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.h"
  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: (skip)
  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: 2.9.4: Focus tracking has been dropped as a feature
 104  * to be implemented by ATK itself.
 105  *
 106  **/
 107 void
 108 atk_focus_tracker_init (AtkEventListenerInit    init)
 109 {
 110   if (!focus_tracker_init)
 111     focus_tracker_init = init;
 112 }
 113
 114 /**
 115  * atk_add_focus_tracker: (skip)
 116  * @focus_tracker: Function to be added to the list of functions to be called
 117  * when an object receives focus.
 118  *
 119  * Adds the specified function to the list of functions to be called
 120  * when an object receives focus.
 121  *
 122  * Deprecated: 2.9.4: Focus tracking has been dropped as a feature
 123  * to be implemented by ATK itself. If you need focus tracking on your
 124  * implementation, subscribe to the #AtkObject::state-change "focused" signal.
 125  *
 126  * Returns: added focus tracker id, or 0 on failure.
 127  **/
 128 guint
 129 atk_add_focus_tracker (AtkEventListener   focus_tracker)
 130 {
 131   g_return_val_if_fail (focus_tracker, 0);
 132
 133   if (!init_done)
 134   {
 135     if (focus_tracker_init)
 136     {
 137       focus_tracker_init ();
 138     }
 139     trackers = g_array_sized_new (FALSE, TRUE, sizeof (FocusTracker), 0);
 140     init_done = TRUE;
 141   }
 142   if (init_done)
 143   {
 144     FocusTracker item;
 145
 146     item.index = ++global_index;
 147     item.func = focus_tracker;
 148     trackers = g_array_append_val (trackers, item);
 149     return global_index;
 150   }
 151   else
 152   {
 153     return 0;
 154   }
 155 }
 156
 157 /**
 158  * atk_remove_focus_tracker:
 159  * @tracker_id: the id of the focus tracker to remove
 160  *
 161  * Deprecated: 2.9.4: Focus tracking has been dropped as a feature
 162  * to be implemented by ATK itself. If you need focus tracking on your
 163  * implementation, subscribe to the #AtkObject::state-change "focused" signal.
 164  *
 165  * Removes the specified focus tracker from the list of functions
 166  * to be called when any object receives focus.
 167  **/
 168 void
 169 atk_remove_focus_tracker (guint            tracker_id)
 170 {
 171   FocusTracker *item;
 172   guint i;
 173
 174   if (trackers == NULL)
 175     return;
 176
 177   if (tracker_id == 0)
 178     return;
 179
 180   for (i = 0; i < trackers->len; i++)
 181   {
 182     item = &g_array_index (trackers, FocusTracker, i);
 183     if (item->index == tracker_id)
 184     {
 185       trackers = g_array_remove_index (trackers, i);
 186       break;
 187     }
 188   }
 189 }
 190
 191 /**
 192  * atk_focus_tracker_notify:
 193  * @object: an #AtkObject
 194  *
 195  * Cause the focus tracker functions which have been specified to be
 196  * executed for the object.
 197  *
 198  * Deprecated: 2.9.4: Focus tracking has been dropped as a feature
 199  * to be implemented by ATK itself. As #AtkObject::focus-event was
 200  * deprecated in favor of a #AtkObject::state-change signal, in order
 201  * to notify a focus change on your implementation, you can use
 202  * atk_object_notify_state_change() instead.
