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578 行
21 KiB
578 行
21 KiB
using System;
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using System.Collections.Generic;
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using Unity.UIWidgets.animation;
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using Unity.UIWidgets.async2;
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using Unity.UIWidgets.foundation;
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using Unity.UIWidgets.gestures;
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using Unity.UIWidgets.painting;
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using Unity.UIWidgets.rendering;
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using Unity.UIWidgets.scheduler2;
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using Unity.UIWidgets.ui;
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namespace Unity.UIWidgets.widgets {
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public delegate void DismissDirectionCallback(DismissDirection? direction);
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public delegate Future<bool> ConfirmDismissCallback(DismissDirection? direction);
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public enum DismissDirection {
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vertical,
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horizontal,
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endToStart,
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startToEnd,
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up,
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down
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}
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public class Dismissible : StatefulWidget {
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public Dismissible(
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Key key = null,
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Widget child = null,
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Widget background = null,
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Widget secondaryBackground = null,
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ConfirmDismissCallback confirmDismiss = null,
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VoidCallback onResize = null,
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DismissDirectionCallback onDismissed = null,
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DismissDirection direction = DismissDirection.horizontal,
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TimeSpan? resizeDuration = null,
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Dictionary<DismissDirection?, float?> dismissThresholds = null,
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TimeSpan? movementDuration = null,
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float crossAxisEndOffset = 0.0f,
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DragStartBehavior dragStartBehavior = DragStartBehavior.start
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) : base(key: key) {
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D.assert(key != null);
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D.assert(secondaryBackground == null || background != null);
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this.resizeDuration = resizeDuration ?? new TimeSpan(0, 0, 0, 0, 300);
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this.dismissThresholds = dismissThresholds ?? new Dictionary<DismissDirection?, float?>();
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this.movementDuration = movementDuration ?? new TimeSpan(0, 0, 0, 0, 200);
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this.child = child;
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this.background = background;
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this.secondaryBackground = secondaryBackground;
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this.confirmDismiss = confirmDismiss;
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this.onResize = onResize;
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this.onDismissed = onDismissed;
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this.direction = direction;
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this.crossAxisEndOffset = crossAxisEndOffset;
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this.dragStartBehavior = dragStartBehavior;
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}
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public readonly Widget child;
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public readonly Widget background;
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public readonly Widget secondaryBackground;
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public readonly VoidCallback onResize;
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public readonly DismissDirectionCallback onDismissed;
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public readonly ConfirmDismissCallback confirmDismiss;
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public readonly DismissDirection direction;
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public readonly TimeSpan? resizeDuration;
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public readonly Dictionary<DismissDirection?, float?> dismissThresholds;
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public readonly TimeSpan? movementDuration;
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public readonly float crossAxisEndOffset;
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public readonly DragStartBehavior dragStartBehavior;
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public override State createState() {
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return new _DismissibleState();
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}
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}
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class _AutomaticWidgetTicker<T> : Ticker where T : StatefulWidget {
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internal _AutomaticWidgetTicker(
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TickerCallback onTick,
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AutomaticKeepAliveClientWithTickerProviderStateMixin<T> creator,
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string debugLabel = null) :
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base(onTick: onTick, debugLabel: debugLabel) {
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_creator = creator;
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}
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readonly AutomaticKeepAliveClientWithTickerProviderStateMixin<T> _creator;
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public override void Dispose() {
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_creator._removeTicker(this);
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base.Dispose();
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}
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}
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class _DismissibleClipper : CustomClipper<Rect> {
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public _DismissibleClipper(
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Axis axis,
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Animation<Offset> moveAnimation
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) : base(reclip: moveAnimation) {
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this.axis = axis;
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this.moveAnimation = moveAnimation;
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}
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public readonly Axis axis;
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public readonly Animation<Offset> moveAnimation;
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public override Rect getClip(Size size) {
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switch (axis) {
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case Axis.horizontal:
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float offset1 = moveAnimation.value.dx * size.width;
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if (offset1 < 0) {
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return Rect.fromLTRB(size.width + offset1, 0.0f, size.width, size.height);
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}
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return Rect.fromLTRB(0.0f, 0.0f, offset1, size.height);
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case Axis.vertical:
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float offset = moveAnimation.value.dy * size.height;
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if (offset < 0) {
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return Rect.fromLTRB(0.0f, size.height + offset, size.width, size.height);
