accessibility_delegate.h

// Copyright 2013 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 ASH_ACCESSIBILITY_ACCESSIBILITY_DELEGATE_H_
#define ASH_ACCESSIBILITY_ACCESSIBILITY_DELEGATE_H_

#include <vector>

#include "ash/ash_export.h"
#include "ui/accessibility/ax_tree_id.h"
#include "ui/accessibility/ax_tree_update.h"

namespace ui {
struct AXEvent;
}

namespace ash {

// A delegate class to control and query accessibility features.
//
// NOTE: Methods in this class are migrating to AccessibilityController to
// support mash (because ash is in a separate process and cannot call back into
// chrome). Add new methods there, not here.
class ASH_EXPORT AccessibilityDelegate {
 public:
  virtual ~AccessibilityDelegate() {}

  // Invoked to enable the screen magnifier.
  virtual void SetMagnifierEnabled(bool enabled) = 0;

  // Returns true if the screen magnifier is enabled.
  virtual bool IsMagnifierEnabled() const = 0;

  // Returns true when the accessibility menu should be shown.
  virtual bool ShouldShowAccessibilityMenu() const = 0;

  // Saves the zoom scale of the full screen magnifier.
  virtual void SaveScreenMagnifierScale(double scale) = 0;

  // Gets a saved value of the zoom scale of full screen magnifier. If a value
  // is not saved, return a negative value.
  virtual double GetSavedScreenMagnifierScale() = 0;

  // Automation API support for remote mojo apps.
  // TODO(jamescook): Convert to mojo API.
  virtual void DispatchAccessibilityEvent(
      const ui::AXTreeID& tree_id,
      const std::vector<ui::AXTreeUpdate>& updates,
      const ui::AXEvent& event) = 0;
  virtual void DispatchTreeDestroyedEvent(const ui::AXTreeID& tree_id) = 0;

  // NOTE: Prefer adding methods to AccessibilityController, see class comment.
};

}  // namespace ash

#endif  // ASH_ACCESSIBILITY_ACCESSIBILITY_DELEGATE_H_