 203  **/
 204 void
 205 atk_focus_tracker_notify (AtkObject       *object)
 206 {
 207   FocusTracker *item;
 208   guint i;
 209
 210   if (trackers == NULL)
 211     return;
 212
 213   if (object == previous_focus_object)
 214     return;
 215   else
 216     {
 217       if (previous_focus_object)
 218         g_object_unref (previous_focus_object);
 219
 220       previous_focus_object = object;
 221       if (object)
 222         {
 223           g_object_ref (object);
 224
 225           for (i = 0; i < trackers->len; i++)
 226             {
 227               item = &g_array_index (trackers, FocusTracker, i);
 228               g_return_if_fail (item != NULL);
 229               item->func (object);
 230             }
 231         }
 232
 233     }
 234 }
 235
 236 static guint
 237 add_listener (GSignalEmissionHook listener,
 238               const gchar         *object_type,
 239               const gchar         *signal_name,
 240               const gchar         *detail_string,
 241               const gchar         *hook_data)
 242 {
 243   GType type;
 244   guint signal_id;
 245   gint  rc = 0;
 246   static gint listener_idx = 1;
 247   GQuark detail_quark = 0;
 248
 249   type = g_type_from_name (object_type);
 250   if (type)
 251     {
 252       signal_id  = g_signal_lookup (signal_name, type);
 253       detail_quark = g_quark_from_string (detail_string);
 254
 255       if (signal_id > 0)
 256         {
 257           AtkUtilListenerInfo *listener_info;
 258
 259           rc = listener_idx;
 260
 261           listener_info = g_new (AtkUtilListenerInfo, 1);
 262           listener_info->key = listener_idx;
 263           listener_info->hook_id =
 264             g_signal_add_emission_hook (signal_id, detail_quark, listener,
 265                                         g_strdup (hook_data),
 266                                         (GDestroyNotify) g_free);
 267           listener_info->signal_id = signal_id;
 268
 269           g_hash_table_insert(listener_list, &(listener_info->key), listener_info);
 270           listener_idx++;
 271         }
 272       else
 273         {
 274           g_debug ("Signal type %s not supported\n", signal_name);
 275         }
 276     }
 277   else
 278     {
 279       g_warning("Invalid object type %s\n", object_type);
 280     }
 281   return rc;
 282 }
 283
 284 static guint
 285 atk_util_real_add_global_event_listener (GSignalEmissionHook listener,
 286                                          const gchar *event_type)
 287 {
 288   guint rc = 0;
 289   gchar **split_string;
 290   guint length;
 291
 292   split_string = g_strsplit (event_type, ":", 0);
 293   length = g_strv_length (split_string);
 294
 295   if ((length == 3) || (length == 4))
 296     rc = add_listener (listener, split_string[1], split_string[2],
 297                        split_string[3], event_type);
 298
 299   g_strfreev (split_string);
 300
 301   return rc;
 302 }
 303
 304 static void
 305 atk_util_real_remove_global_event_listener (guint remove_listener)
 306 {
 307   if (remove_listener > 0)
 308     {
 309       AtkUtilListenerInfo *listener_info;
 310       gint tmp_idx = remove_listener;
 311
 312       listener_info = (AtkUtilListenerInfo *)
 313         g_hash_table_lookup(listener_list, &tmp_idx);
 314
 315       if (listener_info != NULL)
 316         {
 317           /* Hook id of 0 and signal id of 0 are invalid */
 318           if (listener_info->hook_id != 0 && listener_info->signal_id != 0)
 319             {
 320               /* Remove the emission hook */
 321               g_signal_remove_emission_hook(listener_info->signal_id,
 322                                             listener_info->hook_id);
 323
 324               /* Remove the element from the hash */
 325               g_hash_table_remove(listener_list, &tmp_idx);
 326             }
 327           else
 328             {
 329               g_warning("Invalid listener hook_id %ld or signal_id %d\n",
 330                         listener_info->hook_id, listener_info->signal_id);
 331             }
 332         }
 333       else
 334         {
 335           g_warning("No listener with the specified listener id %d",
 336                     remove_listener);
 337         }
 338     }
 339   else
 340     {
 341       g_warning("Invalid listener_id %d", remove_listener);
 342     }
 343 }
 344
 345
 346 /**
 347  * atk_add_global_event_listener: (skip)
 348  * @listener: the listener to notify
 349  * @event_type: the type of event for which notification is requested
 350  *
 351  * Adds the specified function to the list of functions to be called
 352  * when an ATK event of type event_type occurs.
