blob: 3f1bae1e91d28a5c49c1e52427b9cd0a16b08a88 [file] [log] [blame]
// Copyright 2015 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"
namespace gfx {
class PointF;
namespace exo {
class Surface;
class Touch;
// Handles events on touch devices in context-specific ways.
class TouchDelegate {
// Called at the top of the touch device's destructor, to give observers a
// chance to remove themselves.
virtual void OnTouchDestroying(Touch* touch) = 0;
// This should return true if |surface| is a valid target for this touch
// device. E.g. the surface is owned by the same client as the touch device.
virtual bool CanAcceptTouchEventsForSurface(Surface* surface) const = 0;
// Called when a new touch point has appeared on the surface. This touch
// point is assigned a unique ID. Future events from this touch point
// reference this ID. |location| is the initial location of touch point
// relative to the origin of the surface.
virtual void OnTouchDown(Surface* surface,
base::TimeTicks time_stamp,
int id,
const gfx::PointF& location) = 0;
// Called when a touch point has disappeared. No further events will be sent
// for this touch point.
virtual void OnTouchUp(base::TimeTicks time_stamp, int id) = 0;
// Called when a touch point has changed coordinates.
virtual void OnTouchMotion(base::TimeTicks time_stamp,
int id,
const gfx::PointF& location) = 0;
// Called when a touch point has changed its shape.
virtual void OnTouchShape(int id, float major, float minor) = 0;
// Called when the client should apply all updated touches.
virtual void OnTouchFrame() = 0;
// Called when the touch session has been canceled. Touch cancellation
// applies to all touch points currently active.
virtual void OnTouchCancel() = 0;
virtual ~TouchDelegate() {}
} // namespace exo