Implement Chrome OS accessibility features to highlight focus, caret & cursor.

chrome/browser/chromeos/accessibility/accessibility_highlight_manager.h

+// Copyright (c) 2016 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 CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_HIGHLIGHT_MANAGER_H_
+#define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_HIGHLIGHT_MANAGER_H_
+
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/notification_source.h"
+#include "ui/base/ime/input_method.h"
+#include "ui/base/ime/input_method_observer.h"
+#include "ui/base/ime/text_input_client.h"
+#include "ui/events/event.h"
+#include "ui/events/event_handler.h"
+
+namespace chromeos {
+
+// Manage visual highlights that Chrome OS can draw around the focused
+// object, the cursor, and the text caret for accessibility.
+class AccessibilityHighlightManager : public ui::EventHandler,
+                                      public content::NotificationObserver,
+                                      public ui::InputMethodObserver {
+ public:
+  AccessibilityHighlightManager();
+  ~AccessibilityHighlightManager() override;
+
+  void HighlightFocus(bool focus);
+  void HighlightCursor(bool cursor);
+  void HighlightCaret(bool caret);
+
+ private:
+  // ui::EventHandler overrides:
+  void OnMouseEvent(ui::MouseEvent* event) override;
+
+  // content::NotificationObserver overrides:
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
+
+  // ui::InputMethodObserver overrides:
+  void OnTextInputTypeChanged(const ui::TextInputClient* client) override {}
+  void OnFocus() override {}
+  void OnBlur() override {}
+  void OnInputMethodDestroyed(const ui::InputMethod* input_method) override {}
+  void OnShowImeIfNeeded() override {}
+  void OnTextInputStateChanged(const ui::TextInputClient* client) override;
+  void OnCaretBoundsChanged(const ui::TextInputClient* client) override;
+
+  bool focus_ = false;
+  gfx::Rect focus_rect_;
+
+  bool cursor_ = false;
+  gfx::Point cursor_point_;
+
+  bool caret_ = false;
+  gfx::Point caret_point_;
+
+  content::NotificationRegistrar registrar_;
+};

[xiyuan, 2016/03/21 22:59:31]

nit: DISALLOW_COPY_AND_ASSIGN(AccessibilityHighlightManager);

[dmazzoni, 2016/03/22 04:09:30]

Done.

+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_HIGHLIGHT_MANAGER_H_