[Android] Add a flag to disable the pull-to-refresh effect

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/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "ui/gfx/size_f.h"
 #include "ui/gfx/vector2d_f.h"
 
 namespace cc {
 class Layer;
 }
 
 namespace content {
 
 class EdgeEffectBase;
 
+// Provides lazy, customized EdgeEffect creation.
+class OverscrollGlowClient {
+ public:
+  virtual ~OverscrollGlowClient() {}
+
+  // Called lazily, after the initial overscrolling event.
+  virtual scoped_ptr<EdgeEffectBase> CreateEdgeEffect() = 0;
+};
+
 /* |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:
   enum Edge { EDGE_TOP = 0, EDGE_LEFT, EDGE_BOTTOM, EDGE_RIGHT, EDGE_COUNT };
 
-  // Allows lazy creation of the edge effects.
-  typedef base::Callback<scoped_ptr<EdgeEffectBase>(void)> EdgeEffectProvider;
-
-  // |edge_effect_provider| must be valid for the duration of the effect's
-  // lifetime.  The effect is enabled by default, but will remain dormant until
-  // the first overscroll event.
-  explicit OverscrollGlow(const EdgeEffectProvider& edge_effect_provider);
-
+  // |client| must be valid for the duration of the effect's lifetime.
+  // The effect is enabled by default, but will remain dormant until the first
+  // overscroll event.
+  explicit OverscrollGlow(OverscrollGlowClient* client);
   ~OverscrollGlow();
 
   // Called when the root content layer overscrolls.
   // |accumulated_overscroll| and |overscroll_delta| are in device pixels, while
   // |velocity| is in device pixels / second.
   // Returns true if the effect still needs animation ticks.
   bool OnOverscrolled(base::TimeTicks current_time,
                       gfx::Vector2dF accumulated_overscroll,
                       gfx::Vector2dF overscroll_delta,
                       gfx::Vector2dF velocity,
@@ skipping 25 matching lines @@
             const gfx::Vector2dF& overscroll_delta,
             const gfx::Vector2dF& overscroll_location);
   void Absorb(base::TimeTicks current_time,
               const gfx::Vector2dF& velocity,
               bool x_overscroll_started,
               bool y_overscroll_started);
   void Release(base::TimeTicks current_time);
 
   EdgeEffectBase* GetOppositeEdge(int edge_index);
 
-  EdgeEffectProvider edge_effect_provider_;
+  OverscrollGlowClient* const client_;
   scoped_ptr<EdgeEffectBase> edge_effects_[EDGE_COUNT];
 
   gfx::SizeF viewport_size_;
   float edge_offsets_[EDGE_COUNT];
   bool initialized_;
 
   scoped_refptr<cc::Layer> root_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_SCROLL_GLOW_H_