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feat(ui): update scrollable_positioned_list with the latest changes.

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Signed-off-by: xsahil03x <[email protected]>
This commit is contained in:
Sahil Kumar
2023-05-03 15:47:53 +05:30
committed by xsahil03x
parent c50a435515
commit b4413be47d
14 changed files with 2333 additions and 397 deletions
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packages/stream_chat_flutter/lib/scrollable_positioned_list/src/positioned_list.dart
+59 -34
View File
@@ -11,6 +11,7 @@ import 'package:stream_chat_flutter/scrollable_positioned_list/src/indexed_key.d
import 'package:stream_chat_flutter/scrollable_positioned_list/src/item_positions_listener.dart';
import 'package:stream_chat_flutter/scrollable_positioned_list/src/item_positions_notifier.dart';
import 'package:stream_chat_flutter/scrollable_positioned_list/src/scroll_view.dart';
import 'package:stream_chat_flutter/scrollable_positioned_list/src/wrapping.dart';
/// A list of widgets similar to [ListView], except scroll control
/// and position reporting is based on index rather than pixel offset.
@@ -35,28 +36,20 @@ class PositionedList extends StatefulWidget {
this.alignment = 0,
this.scrollDirection = Axis.vertical,
this.reverse = false,
this.shrinkWrap = false,
this.physics,
this.padding,
this.cacheExtent,
this.semanticChildCount,
this.findChildIndexCallback,
this.addSemanticIndexes = true,
this.addRepaintBoundaries = true,
this.addAutomaticKeepAlives = true,
this.keyboardDismissBehavior,
}) : assert((positionedIndex == 0) || (positionedIndex < itemCount),
'positionedIndex cannot be 0 and must be smaller than itemCount');
/// Called to find the new index of a child based on its key in case of
/// reordering.
///
/// If not provided, a child widget may not map to its existing [RenderObject]
/// when the order in which children are returned from [builder] changes.
/// This may result in state-loss.
///
/// This callback should take an input [Key], and it should return the
/// index of the child element with that associated key, or null if not found.
final ChildIndexGetter? findChildIndexCallback;
this.findChildIndexCallback,
this.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
}) : assert(
(positionedIndex == 0) || (positionedIndex < itemCount),
'positionedIndex must be 0 or a value less than itemCount',
);
/// Number of items the [itemBuilder] can produce.
final int itemCount;
@@ -98,6 +91,15 @@ class PositionedList extends StatefulWidget {
/// See [ScrollView.reverse].
final bool reverse;
/// {@template flutter.widgets.scroll_view.shrinkWrap}
/// Whether the extent of the scroll view in the [scrollDirection] should be
/// determined by the contents being viewed.
///
/// Defaults to false.
///
/// See [ScrollView.shrinkWrap].
final bool shrinkWrap;
/// How the scroll view should respond to user input.
///
/// For example, determines how the scroll view continues to animate after the
@@ -132,9 +134,22 @@ class PositionedList extends StatefulWidget {
/// See [SliverChildBuilderDelegate.addAutomaticKeepAlives].
final bool addAutomaticKeepAlives;
/// [ScrollViewKeyboardDismissBehavior] the defines how this [PositionedList] will
/// dismiss the keyboard automatically.
final ScrollViewKeyboardDismissBehavior? keyboardDismissBehavior;
/// Called to find the new index of a child based on its key in case of reordering.
///
/// If not provided, a child widget may not map to its existing [RenderObject]
/// when the order of children returned from the children builder changes.
/// This may result in state-loss.
///
/// This callback should take an input [Key], and it should return the
/// index of the child element with that associated key, or null if not found.
///
/// See [SliverChildBuilderDelegate.findChildIndexCallback].
final ChildIndexGetter? findChildIndexCallback;
/// Defines how this [ScrollView] will dismiss the keyboard automatically.
