Tmp store.

Runtime/async/timer.cs

             }
         }
 
-        class TimerImpl : Timer, IComparable<TimerImpl> {
+        public class TimerImpl : Timer, IComparable<TimerImpl> {
             float _deadline;
             readonly Action _callback;
             bool _done;

Runtime/material/reorderable_list.cs

     public delegate void ReorderCallback(int oldIndex, int newIndex);
 
     public class ReorderableListView : StatefulWidget {
-        ReorderableListView(
+        public ReorderableListView(
             Widget header = null,
             List<Widget> children = null,
             ReorderCallback onReorder = null,
 
         Widget _wrap(Widget toWrap, int index, BoxConstraints constraints) {
             D.assert(toWrap.key != null);
-            GlobalObjectKey<State> keyIndexGlobalKey = new GlobalObjectKey<State>(toWrap.key);
+            GlobalObjectKey<State<_ReorderableListContent>> keyIndexGlobalKey = new GlobalObjectKey<State<_ReorderableListContent>>(toWrap.key);
 
             void onDragStarted() {
                 this.setState(() => {
             void onDragEnded() {
                 reorder(this._dragStartIndex, this._currentIndex);
             }
+            
+            
+            Widget wrapWithKeyedSubtree() {
+              return new KeyedSubtree(
+                key: keyIndexGlobalKey,
+                child: toWrap
+              );
+            }
+                Widget toWrapWithKeyedSubtree = wrapWithKeyedSubtree();
-                    child: new SizedBox(),
+                    feedback: new Container(
+                        alignment: Alignment.topLeft,
+                        // These constraints will limit the cross axis of the drawn widget.
+                        constraints: constraints,
+                        child: new Material(
+                            elevation: 6.0f,
+                            child: toWrapWithKeyedSubtree
+                        )
+                    ),
+                    child: this._dragging == toWrap.key ? new SizedBox() : toWrapWithKeyedSubtree,
                     childWhenDragging: new SizedBox(),
                     dragAnchor: DragAnchor.child,
                     onDragStarted: onDragStarted,
                             this._nextIndex = index;
                             this._requestAnimationToNextIndex();
                         });
-                        this._scrollTo(this.context);
+                        this._scrollTo(context);
                         return this._dragging == toAccept && toAccept != toWrap.key;
                     },
                     onAccept: (Key accepted) => { },

Runtime/widgets/scroll_view.cs

         }
 
         public GridView(
-            Key key,
+            Key key = null,
             Axis scrollDirection = Axis.vertical,
             bool reverse = false,
             ScrollController controller = null,
         }
 
         public static GridView count(
-            Key key,
+            Key key = null,
             Axis scrollDirection = Axis.vertical,
             bool reverse = false,
             ScrollController controller = null,

