mirror of
https://github.com/bggRGjQaUbCoE/PiliPlus.git
synced 2026-04-20 11:08:03 +08:00
refa persistent header & dynamic sliver appbar
Signed-off-by: dom <githubaccount56556@proton.me>
This commit is contained in:
dom
385
lib/common/widgets/flutter/chat_list_view.dart
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385
lib/common/widgets/flutter/chat_list_view.dart
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@@ -0,0 +1,385 @@
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// Copyright 2014 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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import 'dart:math' as math;
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import 'package:flutter/foundation.dart';
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import 'package:flutter/material.dart';
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import 'package:flutter/rendering.dart';
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class ChatListView extends BoxScrollView {
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ChatListView.separated({
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super.key,
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super.scrollDirection,
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super.controller,
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super.primary,
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super.physics,
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super.padding,
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required NullableIndexedWidgetBuilder itemBuilder,
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@Deprecated(
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'Use findItemIndexCallback instead. '
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'findChildIndexCallback returns child indices (which include separators), '
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'while findItemIndexCallback returns item indices (which do not). '
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'If you were multiplying results by 2 to account for separators, '
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'you can remove that workaround when migrating to findItemIndexCallback. '
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'This feature was deprecated after v3.37.0-1.0.pre.',
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)
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ChildIndexGetter? findChildIndexCallback,
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ChildIndexGetter? findItemIndexCallback,
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required IndexedWidgetBuilder separatorBuilder,
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required int itemCount,
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bool addAutomaticKeepAlives = true,
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bool addRepaintBoundaries = true,
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bool addSemanticIndexes = true,
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super.cacheExtent,
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super.dragStartBehavior,
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super.keyboardDismissBehavior,
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super.restorationId,
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super.clipBehavior,
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super.hitTestBehavior,
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}) : assert(itemCount >= 0),
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assert(
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findItemIndexCallback == null || findChildIndexCallback == null,
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'Cannot provide both findItemIndexCallback and findChildIndexCallback. '
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'Use findItemIndexCallback as findChildIndexCallback is deprecated.',
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),
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childrenDelegate = SliverChildBuilderDelegate(
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(BuildContext context, int index) {
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final int itemIndex = index ~/ 2;
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if (index.isEven) {
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return itemBuilder(context, itemIndex);
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}
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return separatorBuilder(context, itemIndex);
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},
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findChildIndexCallback: findItemIndexCallback != null
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? (Key key) {
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final int? itemIndex = findItemIndexCallback(key);
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return itemIndex == null ? null : itemIndex * 2;
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}
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: findChildIndexCallback,
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childCount: _computeActualChildCount(itemCount),
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addAutomaticKeepAlives: addAutomaticKeepAlives,
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addRepaintBoundaries: addRepaintBoundaries,
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addSemanticIndexes: addSemanticIndexes,
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semanticIndexCallback: (Widget widget, int index) {
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return index.isEven ? index ~/ 2 : null;
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},
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),
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super(semanticChildCount: itemCount, reverse: true);
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final SliverChildDelegate childrenDelegate;
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@override
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Widget buildChildLayout(BuildContext context) {
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return SliverChatList(delegate: childrenDelegate);
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}
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static int _computeActualChildCount(int itemCount) {
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return math.max(0, itemCount * 2 - 1);
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}
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}
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class SliverChatList extends SliverMultiBoxAdaptorWidget {
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const SliverChatList({super.key, required super.delegate});
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@override
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SliverMultiBoxAdaptorElement createElement() =>
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SliverMultiBoxAdaptorElement(this, replaceMovedChildren: true);
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@override
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RenderSliverChatList createRenderObject(BuildContext context) {
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final element = context as SliverMultiBoxAdaptorElement;
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return RenderSliverChatList(childManager: element);
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}
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}
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class RenderSliverChatList extends RenderSliverMultiBoxAdaptor
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with ExtendedRenderObjectMixin {
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RenderSliverChatList({required super.childManager});
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@override
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void performLayout() {
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final SliverConstraints constraints = this.constraints;
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childManager
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..didStartLayout()
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..setDidUnderflow(false);
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final double scrollOffset =
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constraints.scrollOffset + constraints.cacheOrigin;
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assert(scrollOffset >= 0.0);
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final double remainingExtent = constraints.remainingCacheExtent;
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assert(remainingExtent >= 0.0);
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final double targetEndScrollOffset = scrollOffset + remainingExtent;
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final BoxConstraints childConstraints = constraints.asBoxConstraints();
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var leadingGarbage = 0;
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var trailingGarbage = 0;
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var reachedEnd = false;
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if (firstChild == null) {