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}
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return Rect.fromLTRB(0.0f, 0.0f, size.width, offset);
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}
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return null;
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}
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public override Rect getApproximateClipRect(Size size) {
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return getClip(size);
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}
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public override bool shouldReclip(CustomClipper<Rect> oldClipper) {
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//D.assert(oldClipper is _DismissibleClipper);
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_DismissibleClipper clipper = oldClipper as _DismissibleClipper;
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return clipper.axis != axis
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|| clipper.moveAnimation.value != moveAnimation.value;
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}
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}
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enum _FlingGestureKind {
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none,
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forward,
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reverse
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}
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public class _DismissibleState : AutomaticKeepAliveClientWithTickerProviderStateMixin<Dismissible> {
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static readonly Curve _kResizeTimeCurve = new Interval(0.4f, 1.0f, curve: Curves.ease);
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const float _kMinFlingVelocity = 700.0f;
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const float _kMinFlingVelocityDelta = 400.0f;
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const float _kFlingVelocityScale = 1.0f / 300.0f;
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const float _kDismissThreshold = 0.4f;
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public override void initState() {
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base.initState();
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_moveController = new AnimationController(duration: widget.movementDuration, vsync: this);
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_moveController.addStatusListener(_handleDismissStatusChanged);
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_updateMoveAnimation();
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}
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AnimationController _moveController;
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Animation<Offset> _moveAnimation;
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AnimationController _resizeController;
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Animation<float> _resizeAnimation;
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float _dragExtent = 0.0f;
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bool _dragUnderway = false;
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Size _sizePriorToCollapse;
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protected override bool wantKeepAlive {
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get { return _moveController?.isAnimating == true || _resizeController?.isAnimating == true; }
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}
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public override void dispose() {
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_moveController.dispose();
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_resizeController?.dispose();
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base.dispose();
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}
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bool _directionIsXAxis {
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get {
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return widget.direction == DismissDirection.horizontal
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|| widget.direction == DismissDirection.endToStart
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|| widget.direction == DismissDirection.startToEnd;
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}
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}
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DismissDirection? _extentToDirection(float? extent) {
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if (extent == 0.0) {
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return null;
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}
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if (_directionIsXAxis) {
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switch (Directionality.of(context)) {
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case TextDirection.rtl:
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return extent < 0 ? DismissDirection.startToEnd : DismissDirection.endToStart;
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case TextDirection.ltr:
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return extent > 0 ? DismissDirection.startToEnd : DismissDirection.endToStart;
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}
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D.assert(false);
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return null;
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}
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return extent > 0 ? DismissDirection.down : DismissDirection.up;
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}
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DismissDirection? _dismissDirection {
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get { return _extentToDirection(_dragExtent); }
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}
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bool _isActive {
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get { return _dragUnderway || _moveController.isAnimating; }
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}
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float _overallDragAxisExtent {
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get {
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Size size = context.size;
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return _directionIsXAxis ? size.width : size.height;
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}
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}
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void _handleDragStart(DragStartDetails details) {
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_dragUnderway = true;
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if (_moveController.isAnimating) {
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_dragExtent = _moveController.value * _overallDragAxisExtent * _dragExtent.sign();
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_moveController.stop();
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}
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else {
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_dragExtent = 0.0f;
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_moveController.setValue(0.0f);
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}
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setState(() => { _updateMoveAnimation(); });
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}
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void _handleDragUpdate(DragUpdateDetails details) {
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if (!_isActive || _moveController.isAnimating) {
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return;
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}
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float delta = details.primaryDelta ?? 0.0f;
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float oldDragExtent = _dragExtent;
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switch (widget.direction) {
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case DismissDirection.horizontal:
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case DismissDirection.vertical:
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_dragExtent += delta;
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break;
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case DismissDirection.up:
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if (_dragExtent + delta < 0) {
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_dragExtent += delta;
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}
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break;
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case DismissDirection.down:
