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// Copyright 2012 The Chromium Authors
// 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 <optional>
#include "base/memory/weak_ptr.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();
OverscrollControllerDelegate(const OverscrollControllerDelegate&) = delete;
OverscrollControllerDelegate& operator=(const OverscrollControllerDelegate&) =
delete;
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 std::optional<float> GetMaxOverscrollDelta() const = 0;
base::WeakPtr<OverscrollControllerDelegate> GetWeakPtr();
private:
base::WeakPtrFactory<OverscrollControllerDelegate> weak_factory_{this};
};
} // namespace content
#endif // CONTENT_BROWSER_RENDERER_HOST_OVERSCROLL_CONTROLLER_DELEGATE_H_
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