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if (!addInitialChild()) {
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geometry = SliverGeometry.zero;
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childManager.didFinishLayout();
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return;
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}
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}
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///
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handleCloseToTrailingBegin();
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RenderBox? leadingChildWithLayout, trailingChildWithLayout;
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RenderBox? earliestUsefulChild = firstChild;
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if (childScrollOffset(firstChild!) == null) {
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var leadingChildrenWithoutLayoutOffset = 0;
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while (earliestUsefulChild != null &&
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childScrollOffset(earliestUsefulChild) == null) {
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earliestUsefulChild = childAfter(earliestUsefulChild);
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leadingChildrenWithoutLayoutOffset += 1;
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}
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collectGarbage(leadingChildrenWithoutLayoutOffset, 0);
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if (firstChild == null) {
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if (!addInitialChild()) {
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geometry = SliverGeometry.zero;
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childManager.didFinishLayout();
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return;
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}
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}
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}
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earliestUsefulChild = firstChild;
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for (
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double earliestScrollOffset = childScrollOffset(earliestUsefulChild!)!;
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earliestScrollOffset > scrollOffset;
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earliestScrollOffset = childScrollOffset(earliestUsefulChild)!
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) {
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earliestUsefulChild = insertAndLayoutLeadingChild(
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childConstraints,
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parentUsesSize: true,
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);
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if (earliestUsefulChild == null) {
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final childParentData =
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firstChild!.parentData! as SliverMultiBoxAdaptorParentData;
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childParentData.layoutOffset = 0.0;
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if (scrollOffset == 0.0) {
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firstChild!.layout(childConstraints, parentUsesSize: true);
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earliestUsefulChild = firstChild;
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leadingChildWithLayout = earliestUsefulChild;
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trailingChildWithLayout ??= earliestUsefulChild;
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break;
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} else {
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geometry = SliverGeometry(scrollOffsetCorrection: -scrollOffset);
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return;
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}
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}
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final double firstChildScrollOffset =
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earliestScrollOffset - paintExtentOf(firstChild!);
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if (firstChildScrollOffset < -precisionErrorTolerance) {
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geometry = SliverGeometry(
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scrollOffsetCorrection: -firstChildScrollOffset,
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);
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final childParentData =
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firstChild!.parentData! as SliverMultiBoxAdaptorParentData;
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childParentData.layoutOffset = 0.0;
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return;
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}
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final childParentData =
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earliestUsefulChild.parentData! as SliverMultiBoxAdaptorParentData;
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childParentData.layoutOffset = firstChildScrollOffset;
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assert(earliestUsefulChild == firstChild);
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leadingChildWithLayout = earliestUsefulChild;
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trailingChildWithLayout ??= earliestUsefulChild;
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}
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assert(childScrollOffset(firstChild!)! > -precisionErrorTolerance);
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if (scrollOffset < precisionErrorTolerance) {
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while (indexOf(firstChild!) > 0) {
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final double earliestScrollOffset = childScrollOffset(firstChild!)!;
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earliestUsefulChild = insertAndLayoutLeadingChild(
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childConstraints,
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parentUsesSize: true,
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);
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assert(earliestUsefulChild != null);
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final double firstChildScrollOffset =
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earliestScrollOffset - paintExtentOf(firstChild!);
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final childParentData =
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firstChild!.parentData! as SliverMultiBoxAdaptorParentData;
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childParentData.layoutOffset = 0.0;
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if (firstChildScrollOffset < -precisionErrorTolerance) {
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geometry = SliverGeometry(
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scrollOffsetCorrection: -firstChildScrollOffset,
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);
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return;
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}
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}
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}
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assert(earliestUsefulChild == firstChild);
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assert(childScrollOffset(earliestUsefulChild!)! <= scrollOffset);
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if (leadingChildWithLayout == null) {
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earliestUsefulChild!.layout(childConstraints, parentUsesSize: true);
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leadingChildWithLayout = earliestUsefulChild;
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trailingChildWithLayout = earliestUsefulChild;
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}
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var inLayoutRange = true;
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var child = earliestUsefulChild;
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int index = indexOf(child!);
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double endScrollOffset = childScrollOffset(child)! + paintExtentOf(child);
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bool advance() {
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assert(child != null);
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if (child == trailingChildWithLayout) {
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inLayoutRange = false;
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}
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child = childAfter(child!);
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if (child == null) {
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inLayoutRange = false;
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}
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index += 1;
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if (!inLayoutRange) {