///
/// See [ScrollView.keyboardDismissBehavior].
final ScrollViewKeyboardDismissBehavior keyboardDismissBehavior;
@override
State<StatefulWidget> createState() => _PositionedListState();
@@ -175,12 +190,13 @@ class _PositionedListState extends State<PositionedList> {
anchor: widget.alignment,
center: _centerKey,
controller: scrollController,
keyboardDismissBehavior: widget.keyboardDismissBehavior,
scrollDirection: widget.scrollDirection,
reverse: widget.reverse,
cacheExtent: widget.cacheExtent,
physics: widget.physics,
shrinkWrap: widget.shrinkWrap,
semanticChildCount: widget.semanticChildCount ?? widget.itemCount,
keyboardDismissBehavior: widget.keyboardDismissBehavior,
slivers: <Widget>[
if (widget.positionedIndex > 0)
SliverPadding(
@@ -196,9 +212,9 @@ class _PositionedListState extends State<PositionedList> {
? widget.positionedIndex
: widget.positionedIndex * 2,
addSemanticIndexes: false,
findChildIndexCallback: widget.findChildIndexCallback,
addRepaintBoundaries: widget.addRepaintBoundaries,
addAutomaticKeepAlives: widget.addAutomaticKeepAlives,
findChildIndexCallback: widget.findChildIndexCallback,
),
),
),
@@ -213,10 +229,10 @@ class _PositionedListState extends State<PositionedList> {
index + widget.positionedIndex * 2,
),
childCount: widget.itemCount != 0 ? 1 : 0,
findChildIndexCallback: widget.findChildIndexCallback,
addSemanticIndexes: false,
addRepaintBoundaries: widget.addRepaintBoundaries,
addAutomaticKeepAlives: widget.addAutomaticKeepAlives,
findChildIndexCallback: widget.findChildIndexCallback,
),
),
),
@@ -234,10 +250,10 @@ class _PositionedListState extends State<PositionedList> {
childCount: widget.separatorBuilder == null
? widget.itemCount - widget.positionedIndex - 1
: 2 * (widget.itemCount - widget.positionedIndex - 1),
findChildIndexCallback: widget.findChildIndexCallback,
addSemanticIndexes: false,
addRepaintBoundaries: widget.addRepaintBoundaries,
addAutomaticKeepAlives: widget.addAutomaticKeepAlives,
findChildIndexCallback: widget.findChildIndexCallback,
),
),
),
@@ -319,25 +335,33 @@ class _PositionedListState extends State<PositionedList> {
if (!updateScheduled) {
updateScheduled = true;
SchedulerBinding.instance.addPostFrameCallback((_) {
if (registeredElements.value == null) {
final elements = registeredElements.value;
if (elements == null) {
updateScheduled = false;
return;
}
final positions = <ItemPosition>[];
RenderViewport? viewport;
for (final element in registeredElements.value!) {
final box = element.renderObject as RenderBox?;
viewport ??= RenderAbstractViewport.of(box) as RenderViewport?;
if (viewport == null || box == null) {
break;
RenderViewportBase? viewport;
for (final element in elements) {
final box = element.renderObject! as RenderBox;
viewport ??= RenderAbstractViewport.of(box) as RenderViewportBase?;
var anchor = 0.0;
if (viewport is RenderViewport) {
anchor = viewport.anchor;
}
final key = element.widget.key as IndexedKey;
if (viewport is CustomRenderViewport) {
anchor = viewport.anchor;
}
final key = element.widget.key! as IndexedKey;
// Skip this element if `box` has never been laid out.
