atk/atkutil.c

   1 /* ATK -  Accessibility Toolkit
   2  * Copyright 2001 Sun Microsystems Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include "config.h"
  21
  22 #include "atkutil.h"
  23 #include "atkmarshal.c"
  24
  25 /**
  26  * SECTION:atkutil
  27  * @Short_description: A set of ATK utility functions for event and toolkit support.
  28  * @Title:AtkUtil
  29  *
  30  * A set of ATK utility functions which are used to support event
  31  * registration of various types, and obtaining the 'root' accessible
  32  * of a process and information about the current ATK implementation
  33  * and toolkit version.
  34  */
  35
  36 static void atk_util_class_init (AtkUtilClass *klass);
  37
  38 static AtkObject *previous_focus_object = NULL;
  39
  40 typedef struct _AtkUtilListenerInfo AtkUtilListenerInfo;
  41 struct _AtkUtilListenerInfo
  42 {
  43   gint key;
  44   guint signal_id;
  45   gulong hook_id;
  46 };
  47 static GHashTable *listener_list = NULL;
  48
  49 GType
  50 atk_util_get_type (void)
  51 {
  52   static GType type = 0;
  53
  54   if (!type)
  55     {
  56       static const GTypeInfo typeInfo =
  57       {
  58         sizeof (AtkUtilClass),
  59         (GBaseInitFunc) NULL,
  60         (GBaseFinalizeFunc) NULL,
  61         (GClassInitFunc) atk_util_class_init,
  62         (GClassFinalizeFunc) NULL,
  63         NULL,
  64         sizeof (AtkUtil),
  65         0,
  66         (GInstanceInitFunc) NULL,
  67       } ;
  68       type = g_type_register_static (G_TYPE_OBJECT, "AtkUtil", &typeInfo, 0) ;
  69     }
  70   return type;
  71 }
  72
  73 /*
  74  * This file supports the addition and removal of multiple focus handlers
  75  * as long as they are all called in the same thread.
  76  */
  77 static AtkEventListenerInit  focus_tracker_init = (AtkEventListenerInit) NULL;
  78
  79 static gboolean init_done = FALSE;
  80
  81 /*
  82  * Array of FocusTracker structs
  83  */
  84 static GArray *trackers = NULL;
  85 static guint  global_index = 0;
  86
  87 typedef struct _FocusTracker FocusTracker;
  88
  89 struct _FocusTracker {
  90   guint index;
  91   AtkEventListener func;
  92 };
  93
  94 /**
  95  * atk_focus_tracker_init:
  96  * @init: Function to be called for focus tracker initialization
  97  *
  98  * Specifies the function to be called for focus tracker initialization.
  99  * This function should be called by an implementation of the
 100  * ATK interface if any specific work needs to be done to enable
 101  * focus tracking.
 102  *
 103  * Deprecated: This method is deprecated since ATK version
 104  * 2.9.4. Focus tracking has been dropped as a feature to be
 105  * implemented by ATK itself.
 106  *
 107  **/
 108 void
 109 atk_focus_tracker_init (AtkEventListenerInit    init)
 110 {
 111   if (!focus_tracker_init)
 112     focus_tracker_init = init;
 113 }
 114
 115 /**
 116  * atk_add_focus_tracker:
 117  * @focus_tracker: Function to be added to the list of functions to be called
 118  * when an object receives focus.
 119  *
 120  * Adds the specified function to the list of functions to be called
 121  * when an object receives focus.
 122  *
 123  * Deprecated: This method is deprecated since ATK version
 124  * 2.9.4. Focus tracking has been dropped as a feature to be
 125  * implemented by ATK itself. If you need focus tracking on your
 126  * implementation, subscribe to the state-changed:focused signal.
 127  *
 128  * Returns: added focus tracker id, or 0 on failure.
 129  **/
 130 guint
 131 atk_add_focus_tracker (AtkEventListener   focus_tracker)
 132 {
 133   g_return_val_if_fail (focus_tracker, 0);
 134
 135   if (!init_done)
 136   {
 137     if (focus_tracker_init)
 138     {
 139       focus_tracker_init ();
 140     }
 141     trackers = g_array_sized_new (FALSE, TRUE, sizeof (FocusTracker), 0);
 142     init_done = TRUE;
 143   }
 144   if (init_done)
 145   {
 146     FocusTracker item;
 147
 148     item.index = ++global_index;
 149     item.func = focus_tracker;
 150     trackers = g_array_append_val (trackers, item);
 151     return global_index;
 152   }
 153   else
 154   {
 155     return 0;
 156   }
 157 }
 158
 159 /**
 160  * atk_remove_focus_tracker:
 161  * @tracker_id: the id of the focus tracker to remove
 162  *
 163  * Deprecated: This method is deprecated since ATK version
 164  * 2.9.4. Focus tracking has been dropped as a feature to be
 165  * implemented by ATK itself. If you need focus tracking on your
 166  * implementation, subscribe to the state-changed:focused signal.
