src/content/browser/accessibility/browser_accessibility_gtk.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/accessibility/browser_accessibility_gtk.h"
   6
   7 #include <gtk/gtk.h>
   8
   9 #include "base/strings/utf_string_conversions.h"
  10 #include "content/browser/accessibility/browser_accessibility_manager_gtk.h"
  11 #include "content/common/accessibility_messages.h"
  12
  13 namespace content {
  14
  15 static gpointer browser_accessibility_parent_class = NULL;
  16
  17 static BrowserAccessibilityGtk* ToBrowserAccessibilityGtk(
  18     BrowserAccessibilityAtk* atk_object) {
  19   if (!atk_object)
  20     return NULL;
  21
  22   return atk_object->m_object;
  23 }
  24
  25 //
  26 // AtkComponent interface.
  27 //
  28
  29 static BrowserAccessibilityGtk* ToBrowserAccessibilityGtk(
  30     AtkComponent* atk_object) {
  31   if (!IS_BROWSER_ACCESSIBILITY(atk_object))
  32     return NULL;
  33
  34   return ToBrowserAccessibilityGtk(BROWSER_ACCESSIBILITY(atk_object));
  35 }
  36
  37 static AtkObject* browser_accessibility_accessible_at_point(
  38     AtkComponent* component, gint x, gint y, AtkCoordType coord_type) {
  39   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(component);
  40   if (!obj)
  41     return NULL;
  42
  43   gfx::Point point(x, y);
  44   if (!obj->GetGlobalBoundsRect().Contains(point))
  45     return NULL;
  46
  47   BrowserAccessibility* result = obj->BrowserAccessibilityForPoint(point);
  48   if (!result)
  49     return NULL;
  50
  51   AtkObject* atk_result = result->ToBrowserAccessibilityGtk()->GetAtkObject();
  52   g_object_ref(atk_result);
  53   return atk_result;
  54 }
  55
  56 static void browser_accessibility_get_extents(
  57     AtkComponent* component, gint* x, gint* y, gint* width, gint* height,
  58     AtkCoordType coord_type) {
  59   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(component);
  60   if (!obj)
  61     return;
  62
  63   gfx::Rect bounds = obj->GetGlobalBoundsRect();
  64   *x = bounds.x();
  65   *y = bounds.y();
  66   *width = bounds.width();
  67   *height = bounds.height();
  68 }
  69
  70 static gboolean browser_accessibility_grab_focus(AtkComponent* component) {
  71   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(component);
  72   if (!obj)
  73     return false;
  74
  75   obj->manager()->SetFocus(obj, true);
  76   return true;
  77 }
  78
  79 static void ComponentInterfaceInit(AtkComponentIface* iface) {
  80   iface->ref_accessible_at_point = browser_accessibility_accessible_at_point;
  81   iface->get_extents = browser_accessibility_get_extents;
  82   iface->grab_focus = browser_accessibility_grab_focus;
  83 }
  84
  85 static const GInterfaceInfo ComponentInfo = {
  86   reinterpret_cast<GInterfaceInitFunc>(ComponentInterfaceInit), 0, 0
  87 };
  88
  89 //
  90 // AtkValue interface.