if (!box.hasSize) continue;
if (widget.scrollDirection == Axis.vertical) {
final reveal = viewport.getOffsetToReveal(box, 0).offset;
final reveal = viewport!.getOffsetToReveal(box, 0).offset;
if (!reveal.isFinite) continue;
final itemOffset = reveal -
viewport.offset.pixels +
viewport.anchor * viewport.size.height;
final itemOffset =
reveal - viewport.offset.pixels + anchor * viewport.size.height;
positions.add(ItemPosition(
index: key.index,
itemLeadingEdge: itemOffset.round() /
@@ -348,6 +372,7 @@ class _PositionedListState extends State<PositionedList> {
} else {
final itemOffset =
box.localToGlobal(Offset.zero, ancestor: viewport).dx;
if (!itemOffset.isFinite) continue;
positions.add(ItemPosition(
index: key.index,
itemLeadingEdge: (widget.reverse
packages/stream_chat_flutter/lib/scrollable_positioned_list/src/scroll_view.dart
+16 -12
View File
@@ -5,13 +5,14 @@
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'package:stream_chat_flutter/scrollable_positioned_list/src/viewport.dart';
import 'package:stream_chat_flutter/scrollable_positioned_list/src/wrapping.dart';
/// {@template custom_scroll_view}
/// A version of [CustomScrollView] that does not constrict the extents
/// {@template unbounded_custom_scroll_view}
/// A version of [CustomScrollView] that allows does not constrict the extents
/// to be within 0 and 1. See [CustomScrollView] for more information.
/// {@endtemplate}
class UnboundedCustomScrollView extends CustomScrollView {
/// {@macro custom_scroll_view}
/// {@macro unbounded_custom_scroll_view}
const UnboundedCustomScrollView({
super.key,
super.scrollDirection,
@@ -19,19 +20,19 @@ class UnboundedCustomScrollView extends CustomScrollView {
super.controller,
super.primary,
super.physics,
super.shrinkWrap,
bool shrinkWrap = false,
super.center,
double anchor = 0.0,
super.cacheExtent,
super.slivers,
super.semanticChildCount,
super.dragStartBehavior,
ScrollViewKeyboardDismissBehavior? keyboardDismissBehavior,
}) : _anchor = anchor,
super(
keyboardDismissBehavior: keyboardDismissBehavior ??
ScrollViewKeyboardDismissBehavior.manual,
);
super.keyboardDismissBehavior,
}) : _shrinkWrap = shrinkWrap,
_anchor = anchor,
super(shrinkWrap: false);
final bool _shrinkWrap;
// [CustomScrollView] enforces constraints on [CustomScrollView.anchor], so
// we need our own version.
@@ -49,11 +50,14 @@ class UnboundedCustomScrollView extends CustomScrollView {
AxisDirection axisDirection,
List<Widget> slivers,
) {
if (shrinkWrap) {
return ShrinkWrappingViewport(
if (_shrinkWrap) {
return CustomShrinkWrappingViewport(
axisDirection: axisDirection,
offset: offset,
slivers: slivers,
cacheExtent: cacheExtent,
center: center,
anchor: anchor,
);
}
return UnboundedViewport(
packages/stream_chat_flutter/lib/scrollable_positioned_list/src/scrollable_positioned_list.dart
+129 -96
View File
@@ -37,6 +37,7 @@ class ScrollablePositionedList extends StatefulWidget {
required this.itemBuilder,
super.key,
this.itemScrollController,
this.shrinkWrap = false,
ItemPositionsListener? itemPositionsListener,
this.initialScrollIndex = 0,
this.initialAlignment = 0,
@@ -50,7 +51,7 @@ class ScrollablePositionedList extends StatefulWidget {
this.addRepaintBoundaries = true,
this.minCacheExtent,
this.findChildIndexCallback,
this.keyboardDismissBehavior,
this.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
}) : itemPositionsNotifier = itemPositionsListener as ItemPositionsNotifier?,
separatorBuilder = null;
@@ -61,6 +62,7 @@ class ScrollablePositionedList extends StatefulWidget {
required this.itemBuilder,
required IndexedWidgetBuilder this.separatorBuilder,
super.key,
this.shrinkWrap = false,
this.itemScrollController,
ItemPositionsListener? itemPositionsListener,
this.initialScrollIndex = 0,
@@ -75,24 +77,9 @@ class ScrollablePositionedList extends StatefulWidget {
this.addRepaintBoundaries = true,
this.minCacheExtent,
this.findChildIndexCallback,
this.keyboardDismissBehavior,
this.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
}) : itemPositionsNotifier = itemPositionsListener as ItemPositionsNotifier?;
/// Called to find the new index of a child based on its key in case of
/// reordering.
///
/// If not provided, a child widget may not map to its existing [RenderObject]
/// when the order in which children are returned from [builder] changes.
