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921d432092
Enabled displaying a scrollbar in ScrollingLists. The scrollbar is painted as an "overlay", i.e. it's painted on top of the scrolling list's visible children. Added an abstract Painter base class that encapsulates a paint method and the renderer that it's attached to. RenderBlockViewport and HomogenousViewport now support an overlayPainter property. If specified, RenderBlockViewport attaches itself to the overlayPainter when it's attached to the rendering tree. RenderBlockViewport now calls overlayPainter.paint() after it has painted its children. Added an abstract ScrollingListPainter class that exposes ScrollingList's state which might be needed for painting. Like its scroll direction and scrollOffset. The ScrollingListPainter is notified when a scroll starts and ends. Defined a Material-specific ScrollingListPainter that renders a scrollbar. The scrollbar thumb is faded in/out when the scroll starts/ends. Added onScrollStart and onScrollEnd listeners to Scrollable.
68 lines
2.0 KiB
Dart
68 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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class ScrollbarApp extends StatefulComponent {
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ScrollbarApp({ this.navigator });
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final NavigatorState navigator;
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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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NumberFormat dd = new NumberFormat("00", "en_US");
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return new ScrollableList<int>(
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items: new List<int>.generate(_itemCount, (int i) => i),
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itemExtent: _itemExtent,
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itemBuilder: (BuildContext _, int i) => new Text('Item ${dd.format(i)}', style: Theme.of(context).text.title),
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scrollableListPainter: _scrollbarPainter
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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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shrinkWrap: ShrinkWrap.both,
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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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decoration: new BoxDecoration(backgroundColor: Theme.of(context).primarySwatch[50]),
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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: {
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'/': (RouteArguments args) => new ScrollbarApp(navigator: args.navigator),
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}
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));
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}
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