 353  *
 354  * The format of event_type is the following:
 355  *  "ATK:&lt;atk_type&gt;:&lt;atk_event&gt;:&lt;atk_event_detail&gt;
 356  *
 357  * Where "ATK" works as the namespace, &lt;atk_interface&gt; is the name of
 358  * the ATK type (interface or object), &lt;atk_event&gt; is the name of the
 359  * signal defined on that interface and &lt;atk_event_detail&gt; is the
 360  * gsignal detail of that signal. You can find more info about gsignal
 361  * details here:
 362  * http://developer.gnome.org/gobject/stable/gobject-Signals.html
 363  *
 364  * The first three parameters are mandatory. The last one is optional.
 365  *
 366  * For example:
 367  *   ATK:AtkObject:state-change
 368  *   ATK:AtkText:text-selection-changed
 369  *   ATK:AtkText:text-insert:system
 370  *
 371  * Toolkit implementor note: ATK provides a default implementation for
 372  * this virtual method. ATK implementors are discouraged from
 373  * reimplementing this method.
 374  *
 375  * Toolkit implementor note: this method is not intended to be used by
 376  * ATK implementors but by ATK consumers.
 377  *
 378  * ATK consumers note: as this method adds a listener for a given ATK
 379  * type, that type should be already registered on the GType system
 380  * before calling this method. A simple way to do that is creating an
 381  * instance of #AtkNoOpObject. This class implements all ATK
 382  * interfaces, so creating the instance will register all ATK types as
 383  * a collateral effect.
 384  *
 385  * Returns: added event listener id, or 0 on failure.
 386  **/
 387 guint
 388 atk_add_global_event_listener (GSignalEmissionHook listener,
 389                                const gchar        *event_type)
 390 {
 391   guint retval;
 392   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 393
 394   if (klass->add_global_event_listener)
 395     {
 396       retval = klass->add_global_event_listener (listener, event_type);
 397     }
 398   else
 399     {
 400       retval = 0;
 401     }
 402   g_type_class_unref (klass);
 403
 404   return retval;
 405 }
 406
 407 /**
 408  * atk_remove_global_event_listener:
 409  * @listener_id: the id of the event listener to remove
 410  *
 411  * @listener_id is the value returned by #atk_add_global_event_listener
 412  * when you registered that event listener.
 413  *
 414  * Toolkit implementor note: ATK provides a default implementation for
 415  * this virtual method. ATK implementors are discouraged from
 416  * reimplementing this method.
 417  *
 418  * Toolkit implementor note: this method is not intended to be used by
 419  * ATK implementors but by ATK consumers.
 420  *
 421  * Removes the specified event listener
 422  **/
 423 void
 424 atk_remove_global_event_listener (guint listener_id)
 425 {
 426   AtkUtilClass *klass = g_type_class_peek (ATK_TYPE_UTIL);
 427
 428   if (klass && klass->remove_global_event_listener)
 429     klass->remove_global_event_listener (listener_id);
 430 }
 431
 432 /**
 433  * atk_add_key_event_listener: (skip)
 434  * @listener: the listener to notify
 435  * @data: a #gpointer that points to a block of data that should be sent to the registered listeners,
 436  *        along with the event notification, when it occurs.
 437  *
 438  * Adds the specified function to the list of functions to be called
 439  *        when a key event occurs.  The @data element will be passed to the
 440  *        #AtkKeySnoopFunc (@listener) as the @func_data param, on notification.
 441  *
 442  * Returns: added event listener id, or 0 on failure.
 443  **/
 444 guint
 445 atk_add_key_event_listener (AtkKeySnoopFunc listener, gpointer data)
 446 {
 447   guint retval;
 448   AtkUtilClass *klass = g_type_class_peek (ATK_TYPE_UTIL);
 449   if (klass && klass->add_key_event_listener)
 450     {
 451       retval = klass->add_key_event_listener (listener, data);
 452     }
 453   else
 454     {
 455       retval = 0;
 456     }
 457
 458   return retval;
 459 }
 460
 461 /**
 462  * atk_remove_key_event_listener:
 463  * @listener_id: the id of the event listener to remove
 464  *
 465  * @listener_id is the value returned by #atk_add_key_event_listener
 466  * when you registered that event listener.
