tween.h revision 4e180b6a0b4720a9b8e9e959a882386f690f08ff 
1// Copyright (c) 2012 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 UI_GFX_ANIMATION_TWEEN_H_
6#define UI_GFX_ANIMATION_TWEEN_H_
7
8#include "base/basictypes.h"
9#include "ui/gfx/gfx_export.h"
10#include "ui/gfx/rect.h"
11#include "ui/gfx/transform.h"
12
13namespace gfx {
14
15class GFX_EXPORT 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_2,     // Variant of EASE_IN that starts out slower.
22    EASE_IN_OUT,   // Slow in and out, fast in the middle.
23    FAST_IN_OUT,   // Fast in and out, slow in the middle.
24    EASE_OUT_SNAP, // Fast in, slow out, snap to final value.
25    SMOOTH_IN_OUT, // Smooth, consistent speeds in and out (sine wave).
26    ZERO,          // Returns a value of 0 always.
27  };
28
29  // Returns the value based on the tween type. |state| is from 0-1.
30  static double CalculateValue(Type type, double state);
31
32  // Conveniences for getting a value between a start and end point.
33  static double DoubleValueBetween(double value, double start, double target);
34  static float FloatValueBetween(double value, float start, float target);
35  static int IntValueBetween(double value, int start, int target);
36  static gfx::Rect RectValueBetween(double value,
37                                    const gfx::Rect& start_bounds,
38                                    const gfx::Rect& target_bounds);
39  static gfx::Transform TransformValueBetween(
40      double value,
41      const gfx::Transform& start_transform,
42      const gfx::Transform& target_transform);
43
44 private:
45  Tween();
46  ~Tween();
47
48  DISALLOW_COPY_AND_ASSIGN(Tween);
49};
50
51}  // namespace gfx
52
53#endif  // UI_GFX_ANIMATION_TWEEN_H_
54