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if (_dragExtent + delta > 0) {
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_dragExtent += delta;
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}
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break;
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case DismissDirection.endToStart:
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switch (Directionality.of(context)) {
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case TextDirection.rtl:
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if (_dragExtent + delta > 0) {
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_dragExtent += delta;
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}
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break;
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case TextDirection.ltr:
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if (_dragExtent + delta < 0) {
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_dragExtent += delta;
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}
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break;
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}
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break;
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case DismissDirection.startToEnd:
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switch (Directionality.of(context)) {
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case TextDirection.rtl:
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if (_dragExtent + delta < 0) {
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_dragExtent += delta;
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}
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break;
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case TextDirection.ltr:
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if (_dragExtent + delta > 0) {
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_dragExtent += delta;
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}
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break;
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}
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break;
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}
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if (oldDragExtent.sign() != _dragExtent.sign()) {
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setState(() => { _updateMoveAnimation(); });
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}
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if (!_moveController.isAnimating) {
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_moveController.setValue(_dragExtent.abs() / _overallDragAxisExtent);
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}
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}
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void _updateMoveAnimation() {
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float end = _dragExtent.sign();
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_moveAnimation = _moveController.drive(
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new OffsetTween(
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begin: Offset.zero,
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end: _directionIsXAxis
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? new Offset(end, widget.crossAxisEndOffset)
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: new Offset(widget.crossAxisEndOffset, end)
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)
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);
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}
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_FlingGestureKind _describeFlingGesture(Velocity velocity) {
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D.assert(widget.direction != null);
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if (_dragExtent == 0.0f) {
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return _FlingGestureKind.none;
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}
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float vx = velocity.pixelsPerSecond.dx;
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float vy = velocity.pixelsPerSecond.dy;
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DismissDirection? flingDirection;
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if (_directionIsXAxis) {
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if (vx.abs() - vy.abs() < _kMinFlingVelocityDelta || vx.abs() < _kMinFlingVelocity) {
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return _FlingGestureKind.none;
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}
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D.assert(vx != 0.0f);
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flingDirection = _extentToDirection(vx);
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}
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else {
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if (vy.abs() - vx.abs() < _kMinFlingVelocityDelta || vy.abs() < _kMinFlingVelocity) {
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return _FlingGestureKind.none;
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}
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D.assert(vy != 0.0);
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flingDirection = _extentToDirection(vy);
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}
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D.assert(_dismissDirection != null);
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if (flingDirection == _dismissDirection) {
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return _FlingGestureKind.forward;
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}
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return _FlingGestureKind.reverse;
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}
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void _handleDragEnd(DragEndDetails details) {
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if (!_isActive || _moveController.isAnimating) {
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return;
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}
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_dragUnderway = false;
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_confirmStartResizeAnimation().then_((value) => {
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if (_moveController.isCompleted && value) {
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_startResizeAnimation();
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}
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else {
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float flingVelocity = _directionIsXAxis
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? details.velocity.pixelsPerSecond.dx
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: details.velocity.pixelsPerSecond.dy;
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switch (_describeFlingGesture(details.velocity)) {
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case _FlingGestureKind.forward:
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D.assert(_dragExtent != 0.0f);
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D.assert(!_moveController.isDismissed);
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if ((widget.dismissThresholds.getOrDefault(_dismissDirection) ??
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_kDismissThreshold) >= 1.0) {
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_moveController.reverse();
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break;
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}
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_dragExtent = flingVelocity.sign();
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_moveController.fling(velocity: flingVelocity.abs() * _kFlingVelocityScale);
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break;
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case _FlingGestureKind.reverse:
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D.assert(_dragExtent != 0.0f);
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D.assert(!_moveController.isDismissed);
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_dragExtent = flingVelocity.sign();
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_moveController.fling(velocity: -flingVelocity.abs() * _kFlingVelocityScale);
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break;
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case _FlingGestureKind.none:
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if (!_moveController.isDismissed) {
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// we already know it's not completed, we check that above
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if (_moveController.value >
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(widget.dismissThresholds.getOrDefault(_dismissDirection) ??
