// 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/widgets.dart'; import 'package:flutter_test/flutter_test.dart'; const String kApiDocsLink = 'See "Types with special considerations" at https://api.flutter.dev/flutter/animation/Tween-class.html for more information.'; void main() { test('throws flutter error when tweening types that do not fully satisfy tween requirements - Object', () { final Tween<Object> objectTween = Tween<Object>( begin: Object(), end: Object(), ); expect( () => objectTween.transform(0.1), throwsA(isA<FlutterError>().having( (FlutterError error) => error.diagnostics.map((DiagnosticsNode node) => node.toString()), 'diagnostics', <String>[ 'Cannot lerp between "Instance of \'Object\'" and "Instance of \'Object\'".', 'The type Object might not fully implement `+`, `-`, and/or `*`. $kApiDocsLink', 'There may be a dedicated "ObjectTween" for this type, or you may need to create one.', ], )), ); }); test('throws flutter error when tweening types that do not fully satisfy tween requirements - Color', () { final Tween<Color> colorTween = Tween<Color>( begin: const Color(0xFF000000), end: const Color(0xFFFFFFFF), ); expect( () => colorTween.transform(0.1), throwsA(isA<FlutterError>().having( (FlutterError error) => error.diagnostics.map((DiagnosticsNode node) => node.toString()), 'diagnostics', <String>[ 'Cannot lerp between "Color(0xff000000)" and "Color(0xffffffff)".', 'The type Color might not fully implement `+`, `-`, and/or `*`. $kApiDocsLink', 'To lerp colors, consider ColorTween instead.', ], )), ); }); test('throws flutter error when tweening types that do not fully satisfy tween requirements - Rect', () { final Tween<Rect> rectTween = Tween<Rect>( begin: const Rect.fromLTWH(0, 0, 10, 10), end: const Rect.fromLTWH(2, 2, 2, 2), ); expect( () => rectTween.transform(0.1), throwsA(isA<FlutterError>().having( (FlutterError error) => error.diagnostics.map((DiagnosticsNode node) => node.toString()), 'diagnostics', <String>[ 'Cannot lerp between "Rect.fromLTRB(0.0, 0.0, 10.0, 10.0)" and "Rect.fromLTRB(2.0, 2.0, 4.0, 4.0)".', 'The type Rect might not fully implement `+`, `-`, and/or `*`. $kApiDocsLink', 'To lerp rects, consider RectTween instead.', ], )), ); }); test('throws flutter error when tweening types that do not fully satisfy tween requirements - int', () { final Tween<int> colorTween = Tween<int>( begin: 0, end: 1, ); expect( () => colorTween.transform(0.1), throwsA(isA<FlutterError>().having( (FlutterError error) => error.diagnostics.map((DiagnosticsNode node) => node.toString()), 'diagnostics', <String>[ 'Cannot lerp between "0" and "1".', 'The type int returned a double after multiplication with a double value. $kApiDocsLink', 'To lerp int values, consider IntTween or StepTween instead.', ], )), ); }); test('Can chain tweens', () { final Tween<double> tween = Tween<double>(begin: 0.30, end: 0.50); expect(tween, hasOneLineDescription); final Animatable<double> chain = tween.chain(Tween<double>(begin: 0.50, end: 1.0)); final AnimationController controller = AnimationController( vsync: const TestVSync(), ); expect(chain.evaluate(controller), 0.40); expect(chain, hasOneLineDescription); }); test('Can animate tweens', () { final Tween<double> tween = Tween<double>(begin: 0.30, end: 0.50); final AnimationController controller = AnimationController( vsync: const TestVSync(), ); final Animation<double> animation = tween.animate(controller); controller.value = 