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 "third_party/skia/include/core/SkColor.h" 10 #include "ui/gfx/gfx_export.h" 11 #include "ui/gfx/rect.h" 12 #include "ui/gfx/transform.h" 13 14 namespace gfx { 15 16 class GFX_EXPORT Tween { 17 public: 18 enum Type { 19 LINEAR, // Linear. 20 EASE_OUT, // Fast in, slow out (default). 21 EASE_IN, // Slow in, fast out. 22 EASE_IN_2, // Variant of EASE_IN that starts out slower than 23 // EASE_IN. 24 EASE_IN_OUT, // Slow in and out, fast in the middle. 25 FAST_IN_OUT, // Fast in and out, slow in the middle. 26 EASE_OUT_SNAP, // Fast in, slow out, snap to final value. 27 SMOOTH_IN_OUT, // Smooth, consistent speeds in and out (sine wave). 28 FAST_OUT_SLOW_IN, // Variant of EASE_IN_OUT which should be used in most 29 // cases. 30 LINEAR_OUT_SLOW_IN, // Variant of EASE_OUT which should be used for 31 // fading in from 0% or motion when entering a scene. 32 FAST_OUT_LINEAR_IN, // Variant of EASE_IN which should should be used for 33 // fading out to 0% or motion when exiting a scene. 34 ZERO, // Returns a value of 0 always. 35 }; 36 37 // Returns the value based on the tween type. |state| is from 0-1. 38 static double CalculateValue(Type type, double state); 39 40 // Conveniences for getting a value between a start and end point. 41 static SkColor ColorValueBetween(double value, SkColor start, SkColor target); 42 static double DoubleValueBetween(double value, double start, double target); 43 static float FloatValueBetween(double value, float start, float target); 44 45 // Interpolated between start and target, with every integer in this range 46 // given equal weight. 47 static int IntValueBetween(double value, int start, int target); 48 49 // Interpolates between start and target as real numbers, and rounds the 50 // result to the nearest integer, with ties broken by rounding towards 51 // positive infinity. This gives start and target half the weight of the 52 // other integers in the range. This is the integer interpolation approach 53 // specified by www.w3.org/TR/css3-transitions. 54 static int LinearIntValueBetween(double value, int start, int target); 55 static gfx::Rect RectValueBetween(double value, 56 const gfx::Rect& start_bounds, 57 const gfx::Rect& target_bounds); 58 static gfx::Transform TransformValueBetween( 59 double value, 60 const gfx::Transform& start_transform, 61 const gfx::Transform& target_transform); 62 63 private: 64 Tween(); 65 ~Tween(); 66 67 DISALLOW_COPY_AND_ASSIGN(Tween); 68 }; 69 70 } // namespace gfx 71 72 #endif // UI_GFX_ANIMATION_TWEEN_H_ 73