ash/accelerators/magnifier_key_scroller.h

   1 // Copyright 2014 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 ASH_ACCELERATORS_MAGNIFIER_KEY_SCROLLER_H_
   6 #define ASH_ACCELERATORS_MAGNIFIER_KEY_SCROLLER_H_
   7
   8 #include "ash/accelerators/key_hold_detector.h"
   9 #include "ash/ash_export.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "ui/events/event_handler.h"
  12
  13 namespace ui {
  14 class KeyEvent;
  15 }
  16
  17 namespace ash {
  18
  19 // A KeyHoldDetector delegate to control control magnified screen.
  20 class ASH_EXPORT MagnifierKeyScroller : public KeyHoldDetector::Delegate {
  21  public:
  22   static bool IsEnabled();
  23   static void SetEnabled(bool enabled);
  24   static scoped_ptr<ui::EventHandler> CreateHandler();
  25
  26   // A scoped object to enable and disable the magnifier accelerator for test.
  27   class ScopedEnablerForTest {
  28    public:
  29     ScopedEnablerForTest() {
  30       SetEnabled(true);
  31     }
  32     ~ScopedEnablerForTest() {
  33       SetEnabled(false);
  34     }
  35
  36    private:
  37     DISALLOW_COPY_AND_ASSIGN(ScopedEnablerForTest);
  38   };
  39
  40  private:
  41   // KeyHoldDetector overrides:
  42   bool ShouldProcessEvent(const ui::KeyEvent* event) const override;
  43   bool IsStartEvent(const ui::KeyEvent* event) const override;
  44   bool ShouldStopEventPropagation() const override;
  45   void OnKeyHold(const ui::KeyEvent* event) override;
  46   void OnKeyUnhold(const ui::KeyEvent* event) override;
  47
  48   MagnifierKeyScroller();
  49   ~MagnifierKeyScroller() override;
  50
  51   DISALLOW_COPY_AND_ASSIGN(MagnifierKeyScroller);
  52 };
  53
  54 }  // namespace ash
  55
  56 #endif  // ASH_ACCELERATORS_MAGNIFIER_KEY_SCROLLER_H_