27 lines
830 B
Dart
27 lines
830 B
Dart
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import 'dart:async';
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import 'package:flutter/rendering.dart';
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import 'package:wonders/common_libs.dart';
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class MeasurableWidget extends SingleChildRenderObjectWidget {
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const MeasurableWidget({Key? key, required this.onChange, required Widget child}) : super(key: key, child: child);
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final void Function(Size size) onChange;
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@override
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RenderObject createRenderObject(BuildContext context) => MeasureSizeRenderObject(onChange);
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}
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class MeasureSizeRenderObject extends RenderProxyBox {
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MeasureSizeRenderObject(this.onChange);
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void Function(Size size) onChange;
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Size _prevSize = Size.zero;
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@override
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void performLayout() {
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super.performLayout();
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Size newSize = child?.size ?? Size.zero;
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if (_prevSize == newSize) return;
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_prevSize = newSize;
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scheduleMicrotask(() => onChange(newSize));
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}
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}
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