Runtime/material/refresh_indicator.cs

+using System;
+using System.Collections.Generic;
+using RSG;
+using Unity.UIWidgets.animation;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.ui;
+using Unity.UIWidgets.widgets;
+using UnityEngine;
+using Color = Unity.UIWidgets.ui.Color;
+
+namespace Unity.UIWidgets.material {
+    class RefreshIndicatorUtils {
+        public const float _kDragContainerExtentPercentage = 0.25f;
+
+        public const float _kDragSizeFactorLimit = 1.5f;
+
+        public static readonly TimeSpan _kIndicatorSnapDuration = new TimeSpan(0, 0, 0, 0, 150);
+
+        public static readonly TimeSpan _kIndicatorScaleDuration = new TimeSpan(0, 0, 0, 0, 200);
+    }
+
+    public delegate Promise RefreshCallback();
+
+    enum _RefreshIndicatorMode {
+        drag, // Pointer is down.
+        armed, // Dragged far enough that an up event will run the onRefresh callback.
+        snap, // Animating to the indicator"s final "displacement".
+        refresh, // Running the refresh callback.
+        done, // Animating the indicator"s fade-out after refreshing.
+        canceled, // Animating the indicator"s fade-out after not arming.
+    }
+
+    public class RefreshIndicator : StatefulWidget {
+        public RefreshIndicator(
+            Key key = null,
+            Widget child = null,
+            float displacement = 40.0f,
+            RefreshCallback onRefresh = null,
+            Color color = null,
+            Color backgroundColor = null,
+            ScrollNotificationPredicate notificationPredicate = null
+        ) : base(key: key) {
+            D.assert(child != null);
+            D.assert(onRefresh != null);
+            this.child = child;
+            this.displacement = displacement;
+            this.onRefresh = onRefresh;
+            this.color = color;
+            this.backgroundColor = backgroundColor;
+            this.notificationPredicate = notificationPredicate ?? ScrollNotification.defaultScrollNotificationPredicate;
+        }
+
+        public readonly Widget child;
+
+        public readonly float displacement;
+
+        public readonly RefreshCallback onRefresh;
+
+        public readonly Color color;
+
+        public readonly Color backgroundColor;
+
+        public readonly ScrollNotificationPredicate notificationPredicate;
+
+        public override State createState() {
+            return new RefreshIndicatorState();
+        }
+    }
+
+    public class RefreshIndicatorState : TickerProviderStateMixin<RefreshIndicator> {
+        AnimationController _positionController;
+        AnimationController _scaleController;
+        Animation<float> _positionFactor;
+        Animation<float> _scaleFactor;
+        Animation<float> _value;
+        Animation<Color> _valueColor;
+
+        _RefreshIndicatorMode? _mode;
+        Promise _pendingRefreshFuture;
+        bool? _isIndicatorAtTop;
+        float? _dragOffset;
+
+        static readonly Animatable<float> _threeQuarterTween = new FloatTween(begin: 0.0f, end: 0.75f);
+
+        static readonly Animatable<float> _kDragSizeFactorLimitTween =
+            new FloatTween(begin: 0.0f, end: RefreshIndicatorUtils._kDragSizeFactorLimit);
+
+        static readonly Animatable<float> _oneToZeroTween = new FloatTween(begin: 1.0f, end: 0.0f);
+
+        public RefreshIndicatorState() {
+        }
+
+        public override void initState() {
+            base.initState();
+            this._positionController = new AnimationController(vsync: this);
+            this._positionFactor = this._positionController.drive(_kDragSizeFactorLimitTween);
+            this._value =
+                this._positionController
+                    .drive(_threeQuarterTween); // The "value" of the circular progress indicator during a drag.
+
+            this._scaleController = new AnimationController(vsync: this);
+            this._scaleFactor = this._scaleController.drive(_oneToZeroTween);
+        }
+
+        public override void didChangeDependencies() {
+            ThemeData theme = Theme.of(this.context);
+            this._valueColor = this._positionController.drive(
+                new ColorTween(
+                    begin: (this.widget.color ?? theme.accentColor).withOpacity(0.0f),
+                    end: (this.widget.color ?? theme.accentColor).withOpacity(1.0f)
+                ).chain(new CurveTween(
+                    curve: new Interval(0.0f, 1.0f / RefreshIndicatorUtils._kDragSizeFactorLimit)
+                ))
+            );
+            base.didChangeDependencies();
+        }
+
+        public override void dispose() {
+            this._positionController.dispose();
+            this._scaleController.dispose();
+            base.dispose();
+        }
+
+        bool _handleScrollNotification(ScrollNotification notification) {
+            if (!this.widget.notificationPredicate(notification)) {
+                return false;
+            }
+
+            if (notification is ScrollStartNotification && notification.metrics.extentBefore() == 0.0f &&
+                this._mode == null && this._start(notification.metrics.axisDirection)) {
+                this.setState(() => { this._mode = _RefreshIndicatorMode.drag; });
+                return false;
+            }
+
+            bool? indicatorAtTopNow = null;
+            switch (notification.metrics.axisDirection) {
+                case AxisDirection.down:
+                    indicatorAtTopNow = true;
+                    break;
+                case AxisDirection.up:
+                    indicatorAtTopNow = false;
+                    break;
+                case AxisDirection.left:
+                case AxisDirection.right:
+                    indicatorAtTopNow = null;
+                    break;
+            }
+
+            if (indicatorAtTopNow != this._isIndicatorAtTop) {
+                if (this._mode == _RefreshIndicatorMode.drag || this._mode == _RefreshIndicatorMode.armed) {
+                    this._dismiss(_RefreshIndicatorMode.canceled);
+                }
+            }
+            else if (notification is ScrollUpdateNotification) {
+                if (this._mode == _RefreshIndicatorMode.drag || this._mode == _RefreshIndicatorMode.armed) {
+                    if (notification.metrics.extentBefore() > 0.0f) {
+                        this._dismiss(_RefreshIndicatorMode.canceled);
+                    }
+                    else {
+                        this._dragOffset -= (notification as ScrollUpdateNotification).scrollDelta;
+                        this._checkDragOffset(notification.metrics.viewportDimension);
+                    }
+                }
+
+                if (this._mode == _RefreshIndicatorMode.armed &&
+                    (notification as ScrollUpdateNotification).dragDetails == null) {
+                    this._show();
+                }
+            }
+            else if (notification is OverscrollNotification) {
+                if (this._mode == _RefreshIndicatorMode.drag || this._mode == _RefreshIndicatorMode.armed) {
+                    this._dragOffset -= (notification as OverscrollNotification).overscroll / 2.0f;
+                    this._checkDragOffset(notification.metrics.viewportDimension);
+                }
+            }
+            else if (notification is ScrollEndNotification) {
+                switch (this._mode) {
+                    case _RefreshIndicatorMode.armed:
+                        this._show();
+                        break;
+                    case _RefreshIndicatorMode.drag:
+                        this._dismiss(_RefreshIndicatorMode.canceled);
+                        break;
+                    default:
+                        break;
+                }
+            }
+
+            return false;
+        }
+
+        bool _handleGlowNotification(OverscrollIndicatorNotification notification) {
+            if (notification.depth != 0 || !notification.leading) {
+                return false;
+            }
+
+            if (this._mode == _RefreshIndicatorMode.drag) {
+                notification.disallowGlow();
+                return true;
+            }
+
+            return false;
+        }
+
+        bool _start(AxisDirection direction) {
+            D.assert(this._mode == null);
+            D.assert(this._isIndicatorAtTop == null);
+            D.assert(this._dragOffset == null);
+            switch (direction) {
+                case AxisDirection.down:
+                    this._isIndicatorAtTop = true;
+                    break;
