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 "ui/gfx/geometry/rect.h"
  12
  13 namespace content {
  14
  15 // The delegate receives overscroll gesture updates from the controller and
  16 // should perform appropriate actions.
  17 class OverscrollControllerDelegate {
  18  public:
  19   OverscrollControllerDelegate() {}
  20   virtual ~OverscrollControllerDelegate() {}
  21
  22   // Get the bounds of the view corresponding to the delegate. Overscroll-ending
  23   // events will only be processed if the visible bounds are non-empty.
  24   virtual gfx::Rect GetVisibleBounds() const = 0;
  25
  26   // This is called for each update in the overscroll amount. Returns true if
  27   // the delegate consumed the event.
  28   virtual bool OnOverscrollUpdate(float delta_x, float delta_y) = 0;
  29
  30   // This is called when the overscroll completes.
  31   virtual void OnOverscrollComplete(OverscrollMode overscroll_mode) = 0;
  32
  33   // This is called when the direction of the overscroll changes.
  34   virtual void OnOverscrollModeChange(OverscrollMode old_mode,
  35                                       OverscrollMode new_mode) = 0;
  36
  37  private:
  38   DISALLOW_COPY_AND_ASSIGN(OverscrollControllerDelegate);
  39 };
  40
  41 }  // namespace content
  42
  43 #endif  // CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_