  91 //
  92
  93 static BrowserAccessibilityGtk* ToBrowserAccessibilityGtk(
  94     AtkValue* atk_object) {
  95   if (!IS_BROWSER_ACCESSIBILITY(atk_object))
  96     return NULL;
  97
  98   return ToBrowserAccessibilityGtk(BROWSER_ACCESSIBILITY(atk_object));
  99 }
 100
 101 static void browser_accessibility_get_current_value(
 102     AtkValue* atk_object, GValue* value) {
 103   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 104   if (!obj)
 105     return;
 106
 107   float float_val;
 108   if (obj->GetFloatAttribute(AccessibilityNodeData::ATTR_VALUE_FOR_RANGE,
 109                              &float_val)) {
 110     memset(value, 0, sizeof(*value));
 111     g_value_init(value, G_TYPE_FLOAT);
 112     g_value_set_float(value, float_val);
 113   }
 114 }
 115
 116 static void browser_accessibility_get_minimum_value(
 117     AtkValue* atk_object, GValue* value) {
 118   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 119   if (!obj)
 120     return;
 121
 122   float float_val;
 123   if (obj->GetFloatAttribute(AccessibilityNodeData::ATTR_MIN_VALUE_FOR_RANGE,
 124                              &float_val)) {
 125     memset(value, 0, sizeof(*value));
 126     g_value_init(value, G_TYPE_FLOAT);
 127     g_value_set_float(value, float_val);
 128   }
 129 }
 130
 131 static void browser_accessibility_get_maximum_value(
 132     AtkValue* atk_object, GValue* value) {
 133   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 134   if (!obj)
 135     return;
 136
 137   float float_val;
 138   if (obj->GetFloatAttribute(AccessibilityNodeData::ATTR_MAX_VALUE_FOR_RANGE,
 139                              &float_val)) {
 140     memset(value, 0, sizeof(*value));
 141     g_value_init(value, G_TYPE_FLOAT);
 142     g_value_set_float(value, float_val);
 143   }
 144 }
 145
 146 static void browser_accessibility_get_minimum_increment(
 147     AtkValue* atk_object, GValue* value) {
 148   // TODO(dmazzoni): get the correct value from an <input type=range>.
 149   memset(value, 0, sizeof(*value));
 150   g_value_init(value, G_TYPE_FLOAT);
 151   g_value_set_float(value, 1.0);
 152 }
 153
 154 static void ValueInterfaceInit(AtkValueIface* iface) {
 155   iface->get_current_value = browser_accessibility_get_current_value;
 156   iface->get_minimum_value = browser_accessibility_get_minimum_value;
 157   iface->get_maximum_value = browser_accessibility_get_maximum_value;
 158   iface->get_minimum_increment = browser_accessibility_get_minimum_increment;
 159 }
 160
 161 static const GInterfaceInfo ValueInfo = {
 162   reinterpret_cast<GInterfaceInitFunc>(ValueInterfaceInit), 0, 0
 163 };
 164
 165 //
 166 // AtkObject interface
 167 //
 168
 169 static BrowserAccessibilityGtk* ToBrowserAccessibilityGtk(
 170     AtkObject* atk_object) {
 171   if (!IS_BROWSER_ACCESSIBILITY(atk_object))
 172     return NULL;
 173
 174   return ToBrowserAccessibilityGtk(BROWSER_ACCESSIBILITY(atk_object));
 175 }
 176
 177 static const gchar* browser_accessibility_get_name(AtkObject* atk_object) {
 178   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 179   if (!obj)
 180     return NULL;
 181
 182   return obj->GetStringAttribute(AccessibilityNodeData::ATTR_NAME).c_str();
 183 }
 184
 185 static const gchar* browser_accessibility_get_description(
 186     AtkObject* atk_object) {
 187   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 188   if (!obj)
 189     return NULL;
 190
 191   return obj->GetStringAttribute(
 192       AccessibilityNodeData::ATTR_DESCRIPTION).c_str();
 193 }
 194
 195 static AtkObject* browser_accessibility_get_parent(AtkObject* atk_object) {
 196   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 197   if (!obj)
 198     return NULL;
 199   if (obj->parent())
 200     return obj->parent()->ToBrowserAccessibilityGtk()->GetAtkObject();
 201
 202   BrowserAccessibilityManagerGtk* manager =
 203       static_cast<BrowserAccessibilityManagerGtk*>(obj->manager());
 204   return gtk_widget_get_accessible(manager->parent_widget());
 205 }
 206
 207 static gint browser_accessibility_get_n_children(AtkObject* atk_object) {
 208   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 209   if (!obj)
 210     return 0;
 211
 212   return obj->PlatformChildCount();
 213 }
 214
 215 static AtkObject* browser_accessibility_ref_child(
 216     AtkObject* atk_object, gint index) {
 217   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 218   if (!obj)
 219     return NULL;
 220
 221   if (index < 0 || index >= static_cast<gint>(obj->PlatformChildCount()))