+                case AxisDirection.up:
+                    this._isIndicatorAtTop = false;
+                    break;
+                case AxisDirection.left:
+                case AxisDirection.right:
+                    this._isIndicatorAtTop = null;
+                    return false;
+            }
+
+            this._dragOffset = 0.0f;
+            this._scaleController.setValue(0.0f);
+            this._positionController.setValue(0.0f);
+            return true;
+        }
+
+        void _checkDragOffset(float containerExtent) {
+            D.assert(this._mode == _RefreshIndicatorMode.drag || this._mode == _RefreshIndicatorMode.armed);
+            float? newValue = this._dragOffset /
+                              (containerExtent * RefreshIndicatorUtils._kDragContainerExtentPercentage);
+            if (this._mode == _RefreshIndicatorMode.armed) {
+                newValue = Mathf.Max(newValue ?? 0.0f, 1.0f / RefreshIndicatorUtils._kDragSizeFactorLimit);
+            }
+
+            this._positionController.setValue(newValue?.clamp(0.0f, 1.0f) ?? 0.0f); // this triggers various rebuilds
+            if (this._mode == _RefreshIndicatorMode.drag && this._valueColor.value.alpha == 0xFF) {
+                this._mode = _RefreshIndicatorMode.armed;
+            }
+        }
+
+        IPromise _dismiss(_RefreshIndicatorMode newMode) {
+            D.assert(newMode == _RefreshIndicatorMode.canceled || newMode == _RefreshIndicatorMode.done);
+            this.setState(() => { this._mode = newMode; });
+            switch (this._mode) {
+                case _RefreshIndicatorMode.done:
+                    return this._scaleController
+                        .animateTo(1.0f, duration: RefreshIndicatorUtils._kIndicatorScaleDuration).Then(() => {
+                            if (this.mounted && this._mode == newMode) {
+                                this._dragOffset = null;
+                                this._isIndicatorAtTop = null;
+                                this.setState(() => { this._mode = null; });
+                            }
+                        });
+                case _RefreshIndicatorMode.canceled:
+                    return this._positionController
+                        .animateTo(0.0f, duration: RefreshIndicatorUtils._kIndicatorScaleDuration).Then(() => {
+                            if (this.mounted && this._mode == newMode) {
+                                this._dragOffset = null;
+                                this._isIndicatorAtTop = null;
+                                this.setState(() => { this._mode = null; });
+                            }
+                        });
+                default:
+                    throw new Exception("Unknown refresh indicator mode: " + this._mode);
+            }
+        }
+
+        void _show() {
+            D.assert(this._mode != _RefreshIndicatorMode.refresh);
+            D.assert(this._mode != _RefreshIndicatorMode.snap);
+            Promise completer = new Promise();
+            this._pendingRefreshFuture = completer;
+            this._mode = _RefreshIndicatorMode.snap;
+            this._positionController
+                .animateTo(1.0f / RefreshIndicatorUtils._kDragSizeFactorLimit,
+                    duration: RefreshIndicatorUtils._kIndicatorSnapDuration)
+                .Then(() => {
+                    if (this.mounted && this._mode == _RefreshIndicatorMode.snap) {
+                        D.assert(this.widget.onRefresh != null);
+                        this.setState(() => { this._mode = _RefreshIndicatorMode.refresh; });
+
+                        Promise refreshResult = this.widget.onRefresh();
+                        D.assert(() => {
+                            if (refreshResult == null) {
+                                UIWidgetsError.reportError(new UIWidgetsErrorDetails(
+                                    exception: new UIWidgetsError(
+                                        "The onRefresh callback returned null.\n" +
+                                        "The RefreshIndicator onRefresh callback must return a Promise."
+                                    ),
+                                    context: "when calling onRefresh",
+                                    library: "material library"
+                                ));
+                            }
+
+                            return true;
+                        });
+                        if (refreshResult == null) {
+                            return;
+                        }
+
+                        refreshResult.Then(() => {
+                            if (this.mounted && this._mode == _RefreshIndicatorMode.refresh) {
+                                completer.Resolve();
+                                this._dismiss(_RefreshIndicatorMode.done);
+                            }
+                        });
+                    }
+                });
+        }
+
+        Promise show(bool atTop = true) {
+            if (this._mode != _RefreshIndicatorMode.refresh && this._mode != _RefreshIndicatorMode.snap) {
+                if (this._mode == null) {
+                    this._start(atTop ? AxisDirection.down : AxisDirection.up);
+                }
+
+                this._show();
+            }
+
+            return this._pendingRefreshFuture;
+        }
+
+        GlobalKey _key = GlobalKey.key();
+
+        public override Widget build(BuildContext context) {
+            D.assert(MaterialD.debugCheckHasMaterialLocalizations(context));
+            Widget child = new NotificationListener<ScrollNotification>(
+                key: this._key,
+                onNotification: this._handleScrollNotification,
+                child: new NotificationListener<OverscrollIndicatorNotification>(
+                    onNotification: this._handleGlowNotification,
+                    child: this.widget.child
+                )
+            );
+            if (this._mode == null) {
+                D.assert(this._dragOffset == null);
+                D.assert(this._isIndicatorAtTop == null);
+                return child;
+            }
+
+            D.assert(this._dragOffset != null);
+            D.assert(this._isIndicatorAtTop != null);
+
+            bool showIndeterminateIndicator =
+                this._mode == _RefreshIndicatorMode.refresh || this._mode == _RefreshIndicatorMode.done;
+
+            return new Stack(
+                children: new List<Widget> {
+                    child,
+                    new Positioned(
+                        top: this._isIndicatorAtTop == true ? 0.0f : (float?) null,
+                        bottom: this._isIndicatorAtTop != true ? 0.0f : (float?) null,
+                        left: 0.0f,
+                        right: 0.0f,
+                        child: new SizeTransition(
+                            axisAlignment: this._isIndicatorAtTop == true ? 1.0f : -1.0f,
+                            sizeFactor: this._positionFactor, // this is what brings it down
+                            child: new Container(
+                                padding: this._isIndicatorAtTop == true
+                                    ? EdgeInsets.only(top: this.widget.displacement)
+                                    : EdgeInsets.only(bottom: this.widget.displacement),
+                                alignment: this._isIndicatorAtTop == true
+                                    ? Alignment.topCenter
+                                    : Alignment.bottomCenter,
+                                child: new ScaleTransition(
+                                    scale: this._scaleFactor,
+                                    child: new AnimatedBuilder(
+                                        animation: this._positionController,
+                                        builder: (BuildContext _context, Widget _child) => {
+                                            return new RefreshProgressIndicator(
+                                                value: showIndeterminateIndicator ? (float?) null : this._value.value,
+                                                valueColor: this._valueColor,
+                                                backgroundColor: this.widget.backgroundColor
+                                            );
+                                        }
+                                    )
+                                )
+                            )
+                        )
+                    )
+                }
+            );
+        }
+    }
+}