 167  *
 168  * Removes the specified focus tracker from the list of functions
 169  * to be called when any object receives focus.
 170  **/
 171 void
 172 atk_remove_focus_tracker (guint            tracker_id)
 173 {
 174   FocusTracker *item;
 175   guint i;
 176
 177   if (trackers == NULL)
 178     return;
 179
 180   if (tracker_id == 0)
 181     return;
 182
 183   for (i = 0; i < trackers->len; i++)
 184   {
 185     item = &g_array_index (trackers, FocusTracker, i);
 186     if (item->index == tracker_id)
 187     {
 188       trackers = g_array_remove_index (trackers, i);
 189       break;
 190     }
 191   }
 192 }
 193
 194 /**
 195  * atk_focus_tracker_notify:
 196  * @object: an #AtkObject
 197  *
 198  * Cause the focus tracker functions which have been specified to be
 199  * executed for the object.
 200  *
 201  * Deprecated: This method is deprecated since ATK version
 202  * 2.9.4. Focus tracking has been dropped as a feature to be
 203  * implemented by ATK itself.
 204  *
 205  **/
 206 void
 207 atk_focus_tracker_notify (AtkObject       *object)
 208 {
 209   FocusTracker *item;
 210   guint i;
 211
 212   if (trackers == NULL)
 213     return;
 214
 215   if (object == previous_focus_object)
 216     return;
 217   else
 218     {
 219       if (previous_focus_object)
 220         g_object_unref (previous_focus_object);
 221
 222       previous_focus_object = object;
 223       if (object)
 224         {
 225           g_object_ref (object);
 226
 227           for (i = 0; i < trackers->len; i++)
 228             {
 229               item = &g_array_index (trackers, FocusTracker, i);
 230               g_return_if_fail (item != NULL);
 231               item->func (object);
 232             }
 233         }
 234
 235     }
 236 }
 237
 238 static guint
 239 add_listener (GSignalEmissionHook listener,
 240               const gchar         *object_type,
 241               const gchar         *signal_name,
 242               const gchar         *detail_string,
 243               const gchar         *hook_data)
 244 {
 245   GType type;
 246   guint signal_id;
 247   gint  rc = 0;
 248   static gint listener_idx = 1;
 249   GQuark detail_quark = 0;
 250
 251   type = g_type_from_name (object_type);
 252   if (type)
 253     {
 254       signal_id  = g_signal_lookup (signal_name, type);
 255       detail_quark = g_quark_from_string (detail_string);
 256
 257       if (signal_id > 0)
 258         {
 259           AtkUtilListenerInfo *listener_info;
 260
 261           rc = listener_idx;
 262
 263           listener_info = g_new (AtkUtilListenerInfo, 1);
 264           listener_info->key = listener_idx;
 265           listener_info->hook_id =
 266             g_signal_add_emission_hook (signal_id, detail_quark, listener,
 267                                         g_strdup (hook_data),
 268                                         (GDestroyNotify) g_free);
 269           listener_info->signal_id = signal_id;
 270
 271           g_hash_table_insert(listener_list, &(listener_info->key), listener_info);
 272           listener_idx++;
 273         }
 274       else
 275         {
 276           g_debug ("Signal type %s not supported\n", signal_name);
 277         }
 278     }
 279   else
 280     {
 281       g_warning("Invalid object type %s\n", object_type);
 282     }
 283   return rc;
 284 }
 285
 286 static guint
 287 atk_util_real_add_global_event_listener (GSignalEmissionHook listener,
 288                                          const gchar *event_type)
 289 {
 290   guint rc = 0;
 291   gchar **split_string;
 292   guint length;
 293
 294   split_string = g_strsplit (event_type, ":", 0);
 295   length = g_strv_length (split_string);
 296
 297   if ((length == 3) || (length == 4))
 298     rc = add_listener (listener, split_string[1], split_string[2],
 299                        split_string[3], event_type);
 300
 301   g_strfreev (split_string);
 302
 303   return rc;
 304 }
 305
 306 static void
 307 atk_util_real_remove_global_event_listener (guint remove_listener)
 308 {
 309   if (remove_listener > 0)
 310     {
 311       AtkUtilListenerInfo *listener_info;
 312       gint tmp_idx = remove_listener;
 313
 314       listener_info = (AtkUtilListenerInfo *)