/// This may result in state-loss.
///
/// This callback should take an input [Key], and it should return the
/// index of the child element with that associated key, or null if not found.
final ChildIndexGetter? findChildIndexCallback;
/// [ScrollViewKeyboardDismissBehavior] the defines how this [PositionedList] will
/// dismiss the keyboard automatically.
final ScrollViewKeyboardDismissBehavior? keyboardDismissBehavior;
/// Number of items the [itemBuilder] can produce.
final int itemCount;
@@ -131,6 +118,15 @@ class ScrollablePositionedList extends StatefulWidget {
/// See [ScrollView.reverse].
final bool reverse;
/// {@template flutter.widgets.scroll_view.shrinkWrap}
/// Whether the extent of the scroll view in the [scrollDirection] should be
/// determined by the contents being viewed.
///
/// Defaults to false.
///
/// See [ScrollView.shrinkWrap].
final bool shrinkWrap;
/// How the scroll view should respond to user input.
///
/// For example, determines how the scroll view continues to animate after the
@@ -171,6 +167,23 @@ class ScrollablePositionedList extends StatefulWidget {
/// cache extent.
final double? minCacheExtent;
/// Called to find the new index of a child based on its key in case of reordering.
///
/// If not provided, a child widget may not map to its existing [RenderObject]
/// when the order of children returned from the children builder changes.
/// This may result in state-loss.
///
/// This callback should take an input [Key], and it should return the
/// index of the child element with that associated key, or null if not found.
///
/// See [SliverChildBuilderDelegate.findChildIndexCallback].
final ChildIndexGetter? findChildIndexCallback;
/// Defines how this [ScrollView] will dismiss the keyboard automatically.
///
/// See [ScrollView.keyboardDismissBehavior].
final ScrollViewKeyboardDismissBehavior keyboardDismissBehavior;
@override
State<StatefulWidget> createState() => _ScrollablePositionedListState();
}
@@ -233,11 +246,15 @@ class ItemScrollController {
Curve curve = Curves.linear,
List<double> opacityAnimationWeights = const [40, 20, 40],
}) {
assert(_scrollableListState != null, '_scrollableListState cannot be null');
assert(opacityAnimationWeights.length == 3,
'opacityAnimationWeights.length is not equal to 3');
assert(duration > Duration.zero,
'duration needs to be bigger than Duration.zero');
assert(
_scrollableListState != null,
'''ScrollController must be attached to a ScrollablePositionedList to scroll.''',
);
assert(
opacityAnimationWeights.length == 3,
'opacityAnimationWeights must have exactly three elements.',
);
assert(duration > Duration.zero, 'Duration must be greater than zero.');
return _scrollableListState!._scrollTo(
index: index,
alignment: alignment,
@@ -249,7 +266,9 @@ class ItemScrollController {
void _attach(_ScrollablePositionedListState scrollableListState) {
assert(
_scrollableListState == null, '_scrollableListState needs to be null');
_scrollableListState == null,
'''ScrollController must not be attached to multiple ScrollablePositionedLists.''',
);
_scrollableListState = scrollableListState;
}
@@ -273,11 +292,12 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
bool _isTransitioning = false;
AnimationController? _animationController;
@override
void initState() {
super.initState();
final ItemPosition? initialPosition =
PageStorage.of(context).readState(context);
final initialPosition = PageStorage.of(context).readState(context);
primary
..target = initialPosition?.index ?? widget.initialScrollIndex
..alignment = initialPosition?.itemLeadingEdge ?? widget.initialAlignment;
@@ -301,6 +321,7 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
.removeListener(_updatePositions);
secondary.itemPositionsNotifier.itemPositions
