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575 行
21 KiB

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