Runtime/material/refresh_indicator.cs.meta

+fileFormatVersion: 2
+guid: 74dd879101fe4541a5b42619cf4f309c
+timeCreated: 1554344854

Runtime/material/user_accounts_drawer_header.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+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;
+using Transform = Unity.UIWidgets.widgets.Transform;
+
+namespace Unity.UIWidgets.material {
+    class UserAccountsDrawerHeaderUtils {
+        public const float _kAccountDetailsHeight = 56.0f;
+    }
+
+    class _AccountPictures : StatelessWidget {
+        public _AccountPictures(
+            Key key = null,
+            Widget currentAccountPicture = null,
+            List<Widget> otherAccountsPictures = null
+        ) : base(key: key) {
+            this.currentAccountPicture = currentAccountPicture;
+            this.otherAccountsPictures = otherAccountsPictures;
+        }
+
+        public readonly Widget currentAccountPicture;
+        public readonly List<Widget> otherAccountsPictures;
+
+        public override Widget build(BuildContext context) {
+            return new Stack(
+                children: new List<Widget> {
+                    new Positioned(
+                        top: 0.0f,
+                        right: 0.0f,
+                        child: new Row(
+                            children: (this.otherAccountsPictures ?? new List<Widget> { })
+                            .GetRange(0, Math.Min(3, this.otherAccountsPictures?.Count ?? 0))
+                            .Select<Widget, Widget>(
+                                (Widget picture) => {
+                                    return new Padding(
+                                        padding: EdgeInsets.only(left: 8.0f),
+                                        child: new Container(
+                                            padding: EdgeInsets.only(left: 8.0f, bottom: 8.0f),
+                                            width: 48.0f,
+                                            height: 48.0f,
+                                            child: picture
+                                        )
+                                    );
+                                }).ToList()
+                        )
+                    ),
+                    new Positioned(
+                        top: 0.0f,
+                        child: new SizedBox(
+                            width: 72.0f,
+                            height: 72.0f,
+                            child: this.currentAccountPicture
+                        )
+                    )
+                }
+            );
+        }
+    }
+
+    class _AccountDetails : StatefulWidget {
+        public _AccountDetails(
+            Key key = null,
+            Widget accountName = null,
+            Widget accountEmail = null,
+            VoidCallback onTap = null,
+            bool? isOpen = null
+        ) : base(key: key) {
+            D.assert(accountName != null);
+            D.assert(accountEmail != null);
+            this.accountName = accountName;
+            this.accountEmail = accountEmail;
+            this.onTap = onTap;
+            this.isOpen = isOpen;
+        }
+
+        public readonly Widget accountName;
+        public readonly Widget accountEmail;
+        public readonly VoidCallback onTap;
+        public readonly bool? isOpen;
+
+        public override State createState() {
+            return new _AccountDetailsState();
+        }
+    }
+
+    class _AccountDetailsState : SingleTickerProviderStateMixin<_AccountDetails> {
+        Animation<float> _animation;
+        AnimationController _controller;
+
+        public override void initState() {
+            base.initState();
+            this._controller = new AnimationController(
+                value: this.widget.isOpen == true ? 1.0f : 0.0f,
+                duration: new TimeSpan(0, 0, 0, 0, 200),
+                vsync: this
+            );
+            this._animation = new CurvedAnimation(
+                parent: this._controller,
+                curve: Curves.fastOutSlowIn,
+                reverseCurve: Curves.fastOutSlowIn.flipped
+            );
+            this._animation.addListener(() => this.setState(() => { }));
+        }
+
+        public override void dispose() {
+            this._controller.dispose();
+            base.dispose();
+        }
+
+        public override void didUpdateWidget(StatefulWidget _oldWidget) {
+            base.didUpdateWidget(_oldWidget);
+            _AccountDetails oldWidget = _oldWidget as _AccountDetails;
+            if (this._animation.status == AnimationStatus.dismissed ||
+                this._animation.status == AnimationStatus.reverse) {
+                this._controller.forward();
+            }
+            else {
+                this._controller.reverse();
+            }
+        }
+
+        public override Widget build(BuildContext context) {
+            D.assert(WidgetsD.debugCheckHasDirectionality(context));
+            D.assert(MaterialD.debugCheckHasMaterialLocalizations(context));
+            D.assert(MaterialD.debugCheckHasMaterialLocalizations(context));
+
+            ThemeData theme = Theme.of(context);
+            List<Widget> children = new List<Widget> { };
+
+            if (this.widget.accountName != null) {
+                Widget accountNameLine = new LayoutId(
+                    id: _AccountDetailsLayout.accountName,
+                    child: new Padding(
+                        padding: EdgeInsets.symmetric(vertical: 2.0f),
+                        child: new DefaultTextStyle(
+                            style: theme.primaryTextTheme.body2,
+                            overflow: TextOverflow.ellipsis,
+                            child: this.widget.accountName
+                        )
+                    )
+                );
+                children.Add(accountNameLine);
+            }
+
+            if (this.widget.accountEmail != null) {
+                Widget accountEmailLine = new LayoutId(
+                    id: _AccountDetailsLayout.accountEmail,
+                    child: new Padding(
+                        padding: EdgeInsets.symmetric(vertical: 2.0f),
+                        child: new DefaultTextStyle(
+                            style: theme.primaryTextTheme.body1,
+                            overflow: TextOverflow.ellipsis,
+                            child: this.widget.accountEmail
+                        )
+                    )
+                );
+                children.Add(accountEmailLine);
+            }
+
+            if (this.widget.onTap != null) {
+                MaterialLocalizations localizations = MaterialLocalizations.of(context);
+                Widget dropDownIcon = new LayoutId(
+                    id: _AccountDetailsLayout.dropdownIcon,
+                    child: new SizedBox(
+                        height: UserAccountsDrawerHeaderUtils._kAccountDetailsHeight,
+                        width: UserAccountsDrawerHeaderUtils._kAccountDetailsHeight,
+                        child: new Center(
+                            child: Transform.rotate(
+                                degree: this._animation.value * Mathf.PI,
