app/tween.h

   1 // Copyright (c) 2010 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 APP_TWEEN_H_
   6 #define APP_TWEEN_H_
   7 #pragma once
   8
   9 #include "base/basictypes.h"
  10
  11 namespace gfx {
  12 class Rect;
  13 }
  14
  15 class Tween {
  16  public:
  17   enum Type {
  18     LINEAR,        // Linear.
  19     EASE_OUT,      // Fast in, slow out (default).
  20     EASE_IN,       // Slow in, fast out.
  21     EASE_IN_OUT,   // Slow in and out, fast in the middle.
  22     FAST_IN_OUT,   // Fast in and out, slow in the middle.
  23     EASE_OUT_SNAP, // Fast in, slow out, snap to final value.
  24     ZERO,          // Returns a value of 0 always.
  25   };
  26
  27   // Returns the value based on the tween type. |state| is from 0-1.
  28   static double CalculateValue(Type type, double state);
  29
  30   // Conveniences for getting a value between a start and end point.
  31   static double ValueBetween(double value, double start, double target);
  32   static int ValueBetween(double value, int start, int target);
  33   static gfx::Rect ValueBetween(double value,
  34                                 const gfx::Rect& start_bounds,
  35                                 const gfx::Rect& target_bounds);
  36
  37  private:
  38   Tween();
  39   ~Tween();
  40
  41   DISALLOW_COPY_AND_ASSIGN(Tween);
  42 };
  43
  44 #endif  // APP_TWEEN_H_