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_kDismissThreshold)) {
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_moveController.forward();
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}
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else {
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_moveController.reverse();
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}
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}
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break;
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}
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}
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});
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}
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void _handleDismissStatusChanged(AnimationStatus status) {
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if (status == AnimationStatus.completed && !_dragUnderway) {
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_confirmStartResizeAnimation().then_((value) => {
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if (value) {
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_startResizeAnimation();
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}
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else {
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_moveController.reverse();
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}
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updateKeepAlive();
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});
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}
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}
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Future<bool> _confirmStartResizeAnimation() {
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if (widget.confirmDismiss != null) {
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DismissDirection? direction = _dismissDirection;
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D.assert(direction != null);
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return widget.confirmDismiss(direction);
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}
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return Future.value(true).to<bool>();
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}
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void _startResizeAnimation() {
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D.assert(_moveController != null);
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D.assert(_moveController.isCompleted);
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D.assert(_resizeController == null);
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D.assert(_sizePriorToCollapse == null);
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if (widget.resizeDuration == null) {
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if (widget.onDismissed != null) {
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DismissDirection? direction = _dismissDirection;
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D.assert(direction != null);
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widget.onDismissed(direction);
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}
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}
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else {
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_resizeController = new AnimationController(duration: widget.resizeDuration, vsync: this);
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_resizeController.addListener(_handleResizeProgressChanged);
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_resizeController.addStatusListener((AnimationStatus status) => updateKeepAlive());
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_resizeController.forward();
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setState(() => {
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_sizePriorToCollapse = context.size;
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_resizeAnimation = _resizeController.drive(
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new CurveTween(
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curve: _kResizeTimeCurve
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)
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).drive(
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new FloatTween(
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begin: 1.0f,
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end: 0.0f
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)
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);
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});
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}
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}
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void _handleResizeProgressChanged() {
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if (_resizeController.isCompleted) {
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if (widget.onDismissed != null) {
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DismissDirection? direction = _dismissDirection;
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D.assert(direction != null);
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widget.onDismissed(direction);
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}
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}
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else {
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if (widget.onResize != null) {
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widget.onResize();
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}
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}
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}
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public override Widget build(BuildContext context) {
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base.build(context); // See AutomaticKeepAliveClientMixin.
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D.assert(!_directionIsXAxis || WidgetsD.debugCheckHasDirectionality(context));
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Widget background = widget.background;
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if (widget.secondaryBackground != null) {
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DismissDirection? direction = _dismissDirection;
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if (direction == DismissDirection.endToStart || direction == DismissDirection.up) {
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background = widget.secondaryBackground;
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}
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}
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if (_resizeAnimation != null) {
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// we've been dragged aside, and are now resizing.
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D.assert(() => {
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if (_resizeAnimation.status != AnimationStatus.forward) {
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D.assert(_resizeAnimation.status == AnimationStatus.completed);
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throw new UIWidgetsError(new List<DiagnosticsNode>{
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new ErrorSummary("A dismissed Dismissible widget is still part of the tree."),
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new ErrorHint(
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"Make sure to implement the onDismissed handler and to immediately remove the Dismissible " +
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"widget from the application once that handler has fired."
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)
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});
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}
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return true;
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});
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return new SizeTransition(
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sizeFactor: _resizeAnimation,
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axis: _directionIsXAxis ? Axis.vertical : Axis.horizontal,
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child: new SizedBox(
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width: _sizePriorToCollapse.width,
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height: _sizePriorToCollapse.height,
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child: background
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)
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);
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}
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Widget content = new SlideTransition(
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position: _moveAnimation,
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child: widget.child
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);
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if (background != null) {
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List<Widget> children = new List<Widget>();
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if (!_moveAnimation.isDismissed) {
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children.Add(Positioned.fill(
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child: new ClipRect(
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clipper: new _DismissibleClipper(
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axis: _directionIsXAxis ? Axis.horizontal : Axis.vertical,
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moveAnimation: _moveAnimation
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),
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child: background
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)
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));
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}
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children.Add(content);
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content = new Stack(children: children);
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}
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return new GestureDetector(
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onHorizontalDragStart: _directionIsXAxis ? (GestureDragStartCallback) _handleDragStart : null,
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onHorizontalDragUpdate: _directionIsXAxis
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? (GestureDragUpdateCallback) _handleDragUpdate
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: null,
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onHorizontalDragEnd: _directionIsXAxis ? (GestureDragEndCallback) _handleDragEnd : null,
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|
onVerticalDragStart: _directionIsXAxis ? null : (GestureDragStartCallback) _handleDragStart,
|
|
onVerticalDragUpdate: _directionIsXAxis
|
|
? null
|
|
: (GestureDragUpdateCallback) _handleDragUpdate,
|
|
onVerticalDragEnd: _directionIsXAxis ? null : (GestureDragEndCallback) _handleDragEnd,
|
|
behavior: HitTestBehavior.opaque,
|
|
child: content,
|
|
dragStartBehavior: widget.dragStartBehavior
|
|
);
|
|
}
|
|
}
|
|
}
|