content/browser/renderer_host/overscroll_controller_delegate.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "content/browser/renderer_host/overscroll_controller.h"
  11 #include "content/common/content_export.h"
  12 #include "ui/gfx/geometry/rect.h"
  13
  14 namespace content {
  15
  16 // The delegate receives overscroll gesture updates from the controller and
  17 // should perform appropriate actions.
  18 class CONTENT_EXPORT OverscrollControllerDelegate {
  19  public:
  20   OverscrollControllerDelegate() {}
  21   virtual ~OverscrollControllerDelegate() {}
  22
  23   // Get the bounds of the view corresponding to the delegate. Overscroll-ending
  24   // events will only be processed if the visible bounds are non-empty.
  25   virtual gfx::Rect GetVisibleBounds() const = 0;
  26
  27   // This is called for each update in the overscroll amount. Returns true if
  28   // the delegate consumed the event.
  29   virtual bool OnOverscrollUpdate(float delta_x, float delta_y) = 0;
  30
  31   // This is called when the overscroll completes.
  32   virtual void OnOverscrollComplete(OverscrollMode overscroll_mode) = 0;
  33
  34   // This is called when the direction of the overscroll changes.
  35   virtual void OnOverscrollModeChange(OverscrollMode old_mode,
  36                                       OverscrollMode new_mode) = 0;
  37
  38  private:
  39   DISALLOW_COPY_AND_ASSIGN(OverscrollControllerDelegate);
  40 };
  41
  42 }  // namespace content
  43
  44 #endif  // CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_