android: Use UIResource for overscroll glow

content/browser/android/overscroll_glow.h

 // Copyright (c) 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 CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
 #define CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "content/browser/android/edge_effect.h"
 #include "ui/gfx/size_f.h"
 #include "ui/gfx/vector2d_f.h"
 
 class SkBitmap;
 
 namespace cc {
 class Layer;
 }
 
+namespace ui {
+class SystemUIResourceManager;
+}
+
 namespace content {
 
+// A wrapper class over the cc::Layer.
+class OverscrollGlowLayerWrapper {

[jdduke (slow), 2014/07/12 01:01:09]

Could we have EdgeEffect define this interface (in edge_effect.h)?
EdgeEffectLayerWrapper? I'd like to keep EdgeEffect from having an
OverscrollGlow dependency.

[powei, 2014/07/16 17:10:52]

Done.

+ public:
+  virtual scoped_refptr<cc::Layer> layer() = 0;

[jdduke (slow), 2014/07/12 01:01:09]

What about just returning a naked pointer?

[powei, 2014/07/16 17:10:51]

Done.

+  virtual ~OverscrollGlowLayerWrapper() {}
+};
+
 /* |OverscrollGlow| mirrors its Android counterpart, OverscrollGlow.java.
  * Conscious tradeoffs were made to align this as closely as possible with the
  * original Android Java version.
  */
 class OverscrollGlow {
  public:
-  // Create a new effect. If |enabled| is false, the effect will remain
-  // deactivated until explicitly enabled.
-  // Note: No resources will be allocated until the effect is both
-  //       enabled and an overscroll event has occurred.
-  static scoped_ptr<OverscrollGlow> Create(bool enabled);
+  // Create a new effect. WindowAndroid provides the resource for the effect.

[jdduke (slow), 2014/07/12 01:01:09]

Hmm, did you mean to reference WindowAndroid instead of SystemUIResourceManager?
Maybe put a brief note that |resource_manager| must outlive the effect?

[powei, 2014/07/16 17:10:52]

Done.

+  // If |enabled| is false, the effect will remain deactivated until explicitly
+  // enabled.
+  static scoped_ptr<OverscrollGlow> Create(
+      ui::SystemUIResourceManager* resource_manager);
 
   ~OverscrollGlow();
 
   // Enable the effect. If the effect was previously disabled, it will remain
   // dormant until subsequent calls to |OnOverscrolled()|.
   void Enable();
 
   // Deactivate and detach the effect. Subsequent calls to |OnOverscrolled()| or
   // |Animate()| will have no effect.
   void Disable();
@@ skipping 19 matching lines @@
     gfx::SizeF size;
     float edge_offsets[EdgeEffect::EDGE_COUNT];
     float device_scale_factor;
   };
   void UpdateDisplayParameters(const DisplayParameters& params);
 
 
  private:
   enum Axis { AXIS_X, AXIS_Y };
 
-  OverscrollGlow(bool enabled);
+  OverscrollGlow(ui::SystemUIResourceManager* resource_manager);
 
   // Returns whether the effect is initialized.
   bool InitializeIfNecessary();
   bool NeedsAnimate() const;
   void UpdateLayerAttachment(cc::Layer* parent);
   void Detach();
   void Pull(base::TimeTicks current_time, gfx::Vector2dF overscroll_delta);
   void Absorb(base::TimeTicks current_time,
               gfx::Vector2dF velocity,
               bool x_overscroll_started,
               bool y_overscroll_started);
   void Release(base::TimeTicks current_time);
   void ReleaseAxis(Axis axis, base::TimeTicks current_time);
 
   EdgeEffect* GetOppositeEdge(int edge_index);
 
   scoped_ptr<EdgeEffect> edge_effects_[EdgeEffect::EDGE_COUNT];
 
   DisplayParameters display_params_;
   bool enabled_;
   bool initialized_;
 
   scoped_refptr<cc::Layer> root_layer_;
+  ui::SystemUIResourceManager* resource_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_SCROLL_GLOW_H_