chromium/cc/input/snap_fling_controller.h

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_INPUT_SNAP_FLING_CONTROLLER_H_
#define CC_INPUT_SNAP_FLING_CONTROLLER_H_

#include <memory>

#include "base/memory/raw_ptr.h"
#include "base/time/time.h"
#include "cc/cc_export.h"
#include "ui/gfx/geometry/point_f.h"
#include "ui/gfx/geometry/vector2d_f.h"

namespace cc {
namespace test {
class SnapFlingControllerTest;
}

class SnapFlingCurve;

// A client that provides information to the controller. It also executes the
// scroll operations and requests animation frames. All the inputs and outputs
// are in the same coordinate space.
class SnapFlingClient { … };

// SnapFlingController ensures that an incoming fling event (or inertial-phase
// scroll event) would land on a snap position if there is a valid one nearby.
// It takes an input event, filters it if it conflicts with the current fling,
// or generates a curve if the SnapFlingClient finds a valid snap position.
// It also animates the curve by notifying the client to scroll when clock
// ticks.
class CC_EXPORT SnapFlingController { … };

}  // namespace cc

#endif  // CC_INPUT_SNAP_FLING_CONTROLLER_H_