1 files changed, 48 insertions, 0 deletions
diff --git a/ui/base/animation/tween.h b/ui/base/animation/tween.h
new file mode 100644
index 0000000..873281f
--- /dev/null
+++ b/ui/base/animation/tween.h
@@ -0,0 +1,48 @@
+// Copyright (c) 2011 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_BASE_ANIMATION_TWEEN_H_
+#define UI_BASE_ANIMATION_TWEEN_H_
+#pragma once
+
+#include "base/basictypes.h"
+
+namespace gfx {
+class Rect;
+}
+
+namespace ui {
+
+class Tween {
+ public:
+  enum Type {
+    LINEAR,        // Linear.
+    EASE_OUT,      // Fast in, slow out (default).
+    EASE_IN,       // Slow in, fast out.
+    EASE_IN_OUT,   // Slow in and out, fast in the middle.
+    FAST_IN_OUT,   // Fast in and out, slow in the middle.
+    EASE_OUT_SNAP, // Fast in, slow out, snap to final value.
+    ZERO,          // Returns a value of 0 always.
+  };
+
+  // Returns the value based on the tween type. |state| is from 0-1.
+  static double CalculateValue(Type type, double state);
+
+  // Conveniences for getting a value between a start and end point.
+  static double ValueBetween(double value, double start, double target);
+  static int ValueBetween(double value, int start, int target);
+  static gfx::Rect ValueBetween(double value,
+                                const gfx::Rect& start_bounds,
+                                const gfx::Rect& target_bounds);
+
+ private:
+  Tween();
+  ~Tween();
+
+  DISALLOW_COPY_AND_ASSIGN(Tween);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_ANIMATION_TWEEN_H_