56 lines
1.6 KiB
Dart
56 lines
1.6 KiB
Dart
// 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:async';
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import 'package:flutter/material.dart';
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/// Displays a new (from image cache's perspective) large image every 500ms.
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class LargeImageChangerPage extends StatefulWidget {
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@override
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_LargeImageChangerState createState() => _LargeImageChangerState();
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}
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class _LargeImageChangerState extends State<LargeImageChangerPage> {
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Timer _timer;
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int imageIndex = 0;
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ImageProvider currentImage;
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@override
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void didChangeDependencies() {
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super.didChangeDependencies();
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currentImage = ResizeImage(
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const ExactAssetImage('assets/999x1000.png'),
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width: (MediaQuery.of(context).size.width * 2).toInt() + imageIndex,
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height: (MediaQuery.of(context).size.height * 2).toInt() + imageIndex,
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allowUpscaling: true,
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);
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_timer?.cancel();
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_timer = Timer.periodic(const Duration(seconds: 3), (Timer timer) {
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currentImage.evict().then((_) {
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setState(() {
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imageIndex = (imageIndex + 1) % 6;
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currentImage = ResizeImage(
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const ExactAssetImage('assets/999x1000.png'),
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width: (MediaQuery.of(context).size.width * 2).toInt() + imageIndex,
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height: (MediaQuery.of(context).size.height * 2).toInt() + imageIndex,
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allowUpscaling: true,
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);
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});
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});
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});
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}
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@override
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void dispose() {
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_timer?.cancel();
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super.dispose();
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}
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@override
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Widget build(BuildContext context) {
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return Image(image: currentImage);
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}
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}
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