blob: 43e4ec33b08c3c92474aa0639bbfedc16f64e017 [file] [log] [blame]
// Copyright 2016 The Chromium 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.
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 =,
this.curve = Curves.linear,
@required this.duration,
@required this.vsync,
}) : 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 [].
/// 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;
RenderAnimatedSize createRenderObject(BuildContext context) {
return RenderAnimatedSize(
alignment: alignment,
duration: duration,
reverseDuration: reverseDuration,
curve: curve,
vsync: vsync,
textDirection: Directionality.of(context),
void updateRenderObject(BuildContext context, RenderAnimatedSize renderObject) {
..alignment = alignment
..duration = duration
..reverseDuration = reverseDuration
..curve = curve
..vsync = vsync
..textDirection = Directionality.of(context);
void debugFillProperties(DiagnosticPropertiesBuilder 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));