| // 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_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_ |
| #define CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_ |
| |
| #include "base/compiler_specific.h" |
| #include "base/macros.h" |
| #include "base/optional.h" |
| #include "content/browser/renderer_host/overscroll_controller.h" |
| #include "content/common/content_export.h" |
| #include "ui/gfx/geometry/size.h" |
| |
| namespace content { |
| |
| // The delegate receives overscroll gesture updates from the controller and |
| // should perform appropriate actions. The delegate can optionally cap the |
| // overscroll deltas maintained and reported by the controller. |
| class CONTENT_EXPORT OverscrollControllerDelegate { |
| public: |
| OverscrollControllerDelegate() {} |
| virtual ~OverscrollControllerDelegate() {} |
| |
| // Get the size of the display containing the view corresponding to the |
| // delegate. |
| virtual gfx::Size GetDisplaySize() const = 0; |
| |
| // This is called for each update in the overscroll amount. Returns true if |
| // the delegate consumed the event. |
| virtual bool OnOverscrollUpdate(float delta_x, float delta_y) = 0; |
| |
| // This is called when the overscroll completes. |
| virtual void OnOverscrollComplete(OverscrollMode overscroll_mode) = 0; |
| |
| // This is called when the direction of the overscroll changes. When a new |
| // overscroll is started (i.e. when |new_mode| is not equal to |
| // OVERSCROLL_NONE), |source| will be set to the device that triggered the |
| // overscroll gesture. |behavior| is the value of overscroll-behavior CSS |
| // property for the root element. |
| virtual void OnOverscrollModeChange(OverscrollMode old_mode, |
| OverscrollMode new_mode, |
| OverscrollSource source, |
| cc::OverscrollBehavior behavior) = 0; |
| |
| // Returns the optional maximum amount allowed for the absolute value of |
| // overscroll delta corresponding to the current overscroll mode. |
| virtual base::Optional<float> GetMaxOverscrollDelta() const = 0; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(OverscrollControllerDelegate); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_ |