Index: cc/page_scale_animation.h |
diff --git a/cc/page_scale_animation.h b/cc/page_scale_animation.h |
index 638cbb270ce9b24689d5095baf174ade4f4d1a13..f597026f90e786ab9b313870175fe7f7d457c054 100644 |
--- a/cc/page_scale_animation.h |
+++ b/cc/page_scale_animation.h |
@@ -1,3 +1,74 @@ |
-// Copyright 2012 The Chromium Authors. All rights reserved. |
+// Copyright 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 CCPageScaleAnimation_h |
+#define CCPageScaleAnimation_h |
+ |
+#include "IntSize.h" |
+#include <wtf/PassOwnPtr.h> |
+ |
+namespace cc { |
+ |
+// A small helper class that does the math for zoom animations, primarily for |
+// double-tap zoom. Initialize it with starting and ending scroll/page scale |
+// positions and an animation length time, then call ...AtTime() at every frame |
+// to obtain the current interpolated position. |
+class CCPageScaleAnimation { |
+public: |
+ // Construct with the starting page scale and scroll offset (which is in |
+ // pageScaleStart space). The window size is the user-viewable area |
+ // in pixels. |
+ static PassOwnPtr<CCPageScaleAnimation> create(const IntSize& scrollStart, float pageScaleStart, const IntSize& windowSize, const IntSize& contentSize, double startTime); |
+ |
+ // The following methods initialize the animation. Call one of them |
+ // immediately after construction to set the final scroll and page scale. |
+ |
+ // Zoom while explicitly specifying the top-left scroll position. The |
+ // scroll offset is in finalPageScale coordinates. |
+ void zoomTo(const IntSize& finalScroll, float finalPageScale, double duration); |
+ |
+ // Zoom based on a specified onscreen anchor, which will remain at the same |
+ // position on the screen throughout the animation. The anchor is in local |
+ // space relative to scrollStart. |
+ void zoomWithAnchor(const IntSize& anchor, float finalPageScale, double duration); |
+ |
+ // Call these functions while the animation is in progress to output the |
+ // current state. |
+ IntSize scrollOffsetAtTime(double time) const; |
+ float pageScaleAtTime(double time) const; |
+ bool isAnimationCompleteAtTime(double time) const; |
+ |
+ // The following methods return state which is invariant throughout the |
+ // course of the animation. |
+ double startTime() const { return m_startTime; } |
+ double duration() const { return m_duration; } |
+ double endTime() const { return m_startTime + m_duration; } |
+ const IntSize& finalScrollOffset() const { return m_scrollEnd; } |
+ float finalPageScale() const { return m_pageScaleEnd; } |
+ |
+protected: |
+ CCPageScaleAnimation(const IntSize& scrollStart, float pageScaleStart, const IntSize& windowSize, const IntSize& contentSize, double startTime); |
+ |
+private: |
+ float progressRatioForTime(double time) const; |
+ IntSize scrollOffsetAtRatio(float ratio) const; |
+ float pageScaleAtRatio(float ratio) const; |
+ |
+ IntSize m_scrollStart; |
+ float m_pageScaleStart; |
+ IntSize m_windowSize; |
+ IntSize m_contentSize; |
+ |
+ bool m_anchorMode; |
+ IntSize m_anchor; |
+ IntSize m_scrollEnd; |
+ float m_pageScaleEnd; |
+ |
+ double m_startTime; |
+ double m_duration; |
+}; |
+ |
+} // namespace cc |
+ |
+#endif |