mirror of
https://github.com/flutter/flutter
synced 2024-10-13 19:52:53 +00:00
This reverts commit c8e4cbf27d
.
This commit is contained in:
parent
0cef0aaf35
commit
6ccc618abd
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@ -76,7 +76,7 @@ class EntryItem extends StatelessWidget {
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if (root.children.isEmpty)
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return new ListTile(title: new Text(root.title));
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return new ExpansionTile(
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key: new PageStorageKey<Entry>(root),
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key: new ValueKey<Entry>(root),
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title: new Text(root.title),
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children: root.children.map(_buildTiles).toList(),
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);
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@ -322,10 +322,10 @@ class LabeledGlobalKey<T extends State<StatefulWidget>> extends GlobalKey<T> {
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@override
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String toString() {
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final String label = _debugLabel != null ? ' $_debugLabel' : '';
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final String tag = _debugLabel != null ? ' $_debugLabel' : '#$hashCode';
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if (runtimeType == LabeledGlobalKey)
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return '[GlobalKey#$hashCode$label]';
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return '[$runtimeType#$hashCode$label]';
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return '[GlobalKey$tag]';
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return '[$runtimeType$tag]';
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}
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}
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@ -6,67 +6,43 @@ import 'package:flutter/foundation.dart';
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import 'framework.dart';
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/// A [ValueKey] that defines where [PageStorage] values will be saved.
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///
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/// [Scrollable]s ([ScrollPosition]s really) use [PageStorage] to save their
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/// scroll offset. Each time a scroll completes, the scrollable's page
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/// storage is updated.
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///
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/// [PageStorage] is used to save and restore values that can outlive the widget.
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/// The values are stored in a per-route [Map] whose keys are defined by the
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/// [PageStorageKey]s for the widget and its ancestors. To make it possible
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/// for a saved value to be found when a widget is recreated, the key's values
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/// must not be objects whose identity will change each time the widget is created.
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///
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/// For example, to ensure that the scroll offsets for the scrollable within
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/// each `MyScrollableTabView` below are restored when the [TabBarView]
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/// is recreated, we've specified [PageStorageKey]s whose values are the the
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/// tabs' string labels.
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///
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/// ```dart
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/// new TabBarView(
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/// children: myTabs.map((Tab tab) {
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/// new MyScrollableTabView(
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/// key: new PageStorageKey<String>(tab.text), // like 'Tab 1'
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/// tab: tab,
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/// ),
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/// }),
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///)
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/// ```
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class PageStorageKey<T> extends ValueKey<T> {
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/// Creates a [ValueKey] that defines where [PageStorage] values will be saved.
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const PageStorageKey(T value) : super(value);
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}
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class _StorageEntryIdentifier {
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_StorageEntryIdentifier(this.clientType, this.keys) {
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assert(clientType != null);
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assert(keys != null);
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Type clientType;
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List<Key> keys;
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void addKey(Key key) {
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assert(key != null);
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assert(key is! GlobalKey);
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keys ??= <Key>[];
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keys.add(key);
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}
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final Type clientType;
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final List<PageStorageKey<dynamic>> keys;
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GlobalKey scopeKey;
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@override
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bool operator ==(dynamic other) {
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if (other.runtimeType != runtimeType)
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if (other is! _StorageEntryIdentifier)
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return false;
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final _StorageEntryIdentifier typedOther = other;
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if (clientType != typedOther.clientType || keys.length != typedOther.keys.length)
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if (clientType != typedOther.clientType ||
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scopeKey != typedOther.scopeKey ||
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keys?.length != typedOther.keys?.length)
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return false;
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if (keys != null) {
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for (int index = 0; index < keys.length; index += 1) {
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if (keys[index] != typedOther.keys[index])
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return false;
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}
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}
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return true;
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}
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@override
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int get hashCode => hashValues(clientType, hashList(keys));
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int get hashCode => hashValues(clientType, scopeKey, hashList(keys));
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@override
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String toString() {
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return 'StorageEntryIdentifier($clientType, ${keys?.join(":")})';
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return 'StorageEntryIdentifier($clientType, $scopeKey, ${keys?.join(":")})';
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}
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}
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@ -75,26 +51,27 @@ class _StorageEntryIdentifier {
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/// Useful for storing per-page state that persists across navigations from one
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/// page to another.
