using System; using System.Collections.Generic; using Unity.UIWidgets.animation; using Unity.UIWidgets.foundation; using Unity.UIWidgets.gestures; using Unity.UIWidgets.painting; using Unity.UIWidgets.rendering; using Unity.UIWidgets.ui; using Unity.UIWidgets.widgets; using UnityEngine; namespace Unity.UIWidgets.material { static class DrawerUtils { public const float _kWidth = 304.0f; public const float _kEdgeDragWidth = 20.0f; public const float _kMinFlingVelocity = 365.0f; public static readonly TimeSpan _kBaseSettleDuration = new TimeSpan(0, 0, 0, 0, 246); } public enum DrawerAlignment { start, end } public class Drawer : StatelessWidget { public Drawer( Key key = null, float elevation = 16.0f, Widget child = null) : base(key: key) { D.assert(elevation >= 0.0f); this.elevation = elevation; this.child = child; } public readonly float elevation; public readonly Widget child; public override Widget build(BuildContext context) { return new ConstrainedBox( constraints: BoxConstraints.expand(width: DrawerUtils._kWidth), child: new Material( elevation: this.elevation, child: this.child ) ); } } public delegate void DrawerCallback(bool isOpened); public class DrawerController : StatefulWidget { public DrawerController( GlobalKey key = null, Widget child = null, DrawerAlignment? alignment = null, DrawerCallback drawerCallback = null, DragStartBehavior? dragStartBehavior = null ) : base(key: key) { D.assert(child != null); D.assert(alignment != null); D.assert(dragStartBehavior != null); this.child = child; this.alignment = alignment ?? DrawerAlignment.start; this.drawerCallback = drawerCallback; this.dragStartBehavior = dragStartBehavior; } public readonly Widget child; public readonly DrawerAlignment alignment; public readonly DragStartBehavior? dragStartBehavior; public readonly DrawerCallback drawerCallback; public override State createState() { return new DrawerControllerState(); } } public class DrawerControllerState : SingleTickerProviderStateMixin { public override void initState() { base.initState(); this._controller = new AnimationController(duration: DrawerUtils._kBaseSettleDuration, vsync: this); this._controller.addListener(this._animationChanged); this._controller.addStatusListener(this._animationStatusChanged); } public override void dispose() { this._historyEntry?.remove(); this._controller.dispose(); base.dispose(); } void _animationChanged() { this.setState(() => { }); } LocalHistoryEntry _historyEntry; readonly FocusScopeNode _focusScopeNode = new FocusScopeNode(); void _ensureHistoryEntry() { if (this._historyEntry == null) { ModalRoute route = ModalRoute.of(this.context); if (route != null) { this._historyEntry = new LocalHistoryEntry(onRemove: this._handleHistoryEntryRemoved); route.addLocalHistoryEntry(this._historyEntry); FocusScope.of(this.context).setFirstFocus(this._focusScopeNode); } } } void _animationStatusChanged(AnimationStatus status) { switch (status) { case AnimationStatus.forward: this._ensureHistoryEntry(); break; case AnimationStatus.reverse: this._historyEntry?.remove(); this._historyEntry = null; break; case AnimationStatus.dismissed: break; case AnimationStatus.completed: break; } } void _handleHistoryEntryRemoved() { this._historyEntry = null; this.close(); } AnimationController _controller; void _handleDragDown(DragDownDetails details) { this._controller.stop(); this._ensureHistoryEntry(); } void _handleDragCancel() { if (this._controller.isDismissed || this._controller.isAnimating) { return; } if (this._controller.value < 0.5) { this.close(); } else { this.open(); } } public readonly GlobalKey _drawerKey = GlobalKey.key(); float _width { get { RenderBox box = (RenderBox) this._drawerKey.currentContext?.findRenderObject(); if (box != null) { return box.size.width; } return DrawerUtils._kWidth; } } bool _previouslyOpened = false; void _move(DragUpdateDetails details) { float delta = (details.primaryDelta ?? 0) / this._width; switch (this.widget.alignment) { case DrawerAlignment.start: break; case DrawerAlignment.end: delta = -delta; break; } this._controller.setValue(this._controller.value + delta); bool opened = this._controller.value > 0.5; if (opened != this._previouslyOpened && this.widget.drawerCallback != null) { this.widget.drawerCallback(opened); } this._previouslyOpened = opened; } void _settle(DragEndDetails details) { if (this._controller.isDismissed) { return; } if (details.velocity.pixelsPerSecond.dx.abs() >= DrawerUtils._kMinFlingVelocity) { float visualVelocity = details.velocity.pixelsPerSecond.dx / DrawerUtils._kWidth; switch (this.widget.alignment) { case DrawerAlignment.start: break; case DrawerAlignment.end: visualVelocity = -visualVelocity; break; } this._controller.fling(velocity: visualVelocity); } else if (this._controller.value < 0.5) { this.close(); } else { this.open(); } } public void open() { this._controller.fling(velocity: 1.0f); if (this.widget.drawerCallback != null) { this.widget.drawerCallback(true); } } public void close() { this._controller.fling(velocity: -1.0f); if (this.widget.drawerCallback != null) { this.widget.drawerCallback(false); } } ColorTween _color = new ColorTween(begin: Colors.transparent, end: Colors.black54); GlobalKey _gestureDetectorKey = GlobalKey.key(); Alignment _drawerOuterAlignment { get { switch (this.widget.alignment) { case DrawerAlignment.start: return Alignment.centerLeft; case DrawerAlignment.end: return Alignment.centerRight; } return null; } } Alignment _drawerInnerAlignment { get { switch (this.widget.alignment) { case DrawerAlignment.start: return Alignment.centerRight; case DrawerAlignment.end: return Alignment.centerLeft; } return null; } } Widget _buildDrawer(BuildContext context) { bool drawerIsStart = this.widget.alignment == DrawerAlignment.start; EdgeInsets padding = MediaQuery.of(context).padding; float dragAreaWidth = drawerIsStart ? padding.left : padding.right; dragAreaWidth = Mathf.Max(dragAreaWidth, DrawerUtils._kEdgeDragWidth); if (this._controller.status == AnimationStatus.dismissed) { return new Align( alignment: this._drawerOuterAlignment, child: new GestureDetector( key: this._gestureDetectorKey, onHorizontalDragUpdate: this._move, onHorizontalDragEnd: this._settle, behavior: HitTestBehavior.translucent, dragStartBehavior: this.widget.dragStartBehavior ?? DragStartBehavior.down, child: new Container(width: dragAreaWidth) ) ); } else { return new GestureDetector( key: this._gestureDetectorKey, onHorizontalDragDown: this._handleDragDown, onHorizontalDragUpdate: this._move, onHorizontalDragEnd: this._settle, onHorizontalDragCancel: this._handleDragCancel, dragStartBehavior: this.widget.dragStartBehavior ?? DragStartBehavior.down, child: new RepaintBoundary( child: new Stack( children: new List { new GestureDetector( onTap: this.close, child: new Container( color: this._color.evaluate(this._controller) ) ), new Align( alignment: this._drawerOuterAlignment, child: new Align( alignment: this._drawerInnerAlignment, widthFactor: this._controller.value, child: new RepaintBoundary( child: new FocusScope( key: this._drawerKey, node: this._focusScopeNode, child: this.widget.child) ) ) ) } ) ) ); } } public override Widget build(BuildContext context) { return new ListTileTheme( style: ListTileStyle.drawer, child: this._buildDrawer(context)); } } }