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* Update project.pbxproj files to say Flutter rather than Chromium Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright. * Update the copyright notice checker to require a standard notice on all files * Update copyrights on Dart files. (This was a mechanical commit.) * Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine. Some were already marked "The Flutter Authors", not clear why. Their dates have been normalized. Some were missing the blank line after the license. Some were randomly different in trivial ways for no apparent reason (e.g. missing the trailing period). * Clean up the copyrights in non-Dart files. (Manual edits.) Also, make sure templates don't have copyrights. * Fix some more ORGANIZATIONNAMEs
69 lines
2.7 KiB
Dart
69 lines
2.7 KiB
Dart
// Copyright 2014 The Flutter 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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// This example shows how to perform a simple animation using the underlying
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// render tree.
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import 'dart:math' as math;
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import 'package:flutter/animation.dart';
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import 'package:flutter/rendering.dart';
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import 'package:flutter/scheduler.dart';
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class NonStopVSync implements TickerProvider {
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const NonStopVSync();
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@override
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Ticker createTicker(TickerCallback onTick) => Ticker(onTick);
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}
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void main() {
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// We first create a render object that represents a green box.
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final RenderBox green = RenderDecoratedBox(
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decoration: const BoxDecoration(color: Color(0xFF00FF00))
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);
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// Second, we wrap that green box in a render object that forces the green box
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// to have a specific size.
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final RenderBox square = RenderConstrainedBox(
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additionalConstraints: const BoxConstraints.tightFor(width: 200.0, height: 200.0),
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child: green,
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);
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// Third, we wrap the sized green square in a render object that applies rotation
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// transform before painting its child. Each frame of the animation, we'll
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// update the transform of this render object to cause the green square to
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// spin.
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final RenderTransform spin = RenderTransform(
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transform: Matrix4.identity(),
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alignment: Alignment.center,
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child: square,
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);
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// Finally, we center the spinning green square...
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final RenderBox root = RenderPositionedBox(
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alignment: Alignment.center,
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child: spin,
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);
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// and attach it to the window.
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RenderingFlutterBinding(root: root);
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// To make the square spin, we use an animation that repeats every 1800
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// milliseconds.
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final AnimationController animation = AnimationController(
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duration: const Duration(milliseconds: 1800),
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vsync: const NonStopVSync(),
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)..repeat();
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// The animation will produce a value between 0.0 and 1.0 each frame, but we
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// want to rotate the square using a value between 0.0 and math.pi. To change
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// the range of the animation, we use a Tween.
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final Tween<double> tween = Tween<double>(begin: 0.0, end: math.pi);
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// We add a listener to the animation, which will be called every time the
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// animation ticks.
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animation.addListener(() {
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// This code runs every tick of the animation and sets a new transform on
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// the "spin" render object by evaluating the tween on the current value
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// of the animation. Setting this value will mark a number of dirty bits
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// inside the render tree, which cause the render tree to repaint with the
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// new transform value this frame.
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spin.transform = Matrix4.rotationZ(tween.evaluate(animation));
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});
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}
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