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class PageStorageBucket {
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bool _maybeAddKey(BuildContext context, List<PageStorageKey<dynamic>> keys) {
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final Widget widget = context.widget;
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final Key key = widget.key;
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if (key is PageStorageKey)
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keys.add(key);
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return widget is! PageStorage;
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}
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List<PageStorageKey<dynamic>> _allKeys(BuildContext context) {
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final List<PageStorageKey<dynamic>> keys = <PageStorageKey<dynamic>>[];
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if (_maybeAddKey(context, keys)) {
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_StorageEntryIdentifier _computeStorageIdentifier(BuildContext context) {
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final _StorageEntryIdentifier result = new _StorageEntryIdentifier();
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result.clientType = context.widget.runtimeType;
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Key lastKey = context.widget.key;
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if (lastKey is! GlobalKey) {
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if (lastKey != null)
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result.addKey(lastKey);
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context.visitAncestorElements((Element element) {
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return _maybeAddKey(element, keys);
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if (element.widget.key is GlobalKey) {
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lastKey = element.widget.key;
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return false;
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} else if (element.widget.key != null) {
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result.addKey(element.widget.key);
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}
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return true;
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});
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return result;
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}
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return keys;
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}
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_StorageEntryIdentifier _computeIdentifier(BuildContext context) {
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return new _StorageEntryIdentifier(context.widget.runtimeType, _allKeys(context));
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assert(lastKey is GlobalKey);
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result.scopeKey = lastKey;
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return result;
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}
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Map<Object, dynamic> _storage;
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@ -112,13 +89,13 @@ class PageStorageBucket {
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/// identifier will change.
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void writeState(BuildContext context, dynamic data, { Object identifier }) {
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_storage ??= <Object, dynamic>{};
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_storage[identifier ?? _computeIdentifier(context)] = data;
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_storage[identifier ?? _computeStorageIdentifier(context)] = data;
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}
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/// Read given data from into this page storage bucket using an identifier
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/// computed from the given context. More about [identifier] in [writeState].
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dynamic readState(BuildContext context, { Object identifier }) {
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return _storage != null ? _storage[identifier ?? _computeIdentifier(context)] : null;
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return _storage != null ? _storage[identifier ?? _computeStorageIdentifier(context)] : null;
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}
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}
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@ -38,36 +38,17 @@ import 'viewport.dart';
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class PageController extends ScrollController {
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/// Creates a page controller.
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///
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/// The [initialPage], [keepPage], and [viewportFraction] arguments must not be null.
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/// The [initialPage] and [viewportFraction] arguments must not be null.
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PageController({
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this.initialPage: 0,
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this.keepPage: true,
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this.viewportFraction: 1.0,
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}) : assert(initialPage != null),
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assert(keepPage != null),
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assert(viewportFraction != null),
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assert(viewportFraction > 0.0);
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/// The page to show when first creating the [PageView].
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final int initialPage;
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/// Save the current [page] with [PageStorage] and restore it if
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/// this controller's scrollable is recreated.
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///
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/// If this property is set to false, the current [page] is never saved
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/// and [initialPage] is always used to initialize the scroll offset.
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/// If true (the default), the initial page is used the first time the
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/// controller's scrollable is created, since there's isn't a page to
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/// restore yet. Subsequently the saved page is restored and
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/// [initialPage] is ignored.
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///
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/// See also:
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///
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/// * [PageStorageKey], which should be used when more than one
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//// scrollable appears in the same route, to distinguish the [PageStorage]
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/// locations used to save scroll offsets.
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final bool keepPage;
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/// The fraction of the viewport that each page should occupy.