 222     return NULL;
 223
 224   AtkObject* result =
 225       obj->children()[index]->ToBrowserAccessibilityGtk()->GetAtkObject();
 226   g_object_ref(result);
 227   return result;
 228 }
 229
 230 static gint browser_accessibility_get_index_in_parent(AtkObject* atk_object) {
 231   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 232   if (!obj)
 233     return 0;
 234   return obj->index_in_parent();
 235 }
 236
 237 static AtkAttributeSet* browser_accessibility_get_attributes(
 238     AtkObject* atk_object) {
 239   return NULL;
 240 }
 241
 242 static AtkRole browser_accessibility_get_role(AtkObject* atk_object) {
 243   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 244   if (!obj)
 245     return ATK_ROLE_INVALID;
 246   return obj->atk_role();
 247 }
 248
 249 static AtkStateSet* browser_accessibility_ref_state_set(AtkObject* atk_object) {
 250   BrowserAccessibilityGtk* obj = ToBrowserAccessibilityGtk(atk_object);
 251   if (!obj)
 252     return NULL;
 253   AtkStateSet* state_set =
 254       ATK_OBJECT_CLASS(browser_accessibility_parent_class)->
 255           ref_state_set(atk_object);
 256   int32 state = obj->state();
 257
 258   if (state & (1 << WebKit::WebAXStateFocusable))
 259     atk_state_set_add_state(state_set, ATK_STATE_FOCUSABLE);
 260   if (obj->manager()->GetFocus(NULL) == obj)
 261     atk_state_set_add_state(state_set, ATK_STATE_FOCUSED);
 262   if (state & (1 << WebKit::WebAXStateEnabled))
 263     atk_state_set_add_state(state_set, ATK_STATE_ENABLED);
 264
 265   return state_set;
 266 }
 267
 268 static AtkRelationSet* browser_accessibility_ref_relation_set(
 269     AtkObject* atk_object) {
 270   AtkRelationSet* relation_set =
 271       ATK_OBJECT_CLASS(browser_accessibility_parent_class)
 272           ->ref_relation_set(atk_object);
 273   return relation_set;
 274 }
 275
 276 //
 277 // The rest of the BrowserAccessibilityGtk code, not specific to one
 278 // of the Atk* interfaces.
 279 //
 280
 281 static void browser_accessibility_init(AtkObject* atk_object, gpointer data) {
 282   if (ATK_OBJECT_CLASS(browser_accessibility_parent_class)->initialize) {
 283     ATK_OBJECT_CLASS(browser_accessibility_parent_class)->initialize(
 284         atk_object, data);
 285   }
 286
 287   BROWSER_ACCESSIBILITY(atk_object)->m_object =
 288       reinterpret_cast<BrowserAccessibilityGtk*>(data);
 289 }
 290
 291 static void browser_accessibility_finalize(GObject* atk_object) {
 292   G_OBJECT_CLASS(browser_accessibility_parent_class)->finalize(atk_object);
 293 }
 294
 295 static void browser_accessibility_class_init(AtkObjectClass* klass) {
 296   GObjectClass* gobject_class = G_OBJECT_CLASS(klass);
 297   browser_accessibility_parent_class = g_type_class_peek_parent(klass);
 298
 299   gobject_class->finalize = browser_accessibility_finalize;
 300   klass->initialize = browser_accessibility_init;
 301   klass->get_name = browser_accessibility_get_name;
 302   klass->get_description = browser_accessibility_get_description;
 303   klass->get_parent = browser_accessibility_get_parent;
 304   klass->get_n_children = browser_accessibility_get_n_children;
 305   klass->ref_child = browser_accessibility_ref_child;
 306   klass->get_role = browser_accessibility_get_role;
 307   klass->ref_state_set = browser_accessibility_ref_state_set;
 308   klass->get_index_in_parent = browser_accessibility_get_index_in_parent;
 309   klass->get_attributes = browser_accessibility_get_attributes;
 310   klass->ref_relation_set = browser_accessibility_ref_relation_set;
 311 }
 312
 313 GType browser_accessibility_get_type() {
 314   static volatile gsize type_volatile = 0;
 315
 316   if (g_once_init_enter(&type_volatile)) {
 317     static const GTypeInfo tinfo = {
 318       sizeof(BrowserAccessibilityAtkClass),
 319       (GBaseInitFunc) 0,
 320       (GBaseFinalizeFunc) 0,
 321       (GClassInitFunc) browser_accessibility_class_init,
 322       (GClassFinalizeFunc) 0,
 323       0, /* class data */
 324       sizeof(BrowserAccessibilityAtk), /* instance size */
 325       0, /* nb preallocs */
 326       (GInstanceInitFunc) 0,
 327       0 /* value table */
 328     };
 329
 330     GType type = g_type_register_static(
 331         ATK_TYPE_OBJECT, "BrowserAccessibility", &tinfo, GTypeFlags(0));
 332     g_once_init_leave(&type_volatile, type);
 333   }
 334
 335   return type_volatile;
 336 }
 337
 338 static const char* GetUniqueAccessibilityTypeName(int interface_mask)
 339 {
 340   // 20 characters is enough for "Chrome%x" with any integer value.
