wehub-resource-sync
80 lines
1.8 KiB
Dart
80 lines
1.8 KiB
Dart
import 'dart:async';
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import 'package:common/util/sleep.dart';
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import 'package:flutter/material.dart';
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/// A slideshow of widgets using [AnimatedOpacity] as transition.
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class OpacitySlideshow extends StatefulWidget {
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final List<Widget> children;
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final int durationMillis;
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final int switchDurationMillis;
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final bool running;
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const OpacitySlideshow({
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required this.children,
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required this.durationMillis,
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this.switchDurationMillis = 300,
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this.running = true,
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super.key,
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});
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@override
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State<OpacitySlideshow> createState() => _OpacitySlideshowState();
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}
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class _OpacitySlideshowState extends State<OpacitySlideshow> {
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Timer? _timer;
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int _index = 0;
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double _opacity = 1;
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@override
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void initState() {
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super.initState();
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_startTimer();
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}
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@override
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void dispose() {
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super.dispose();
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_timer?.cancel();
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}
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@override
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void didUpdateWidget(OpacitySlideshow oldWidget) {
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super.didUpdateWidget(oldWidget);
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if (oldWidget.running && !widget.running) {
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_timer?.cancel();
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} else if (!oldWidget.running && widget.running) {
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_startTimer();
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}
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}
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void _startTimer() {
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if (widget.children.length <= 1) {
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return;
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}
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_timer = Timer.periodic(Duration(milliseconds: widget.durationMillis), (_) async {
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if (!mounted) return;
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setState(() {
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_opacity = 0;
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});
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await sleepAsync(widget.switchDurationMillis);
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if (!mounted) return;
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setState(() {
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_index = (_index + 1) % widget.children.length;
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_opacity = 1;
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});
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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 AnimatedOpacity(
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opacity: _opacity,
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duration: Duration(milliseconds: widget.switchDurationMillis),
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child: widget.children[_index],
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);
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}
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}
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