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///
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/// Defaults to 1.0, which means each page fills the viewport in the scrolling
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@ -135,7 +116,6 @@ class PageController extends ScrollController {
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physics: physics,
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context: context,
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initialPage: initialPage,
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keepPage: keepPage,
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viewportFraction: viewportFraction,
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oldPosition: oldPosition,
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);
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@ -170,11 +150,9 @@ class _PagePosition extends ScrollPositionWithSingleContext {
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ScrollPhysics physics,
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ScrollContext context,
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this.initialPage: 0,
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bool keepPage: true,
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double viewportFraction: 1.0,
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ScrollPosition oldPosition,
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}) : assert(initialPage != null),
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assert(keepPage != null),
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assert(viewportFraction != null),
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assert(viewportFraction > 0.0),
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_viewportFraction = viewportFraction,
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@ -183,7 +161,6 @@ class _PagePosition extends ScrollPositionWithSingleContext {
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physics: physics,
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context: context,
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initialPixels: null,
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keepScrollOffset: keepPage,
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oldPosition: oldPosition,
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);
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@ -39,40 +39,20 @@ import 'scroll_position_with_single_context.dart';
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class ScrollController extends ChangeNotifier {
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/// Creates a controller for a scrollable widget.
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///
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/// The values of `initialScrollOffset` and `keepScrollOffset` must not be null.
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/// The [initialScrollOffset] must not be null.
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ScrollController({
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this.initialScrollOffset: 0.0,
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this.keepScrollOffset: true,
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this.debugLabel,
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}) : assert(initialScrollOffset != null),
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assert(keepScrollOffset != null);
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}) : assert(initialScrollOffset != null);
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/// The initial value to use for [offset].
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///
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/// New [ScrollPosition] objects that are created and attached to this
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/// controller will have their offset initialized to this value
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/// if [keepScrollOffset] is false or a scroll offset hasn't been saved yet.
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/// controller will have their offset initialized to this value.
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///
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/// Defaults to 0.0.
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final double initialScrollOffset;
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/// Each time a scroll completes, save the current scroll [offset] with
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/// [PageStorage] and restore it if this controller's scrollable is recreated.
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///
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/// If this property is set to false, the scroll offset is never saved
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/// and [initialScrollOffset] is always used to initialize the scroll
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/// offset. If true (the default), the initial scroll offset is used the
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/// first time the controller's scrollable is created, since there's no
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/// scroll offset to restore yet. Subsequently the saved offset is
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/// restored and [initialScrollOffset] is ignored.
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///
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/// See also:
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///
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/// * [PageStorageKey], which should be used when more than one
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//// scrollable appears in the same route, to distinguish the [PageStorage]
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/// locations used to save scroll offsets.
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final bool keepScrollOffset;
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/// A label that is used in the [toString] output. Intended to aid with
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/// identifying scroll controller instances in debug output.
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final String debugLabel;
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@ -224,7 +204,6 @@ class ScrollController extends ChangeNotifier {
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physics: physics,
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context: context,
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initialPixels: initialScrollOffset,
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keepScrollOffset: keepScrollOffset,
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oldPosition: oldPosition,
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debugLabel: debugLabel,
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);
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@ -61,21 +61,16 @@ export 'scroll_activity.dart' show ScrollHoldController;
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abstract class ScrollPosition extends ViewportOffset with ScrollMetrics {
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/// Creates an object that determines which portion of the content is visible
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/// in a scroll view.
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///
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/// The [physics], [context], and [keepScrollOffset] parameters must not be null.
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ScrollPosition({
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@required this.physics,
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@required this.context,
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this.keepScrollOffset: true,
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ScrollPosition oldPosition,
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this.debugLabel,
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}) : assert(physics != null),
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assert(context != null),
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assert(context.vsync != null),
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assert(keepScrollOffset != null) {
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assert(context.vsync != null) {
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if (oldPosition != null)
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absorb(oldPosition);
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if (keepScrollOffset)
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restoreScrollOffset();
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}
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@ -90,15 +85,6 @@ abstract class ScrollPosition extends ViewportOffset with ScrollMetrics {
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/// Typically implemented by [ScrollableState].
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final ScrollContext context;
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/// Save the current scroll [offset] with [PageStorage] and restore it if
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/// this scroll position's scrollable is recreated.
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///
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/// See also:
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///
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/// * [ScrollController.keepScrollOffset] and [PageController.keepPage], which
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/// create scroll positions and initialize this property.
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final bool keepScrollOffset;
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/// A label that is used in the [toString] output. Intended to aid with
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/// identifying animation controller instances in debug output.