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if (child == null || indexOf(child!) != index) {
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child = insertAndLayoutChild(
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childConstraints,
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after: trailingChildWithLayout,
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parentUsesSize: true,
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);
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if (child == null) {
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return false;
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}
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} else {
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child!.layout(childConstraints, parentUsesSize: true);
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}
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trailingChildWithLayout = child;
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}
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assert(child != null);
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final childParentData =
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child!.parentData! as SliverMultiBoxAdaptorParentData;
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childParentData.layoutOffset = endScrollOffset;
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assert(childParentData.index == index);
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endScrollOffset = childScrollOffset(child!)! + paintExtentOf(child!);
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return true;
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}
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while (endScrollOffset < scrollOffset) {
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leadingGarbage += 1;
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if (!advance()) {
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assert(leadingGarbage == childCount);
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assert(child == null);
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collectGarbage(leadingGarbage - 1, 0);
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assert(firstChild == lastChild);
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final double extent =
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childScrollOffset(lastChild!)! + paintExtentOf(lastChild!);
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geometry = SliverGeometry(scrollExtent: extent, maxPaintExtent: extent);
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return;
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}
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}
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while (endScrollOffset < targetEndScrollOffset) {
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if (!advance()) {
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reachedEnd = true;
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break;
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}
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}
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if (child != null) {
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child = childAfter(child!);
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while (child != null) {
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trailingGarbage += 1;
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child = childAfter(child!);
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}
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}
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collectGarbage(leadingGarbage, trailingGarbage);
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assert(debugAssertChildListIsNonEmptyAndContiguous());
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final double estimatedMaxScrollOffset;
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///
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endScrollOffset = handleCloseToTrailingEnd(endScrollOffset);
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if (reachedEnd) {
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estimatedMaxScrollOffset = endScrollOffset;
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} else {
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estimatedMaxScrollOffset = childManager.estimateMaxScrollOffset(
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constraints,
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firstIndex: indexOf(firstChild!),
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lastIndex: indexOf(lastChild!),
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leadingScrollOffset: childScrollOffset(firstChild!),
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trailingScrollOffset: endScrollOffset,
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);
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assert(
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estimatedMaxScrollOffset >=
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endScrollOffset - childScrollOffset(firstChild!)!,
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);
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}
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final double firstChildScrollOffset = childScrollOffset(firstChild!)!;
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double paintExtent = calculatePaintOffset(
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constraints,
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from: firstChildScrollOffset,
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to: endScrollOffset,
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);
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final double cacheExtent = calculateCacheOffset(
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constraints,
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from: firstChildScrollOffset,
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to: endScrollOffset,
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);
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final double targetEndScrollOffsetForPaint =
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constraints.scrollOffset + constraints.remainingPaintExtent;
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///
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paintExtent += _closeToTrailingDistance;
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geometry = SliverGeometry(
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scrollExtent: estimatedMaxScrollOffset,
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paintExtent: paintExtent,
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cacheExtent: cacheExtent,
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maxPaintExtent: estimatedMaxScrollOffset,
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hasVisualOverflow:
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endScrollOffset > targetEndScrollOffsetForPaint ||
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constraints.scrollOffset > 0.0,
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);
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if (estimatedMaxScrollOffset == endScrollOffset) {
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childManager.setDidUnderflow(true);
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}
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childManager.didFinishLayout();
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}
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}
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const double kChatListPadding = 14.0;
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/// from https://github.com/fluttercandies/extended_list
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mixin ExtendedRenderObjectMixin on RenderSliverMultiBoxAdaptor {
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void handleCloseToTrailingBegin() {
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_closeToTrailingDistance = 0.0;
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}
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double handleCloseToTrailingEnd(double endScrollOffset) {
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final extent = constraints.remainingPaintExtent - kChatListPadding;
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if (endScrollOffset < extent) {
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_closeToTrailingDistance = extent - endScrollOffset;
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return extent;
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}
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return endScrollOffset;
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}
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double _closeToTrailingDistance = 0.0;
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@override
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double? childScrollOffset(RenderObject child) {
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return (super.childScrollOffset(child) ?? 0.0) + _closeToTrailingDistance;
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}
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}
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Block a user