+                                child: new Icon(
+                                    Icons.arrow_drop_down,
+                                    color: Colors.white
+                                )
+                            )
+                        )
+                    )
+                );
+                children.Add(dropDownIcon);
+            }
+
+            Widget accountDetails = new CustomMultiChildLayout(
+                layoutDelegate: new _AccountDetailsLayout(),
+                children: children
+            );
+
+            if (this.widget.onTap != null) {
+                accountDetails = new InkWell(
+                    onTap: this.widget.onTap == null ? (GestureTapCallback) null : () => { this.widget.onTap(); },
+                    child: accountDetails
+                );
+            }
+
+            return new SizedBox(
+                height: UserAccountsDrawerHeaderUtils._kAccountDetailsHeight,
+                child: accountDetails
+            );
+        }
+    }
+
+
+    class _AccountDetailsLayout : MultiChildLayoutDelegate {
+        public _AccountDetailsLayout() {
+        }
+
+        public const string accountName = "accountName";
+        public const string accountEmail = "accountEmail";
+        public const string dropdownIcon = "dropdownIcon";
+
+        public override void performLayout(Size size) {
+            Size iconSize = null;
+            if (this.hasChild(dropdownIcon)) {
+                iconSize = this.layoutChild(dropdownIcon, BoxConstraints.loose(size));
+                this.positionChild(dropdownIcon, this._offsetForIcon(size, iconSize));
+            }
+
+            string bottomLine = this.hasChild(accountEmail)
+                ? accountEmail
+                : (this.hasChild(accountName) ? accountName : null);
+
+            if (bottomLine != null) {
+                Size constraintSize = iconSize == null ? size : size - new Offset(iconSize.width, 0.0f);
+                iconSize = iconSize ?? new Size(UserAccountsDrawerHeaderUtils._kAccountDetailsHeight,
+                               UserAccountsDrawerHeaderUtils._kAccountDetailsHeight);
+
+                Size bottomLineSize = this.layoutChild(bottomLine, BoxConstraints.loose(constraintSize));
+                Offset bottomLineOffset = this._offsetForBottomLine(size, iconSize, bottomLineSize);
+                this.positionChild(bottomLine, bottomLineOffset);
+
+                if (bottomLine == accountEmail && this.hasChild(accountName)) {
+                    Size nameSize = this.layoutChild(accountName, BoxConstraints.loose(constraintSize));
+                    this.positionChild(accountName, this._offsetForName(size, nameSize, bottomLineOffset));
+                }
+            }
+        }
+
+        public override bool shouldRelayout(MultiChildLayoutDelegate oldDelegate) {
+            return true;
+        }
+
+        Offset _offsetForIcon(Size size, Size iconSize) {
+            return new Offset(size.width - iconSize.width, size.height - iconSize.height);
+        }
+
+        Offset _offsetForBottomLine(Size size, Size iconSize, Size bottomLineSize) {
+            float y = size.height - 0.5f * iconSize.height - 0.5f * bottomLineSize.height;
+            return new Offset(0.0f, y);
+        }
+
+        Offset _offsetForName(Size size, Size nameSize, Offset bottomLineOffset) {
+            float y = bottomLineOffset.dy - nameSize.height;
+            return new Offset(0.0f, y);
+        }
+    }
+
+    public class UserAccountsDrawerHeader : StatefulWidget {
+        public UserAccountsDrawerHeader(
+            Key key = null,
+            Decoration decoration = null,
+            EdgeInsets margin = null,
+            Widget currentAccountPicture = null,
+            List<Widget> otherAccountsPictures = null,
+            Widget accountName = null,
+            Widget accountEmail = null,
+            VoidCallback onDetailsPressed = null
+        ) : base(key: key) {
+            D.assert(accountName != null);
+            D.assert(accountEmail != null);
+            this.decoration = decoration;
+            this.margin = margin ?? EdgeInsets.only(bottom: 8.0f);
+            this.currentAccountPicture = currentAccountPicture;
+            this.otherAccountsPictures = otherAccountsPictures;
+            this.accountName = accountName;
+            this.accountEmail = accountEmail;
+            this.onDetailsPressed = onDetailsPressed;
+        }
+
+        public readonly Decoration decoration;
+
+        public readonly EdgeInsets margin;
+
+        public readonly Widget currentAccountPicture;
+
+        public readonly List<Widget> otherAccountsPictures;
+
+        public readonly Widget accountName;
+
+        public readonly Widget accountEmail;
+
+        public readonly VoidCallback onDetailsPressed;
+
+        public override State createState() {
+            return new _UserAccountsDrawerHeaderState();
+        }
+    }
+
+    class _UserAccountsDrawerHeaderState : State<UserAccountsDrawerHeader> {
+        bool _isOpen = false;
+
+        void _handleDetailsPressed() {
+            this.setState(() => { this._isOpen = !this._isOpen; });
+            this.widget.onDetailsPressed();
+        }
+
+        public override Widget build(BuildContext context) {
+            D.assert(MaterialD.debugCheckHasMaterial(context));
+            D.assert(MaterialD.debugCheckHasMaterialLocalizations(context));
+            return new DrawerHeader(
+                decoration: this.widget.decoration ?? new BoxDecoration(
+                                color: Theme.of(context).primaryColor
+                            ),
+                margin: this.widget.margin,
+                padding: EdgeInsets.only(top: 16.0f, left: 16.0f),
+                child: new SafeArea(
+                    bottom: false,
+                    child: new Column(
+                        crossAxisAlignment: CrossAxisAlignment.stretch,
+                        children: new List<Widget> {
+                            new Expanded(
+                                child: new Padding(
+                                    padding: EdgeInsets.only(right: 16.0f),
+                                    child: new _AccountPictures(
+                                        currentAccountPicture: this.widget.currentAccountPicture,
+                                        otherAccountsPictures: this.widget.otherAccountsPictures
+                                    )
+                                )
+                            ),
+                            new _AccountDetails(
+                                accountName: this.widget.accountName,
+                                accountEmail: this.widget.accountEmail,
+                                isOpen: this._isOpen,
+                                onTap: this.widget.onDetailsPressed == null
+                                    ? (VoidCallback) null
+                                    : () => { this._handleDetailsPressed(); })
+                        }
+                    )
+                )
+            );
+        }
+    }
+}