 315         g_hash_table_lookup(listener_list, &tmp_idx);
 316
 317       if (listener_info != NULL)
 318         {
 319           /* Hook id of 0 and signal id of 0 are invalid */
 320           if (listener_info->hook_id != 0 && listener_info->signal_id != 0)
 321             {
 322               /* Remove the emission hook */
 323               g_signal_remove_emission_hook(listener_info->signal_id,
 324                                             listener_info->hook_id);
 325
 326               /* Remove the element from the hash */
 327               g_hash_table_remove(listener_list, &tmp_idx);
 328             }
 329           else
 330             {
 331               g_warning("Invalid listener hook_id %ld or signal_id %d\n",
 332                         listener_info->hook_id, listener_info->signal_id);
 333             }
 334         }
 335       else
 336         {
 337           g_warning("No listener with the specified listener id %d",
 338                     remove_listener);
 339         }
 340     }
 341   else
 342     {
 343       g_warning("Invalid listener_id %d", remove_listener);
 344     }
 345 }
 346
 347
 348 /**
 349  * atk_add_global_event_listener:
 350  * @listener: the listener to notify
 351  * @event_type: the type of event for which notification is requested
 352  *
 353  * Adds the specified function to the list of functions to be called
 354  * when an ATK event of type event_type occurs.
 355  *
 356  * The format of event_type is the following:
 357  *  "ATK:&lt;atk_type&gt;:&lt;atk_event&gt;:&lt;atk_event_detail&gt;
 358  *
 359  * Where "ATK" works as the namespace, &lt;atk_interface&gt; is the name of
 360  * the ATK type (interface or object), &lt;atk_event&gt; is the name of the
 361  * signal defined on that interface and &lt;atk_event_detail&gt; is the
 362  * gsignal detail of that signal. You can find more info about gsignal
 363  * details here:
 364  * http://developer.gnome.org/gobject/stable/gobject-Signals.html
 365  *
 366  * The first three parameters are mandatory. The last one is optional.
 367  *
 368  * For example:
 369  *   ATK:AtkObject:state-change
 370  *   ATK:AtkText:text-selection-changed
 371  *   ATK:AtkText:text-insert:system
 372  *
 373  * Toolkit implementor note: ATK provides a default implementation for
 374  * this virtual method. ATK implementors are discouraged from
 375  * reimplementing this method.
 376  *
 377  * Toolkit implementor note: this method is not intended to be used by
 378  * ATK implementors but by ATK consumers.
 379  *
 380  * Returns: added event listener id, or 0 on failure.
 381  **/
 382 guint
 383 atk_add_global_event_listener (GSignalEmissionHook listener,
 384                                const gchar        *event_type)
 385 {
 386   guint retval;
 387   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 388
 389   if (klass->add_global_event_listener)
 390     {
 391       retval = klass->add_global_event_listener (listener, event_type);
 392     }
 393   else
 394     {
 395       retval = 0;
 396     }
 397   g_type_class_unref (klass);
 398
 399   return retval;
 400 }
 401
 402 /**
 403  * atk_remove_global_event_listener:
 404  * @listener_id: the id of the event listener to remove
 405  *
 406  * @listener_id is the value returned by #atk_add_global_event_listener
 407  * when you registered that event listener.
 408  *
 409  * Toolkit implementor note: ATK provides a default implementation for
 410  * this virtual method. ATK implementors are discouraged from
 411  * reimplementing this method.
 412  *
 413  * Toolkit implementor note: this method is not intended to be used by
 414  * ATK implementors but by ATK consumers.
 415  *
 416  * Removes the specified event listener
 417  **/
 418 void
 419 atk_remove_global_event_listener (guint listener_id)
 420 {
 421   AtkUtilClass *klass = g_type_class_peek (ATK_TYPE_UTIL);
 422
 423   if (klass && klass->remove_global_event_listener)
 424     klass->remove_global_event_listener (listener_id);
 425 }
 426
 427 /**
 428  * atk_add_key_event_listener:
 429  * @listener: the listener to notify
 430  * @data: a #gpointer that points to a block of data that should be sent to the registered listeners,
 431  *        along with the event notification, when it occurs.
