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// 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_RENDERER_ACCESSIBILITY_RENDERER_ACCESSIBILITY_COMPLETE_H_
#define CONTENT_RENDERER_ACCESSIBILITY_RENDERER_ACCESSIBILITY_COMPLETE_H_
#include <set>
#include <vector>
#include "base/containers/hash_tables.h"
#include "base/memory/weak_ptr.h"
#include "content/public/renderer/render_view_observer.h"
#include "content/renderer/accessibility/blink_ax_tree_source.h"
#include "content/renderer/accessibility/renderer_accessibility.h"
#include "third_party/WebKit/public/web/WebAXEnums.h"
#include "third_party/WebKit/public/web/WebAXObject.h"
#include "ui/accessibility/ax_node_data.h"
#include "ui/accessibility/ax_tree_serializer.h"
namespace blink {
class WebDocument;
class WebNode;
};
namespace content {
class RenderViewImpl;
// This is the subclass of RendererAccessibility that implements
// complete accessibility support for assistive technology (as opposed to
// partial support - see RendererAccessibilityFocusOnly).
//
// This version turns on Blink's accessibility code and sends
// a serialized representation of that tree whenever it changes. It also
// handles requests from the browser to perform accessibility actions on
// nodes in the tree (e.g., change focus, or click on a button).
class CONTENT_EXPORT RendererAccessibilityComplete
: public RendererAccessibility {
public:
explicit RendererAccessibilityComplete(RenderViewImpl* render_view);
virtual ~RendererAccessibilityComplete();
// RenderView::Observer implementation.
virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
virtual void FocusedNodeChanged(const blink::WebNode& node) OVERRIDE;
virtual void DidFinishLoad(blink::WebLocalFrame* frame) OVERRIDE;
// RendererAccessibility.
virtual void HandleWebAccessibilityEvent(
const blink::WebAXObject& obj, blink::WebAXEvent event) OVERRIDE;
virtual RendererAccessibilityType GetType() OVERRIDE;
void HandleAXEvent(const blink::WebAXObject& obj, ui::AXEvent event);
protected:
// Send queued events from the renderer to the browser.
void SendPendingAccessibilityEvents();
// Check the entire accessibility tree to see if any nodes have
// changed location, by comparing their locations to the cached
// versions. If any have moved, send an IPC with the new locations.
void SendLocationChanges();
private:
// Handlers for messages from the browser to the renderer.
void OnDoDefaultAction(int acc_obj_id);
void OnEventsAck();
void OnChangeScrollPosition(int acc_obj_id, int scroll_x, int scroll_y);
void OnScrollToMakeVisible(int acc_obj_id, gfx::Rect subfocus);
void OnScrollToPoint(int acc_obj_id, gfx::Point point);
void OnSetFocus(int acc_obj_id);
void OnSetTextSelection(int acc_obj_id, int start_offset, int end_offset);
void OnFatalError();
// Checks if a Blink accessibility object is an editable text node.
bool IsEditableText(const blink::WebAXObject& node);
// Recursively explore the tree of Blink accessibility objects rooted
// at |src|, and for each editable text node encountered, add a
// corresponding WebAccessibility node as a child of |dst|.
void RecursiveAddEditableTextNodesToTree(
const blink::WebAXObject& src,
ui::AXNodeData* dst);
// So we can queue up tasks to be executed later.
base::WeakPtrFactory<RendererAccessibilityComplete> weak_factory_;
// Events from Blink are collected until they are ready to be
// sent to the browser.
std::vector<AccessibilityHostMsg_EventParams> pending_events_;
// The adapter that exposes Blink's accessibility tree to AXTreeSerializer.
BlinkAXTreeSource tree_source_;
// The serializer that sends accessibility messages to the browser process.
ui::AXTreeSerializer<blink::WebAXObject> serializer_;
// Current location of every object, so we can detect when it moves.
base::hash_map<int, gfx::Rect> locations_;
// The most recently observed scroll offset of the root document element.
// TODO(dmazzoni): remove once https://bugs.webkit.org/show_bug.cgi?id=73460
// is fixed.
gfx::Size last_scroll_offset_;
// Set if we are waiting for an accessibility event ack.
bool ack_pending_;
DISALLOW_COPY_AND_ASSIGN(RendererAccessibilityComplete);
};
#endif // CONTENT_RENDERER_ACCESSIBILITY_RENDERER_ACCESSIBILITY_COMPLETE_H_
} // namespace content
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