blob: 7300e32fc9106d5f527b795355e007bd68159b65 [file] [log] [blame]
// Copyright 2014 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.
#include "base/time/time.h"
#include "ui/gfx/geometry/vector2d_f.h"
namespace ui {
// An abstraction of curve-based gesture motion, allowing platform-specific
// motion tailoring.
class EVENTS_BASE_EXPORT GestureCurve {
virtual ~GestureCurve() {}
// The output |offset| represents the total movement of the curve from its
// start until |time|.
// The output |velocity| represents the instantenous velocity at |time|.
// Returns false if |time| exceeds the fling duration, in which case
// the terminal offset will be reported.
virtual bool ComputeScrollOffset(base::TimeTicks time,
gfx::Vector2dF* offset,
gfx::Vector2dF* velocity) = 0;
} // namespace ui