Add support for calculating the position of the top controls in the cc layer.

cc/top_controls_manager.h

Index: cc/top_controls_manager.h
diff --git a/cc/top_controls_manager.h b/cc/top_controls_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..72ba7ddba2f2cc46a3f17560655fca6fa24841d2
--- /dev/null
+++ b/cc/top_controls_manager.h
@@ -0,0 +1,83 @@
+// Copyright 2012 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 CC_TOP_CONTROLS_MANAGER_H_
+#define CC_TOP_CONTROLS_MANAGER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "cc/layer_impl.h"
+#include "ui/gfx/size.h"
+#include "ui/gfx/vector2d_f.h"
+
+namespace base {
+class TimeTicks;
+}
+
+namespace cc {
+
+class LayerTreeImpl;
+class TopControlsAnimation;
+
+class TopControlsDelegate {
+ public:
+  virtual void setNeedsRedraw() = 0;
+  virtual void setNeedsUpdateDrawProperties() = 0;
+  virtual LayerTreeImpl* activeTree() = 0;
+};
+
+// Manages the position of the top controls.
+class TopControlsManager {
+ public:
+  static const int64 kAutoHideDelayMs = 1500;

[aelias_OOO_until_Jul13, 2012/12/19 08:31:18]

Move these values to the .cc file.

[Ted C, 2012/12/19 21:34:17]

Done.

+  static const double kShowHideMaxDurationMs = 500;
+
+  static scoped_ptr<TopControlsManager> create(TopControlsDelegate* delegate,
+                                               bool enabled,
+                                               float topControlsHeight);

[aelias_OOO_until_Jul13, 2012/12/19 08:31:18]

top_controls_height

[Ted C, 2012/12/19 21:34:17]

Done.

+  virtual ~TopControlsManager();
+
+  float controls_top_offset() { return controls_top_offset_; }
+  float content_top_offset() { return content_top_offset_; }
+  float is_overlay_mode() { return is_overlay_mode_; }
+  TopControlsAnimation* animation() { return top_controls_animation_.get(); }
+
+  void updateDrawPositions();
+
+  void scrollBegin();
+  gfx::Vector2dF scrollBy(const gfx::Vector2dF pendingDelta);
+  void scrollEnd();
+
+  void animate(base::TimeTicks monotonicTime);
+  void resetAnimations();
+
+ protected:
+  TopControlsManager(TopControlsDelegate* delegate, bool enabled,
+                     float topControlsHeight);
+
+ private:
+  LayerImpl* rootScrollLayer();
+  float rootScrollLayerTotalScrollY();
+  void startAnimationIfNecessary();
+  void startAutoHideAnimation(int64 triggeredTime);
+
+  base::WeakPtrFactory<TopControlsManager> weak_ptr_factory_;
+
+  TopControlsDelegate* delegate_;  // owned by this.
+  bool enabled_;
+
+  scoped_ptr<TopControlsAnimation> top_controls_animation_;
+  bool is_overlay_mode_;
+  float controls_top_offset_;
+  float content_top_offset_;
+  float top_controls_height_;
+  int64 top_controls_auto_hide_trigger_time_;
+  float previous_root_scroll_offset_;
+
+  DISALLOW_COPY_AND_ASSIGN(TopControlsManager);
+};
+
+}  // namespace cc
+
+#endif  // CC_TOP_CONTROLS_MANAGER_H_