 341   static char name[20];
 342   snprintf(name, sizeof(name), "Chrome%x", interface_mask);
 343   return name;
 344 }
 345
 346 enum AtkInterfaces {
 347   ATK_ACTION_INTERFACE,
 348   ATK_COMPONENT_INTERFACE,
 349   ATK_DOCUMENT_INTERFACE,
 350   ATK_EDITABLE_TEXT_INTERFACE,
 351   ATK_HYPERLINK_INTERFACE,
 352   ATK_HYPERTEXT_INTERFACE,
 353   ATK_IMAGE_INTERFACE,
 354   ATK_SELECTION_INTERFACE,
 355   ATK_TABLE_INTERFACE,
 356   ATK_TEXT_INTERFACE,
 357   ATK_VALUE_INTERFACE,
 358 };
 359
 360 static int GetInterfaceMaskFromObject(BrowserAccessibilityGtk* obj) {
 361   int interface_mask = 0;
 362
 363   // Component interface is always supported.
 364   interface_mask |= 1 << ATK_COMPONENT_INTERFACE;
 365
 366   int role = obj->role();
 367   if (role == WebKit::WebAXRoleProgressIndicator ||
 368       role == WebKit::WebAXRoleScrollBar ||
 369       role == WebKit::WebAXRoleSlider) {
 370     interface_mask |= 1 << ATK_VALUE_INTERFACE;
 371   }
 372
 373   return interface_mask;
 374 }
 375
 376 static GType GetAccessibilityTypeFromObject(BrowserAccessibilityGtk* obj) {
 377   static const GTypeInfo type_info = {
 378     sizeof(BrowserAccessibilityAtkClass),
 379     (GBaseInitFunc) 0,
 380     (GBaseFinalizeFunc) 0,
 381     (GClassInitFunc) 0,
 382     (GClassFinalizeFunc) 0,
 383     0, /* class data */
 384     sizeof(BrowserAccessibilityAtk), /* instance size */
 385     0, /* nb preallocs */
 386     (GInstanceInitFunc) 0,
 387     0 /* value table */
 388   };
 389
 390   int interface_mask = GetInterfaceMaskFromObject(obj);
 391   const char* atk_type_name = GetUniqueAccessibilityTypeName(interface_mask);
 392   GType type = g_type_from_name(atk_type_name);
 393   if (type)
 394     return type;
 395
 396   type = g_type_register_static(BROWSER_ACCESSIBILITY_TYPE,
 397                                 atk_type_name,
 398                                 &type_info,
 399                                 GTypeFlags(0));
 400   if (interface_mask & (1 << ATK_COMPONENT_INTERFACE))
 401     g_type_add_interface_static(type, ATK_TYPE_COMPONENT, &ComponentInfo);
 402   if (interface_mask & (1 << ATK_VALUE_INTERFACE))
 403     g_type_add_interface_static(type, ATK_TYPE_VALUE, &ValueInfo);
 404
 405   return type;
 406 }
 407
 408 BrowserAccessibilityAtk* browser_accessibility_new(
 409     BrowserAccessibilityGtk* obj) {
 410   GType type = GetAccessibilityTypeFromObject(obj);
 411   AtkObject* atk_object = static_cast<AtkObject*>(g_object_new(type, 0));
 412
 413   atk_object_initialize(atk_object, obj);
 414
 415   return BROWSER_ACCESSIBILITY(atk_object);
 416 }
 417
 418 void browser_accessibility_detach(BrowserAccessibilityAtk* atk_object) {
 419   atk_object->m_object = NULL;
 420 }
 421
 422 // static
 423 BrowserAccessibility* BrowserAccessibility::Create() {
 424   return new BrowserAccessibilityGtk();
 425 }
 426
