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183 行
6.4 KiB

using System;
using Unity.UIWidgets.animation;
using Unity.UIWidgets.async;
using Unity.UIWidgets.cupertino;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.ui;
using Unity.UIWidgets.widgets;
using UnityEngine;
using Color = Unity.UIWidgets.ui.Color;
namespace Unity.UIWidgets.material {
static class ScrollbarUtils {
public static readonly TimeSpan _kScrollbarFadeDuration = TimeSpan.FromMilliseconds(300);
public static readonly TimeSpan _kScrollbarTimeToFade = TimeSpan.FromMilliseconds(600);
public const float _kScrollbarThickness = 6.0f;
}
public class Scrollbar : StatefulWidget {
public Scrollbar(
Key key = null,
Widget child = null,
ScrollController controller = null,
bool isAlwaysShown = false) : base(key: key) {
this.child = child;
this.controller = controller;
this.isAlwaysShown = isAlwaysShown;
}
public readonly Widget child;
public readonly ScrollController controller;
public readonly bool isAlwaysShown;
public override State createState() {
return new _ScrollbarState();
}
}
public class _ScrollbarState : TickerProviderStateMixin<Scrollbar> {
public ScrollbarPainter _materialPainter;
public TextDirection _textDirection;
public Color _themeColor;
bool? _useCupertinoScrollbar = null;
public AnimationController _fadeoutAnimationController;
public Animation<float> _fadeoutOpacityAnimation;
public Timer _fadeoutTimer;
public override void initState() {
base.initState();
_fadeoutAnimationController = new AnimationController(
vsync: this,
duration: ScrollbarUtils._kScrollbarFadeDuration
);
_fadeoutOpacityAnimation = new CurvedAnimation(
parent: _fadeoutAnimationController,
curve: Curves.fastOutSlowIn
);
}
public override void didChangeDependencies() {
base.didChangeDependencies();
D.assert((() => {
_useCupertinoScrollbar = null;
return true;
}));
ThemeData theme = Theme.of(context);
switch (theme.platform) {
case RuntimePlatform.IPhonePlayer:
case RuntimePlatform.OSXPlayer:
case RuntimePlatform.OSXEditor:
_fadeoutTimer?.cancel();
_fadeoutTimer = null;
_fadeoutAnimationController.reset();
_useCupertinoScrollbar = true;
break;
default:
_themeColor = theme.highlightColor.withOpacity(1.0f);
_textDirection = Directionality.of(context);
_materialPainter = _buildMaterialScrollbarPainter();
_useCupertinoScrollbar = false;
WidgetsBinding.instance.addPostFrameCallback((TimeSpan duration) => {
if (widget.isAlwaysShown) {
D.assert(widget.controller != null);
widget.controller.position.didUpdateScrollPositionBy(0);
}
});
break;
}
D.assert(_useCupertinoScrollbar != null);
}
public override void didUpdateWidget(StatefulWidget oldWidget) {
var _oldWidget = (Scrollbar) oldWidget;
base.didUpdateWidget(oldWidget);
if (widget.isAlwaysShown != _oldWidget.isAlwaysShown) {
D.assert(widget.controller != null);
if (widget.isAlwaysShown == false) {
_fadeoutAnimationController.reverse();
}
else {
_fadeoutAnimationController.animateTo(1.0f);
}
}
}
public ScrollbarPainter _buildMaterialScrollbarPainter() {
return new ScrollbarPainter(
color: _themeColor,
textDirection: _textDirection,
thickness: ScrollbarUtils._kScrollbarThickness,
fadeoutOpacityAnimation: _fadeoutOpacityAnimation,
padding: MediaQuery.of(context).padding
);
}
bool _handleScrollNotification(ScrollNotification notification) {
ScrollMetrics metrics = notification.metrics;
if (metrics.maxScrollExtent <= metrics.minScrollExtent) {
return false;
}
if (!_useCupertinoScrollbar.Value &&
(notification is ScrollUpdateNotification ||
notification is OverscrollNotification)) {
if (_fadeoutAnimationController.status != AnimationStatus.forward) {
_fadeoutAnimationController.forward();
}
_materialPainter.update(
notification.metrics,
notification.metrics.axisDirection
);
if (!widget.isAlwaysShown) {
_fadeoutTimer?.cancel();
_fadeoutTimer = Timer.create(ScrollbarUtils._kScrollbarTimeToFade, () => {
_fadeoutAnimationController.reverse();
_fadeoutTimer = null;
});
}
}
return false;
}
public override void dispose() {
_fadeoutAnimationController.dispose();
_fadeoutTimer?.cancel();
_materialPainter?.dispose();
base.dispose();
}
public override Widget build(BuildContext context) {
if (_useCupertinoScrollbar.Value) {
return new CupertinoScrollbar(
child: widget.child,
isAlwaysShown: widget.isAlwaysShown,
controller: widget.controller
);
}
return new NotificationListener<ScrollNotification>(
onNotification: _handleScrollNotification,
child: new RepaintBoundary(
child: new CustomPaint(
foregroundPainter: _materialPainter,
child: new RepaintBoundary(
child: widget.child
)
)
)
);
}
}
}