.removeListener(_updatePositions);
_animationController?.dispose();
super.dispose();
}
@@ -329,84 +350,90 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
}
@override
Widget build(BuildContext context) => LayoutBuilder(
builder: (context, constraints) {
final cacheExtent = _cacheExtent(constraints);
return GestureDetector(
onPanDown: (_) => _stopScroll(canceled: true),
excludeFromSemantics: true,
child: Stack(
children: <Widget>[
Widget build(BuildContext context) {
return LayoutBuilder(
builder: (context, constraints) {
final cacheExtent = _cacheExtent(constraints);
return GestureDetector(
onPanDown: (_) => _stopScroll(canceled: true),
excludeFromSemantics: true,
child: Stack(
children: <Widget>[
PostMountCallback(
key: primary.key,
callback: startAnimationCallback,
child: FadeTransition(
opacity: ReverseAnimation(opacity),
child: NotificationListener<ScrollNotification>(
onNotification: (_) => _isTransitioning,
child: PositionedList(
itemBuilder: widget.itemBuilder,
separatorBuilder: widget.separatorBuilder,
itemCount: widget.itemCount,
positionedIndex: primary.target,
controller: primary.scrollController,
itemPositionsNotifier: primary.itemPositionsNotifier,
scrollDirection: widget.scrollDirection,
reverse: widget.reverse,
cacheExtent: cacheExtent,
alignment: primary.alignment,
physics: widget.physics,
shrinkWrap: widget.shrinkWrap,
addSemanticIndexes: widget.addSemanticIndexes,
semanticChildCount: widget.semanticChildCount,
padding: widget.padding,
addAutomaticKeepAlives: widget.addAutomaticKeepAlives,
addRepaintBoundaries: widget.addRepaintBoundaries,
findChildIndexCallback: widget.findChildIndexCallback,
keyboardDismissBehavior: widget.keyboardDismissBehavior,
),
),
),
),
if (_isTransitioning)
PostMountCallback(
key: primary.key,
key: secondary.key,
callback: startAnimationCallback,
child: FadeTransition(
opacity: ReverseAnimation(opacity),
opacity: opacity,
child: NotificationListener<ScrollNotification>(
onNotification: (_) => _isTransitioning,
onNotification: (_) => false,
child: PositionedList(
keyboardDismissBehavior: widget.keyboardDismissBehavior,
itemBuilder: widget.itemBuilder,
separatorBuilder: widget.separatorBuilder,
itemCount: widget.itemCount,
positionedIndex: primary.target,
controller: primary.scrollController,
itemPositionsNotifier: primary.itemPositionsNotifier,
itemPositionsNotifier: secondary.itemPositionsNotifier,
positionedIndex: secondary.target,
controller: secondary.scrollController,
scrollDirection: widget.scrollDirection,
reverse: widget.reverse,
cacheExtent: cacheExtent,
alignment: primary.alignment,
alignment: secondary.alignment,
physics: widget.physics,
shrinkWrap: widget.shrinkWrap,
addSemanticIndexes: widget.addSemanticIndexes,
semanticChildCount: widget.semanticChildCount,
padding: widget.padding,
addAutomaticKeepAlives: widget.addAutomaticKeepAlives,
addRepaintBoundaries: widget.addRepaintBoundaries,
findChildIndexCallback: widget.findChildIndexCallback,
keyboardDismissBehavior: widget.keyboardDismissBehavior,
),
),
),
),
if (_isTransitioning)
PostMountCallback(
key: secondary.key,
callback: startAnimationCallback,
child: FadeTransition(
opacity: opacity,
child: NotificationListener<ScrollNotification>(
onNotification: (_) => false,
child: PositionedList(
keyboardDismissBehavior:
widget.keyboardDismissBehavior,
itemBuilder: widget.itemBuilder,
separatorBuilder: widget.separatorBuilder,
itemCount: widget.itemCount,
itemPositionsNotifier:
secondary.itemPositionsNotifier,
positionedIndex: secondary.target,
controller: secondary.scrollController,
scrollDirection: widget.scrollDirection,
reverse: widget.reverse,
cacheExtent: cacheExtent,
alignment: secondary.alignment,
physics: widget.physics,
addSemanticIndexes: widget.addSemanticIndexes,
