| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_H_ |
| #define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_H_ |
| |
| #include <map> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/basictypes.h" |
| #include "base/strings/string16.h" |
| #include "build/build_config.h" |
| #include "content/common/accessibility_node_data.h" |
| #include "content/common/content_export.h" |
| |
| #if defined(OS_MACOSX) && __OBJC__ |
| @class BrowserAccessibilityCocoa; |
| #endif |
| |
| namespace content { |
| class BrowserAccessibilityManager; |
| #if defined(OS_WIN) |
| class BrowserAccessibilityWin; |
| #elif defined(TOOLKIT_GTK) |
| class BrowserAccessibilityGtk; |
| #endif |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // |
| // BrowserAccessibility |
| // |
| // Class implementing the cross platform interface for the Browser-Renderer |
| // communication of accessibility information, providing accessibility |
| // to be used by screen readers and other assistive technology (AT). |
| // |
| // An implementation for each platform handles platform specific accessibility |
| // APIs. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| class CONTENT_EXPORT BrowserAccessibility { |
| public: |
| // Creates a platform specific BrowserAccessibility. Ownership passes to the |
| // caller. |
| static BrowserAccessibility* Create(); |
| |
| virtual ~BrowserAccessibility(); |
| |
| // Detach all descendants of this subtree and push all of the node pointers, |
| // including this node, onto the end of |nodes|. |
| virtual void DetachTree(std::vector<BrowserAccessibility*>* nodes); |
| |
| // Perform platform-specific initialization. This can be called multiple times |
| // during the lifetime of this instance after the members of this base object |
| // have been reset with new values from the renderer process. |
| // Child dependent initialization can be done here. |
| virtual void PostInitialize() {} |
| |
| // Returns true if this is a native platform-specific object, vs a |
| // cross-platform generic object. |
| virtual bool IsNative() const; |
| |
| // Initialize the tree structure of this object. |
| void InitializeTreeStructure( |
| BrowserAccessibilityManager* manager, |
| BrowserAccessibility* parent, |
| int32 renderer_id, |
| int32 index_in_parent); |
| |
| // Initialize this object's data. |
| void InitializeData(const AccessibilityNodeData& src); |
| |
| virtual void SwapChildren(std::vector<BrowserAccessibility*>& children); |
| |
| // Update the parent and index in parent if this node has been moved. |
| void UpdateParent(BrowserAccessibility* parent, int index_in_parent); |
| |
| // Update this node's location, leaving everything else the same. |
| virtual void SetLocation(const gfx::Rect& new_location); |
| |
| // Return true if this object is equal to or a descendant of |ancestor|. |
| bool IsDescendantOf(BrowserAccessibility* ancestor); |
| |
| // Returns the parent of this object, or NULL if it's the root. |
| BrowserAccessibility* parent() const { return parent_; } |
| |
| // Returns the number of children of this object. |
| uint32 child_count() const { return children_.size(); } |
| |
| // Return a pointer to the child with the given index. |
| BrowserAccessibility* GetChild(uint32 child_index) const; |
| |
| // Return the previous sibling of this object, or NULL if it's the first |
| // child of its parent. |
| BrowserAccessibility* GetPreviousSibling(); |
| |
| // Return the next sibling of this object, or NULL if it's the last child |
| // of its parent. |
| BrowserAccessibility* GetNextSibling(); |
| |
| // Returns the bounds of this object in coordinates relative to the |
| // top-left corner of the overall web area. |
| gfx::Rect GetLocalBoundsRect() const; |
| |
| // Returns the bounds of this object in screen coordinates. |
| gfx::Rect GetGlobalBoundsRect() const; |
| |
| // Returns the deepest descendant that contains the specified point |
| // (in global screen coordinates). |
| BrowserAccessibility* BrowserAccessibilityForPoint(const gfx::Point& point); |
| |
| // Marks this object for deletion, releases our reference to it, and |
| // recursively calls Destroy() on its children. May not delete |
| // immediately due to reference counting. |
| // |
| // Reference counting is used on some platforms because the |
| // operating system may hold onto a reference to a BrowserAccessibility |
| // object even after we're through with it. When a BrowserAccessibility |
| // has had Destroy() called but its reference count is not yet zero, |
| // queries on this object return failure |
| virtual void Destroy(); |
| |
| // Subclasses should override this to support platform reference counting. |
| virtual void NativeAddReference() { } |
| |
| // Subclasses should override this to support platform reference counting. |
| virtual void NativeReleaseReference(); |
| |
| // |
| // Accessors |
| // |
| |
| const std::vector<BrowserAccessibility*>& children() const { |
| return children_; |
| } |
| const std::vector<std::pair<std::string, std::string> >& |
| html_attributes() const { |
| return html_attributes_; |
| } |
| int32 index_in_parent() const { return index_in_parent_; } |
| gfx::Rect location() const { return location_; } |
| BrowserAccessibilityManager* manager() const { return manager_; } |
| const std::string& name() const { return name_; } |
| int32 renderer_id() const { return renderer_id_; } |
| int32 role() const { return role_; } |
| int32 state() const { return state_; } |
| const std::string& value() const { return value_; } |
| bool instance_active() const { return instance_active_; } |
| |
| #if defined(OS_MACOSX) && __OBJC__ |
| BrowserAccessibilityCocoa* ToBrowserAccessibilityCocoa(); |
| #elif defined(OS_WIN) |
| BrowserAccessibilityWin* ToBrowserAccessibilityWin(); |
| #elif defined(TOOLKIT_GTK) |
| BrowserAccessibilityGtk* ToBrowserAccessibilityGtk(); |
| #endif |
| |
| // Accessing accessibility attributes: |