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final String debugLabel;
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@ -553,7 +539,6 @@ abstract class ScrollPosition extends ViewportOffset with ScrollMetrics {
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/// This also saves the scroll offset using [saveScrollOffset].
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void didEndScroll() {
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activity.dispatchScrollEndNotification(cloneMetrics(), context.notificationContext);
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if (keepScrollOffset)
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saveScrollOffset();
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}
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@ -46,24 +46,13 @@ class ScrollPositionWithSingleContext extends ScrollPosition implements ScrollAc
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/// imperative that the value be set, using [correctPixels], as soon as
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/// [applyNewDimensions] is invoked, before calling the inherited
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/// implementation of that method.
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///
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/// If [keepScrollOffset] is true (the default), the current scroll offset is
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/// saved with [PageStorage] and restored it if this scroll position's scrollable
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/// is recreated.
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ScrollPositionWithSingleContext({
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@required ScrollPhysics physics,
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@required ScrollContext context,
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double initialPixels: 0.0,
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bool keepScrollOffset: true,
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ScrollPosition oldPosition,
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String debugLabel,
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}) : super(
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physics: physics,
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context: context,
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keepScrollOffset: keepScrollOffset,
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oldPosition: oldPosition,
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debugLabel: debugLabel,
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) {
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}) : super(physics: physics, context: context, oldPosition: oldPosition, debugLabel: debugLabel) {
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// If oldPosition is not null, the superclass will first call absorb(),
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// which may set _pixels and _activity.
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if (pixels == null && initialPixels != null)
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@ -441,14 +441,12 @@ void main() {
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),
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);
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expect(controller.page, 2);
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final PageController controller2 = new PageController(keepPage: false);
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await tester.pumpWidget(
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new PageStorage(
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bucket: bucket,
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child: new PageView(
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key: const Key('Check it again against your list and see consistency!'),
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controller: controller2,
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controller: controller,
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children: <Widget>[
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const Placeholder(),
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const Placeholder(),
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@ -457,6 +455,6 @@ void main() {
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),
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),
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);
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expect(controller2.page, 0);
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expect(controller.page, 0);
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});
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}
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@ -259,51 +259,4 @@ void main() {
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await tester.drag(find.byType(ListView), const Offset(0.0, -130.0));
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expect(log, isEmpty);
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});
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testWidgets('keepScrollOffset', (WidgetTester tester) async {
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final PageStorageBucket bucket = new PageStorageBucket();
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Widget buildFrame(ScrollController controller) {
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return new PageStorage(
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bucket: bucket,
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child: new ListView(
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key: new UniqueKey(), // it's a different ListView every time
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controller: controller,
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children: new List<Widget>.generate(50, (int index) {
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return new Container(height: 100.0, child: new Text('Item $index'));
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}).toList(),
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),
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);
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}
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// keepScrollOffset: true (the default). The scroll offset is restored
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// when the ListView is recreated with a new ScrollController.
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// The initialScrollOffset is used in this case, because there's no saved
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// scroll offset.
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ScrollController controller = new ScrollController(initialScrollOffset: 200.0);
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await tester.pumpWidget(buildFrame(controller));
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expect(tester.getTopLeft(find.widgetWithText(Container, 'Item 2')), Offset.zero);
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controller.jumpTo(2000.0);
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await tester.pump();
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expect(tester.getTopLeft(find.widgetWithText(Container, 'Item 20')), Offset.zero);
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// The initialScrollOffset isn't used in this case, because the scrolloffset
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// can be restored.
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controller = new ScrollController(initialScrollOffset: 25.0);
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await tester.pumpWidget(buildFrame(controller));
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expect(controller.offset, 2000.0);
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expect(tester.getTopLeft(find.widgetWithText(Container, 'Item 20')), Offset.zero);
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// keepScrollOffset: false. The scroll offset is -not- restored
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// when the ListView is recreated with a new ScrollController and
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// the initialScrollOffset is used.
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controller = new ScrollController(keepScrollOffset: false, initialScrollOffset: 100.0);
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await tester.pumpWidget(buildFrame(controller));
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expect(controller.offset, 100.0);
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expect(tester.getTopLeft(find.widgetWithText(Container, 'Item 1')), Offset.zero);
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});
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}
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