ui/compositor/scoped_animation_duration_scale_mode.h

// Copyright (c) 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 UI_COMPOSITOR_SCOPED_ANIMATION_DURATION_SCALE_MODE_H_
#define UI_COMPOSITOR_SCOPED_ANIMATION_DURATION_SCALE_MODE_H_

#include "ui/compositor/compositor_export.h"

namespace ui {

// Speed up or slow down animations for testing or debugging.
class COMPOSITOR_EXPORT ScopedAnimationDurationScaleMode {
 public:
  // Anumation duration multipliers.
  static constexpr float NORMAL_DURATION = 1.0;
  static constexpr float FAST_DURATION = 1.0 / 4;    // 4 times faster
  static constexpr float SLOW_DURATION = 1.0 * 4.0;  // 4 times slower
  // A very short but guaranteed non-zero duration for individual tests that
  // need to assert things about animations after creating them.
  static constexpr float NON_ZERO_DURATION = 1.0 / 20;  // 20 times faster
  // Animations complete immediately after being created. Used by most tests.
  static constexpr float ZERO_DURATION = 0;

  explicit ScopedAnimationDurationScaleMode(float scoped_multiplier);
  ScopedAnimationDurationScaleMode(const ScopedAnimationDurationScaleMode&) =
      delete;
  ScopedAnimationDurationScaleMode& operator=(
      const ScopedAnimationDurationScaleMode&) = delete;

  ~ScopedAnimationDurationScaleMode();

  static float duration_multiplier() { return duration_multiplier_; }

 private:
  // This is stored previous multiplier version to restore after scoped scale
  // destruction.
  const float old_duration_multiplier_;

  // This is active global multiplier.
  static float duration_multiplier_;
};

}  // namespace ui

#endif  // UI_COMPOSITOR_SCOPED_ANIMATION_DURATION_SCALE_MODE_H