77 lines
2 KiB
Dart
77 lines
2 KiB
Dart
import 'package:flutter/widgets.dart';
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/// StatefulWidget that wraps InheritedSettingsState
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class SettingsStateContainer extends StatefulWidget {
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const SettingsStateContainer({
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Key? key,
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required this.child,
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}) : super(key: key);
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final Widget child;
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@override
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State<SettingsStateContainer> createState() => _SettingsState();
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}
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class _SettingsState extends State<SettingsStateContainer> {
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int _expandedSectionCount = 0;
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void increment() {
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setState(() {
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_expandedSectionCount += 1;
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});
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}
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void decrement() {
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setState(() {
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_expandedSectionCount -= 1;
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});
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}
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@override
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Widget build(BuildContext context) {
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return InheritedSettingsState(
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expandedSectionCount: _expandedSectionCount,
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increment: increment,
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decrement: decrement,
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child: widget.child,
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);
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}
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}
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/// Keep track of the number of expanded sections in an entire menu tree.
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///
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/// Since this is an InheritedWidget, subsections can obtain it from the context
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/// and use the current expansion state to style themselves differently if
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/// needed.
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///
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/// Example usage:
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///
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/// InheritedSettingsState.of(context).increment()
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///
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class InheritedSettingsState extends InheritedWidget {
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final int expandedSectionCount;
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final void Function() increment;
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final void Function() decrement;
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const InheritedSettingsState({
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Key? key,
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required this.expandedSectionCount,
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required this.increment,
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required this.decrement,
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required Widget child,
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}) : super(key: key, child: child);
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bool get isAnySectionExpanded => expandedSectionCount > 0;
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static InheritedSettingsState of(BuildContext context) =>
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context.dependOnInheritedWidgetOfExactType<InheritedSettingsState>()!;
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static InheritedSettingsState? maybeOf(BuildContext context) =>
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context.dependOnInheritedWidgetOfExactType<InheritedSettingsState>();
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@override
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bool updateShouldNotify(covariant InheritedSettingsState oldWidget) {
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return isAnySectionExpanded != oldWidget.isAnySectionExpanded;
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}
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}
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