1 // Copyright (c) 2011 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 #ifndef CHROME_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_ 6 #define CHROME_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_ 7 #pragma once 8 9 #include <vector> 10 11 #include "base/hash_tables.h" 12 #include "base/memory/scoped_ptr.h" 13 #include "build/build_config.h" 14 #include "ui/gfx/native_widget_types.h" 15 #include "webkit/glue/webaccessibility.h" 16 17 class BrowserAccessibility; 18 #if defined(OS_WIN) 19 class BrowserAccessibilityManagerWin; 20 #endif 21 22 struct ViewHostMsg_AccessibilityNotification_Params; 23 24 using webkit_glue::WebAccessibility; 25 26 // Class that can perform actions on behalf of the BrowserAccessibilityManager. 27 class BrowserAccessibilityDelegate { 28 public: ~BrowserAccessibilityDelegate()29 virtual ~BrowserAccessibilityDelegate() {} 30 virtual void SetAccessibilityFocus(int acc_obj_id) = 0; 31 virtual void AccessibilityDoDefaultAction(int acc_obj_id) = 0; 32 virtual bool HasFocus() = 0; 33 virtual gfx::Rect GetViewBounds() const = 0; 34 }; 35 36 class BrowserAccessibilityFactory { 37 public: ~BrowserAccessibilityFactory()38 virtual ~BrowserAccessibilityFactory() {} 39 40 // Create an instance of BrowserAccessibility and return a new 41 // reference to it. 42 virtual BrowserAccessibility* Create(); 43 }; 44 45 // Manages a tree of BrowserAccessibility objects. 46 class BrowserAccessibilityManager { 47 public: 48 // Creates the platform specific BrowserAccessibilityManager. Ownership passes 49 // to the caller. 50 static BrowserAccessibilityManager* Create( 51 gfx::NativeView parent_view, 52 const WebAccessibility& src, 53 BrowserAccessibilityDelegate* delegate, 54 BrowserAccessibilityFactory* factory = new BrowserAccessibilityFactory()); 55 56 virtual ~BrowserAccessibilityManager(); 57 58 // Type is a ViewHostMsg_AccessibilityNotification_Params::NotificationType. 59 // We pass it as int so that we don't include the render message declaration 60 // header here. NotifyAccessibilityEvent(int type,BrowserAccessibility * node)61 virtual void NotifyAccessibilityEvent( 62 int type, 63 BrowserAccessibility* node) { } 64 65 // Returns the next unique child id. 66 static int32 GetNextChildID(); 67 68 // Return a pointer to the root of the tree, does not make a new reference. 69 BrowserAccessibility* GetRoot(); 70 71 // Removes the BrowserAccessibility child_id and renderer_id from the manager. 72 void Remove(int32 child_id, int32 renderer_id); 73 74 // Return a pointer to the object corresponding to the given child_id, 75 // does not make a new reference. 76 BrowserAccessibility* GetFromChildID(int32 child_id); 77 78 // Called to notify the accessibility manager that its associated native 79 // view got focused. 80 void GotFocus(); 81 82 // Update the focused node to |node|, which may be null. 83 // If |notify| is true, send a message to the renderer to set focus 84 // to this node. 85 void SetFocus(BrowserAccessibility* node, bool notify); 86 87 // Tell the renderer to do the default action for this node. 88 void DoDefaultAction(const BrowserAccessibility& node); 89 90 // Retrieve the bounds of the parent View in screen coordinates. 91 gfx::Rect GetViewBounds(); 92 93 // Called when the renderer process has notified us of about tree changes. 94 // Send a notification to MSAA clients of the change. 95 void OnAccessibilityNotifications( 96 const std::vector<ViewHostMsg_AccessibilityNotification_Params>& params); 97 98 gfx::NativeView GetParentView(); 99 100 #if defined(OS_WIN) 101 BrowserAccessibilityManagerWin* toBrowserAccessibilityManagerWin(); 102 #endif 103 104 // Return the object that has focus, if it's a descandant of the 105 // given root (inclusive). Does not make a new reference. 106 BrowserAccessibility* GetFocus(BrowserAccessibility* root); 107 108 protected: 109 BrowserAccessibilityManager( 110 gfx::NativeView parent_view, 111 const WebAccessibility& src, 112 BrowserAccessibilityDelegate* delegate, 113 BrowserAccessibilityFactory* factory); 114 115 private: 116 void OnAccessibilityObjectStateChange( 117 const WebAccessibility& acc_obj); 118 void OnAccessibilityObjectChildrenChange( 119 const WebAccessibility& acc_obj); 120 void OnAccessibilityObjectFocusChange( 121 const WebAccessibility& acc_obj); 122 void OnAccessibilityObjectLoadComplete( 123 const WebAccessibility& acc_obj); 124 void OnAccessibilityObjectValueChange( 125 const WebAccessibility& acc_obj); 126 void OnAccessibilityObjectTextChange( 127 const WebAccessibility& acc_obj); 128 129 // Update an accessibility node with an updated WebAccessibility node 130 // received from the renderer process. When |include_children| is true 131 // the node's children will also be updated, otherwise only the node 132 // itself is updated. Returns the updated node or NULL if no node was 133 // updated. 134 BrowserAccessibility* UpdateNode( 135 const WebAccessibility& src, 136 bool include_children); 137 138 // Recursively build a tree of BrowserAccessibility objects from 139 // the WebAccessibility tree received from the renderer process. 140 BrowserAccessibility* CreateAccessibilityTree( 141 BrowserAccessibility* parent, 142 const WebAccessibility& src, 143 int index_in_parent); 144 145 protected: 146 // The next unique id for a BrowserAccessibility instance. 147 static int32 next_child_id_; 148 149 // The parent view. 150 gfx::NativeView parent_view_; 151 152 // The object that can perform actions on our behalf. 153 BrowserAccessibilityDelegate* delegate_; 154 155 // Factory to create BrowserAccessibility objects (for dependency injection). 156 scoped_ptr<BrowserAccessibilityFactory> factory_; 157 158 // The root of the tree of IAccessible objects and the element that 159 // currently has focus, if any. 160 BrowserAccessibility* root_; 161 BrowserAccessibility* focus_; 162 163 // A mapping from the IDs of objects in the renderer, to the child IDs 164 // we use internally here. 165 base::hash_map<int32, int32> renderer_id_to_child_id_map_; 166 167 // A mapping from child IDs to BrowserAccessibility objects. 168 base::hash_map<int32, BrowserAccessibility*> child_id_map_; 169 170 DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManager); 171 }; 172 173 #endif // CHROME_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_H_ 174