Runtime/material/user_accounts_drawer_header.cs.meta

+fileFormatVersion: 2
+guid: fb34d1a7ff484d05b8074a10730d51a5
+timeCreated: 1554352270

Runtime/widgets/overscroll_indicator.cs

+using System;
+using System.Collections.Generic;
+using Unity.UIWidgets.animation;
+using Unity.UIWidgets.async;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.physics;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.scheduler;
+using Unity.UIWidgets.ui;
+using UnityEngine;
+using Canvas = Unity.UIWidgets.ui.Canvas;
+using Color = Unity.UIWidgets.ui.Color;
+using Rect = Unity.UIWidgets.ui.Rect;
+
+namespace Unity.UIWidgets.widgets {
+    public class GlowingOverscrollIndicator : StatefulWidget {
+        public GlowingOverscrollIndicator(
+            Key key = null,
+            bool showLeading = true,
+            bool showTrailing = true,
+            AxisDirection axisDirection = AxisDirection.up,
+            Color color = null,
+            ScrollNotificationPredicate notificationPredicate = null,
+            Widget child = null
+        ) : base(key: key) {
+            D.assert(color != null);
+            this.showLeading = showLeading;
+            this.showTrailing = showTrailing;
+            this.axisDirection = axisDirection;
+            this.child = child;
+            this.color = color;
+            this.notificationPredicate = notificationPredicate ?? ScrollNotification.defaultScrollNotificationPredicate;
+        }
+
+        public readonly bool showLeading;
+
+        public readonly bool showTrailing;
+
+        public readonly AxisDirection axisDirection;
+
+        public Axis axis {
+            get { return AxisUtils.axisDirectionToAxis(this.axisDirection); }
+        }
+
+        public readonly Color color;
+
+        public readonly ScrollNotificationPredicate notificationPredicate;
+
+        public readonly Widget child;
+
+        public override State createState() {
+            return new _GlowingOverscrollIndicatorState();
+        }
+
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+            base.debugFillProperties(properties);
+            properties.add(new EnumProperty<AxisDirection>("axisDirection", this.axisDirection));
+            string showDescription;
+            if (this.showLeading && this.showTrailing) {
+                showDescription = "both sides";
+            }
+            else if (this.showLeading) {
+                showDescription = "leading side only";
+            }
+            else if (this.showTrailing) {
+                showDescription = "trailing side only";
+            }
+            else {
+                showDescription = "neither side (!)";
+            }
+
+            properties.add(new MessageProperty("show", showDescription));
+            properties.add(new DiagnosticsProperty<Color>("color", this.color, showName: false));
+        }
+    }
+
+    class _GlowingOverscrollIndicatorState : TickerProviderStateMixin<GlowingOverscrollIndicator> {
+        _GlowController _leadingController;
+        _GlowController _trailingController;
+        Listenable _leadingAndTrailingListener;
+
+        public override void initState() {
+            base.initState();
+            this._leadingController =
+                new _GlowController(vsync: this, color: this.widget.color, axis: this.widget.axis);
+            this._trailingController =
+                new _GlowController(vsync: this, color: this.widget.color, axis: this.widget.axis);
+            this._leadingAndTrailingListener = ListenableUtils.merge(new List<Listenable>
+                {this._leadingController, this._trailingController});
+        }
+
+        public override void didUpdateWidget(StatefulWidget _oldWidget) {
+            base.didUpdateWidget(_oldWidget);
+            GlowingOverscrollIndicator oldWidget = _oldWidget as GlowingOverscrollIndicator;
+            if (oldWidget.color != this.widget.color || oldWidget.axis != this.widget.axis) {
+                this._leadingController.color = this.widget.color;
+                this._leadingController.axis = this.widget.axis;
+                this._trailingController.color = this.widget.color;
+                this._trailingController.axis = this.widget.axis;
+            }
+        }
+
+        Type _lastNotificationType;
+        Dictionary<bool, bool> _accepted = new Dictionary<bool, bool> {{false, true}, {true, true}};
+
+        bool _handleScrollNotification(ScrollNotification notification) {
+            if (!this.widget.notificationPredicate(notification)) {
+                return false;
+            }
+
+            if (notification is OverscrollNotification) {
+                _GlowController controller;
+                OverscrollNotification _notification = notification as OverscrollNotification;
+                if (_notification.overscroll < 0.0f) {
+                    controller = this._leadingController;
+                }
+                else if (_notification.overscroll > 0.0f) {
+                    controller = this._trailingController;
+                }
+                else {
+                    throw new Exception("overscroll is 0.0f!");
+                }
+
+                bool isLeading = controller == this._leadingController;
+                if (this._lastNotificationType != typeof(OverscrollNotification)) {
+                    OverscrollIndicatorNotification confirmationNotification =
+                        new OverscrollIndicatorNotification(leading: isLeading);
+                    confirmationNotification.dispatch(this.context);
+                    this._accepted[isLeading] = confirmationNotification._accepted;
+                }
+
+                D.assert(controller != null);
+                D.assert(_notification.metrics.axis() == this.widget.axis);
+                if (this._accepted[isLeading]) {
+                    if (_notification.velocity != 0.0f) {
+                        D.assert(_notification.dragDetails == null);
+                        controller.absorbImpact(_notification.velocity.abs());
+                    }
+                    else {
+                        D.assert(_notification.overscroll != 0.0f);
+                        if (_notification.dragDetails != null) {
+                            D.assert(_notification.dragDetails.globalPosition != null);
+                            RenderBox renderer = (RenderBox) _notification.context.findRenderObject();
+                            D.assert(renderer != null);
+                            D.assert(renderer.hasSize);
+                            Size size = renderer.size;
+                            Offset position = renderer.globalToLocal(_notification.dragDetails.globalPosition);
+                            switch (_notification.metrics.axis()) {
+                                case Axis.horizontal:
+                                    controller.pull(_notification.overscroll.abs(), size.width,
+                                        position.dy.clamp(0.0f, size.height), size.height);
+                                    break;
+                                case Axis.vertical:
+                                    controller.pull(_notification.overscroll.abs(), size.height,
+                                        position.dx.clamp(0.0f, size.width), size.width);
+                                    break;
+                            }