 432  *
 433  * Adds the specified function to the list of functions to be called
 434  *        when a key event occurs.  The @data element will be passed to the
 435  *        #AtkKeySnoopFunc (@listener) as the @func_data param, on notification.
 436  *
 437  * Returns: added event listener id, or 0 on failure.
 438  **/
 439 guint
 440 atk_add_key_event_listener (AtkKeySnoopFunc listener, gpointer data)
 441 {
 442   guint retval;
 443   AtkUtilClass *klass = g_type_class_peek (ATK_TYPE_UTIL);
 444   if (klass && klass->add_key_event_listener)
 445     {
 446       retval = klass->add_key_event_listener (listener, data);
 447     }
 448   else
 449     {
 450       retval = 0;
 451     }
 452
 453   return retval;
 454 }
 455
 456 /**
 457  * atk_remove_key_event_listener:
 458  * @listener_id: the id of the event listener to remove
 459  *
 460  * @listener_id is the value returned by #atk_add_key_event_listener
 461  * when you registered that event listener.
 462  *
 463  * Removes the specified event listener.
 464  **/
 465 void
 466 atk_remove_key_event_listener (guint listener_id)
 467 {
 468   AtkUtilClass *klass = g_type_class_peek (ATK_TYPE_UTIL);
 469
 470   if (klass->remove_key_event_listener)
 471     klass->remove_key_event_listener (listener_id);
 472 }
 473
 474 /**
 475  * atk_get_root:
 476  *
 477  * Gets the root accessible container for the current application.
 478  *
 479  * Returns: (transfer none): the root accessible container for the current
 480  * application
 481  **/
 482 AtkObject*
 483 atk_get_root (void)
 484 {
 485   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 486   AtkObject    *retval;
 487   if (klass->get_root)
 488     {
 489       retval = klass->get_root ();
 490     }
 491   else
 492     {
 493       retval = NULL;
 494     }
 495   g_type_class_unref (klass);
 496
 497   return retval;
 498 }
 499
 500 /**
 501  * atk_get_focus_object:
 502  *
 503  * Gets the currently focused object.
 504  *
 505  * Since: 1.6
 506  *
 507  * Returns: (transfer none): the currently focused object for the current
 508  * application
 509  **/
 510 AtkObject*
 511 atk_get_focus_object (void)
 512 {
 513   return previous_focus_object;
 514 }
 515
 516 /**
 517  * atk_get_toolkit_name:
 518  *
 519  * Gets name string for the GUI toolkit implementing ATK for this application.
 520  *
 521  * Returns: name string for the GUI toolkit implementing ATK for this application
 522  **/
 523 const gchar*
 524 atk_get_toolkit_name (void)
 525 {
 526   const gchar *retval;
 527   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 528   if (klass->get_toolkit_name)
 529     {
 530       retval = klass->get_toolkit_name ();
 531     }
 532   else
 533     {
 534       retval = NULL;
 535     }
 536   g_type_class_unref (klass);
 537
 538   return retval;
 539 }
 540
 541 /**
 542  * atk_get_toolkit_version:
 543  *
 544  * Gets version string for the GUI toolkit implementing ATK for this application.
 545  *
 546  * Returns: version string for the GUI toolkit implementing ATK for this application
 547  **/
 548 const gchar*
 549 atk_get_toolkit_version (void)
 550 {
 551   const gchar *retval;
 552   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 553   if (klass->get_toolkit_version)
 554     {
 555       retval = klass->get_toolkit_version ();
 556     }
 557   else
 558     {
 559       retval = NULL;
 560     }
 561   g_type_class_unref (klass);
 562
 563   return retval;
 564 }
 565
 566 /**
 567  * atk_get_version:
 568  *
 569  * Gets the current version for ATK.
 570  *
 571  * Returns: version string for ATK
 572  *
 573  * Since: 1.20
 574  */
 575 const gchar *
 576 atk_get_version (void)
 577 {
 578   return VERSION;
 579 }
 580
 581 static void
 582 atk_util_class_init (AtkUtilClass *klass)
 583 {
 584   klass->add_global_event_listener = atk_util_real_add_global_event_listener;
 585   klass->remove_global_event_listener = atk_util_real_remove_global_event_listener;
 586   klass->get_root = NULL;
 587   klass->get_toolkit_name = NULL;
 588   klass->get_toolkit_version = NULL;
 589
 590   listener_list = g_hash_table_new_full (g_int_hash, g_int_equal, NULL,
 591                                          g_free);
 592 }