| // |
| // There are dozens of possible attributes for an accessibility node, |
| // but only a few tend to apply to any one object, so we store them |
| // in sparse arrays of <attribute id, attribute value> pairs, organized |
| // by type (bool, int, float, string, int list). |
| // |
| // There are three accessors for each type of attribute: one that returns |
| // true if the attribute is present and false if not, one that takes a |
| // pointer argument and returns true if the attribute is present (if you |
| // need to distinguish between the default value and a missing attribute), |
| // and another that returns the default value for that type if the |
| // attribute is not present. In addition, strings can be returned as |
| // either std::string or string16, for convenience. |
| |
| bool HasBoolAttribute(AccessibilityNodeData::BoolAttribute attr) const; |
| bool GetBoolAttribute(AccessibilityNodeData::BoolAttribute attr) const; |
| bool GetBoolAttribute(AccessibilityNodeData::BoolAttribute attr, |
| bool* value) const; |
| |
| bool HasFloatAttribute(AccessibilityNodeData::FloatAttribute attr) const; |
| float GetFloatAttribute(AccessibilityNodeData::FloatAttribute attr) const; |
| bool GetFloatAttribute(AccessibilityNodeData::FloatAttribute attr, |
| float* value) const; |
| |
| bool HasIntAttribute(AccessibilityNodeData::IntAttribute attribute) const; |
| int GetIntAttribute(AccessibilityNodeData::IntAttribute attribute) const; |
| bool GetIntAttribute(AccessibilityNodeData::IntAttribute attribute, |
| int* value) const; |
| |
| bool HasStringAttribute( |
| AccessibilityNodeData::StringAttribute attribute) const; |
| const std::string& GetStringAttribute( |
| AccessibilityNodeData::StringAttribute attribute) const; |
| bool GetStringAttribute(AccessibilityNodeData::StringAttribute attribute, |
| std::string* value) const; |
| |
| bool GetString16Attribute(AccessibilityNodeData::StringAttribute attribute, |
| string16* value) const; |
| string16 GetString16Attribute( |
| AccessibilityNodeData::StringAttribute attribute) const; |
| |
| bool HasIntListAttribute( |
| AccessibilityNodeData::IntListAttribute attribute) const; |
| const std::vector<int32>& GetIntListAttribute( |
| AccessibilityNodeData::IntListAttribute attribute) const; |
| bool GetIntListAttribute(AccessibilityNodeData::IntListAttribute attribute, |
| std::vector<int32>* value) const; |
| |
| void SetStringAttribute( |
| AccessibilityNodeData::StringAttribute attribute, |
| const std::string& value); |
| |
| // Retrieve the value of a html attribute from the attribute map and |
| // returns true if found. |
| bool GetHtmlAttribute(const char* attr, string16* value) const; |
| bool GetHtmlAttribute(const char* attr, std::string* value) const; |
| |
| // Utility method to handle special cases for ARIA booleans, tristates and |
| // booleans which have a "mixed" state. |
| // |
| // Warning: the term "Tristate" is used loosely by the spec and here, |
| // as some attributes support a 4th state. |
| // |
| // The following attributes are appropriate to use with this method: |
| // aria-selected (selectable) |
| // aria-grabbed (grabbable) |
| // aria-expanded (expandable) |
| // aria-pressed (toggleable/pressable) -- supports 4th "mixed" state |
| // aria-checked (checkable) -- supports 4th "mixed state" |
| bool GetAriaTristate(const char* attr_name, |
| bool* is_defined, |
| bool* is_mixed) const; |
| |
| // Returns true if the bit corresponding to the given state enum is 1. |
| bool HasState(AccessibilityNodeData::State state_enum) const; |
| |
| // Returns true if this node is an editable text field of any kind. |
| bool IsEditableText() const; |
| |
| // Append the text from this node and its children. |
| std::string GetTextRecursive() const; |
| |
| protected: |
| // Perform platform specific initialization. This can be called multiple times |
| // during the lifetime of this instance after the members of this base object |
| // have been reset with new values from the renderer process. |
| // Perform child independent initialization in this method. |
| virtual void PreInitialize() {} |
| |
| BrowserAccessibility(); |
| |
| // The manager of this tree of accessibility objects; needed for |
| // global operations like focus tracking. |
| BrowserAccessibilityManager* manager_; |
| |
| // The parent of this object, may be NULL if we're the root object. |
| BrowserAccessibility* parent_; |
| |
| // The index of this within its parent object. |
| int32 index_in_parent_; |
| |
| // The ID of this object in the renderer process. |
| int32 renderer_id_; |
| |
| // The children of this object. |
| std::vector<BrowserAccessibility*> children_; |
| |
| // Accessibility metadata from the renderer |
| std::string name_; |
| std::string value_; |
| std::vector<std::pair< |
| AccessibilityNodeData::BoolAttribute, bool> > bool_attributes_; |
| std::vector<std::pair< |
| AccessibilityNodeData::FloatAttribute, float> > float_attributes_; |
| std::vector<std::pair< |
| AccessibilityNodeData::IntAttribute, int> > int_attributes_; |
| std::vector<std::pair< |
| AccessibilityNodeData::StringAttribute, std::string> > string_attributes_; |
| std::vector<std::pair< |
| AccessibilityNodeData::IntListAttribute, std::vector<int32> > > |
| intlist_attributes_; |
| std::vector<std::pair<std::string, std::string> > html_attributes_; |
| int32 role_; |
| int32 state_; |
| gfx::Rect location_; |
| |
| // BrowserAccessibility objects are reference-counted on some platforms. |
| // When we're done with this object and it's removed from our accessibility |
| // tree, a client may still be holding onto a pointer to this object, so |
| // we mark it as inactive so that calls to any of this object's methods |
| // immediately return failure. |
| bool instance_active_; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(BrowserAccessibility); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_H_ |