+                        }
+                    }
+                }
+            }
+            else if (notification is ScrollEndNotification || notification is ScrollUpdateNotification) {
+                if ((notification as ScrollEndNotification).dragDetails != null) {
+                    this._leadingController.scrollEnd();
+                    this._trailingController.scrollEnd();
+                }
+            }
+
+            this._lastNotificationType = notification.GetType();
+            return false;
+        }
+
+        public override void dispose() {
+            this._leadingController.dispose();
+            this._trailingController.dispose();
+            base.dispose();
+        }
+
+        public override Widget build(BuildContext context) {
+            return new NotificationListener<ScrollNotification>(
+                onNotification: this._handleScrollNotification,
+                child: new RepaintBoundary(
+                    child: new CustomPaint(
+                        foregroundPainter: new _GlowingOverscrollIndicatorPainter(
+                            leadingController: this.widget.showLeading ? this._leadingController : null,
+                            trailingController: this.widget.showTrailing ? this._trailingController : null,
+                            axisDirection: this.widget.axisDirection,
+                            repaint: this._leadingAndTrailingListener
+                        ),
+                        child: new RepaintBoundary(
+                            child: this.widget.child
+                        )
+                    )
+                )
+            );
+        }
+    }
+
+
+    enum _GlowState {
+        idle,
+        absorb,
+        pull,
+        recede
+    }
+
+    class _GlowController : ChangeNotifier {
+        public _GlowController(
+            TickerProvider vsync,
+            Color color,
+            Axis axis
+        ) {
+            D.assert(vsync != null);
+            D.assert(color != null);
+            this._color = color;
+            this._axis = axis;
+            this._glowController = new AnimationController(vsync: vsync);
+            this._glowController.addStatusListener(this._changePhase);
+            Animation<float> decelerator = new CurvedAnimation(
+                parent: this._glowController,
+                curve: Curves.decelerate
+            );
+            decelerator.addListener(this.notifyListeners);
+            this._glowOpacity = decelerator.drive(this._glowOpacityTween);
+            this._glowSize = decelerator.drive(this._glowSizeTween);
+            this._displacementTicker = vsync.createTicker(this._tickDisplacement);
+        }
+
+        _GlowState _state = _GlowState.idle;
+        AnimationController _glowController;
+        Timer _pullRecedeTimer;
+
+        FloatTween _glowOpacityTween = new FloatTween(begin: 0.0f, end: 0.0f);
+        Animation<float> _glowOpacity;
+        FloatTween _glowSizeTween = new FloatTween(begin: 0.0f, end: 0.0f);
+        Animation<float> _glowSize;
+
+        Ticker _displacementTicker;
+        TimeSpan? _displacementTickerLastElapsed;
+        float _displacementTarget = 0.5f;
+        float _displacement = 0.5f;
+
+        float _pullDistance = 0.0f;
+
+        public Color color {
+            get { return this._color; }
+            set {
+                D.assert(this.color != null);
+                if (this.color == value) {
+                    return;
+                }
+
+                this._color = value;
+                this.notifyListeners();
+            }
+        }
+
+        Color _color;
+
+        public Axis axis {
+            get { return this._axis; }
+            set {
+                if (this.axis == value) {
+                    return;
+                }
+
+                this._axis = value;
+                this.notifyListeners();
+            }
+        }
+
+        Axis _axis;
+
+        readonly TimeSpan _recedeTime = new TimeSpan(0, 0, 0, 0, 600);
+        readonly TimeSpan _pullTime = new TimeSpan(0, 0, 0, 0, 167);
+        readonly TimeSpan _pullHoldTime = new TimeSpan(0, 0, 0, 0, 167);
+        readonly TimeSpan _pullDecayTime = new TimeSpan(0, 0, 0, 0, 2000);
+        static readonly TimeSpan _crossAxisHalfTime = new TimeSpan(0, 0, 0, 0, (1000.0f / 60.0f).round());
+
+        const float _maxOpacity = 0.5f;
+        const float _pullOpacityGlowFactor = 0.8f;
+        const float _velocityGlowFactor = 0.00006f;
+        const float _sqrt3 = 1.73205080757f; // Mathf.Sqrt(3)
+        const float _widthToHeightFactor = (3.0f / 4.0f) * (2.0f - _sqrt3);
+
+        const float _minVelocity = 100.0f; // logical pixels per second
+        const float _maxVelocity = 10000.0f; // logical pixels per second
+
+        public override void dispose() {
+            this._glowController.dispose();
+            this._displacementTicker.dispose();
+            this._pullRecedeTimer?.cancel();
+            base.dispose();
+        }
+
+        public void absorbImpact(float velocity) {
+            D.assert(velocity >= 0.0f);
+            this._pullRecedeTimer?.cancel();
+            this._pullRecedeTimer = null;
+            velocity = velocity.clamp(_minVelocity, _maxVelocity);
+            this._glowOpacityTween.begin = this._state == _GlowState.idle ? 0.3f : this._glowOpacity.value;
+            this._glowOpacityTween.end =
+                (velocity * _velocityGlowFactor).clamp(this._glowOpacityTween.begin, _maxOpacity);
+            this._glowSizeTween.begin = this._glowSize.value;
+            this._glowSizeTween.end = Mathf.Min(0.025f + 7.5e-7f * velocity * velocity, 1.0f);
+            this._glowController.duration = new TimeSpan(0, 0, 0, 0, (0.15f + velocity * 0.02f).round());
+            this._glowController.forward(from: 0.0f);
+            this._displacement = 0.5f;
+            this._state = _GlowState.absorb;
+        }
+
+        public void pull(float overscroll, float extent, float crossAxisOffset, float crossExtent) {
+            this._pullRecedeTimer?.cancel();
+            this._pullDistance +=
+                overscroll / 200.0f; // This factor is magic. Not clear why we need it to match Android.
+            this._glowOpacityTween.begin = this._glowOpacity.value;
+            this._glowOpacityTween.end =
+                Mathf.Min(this._glowOpacity.value + overscroll / extent * _pullOpacityGlowFactor, _maxOpacity);
+            float height = Mathf.Min(extent, crossExtent * _widthToHeightFactor);
+            this._glowSizeTween.begin = this._glowSize.value;
+            this._glowSizeTween.end = Mathf.Max(1.0f - 1.0f / (0.7f * Mathf.Sqrt(this._pullDistance * height)),
+                this._glowSize.value);
+            this._displacementTarget = crossAxisOffset / crossExtent;
+            if (this._displacementTarget != this._displacement) {
+                if (!this._displacementTicker.isTicking) {
+                    D.assert(this._displacementTickerLastElapsed == null);
+                    this._displacementTicker.start();
+                }
+            }
+            else {
+                this._displacementTicker.stop();
+                this._displacementTickerLastElapsed = null;
+            }
+
+            this._glowController.duration = this._pullTime;
+            if (this._state != _GlowState.pull) {
+                this._glowController.forward(from: 0.0f);
