// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'package:flutter/rendering.dart'; import 'package:flutter/scheduler.dart'; import 'basic.dart'; import 'framework.dart'; /// Animated widget that automatically transitions its size over a given /// duration whenever the given child's size changes. /// /// {@tool dartpad --template=stateful_widget_scaffold_center_freeform_state} /// This example makes a [Container] react to being touched, causing the child /// of the [AnimatedSize] widget, here a [FlutterLogo], to animate. /// /// ```dart /// class _MyStatefulWidgetState extends State<MyStatefulWidget> with SingleTickerProviderStateMixin { /// double _size = 50.0; /// bool _large = false; /// /// void _updateSize() { /// setState(() { /// _size = _large ? 250.0 : 100.0; /// _large = !_large; /// }); /// } /// /// @override /// Widget build(BuildContext context) { /// return GestureDetector( /// onTap: () => _updateSize(), /// child: Container( /// color: Colors.amberAccent, /// child: AnimatedSize( /// curve: Curves.easeIn, /// vsync: this, /// duration: Duration(seconds: 1), /// child: FlutterLogo(size: _size), /// ), /// ), /// ); /// } /// } /// ``` /// {@end-tool} /// /// See also: /// /// * [SizeTransition], which changes its size based on an [Animation]. class AnimatedSize extends SingleChildRenderObjectWidget { /// Creates a widget that animates its size to match that of its child. /// /// The [curve] and [duration] arguments must not be null. const AnimatedSize({ Key? key, Widget? child, this.alignment = Alignment.center, this.curve = Curves.linear, required this.duration, this.reverseDuration, required this.vsync, this.clipBehavior = Clip.hardEdge, }) : assert(clipBehavior != null), super(key: key, child: child); /// The alignment of the child within the parent when the parent is not yet /// the same size as the child. /// /// The x and y values of the alignment control the horizontal and vertical /// alignment, respectively. An x value of -1.0 means that the left edge of /// the child is aligned with the left edge of the parent whereas an x value /// of 1.0 means that the right edge of the child is aligned with the right /// edge of the parent. Other values interpolate (and extrapolate) linearly. /// For example, a value of 0.0 means that the center of the child is aligned /// with the center of the parent. /// /// Defaults to [Alignment.center]. /// /// See also: /// /// * [Alignment], a class with convenient constants typically used to /// specify an [AlignmentGeometry]. /// * [AlignmentDirectional], like [Alignment] for specifying alignments /// relative to text direction. final AlignmentGeometry alignment; /// The animation curve when transitioning this widget's size to match the /// child's size. final Curve curve; /// The duration when transitioning this widget's size to match the child's /// size. final Duration duration; /// The duration when transitioning this widget's size to match the child's /// size when going in reverse. /// /// If not specified, defaults to [duration]. final Duration? reverseDuration; /// The [TickerProvider] for this widget. final TickerProvider vsync; /// {@macro flutter.material.Material.clipBehavior} /// /// Defaults to [Clip.hardEdge], and must not be null. final Clip clipBehavior; @override RenderAnimatedSize createRenderObject(BuildContext context) { return RenderAnimatedSize( alignment: alignment, duration: duration, reverseDuration: reverseDuration, curve: curve, vsync: vsync, textDirection: Directionality.maybeOf(context), clipBehavior: clipBehavior, ); } @override void updateRenderObject(BuildContext context, RenderAnimatedSize renderObject) { renderObject ..alignment = alignment ..duration = duration ..reverseDuration = reverseDuration ..curve = curve ..vsync = vsync ..textDirection = Directionality.maybeOf(context) ..clipBehavior = clipBehavior; } @override void debugFillProperties(DiagnosticPropertiesBuilder properties) { super.debugFillProperties(properties); properties.add(DiagnosticsProperty<AlignmentGeometry>('alignment', alignment, defaultValue: Alignment.topCenter)); properties.add(IntProperty('duration', duration.inMilliseconds, unit: 'ms')); properties.add(IntProperty('reverseDuration', reverseDuration?.inMilliseconds, unit: 'ms', defaultValue: null)); } }