blob: 2b255a58252a7045d3d2589f8a573470c39eecd6 [file] [log] [blame]
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'drag_details.dart';
/// Interface for objects that receive updates about drags.
/// This interface is used in various ways. For example,
/// [MultiDragGestureRecognizer] uses it to update its clients when it
/// recognizes a gesture. Similarly, the scrolling infrastructure in the widgets
/// library uses it to notify the [DragScrollActivity] when the user drags the
/// scrollable.
abstract class Drag {
/// The pointer has moved.
void update(DragUpdateDetails details) { }
/// The pointer is no longer in contact with the screen.
/// The velocity at which the pointer was moving when it stopped contacting
/// the screen is available in the `details`.
void end(DragEndDetails details) { }
/// The input from the pointer is no longer directed towards this receiver.
/// For example, the user might have been interrupted by a system-modal dialog
/// in the middle of the drag.
void cancel() { }