 467  *
 468  * Removes the specified event listener.
 469  **/
 470 void
 471 atk_remove_key_event_listener (guint listener_id)
 472 {
 473   AtkUtilClass *klass = g_type_class_peek (ATK_TYPE_UTIL);
 474
 475   if (klass->remove_key_event_listener)
 476     klass->remove_key_event_listener (listener_id);
 477 }
 478
 479 /**
 480  * atk_get_root:
 481  *
 482  * Gets the root accessible container for the current application.
 483  *
 484  * Returns: (transfer none): the root accessible container for the current
 485  * application
 486  **/
 487 AtkObject*
 488 atk_get_root (void)
 489 {
 490   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 491   AtkObject    *retval;
 492   if (klass->get_root)
 493     {
 494       retval = klass->get_root ();
 495     }
 496   else
 497     {
 498       retval = NULL;
 499     }
 500   g_type_class_unref (klass);
 501
 502   return retval;
 503 }
 504
 505 /**
 506  * atk_get_focus_object:
 507  *
 508  * Gets the currently focused object.
 509  *
 510  * Since: 1.6
 511  *
 512  * Returns: (transfer none): the currently focused object for the current
 513  * application
 514  **/
 515 AtkObject*
 516 atk_get_focus_object (void)
 517 {
 518   return previous_focus_object;
 519 }
 520
 521 /**
 522  * atk_get_toolkit_name:
 523  *
 524  * Gets name string for the GUI toolkit implementing ATK for this application.
 525  *
 526  * Returns: name string for the GUI toolkit implementing ATK for this application
 527  **/
 528 const gchar*
 529 atk_get_toolkit_name (void)
 530 {
 531   const gchar *retval;
 532   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 533   if (klass->get_toolkit_name)
 534     {
 535       retval = klass->get_toolkit_name ();
 536     }
 537   else
 538     {
 539       retval = NULL;
 540     }
 541   g_type_class_unref (klass);
 542
 543   return retval;
 544 }
 545
 546 /**
 547  * atk_get_toolkit_version:
 548  *
 549  * Gets version string for the GUI toolkit implementing ATK for this application.
 550  *
 551  * Returns: version string for the GUI toolkit implementing ATK for this application
 552  **/
 553 const gchar*
 554 atk_get_toolkit_version (void)
 555 {
 556   const gchar *retval;
 557   AtkUtilClass *klass = g_type_class_ref (ATK_TYPE_UTIL);
 558   if (klass->get_toolkit_version)
 559     {
 560       retval = klass->get_toolkit_version ();
 561     }
 562   else
 563     {
 564       retval = NULL;
 565     }
 566   g_type_class_unref (klass);
 567
 568   return retval;
 569 }
 570
 571 /**
 572  * atk_get_version:
 573  *
 574  * Gets the current version for ATK.
 575  *
 576  * Returns: version string for ATK
 577  *
 578  * Since: 1.20
 579  */
 580 const gchar *
 581 atk_get_version (void)
 582 {
 583   return VERSION;
 584 }
 585
 586 static void
 587 atk_util_class_init (AtkUtilClass *klass)
 588 {
 589   klass->add_global_event_listener = atk_util_real_add_global_event_listener;
 590   klass->remove_global_event_listener = atk_util_real_remove_global_event_listener;
 591   klass->get_root = NULL;
 592   klass->get_toolkit_name = NULL;
 593   klass->get_toolkit_version = NULL;
 594
 595   listener_list = g_hash_table_new_full (g_int_hash, g_int_equal, NULL,
 596                                          g_free);
 597 }