 427 BrowserAccessibilityGtk* BrowserAccessibility::ToBrowserAccessibilityGtk() {
 428   return static_cast<BrowserAccessibilityGtk*>(this);
 429 }
 430
 431 BrowserAccessibilityGtk::BrowserAccessibilityGtk()
 432     : atk_object_(NULL) {
 433 }
 434
 435 BrowserAccessibilityGtk::~BrowserAccessibilityGtk() {
 436   browser_accessibility_detach(BROWSER_ACCESSIBILITY(atk_object_));
 437   if (atk_object_)
 438     g_object_unref(atk_object_);
 439 }
 440
 441 AtkObject* BrowserAccessibilityGtk::GetAtkObject() const {
 442   if (!G_IS_OBJECT(atk_object_))
 443     return NULL;
 444   return atk_object_;
 445 }
 446
 447 void BrowserAccessibilityGtk::PreInitialize() {
 448   BrowserAccessibility::PreInitialize();
 449   InitRoleAndState();
 450
 451   if (atk_object_) {
 452     // If the object's role changes and that causes its
 453     // interface mask to change, we need to create a new
 454     // AtkObject for it.
 455     int interface_mask = GetInterfaceMaskFromObject(this);
 456     if (interface_mask != interface_mask_) {
 457       g_object_unref(atk_object_);
 458       atk_object_ = NULL;
 459     }
 460   }
 461
 462   if (!atk_object_) {
 463     interface_mask_ = GetInterfaceMaskFromObject(this);
 464     atk_object_ = ATK_OBJECT(browser_accessibility_new(this));
 465     if (this->parent()) {
 466       atk_object_set_parent(
 467           atk_object_,
 468           this->parent()->ToBrowserAccessibilityGtk()->GetAtkObject());
 469     }
 470   }
 471 }
 472
 473 bool BrowserAccessibilityGtk::IsNative() const {
 474   return true;
 475 }
 476
 477 void BrowserAccessibilityGtk::InitRoleAndState() {
 478   switch(role_) {
 479     case WebKit::WebAXRoleDocument:
 480     case WebKit::WebAXRoleRootWebArea:
 481     case WebKit::WebAXRoleWebArea:
 482       atk_role_ = ATK_ROLE_DOCUMENT_WEB;
 483       break;
 484     case WebKit::WebAXRoleGroup:
 485     case WebKit::WebAXRoleDiv:
 486       atk_role_ = ATK_ROLE_SECTION;
 487       break;
 488     case WebKit::WebAXRoleButton:
 489       atk_role_ = ATK_ROLE_PUSH_BUTTON;
 490       break;
 491     case WebKit::WebAXRoleCheckBox:
 492       atk_role_ = ATK_ROLE_CHECK_BOX;
 493       break;
 494     case WebKit::WebAXRoleComboBox:
 495       atk_role_ = ATK_ROLE_COMBO_BOX;
 496       break;
 497     case WebKit::WebAXRoleLink:
 498       atk_role_ = ATK_ROLE_LINK;
 499       break;
 500     case WebKit::WebAXRoleRadioButton:
 501       atk_role_ = ATK_ROLE_RADIO_BUTTON;
 502       break;
 503     case WebKit::WebAXRoleStaticText:
 504       atk_role_ = ATK_ROLE_TEXT;
 505       break;
 506     case WebKit::WebAXRoleTextArea:
 507       atk_role_ = ATK_ROLE_ENTRY;
 508       break;
 509     case WebKit::WebAXRoleTextField:
 510       atk_role_ = ATK_ROLE_ENTRY;
 511       break;
 512     default:
 513       atk_role_ = ATK_ROLE_UNKNOWN;
 514       break;
 515   }
 516 }
 517
 518 }  // namespace content