0.50; expect(animation.value, 0.40); expect(animation, hasOneLineDescription); expect(animation.toStringDetails(), hasOneLineDescription); }); test('Can drive tweens', () { final Tween<double> tween = Tween<double>(begin: 0.30, end: 0.50); final AnimationController controller = AnimationController( vsync: const TestVSync(), ); final Animation<double> animation = controller.drive(tween); controller.value = 0.50; expect(animation.value, 0.40); expect(animation, hasOneLineDescription); expect(animation.toStringDetails(), hasOneLineDescription); }); test('BorderTween nullable test', () { BorderTween tween = BorderTween(); expect(tween.lerp(0.0), null); expect(tween.lerp(1.0), null); tween = BorderTween(end: const Border(top: BorderSide())); expect(tween.lerp(0.0), const Border()); expect(tween.lerp(0.5), const Border(top: BorderSide(width: 0.5))); expect(tween.lerp(1.0), const Border(top: BorderSide())); }); test('SizeTween', () { final SizeTween tween = SizeTween(begin: Size.zero, end: const Size(20.0, 30.0)); expect(tween.lerp(0.5), equals(const Size(10.0, 15.0))); expect(tween, hasOneLineDescription); }); test('IntTween', () { final IntTween tween = IntTween(begin: 5, end: 9); expect(tween.lerp(0.5), 7); expect(tween.lerp(0.7), 8); }); test('RectTween', () { const Rect a = Rect.fromLTWH(5.0, 3.0, 7.0, 11.0); const Rect b = Rect.fromLTWH(8.0, 12.0, 14.0, 18.0); final RectTween tween = RectTween(begin: a, end: b); expect(tween.lerp(0.5), equals(Rect.lerp(a, b, 0.5))); expect(tween, hasOneLineDescription); }); test('Matrix4Tween', () { final Matrix4 a = Matrix4.identity(); final Matrix4 b = a.clone()..translate(6.0, -8.0)..scale(0.5, 1.0, 5.0); final Matrix4Tween tween = Matrix4Tween(begin: a, end: b); expect(tween.lerp(0.0), equals(a)); expect(tween.lerp(1.0), equals(b)); expect( tween.lerp(0.5), equals(a.clone()..translate(3.0, -4.0)..scale(0.75, 1.0, 3.0)), ); final Matrix4 c = a.clone()..rotateZ(1.0); final Matrix4Tween rotationTween = Matrix4Tween(begin: a, end: c); expect(rotationTween.lerp(0.0), equals(a)); expect(rotationTween.lerp(1.0), equals(c)); expect( rotationTween.lerp(0.5).absoluteError(a.clone()..rotateZ(0.5)), moreOrLessEquals(0.0), ); }); test('ConstantTween', () { final ConstantTween<double> tween = ConstantTween<double>(100.0); expect(tween.begin, 100.0); expect(tween.end, 100.0); expect(tween.lerp(0.0), 100.0); expect(tween.lerp(0.5), 100.0); expect(tween.lerp(1.0), 100.0); }); test('ReverseTween', () { final ReverseTween<int> tween = ReverseTween<int>(IntTween(begin: 5, end: 9)); expect(tween.lerp(0.5), 7); expect(tween.lerp(0.7), 6); }); test('ColorTween', () { final ColorTween tween = ColorTween( begin: const Color(0xff000000), end: const Color(0xffffffff), ); expect(tween.lerp(0.0), const Color(0xff000000)); expect(tween.lerp(0.5), const Color(0xff7f7f7f)); expect(tween.lerp(0.7), const Color(0xffb2b2b2)); expect(tween.lerp(1.0), const Color(0xffffffff)); }); test('StepTween', () { final StepTween tween = StepTween(begin: 5, end: 9); expect(tween.lerp(0.5), 7); expect(tween.lerp(0.7), 7); }); test('CurveTween', () { final CurveTween tween = CurveTween(curve: Curves.easeIn); expect(tween.transform(0.0), 0.0); expect(tween.transform(0.5), 0.31640625); expect(tween.transform(1.0), 1.0); }); test('BorderRadiusTween nullable test', () { final BorderRadiusTween tween = BorderRadiusTween(); expect(tween.transform(0.0), null); expect(tween.transform(1.0), null); expect(tween.lerp(0.0), null); }); }