings, name);
 493   if (search)
 494     {
 495       *setting = xsettings_setting_copy (search);
 496       return *setting ? XSETTINGS_SUCCESS : XSETTINGS_NO_MEM;
 497     }
 498   else
 499     return XSETTINGS_NO_ENTRY;
 500 }
 501
 502 Bool
 503 xsettings_client_process_event (XSettingsClient *client,
 504                                 XEvent          *xev)
 505 {
 506   /* The checks here will not unlikely cause us to reread
 507    * the properties from the manager window a number of
 508    * times when the manager changes from A->B. But manager changes
 509    * are going to be pretty rare.
 510    */
 511   if (xev->xany.window == RootWindow (client->display, client->screen))
 512     {
 513       if (xev->xany.type == ClientMessage &&
 514           xev->xclient.message_type == client->manager_atom &&
 515           xev->xclient.data.l[1] == client->selection_atom)
 516         {
 517           check_manager_window (client);
 518           return True;
 519         }
 520     }
 521   else if (xev->xany.window == client->manager_window)
 522     {
 523       if (xev->xany.type == DestroyNotify)
 524         {
 525           check_manager_window (client);
 526           return True;
 527         }
 528       else if (xev->xany.type == PropertyNotify)
 529         {
 530           read_settings (client);
 531           return True;
 532         }
 533     }
 534
 535   return False;
 536 }