+                this._state = _GlowState.pull;
+            }
+            else {
+                if (!this._glowController.isAnimating) {
+                    D.assert(this._glowController.value == 1.0f);
+                    this.notifyListeners();
+                }
+            }
+
+            this._pullRecedeTimer =
+                new TimerProvider.TimerImpl(this._pullHoldTime, () => this._recede(this._pullDecayTime));
+        }
+
+        public void scrollEnd() {
+            if (this._state == _GlowState.pull) {
+                this._recede(this._recedeTime);
+            }
+        }
+
+        void _changePhase(AnimationStatus status) {
+            if (status != AnimationStatus.completed) {
+                return;
+            }
+
+            switch (this._state) {
+                case _GlowState.absorb:
+                    this._recede(this._recedeTime);
+                    break;
+                case _GlowState.recede:
+                    this._state = _GlowState.idle;
+                    this._pullDistance = 0.0f;
+                    break;
+                case _GlowState.pull:
+                case _GlowState.idle:
+                    break;
+            }
+        }
+
+        void _recede(TimeSpan duration) {
+            if (this._state == _GlowState.recede || this._state == _GlowState.idle) {
+                return;
+            }
+
+            this._pullRecedeTimer?.cancel();
+            this._pullRecedeTimer = null;
+            this._glowOpacityTween.begin = this._glowOpacity.value;
+            this._glowOpacityTween.end = 0.0f;
+            this._glowSizeTween.begin = this._glowSize.value;
+            this._glowSizeTween.end = 0.0f;
+            this._glowController.duration = duration;
+            this._glowController.forward(from: 0.0f);
+            this._state = _GlowState.recede;
+        }
+
+        void _tickDisplacement(TimeSpan elapsed) {
+            if (this._displacementTickerLastElapsed != null) {
+                float? t = elapsed.Milliseconds - this._displacementTickerLastElapsed?.Milliseconds;
+                this._displacement = this._displacementTarget - (this._displacementTarget - this._displacement) *
+                                     Mathf.Pow(2.0f, (-t ?? 0.0f) / _crossAxisHalfTime.Milliseconds);
+                this.notifyListeners();
+            }
+
+            if (PhysicsUtils.nearEqual(this._displacementTarget, this._displacement,
+                Tolerance.defaultTolerance.distance)) {
+                this._displacementTicker.stop();
+                this._displacementTickerLastElapsed = null;
+            }
+            else {
+                this._displacementTickerLastElapsed = elapsed;
+            }
+        }
+
+        public void paint(Canvas canvas, Size size) {
+            if (this._glowOpacity.value == 0.0f) {
+                return;
+            }
+
+            float baseGlowScale = size.width > size.height ? size.height / size.width : 1.0f;
+            float radius = size.width * 3.0f / 2.0f;
+            float height = Mathf.Min(size.height, size.width * _widthToHeightFactor);
+            float scaleY = this._glowSize.value * baseGlowScale;
+            Rect rect = Rect.fromLTWH(0.0f, 0.0f, size.width, height);
+            Offset center = new Offset((size.width / 2.0f) * (0.5f + this._displacement), height - radius);
+            Paint paint = new Paint();
+            paint.color = this.color.withOpacity(this._glowOpacity.value);
+            canvas.save();
+            canvas.scale(1.0f, scaleY);
+            canvas.clipRect(rect);
+            canvas.drawCircle(center, radius, paint);
+            canvas.restore();
+        }
+    }
+
+    class _GlowingOverscrollIndicatorPainter : AbstractCustomPainter {
+        public _GlowingOverscrollIndicatorPainter(
+            _GlowController leadingController,
+            _GlowController trailingController,
+            AxisDirection axisDirection,
+            Listenable repaint
+        ) : base(
+            repaint: repaint
+        ) {
+            this.leadingController = leadingController;
+            this.trailingController = trailingController;
+            this.axisDirection = axisDirection;
+        }
+
+        public readonly _GlowController leadingController;
+
+        public readonly _GlowController trailingController;
+
+        public readonly AxisDirection axisDirection;
+
+        const float piOver2 = Mathf.PI / 2.0f;
+
+        void _paintSide(Canvas canvas, Size size, _GlowController controller, AxisDirection axisDirection,
+            GrowthDirection growthDirection) {
+            if (controller == null) {
+                return;
+            }
+
+            switch (GrowthDirectionUtils.applyGrowthDirectionToAxisDirection(axisDirection, growthDirection)) {
+                case AxisDirection.up:
+                    controller.paint(canvas, size);
+                    break;
+                case AxisDirection.down:
+                    canvas.save();
+                    canvas.translate(0.0f, size.height);
+                    canvas.scale(1.0f, -1.0f);
+                    controller.paint(canvas, size);
+                    canvas.restore();
+                    break;
+                case AxisDirection.left:
+                    canvas.save();
+                    canvas.rotate(piOver2);
+                    canvas.scale(1.0f, -1.0f);
+                    controller.paint(canvas, new Size(size.height, size.width));
+                    canvas.restore();
+                    break;
+                case AxisDirection.right:
+                    canvas.save();
+                    canvas.translate(size.width, 0.0f);
+                    canvas.rotate(piOver2);
+                    controller.paint(canvas, new Size(size.height, size.width));
+                    canvas.restore();
+                    break;
+            }
+        }
+
+        public override void paint(Canvas canvas, Size size) {
+            this._paintSide(canvas, size, this.leadingController, this.axisDirection, GrowthDirection.reverse);
+            this._paintSide(canvas, size, this.trailingController, this.axisDirection, GrowthDirection.forward);
+        }
+
+        public override bool shouldRepaint(CustomPainter _oldDelegate) {
+            _GlowingOverscrollIndicatorPainter oldDelegate = _oldDelegate as _GlowingOverscrollIndicatorPainter;
+            return oldDelegate.leadingController != this.leadingController
+                   || oldDelegate.trailingController != this.trailingController;
+        }
+    }
+
+    public class OverscrollIndicatorNotification : ViewportNotificationMixinNotification {
+        public OverscrollIndicatorNotification(
+            bool leading
+        ) {
+            this.leading = leading;
+        }
+
+        public readonly bool leading;
+
+        internal bool _accepted = true;
+
+        public void disallowGlow() {
+            this._accepted = false;
+        }
+
+        protected override void debugFillDescription(List<string> description) {
+            base.debugFillDescription(description);
+            description.Add($"side: {(this.leading ? "leading edge" : "trailing edge")}");
+        }
+    }
+}

Runtime/widgets/overscroll_indicator.cs.meta

+fileFormatVersion: 2
+guid: b87c58140c4b442e82a27b804f8502c7
+timeCreated: 1554348404