semanticChildCount: widget.semanticChildCount,
padding: widget.padding,
addAutomaticKeepAlives: widget.addAutomaticKeepAlives,
addRepaintBoundaries: widget.addRepaintBoundaries,
),
),
),
),
],
),
);
},
);
],
),
);
},
);
}
double _cacheExtent(BoxConstraints constraints) => max(
constraints.maxHeight * _screenScrollCount,
(widget.scrollDirection == Axis.vertical
? constraints.maxHeight
: constraints.maxWidth) *
_screenScrollCount,
widget.minCacheExtent ?? 0,
);
@@ -434,16 +461,19 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
index = widget.itemCount - 1;
}
if (_isTransitioning) {
final scrollCompleter = Completer<void>();
_stopScroll(canceled: true);
SchedulerBinding.instance.addPostFrameCallback((_) {
_startScroll(
SchedulerBinding.instance.addPostFrameCallback((_) async {
await _startScroll(
index: index,
alignment: alignment,
duration: duration,
curve: curve,
opacityAnimationWeights: opacityAnimationWeights,
);
scrollCompleter.complete();
});
await scrollCompleter.future;
} else {
await _startScroll(
index: index,
@@ -486,10 +516,11 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
startAnimationCallback = () {
SchedulerBinding.instance.addPostFrameCallback((_) {
startAnimationCallback = () {};
opacity.parent = _opacityAnimation(opacityAnimationWeights).animate(
AnimationController(vsync: this, duration: duration)..forward(),
);
_animationController?.dispose();
_animationController =
AnimationController(vsync: this, duration: duration)..forward();
opacity.parent = _opacityAnimation(opacityAnimationWeights)
.animate(_animationController!);
secondary.scrollController.jumpTo(-direction *
(_screenScrollCount *
primary.scrollController.position.viewportDimension -
@@ -532,17 +563,19 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
}
}
setState(() {
if (opacity.value >= 0.5) {
// Secondary [ListView] is more visible than the primary; make it the
// new primary.
final temp = primary;
primary = secondary;
secondary = temp;
}
_isTransitioning = false;
opacity.parent = const AlwaysStoppedAnimation<double>(0);
});
if (mounted) {
setState(() {
if (opacity.value >= 0.5) {
// Secondary [ListView] is more visible than the primary; make it the
// new primary.
final temp = primary;
primary = secondary;
secondary = temp;
}
_isTransitioning = false;
opacity.parent = const AlwaysStoppedAnimation<double>(0);
});
}
}
Animatable<double> _opacityAnimation(List<double> opacityAnimationWeights) {
packages/stream_chat_flutter/lib/scrollable_positioned_list/src/viewport.dart
+26 -21
View File
@@ -2,8 +2,6 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// ignore_for_file: lines_longer_than_80_chars
import 'dart:math' as math;
import 'package:flutter/rendering.dart';
@@ -15,7 +13,7 @@ import 'package:flutter/widgets.dart';
/// Version of [Viewport] with some modifications to how extents are
/// computed to allow scroll extents outside 0 to 1. See [Viewport]
/// for more information.
/// description
/// {@endtemplate}
class UnboundedViewport extends Viewport {
/// {@macro unbounded_viewport}
UnboundedViewport({
@@ -37,15 +35,16 @@ class UnboundedViewport extends Viewport {
double get anchor => _anchor;
@override
RenderViewport createRenderObject(BuildContext context) =>
UnboundedRenderViewport(
axisDirection: axisDirection,
crossAxisDirection: crossAxisDirection ??
Viewport.getDefaultCrossAxisDirection(context, axisDirection),
anchor: anchor,
offset: offset,
cacheExtent: cacheExtent,
);
RenderViewport createRenderObject(BuildContext context) {
return UnboundedRenderViewport(
axisDirection: axisDirection,
crossAxisDirection: crossAxisDirection ??
Viewport.getDefaultCrossAxisDirection(context, axisDirection),
anchor: anchor,
offset: offset,
cacheExtent: cacheExtent,
);
}
}
/// A render object that is bigger on the inside.
