app/multi_animation.h

// Copyright (c) 2010 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 APP_MULTI_ANIMATION_H_
#define APP_MULTI_ANIMATION_H_

#include <vector>

#include "app/animation.h"
#include "app/tween.h"

// MultiAnimation is an animation that consists of a number of sub animations.
// To create a MultiAnimation pass in the parts, invoke Start() and the delegate
// is notified as the animation progresses. MultiAnimation runs until Stop is
// invoked.
class MultiAnimation : public Animation {
 public:
  struct Part {
    Part() : time_ms(0), type(Tween::ZERO) {}
    Part(int time_ms, Tween::Type type) : time_ms(time_ms), type(type) {}

    int time_ms;
    Tween::Type type;
  };

  typedef std::vector<Part> Parts;

  explicit MultiAnimation(const Parts& parts);

  // Returns the current value. The current value for a MultiAnimation is
  // determined from the tween type of the current part.
  virtual double GetCurrentValue() const { return current_value_; }

  // Returns the index of the current part.
  size_t current_part_index() const { return current_part_index_; }

 protected:
  // Animation overrides.
  virtual void Step(base::TimeTicks time_now);

 private:
  // Returns the part containing the specified time. |time_ms| is reset to be
  // relative to the part containing the time and |part_index| the index of the
  // part.
  const Part& GetPart(int* time_ms, size_t* part_index);

  // The parts that make up the animation.
  const Parts parts_;

  // Total time of all the parts.
  const int cycle_time_ms_;

  // Current value for the animation.
  double current_value_;

  // Index of the current part.
  size_t current_part_index_;

  DISALLOW_COPY_AND_ASSIGN(MultiAnimation);
};

#endif  // APP_MULTI_ANIMATION_H_