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b1f9138f52
This patch also changed ScrollableList2 to use an Iterable instead of an List for its children. This change lets clients map their underlying data lazily. If the clients actually have a concrete list, we skip the extra copy and grab the child list directly.
77 lines
2.0 KiB
Dart
77 lines
2.0 KiB
Dart
// Copyright 2015 The Chromium 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 'package:intl/intl.dart';
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import 'package:flutter/material.dart';
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final NumberFormat _dd = new NumberFormat("00", "en_US");
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class _Item extends StatelessComponent {
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_Item(this.index);
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int index;
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Widget build(BuildContext context) {
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return new Text('Item ${_dd.format(index)}',
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key: new ValueKey<int>(index),
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style: Theme.of(context).text.title
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);
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}
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}
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class ScrollbarApp extends StatefulComponent {
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ScrollbarAppState createState() => new ScrollbarAppState();
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}
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class ScrollbarAppState extends State<ScrollbarApp> {
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final int _itemCount = 20;
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final double _itemExtent = 50.0;
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final ScrollbarPainter _scrollbarPainter = new ScrollbarPainter();
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Widget _buildMenu(BuildContext context) {
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return new ScrollableList2(
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itemExtent: _itemExtent,
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scrollableListPainter: _scrollbarPainter,
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children: new List<Widget>.generate(_itemCount, (int i) => new _Item(i))
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);
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}
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Widget build(BuildContext context) {
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Widget scrollable = new Container(
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margin: new EdgeDims.symmetric(horizontal: 6.0), // TODO(hansmuller) 6.0 should be based on _kScrollbarThumbWidth
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child: new Center(
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widthFactor: 1.0,
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heightFactor: 1.0,
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child: new Container(
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width: 80.0,
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height: _itemExtent * 5.0,
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child: _buildMenu(context)
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)
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)
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);
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return new Scaffold(
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toolBar: new ToolBar(center: new Text('Scrollbar Demo')),
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body: new Container(
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padding: new EdgeDims.all(12.0),
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child: new Center(child: new Card(child: scrollable))
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)
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);
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}
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}
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void main() {
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runApp(new MaterialApp(
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title: 'ScrollbarApp',
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theme: new ThemeData(
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brightness: ThemeBrightness.light,
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primarySwatch: Colors.blue,
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accentColor: Colors.redAccent[200]
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),
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routes: <String, RouteBuilder>{
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'/': (RouteArguments args) => new ScrollbarApp(),
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}
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));
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}
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