@@ -137,14 +136,20 @@ class UnboundedRenderViewport extends RenderViewport {
@override
void performLayout() {
if (center == null) {
assert(firstChild == null, 'firstChild cannot be null');
assert(
firstChild == null,
'A RenderViewport with no center render object must have no children.',
);
_minScrollExtent = 0.0;
_maxScrollExtent = 0.0;
_hasVisualOverflow = false;
offset.applyContentDimensions(0, 0);
return;
}
assert(center!.parent == this, 'center.parent cannot be equal to this');
assert(
center!.parent == this,
'''The "center" property of a RenderViewport must be a child of the viewport.''',
);
late double mainAxisExtent;
late double crossAxisExtent;
@@ -186,7 +191,7 @@ class UnboundedRenderViewport extends RenderViewport {
} while (count < _maxLayoutCycles);
assert(() {
if (count >= _maxLayoutCycles) {
assert(count != 1, 'count not equal to 1');
assert(count != 1);
throw FlutterError(
'A RenderViewport exceeded its maximum number of layout cycles.\n'
'RenderViewport render objects, during layout, can retry if either their '
@@ -207,7 +212,7 @@ class UnboundedRenderViewport extends RenderViewport {
);
}
return true;
}(), 'count needs to be bigger than _maxLayoutCycles');
}());
}
double _attemptLayout(
@@ -215,11 +220,11 @@ class UnboundedRenderViewport extends RenderViewport {
double crossAxisExtent,
double correctedOffset,
) {
assert(!mainAxisExtent.isNaN, 'assert mainAxisExtent.isNaN');
assert(mainAxisExtent >= 0.0, 'assert mainAxisExtent >= 0.0');
assert(crossAxisExtent.isFinite, 'assert crossAxisExtent.isFinite');
assert(crossAxisExtent >= 0.0, 'assert crossAxisExtent >= 0.0');
assert(correctedOffset.isFinite, 'assert correctedOffset.isFinite');
assert(!mainAxisExtent.isNaN, 'The main axis extent cannot be NaN.');
assert(mainAxisExtent >= 0.0, 'The main axis extent cannot be negative.');
assert(crossAxisExtent.isFinite, 'The cross axis extent must be finite.');
assert(crossAxisExtent >= 0.0, 'The cross axis extent cannot be negative.');
assert(correctedOffset.isFinite, 'The corrected offset must be finite.');
_minScrollExtent = 0.0;
_maxScrollExtent = 0.0;
_hasVisualOverflow = false;
packages/stream_chat_flutter/lib/scrollable_positioned_list/src/wrapping.dart
+1066
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File diff suppressed because it is too large Load Diff
packages/stream_chat_flutter/lib/src/message_list_view/message_list_view.dart
+9 -3
View File
@@ -71,7 +71,7 @@ enum SpacingType {
/// A [StreamChannel] ancestor widget is required in order to provide the
/// information about the channels.
///
/// Uses a [ListView.custom] to render the list of channels.
/// Uses a [ScrollablePositionedList] to render the list of channels.
///
/// The UI is rendered based on the first ancestor of type [StreamChatTheme].
/// Modify it to change the widget's appearance.
@@ -88,8 +88,10 @@ class StreamMessageListView extends StatefulWidget {
this.threadBuilder,
this.onThreadTap,
this.dateDividerBuilder,
this.scrollPhysics =
const ClampingScrollPhysics(), // we need to use ClampingScrollPhysics to avoid the list view to animate and break while loading
// we need to use ClampingScrollPhysics to avoid the list view to bounce
// when we are at the either end of the list view and try to use 'animateTo'
// to animate in the same direction.
this.scrollPhysics = const ClampingScrollPhysics(),
this.initialScrollIndex,
this.initialAlignment,
this.scrollController,
@@ -555,6 +557,10 @@ class _StreamMessageListViewState extends State<StreamMessageListView> {
if (valueKey != null) {
final index = messagesIndex[valueKey.value];
if (index != null) {
// The calculation is as follows:
// * Add 2 to the index retrieved to account for the footer and the bottom loader.
// * Multiply the result by 2 to account for the separators between each pair of items.
// * Subtract 1 to adjust for the 0-based indexing of the list view.
return ((index + 2) * 2) - 1;
}
}