alignment_test.dart 12.9 KB
Newer Older
Ian Hickson's avatar
Ian Hickson committed
1
// Copyright 2014 The Flutter Authors. All rights reserved.
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:math' as math;

import 'package:flutter/painting.dart';
import 'package:flutter_test/flutter_test.dart';

void approxExpect(Alignment a, Alignment b) {
  expect(a.x, moreOrLessEquals(b.x));
  expect(a.y, moreOrLessEquals(b.y));
}

void main() {
  test('Alignment control test', () {
17
    const Alignment alignment = Alignment(0.5, 0.25);
18

19 20
    expect(alignment, hasOneLineDescription);
    expect(alignment.hashCode, equals(const Alignment(0.5, 0.25).hashCode));
21

22
    expect(alignment / 2.0, const Alignment(0.25, 0.125));
23
    expect(alignment ~/ 2.0, Alignment.center);
24
    expect(alignment % 5.0, const Alignment(0.5, 0.25));
25 26 27
  });

  test('Alignment.lerp()', () {
28 29
    const Alignment a = Alignment.topLeft;
    const Alignment b = Alignment.topCenter;
30 31 32 33 34 35 36
    expect(Alignment.lerp(a, b, 0.25), equals(const Alignment(-0.75, -1.0)));

    expect(Alignment.lerp(null, null, 0.25), isNull);
    expect(Alignment.lerp(null, b, 0.25), equals(const Alignment(0.0, -0.25)));
    expect(Alignment.lerp(a, null, 0.25), equals(const Alignment(-0.75, -0.75)));
  });

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
  test('Alignment.lerp identical a,b', () {
    expect(Alignment.lerp(null, null, 0), null);
    const Alignment alignment = Alignment.topLeft;
    expect(identical(Alignment.lerp(alignment, alignment, 0.5), alignment), true);
  });

  test('AlignmentGeometry.lerp identical a,b', () {
    expect(AlignmentGeometry.lerp(null, null, 0), null);
    const AlignmentGeometry alignment = Alignment.topLeft;
    expect(identical(AlignmentGeometry.lerp(alignment, alignment, 0.5), alignment), true);
  });

  test('AlignmentDirectional.lerp identical a,b', () {
    expect(AlignmentDirectional.lerp(null, null, 0), null);
    const AlignmentDirectional alignment = AlignmentDirectional.topStart;
    expect(identical(AlignmentDirectional.lerp(alignment, alignment, 0.5), alignment), true);
  });

55
  test('AlignmentGeometry invariants', () {
56 57
    const AlignmentDirectional topStart = AlignmentDirectional.topStart;
    const AlignmentDirectional topEnd = AlignmentDirectional.topEnd;
58
    const Alignment center = Alignment.center;
59 60
    const Alignment topLeft = Alignment.topLeft;
    const Alignment topRight = Alignment.topRight;
61 62 63 64 65
    final List<double> numbers = <double>[0.0, 1.0, -1.0, 2.0, 0.25, 0.5, 100.0, -999.75];

    expect((topEnd * 0.0).add(topRight * 0.0), center);
    expect(topEnd.add(topRight) * 0.0, (topEnd * 0.0).add(topRight * 0.0));
    expect(topStart.add(topLeft), topLeft.add(topStart));
66 67 68 69
    expect(topStart.add(topLeft).resolve(TextDirection.ltr), (topStart.resolve(TextDirection.ltr)) + topLeft);
    expect(topStart.add(topLeft).resolve(TextDirection.rtl), (topStart.resolve(TextDirection.rtl)) + topLeft);
    expect(topStart.add(topLeft).resolve(TextDirection.ltr), topStart.resolve(TextDirection.ltr).add(topLeft));
    expect(topStart.add(topLeft).resolve(TextDirection.rtl), topStart.resolve(TextDirection.rtl).add(topLeft));
70 71 72 73 74 75 76 77
    expect(topStart.resolve(TextDirection.ltr), topLeft);
    expect(topStart.resolve(TextDirection.rtl), topRight);
    expect(topEnd * 0.0, center);
    expect(topLeft * 0.0, center);
    expect(topStart * 1.0, topStart);
    expect(topEnd * 1.0, topEnd);
    expect(topLeft * 1.0, topLeft);
    expect(topRight * 1.0, topRight);
78
    for (final double n in numbers) {
79 80
      expect((topStart * n).add(topStart), topStart * (n + 1.0));
      expect((topEnd * n).add(topEnd), topEnd * (n + 1.0));
81
      for (final double m in numbers) {
82
        expect((topStart * n).add(topStart * m), topStart * (n + m));
83
      }
84 85
    }
    expect(topStart + topStart + topStart, topStart * 3.0); // without using "add"
86
    for (final TextDirection x in TextDirection.values) {
87 88
      expect((topEnd * 0.0).add(topRight * 0.0).resolve(x), center.add(center).resolve(x));
      expect((topEnd * 0.0).add(topLeft).resolve(x), center.add(topLeft).resolve(x));
89 90
      expect((topEnd * 0.0).resolve(x).add(topLeft.resolve(x)), center.resolve(x).add(topLeft.resolve(x)));
      expect((topEnd * 0.0).resolve(x).add(topLeft), center.resolve(x).add(topLeft));
91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
      expect((topEnd * 0.0).resolve(x), center.resolve(x));
    }
    expect(topStart, isNot(topLeft));
    expect(topEnd, isNot(topLeft));
    expect(topStart, isNot(topRight));
    expect(topEnd, isNot(topRight));
    expect(topStart.add(topLeft), isNot(topLeft));
    expect(topStart.add(topLeft), isNot(topStart));
  });

  test('AlignmentGeometry.resolve()', () {
    expect(const AlignmentDirectional(0.25, 0.3).resolve(TextDirection.ltr), const Alignment(0.25, 0.3));
    expect(const AlignmentDirectional(0.25, 0.3).resolve(TextDirection.rtl), const Alignment(-0.25, 0.3));
    expect(const AlignmentDirectional(-0.25, 0.3).resolve(TextDirection.ltr), const Alignment(-0.25, 0.3));
    expect(const AlignmentDirectional(-0.25, 0.3).resolve(TextDirection.rtl), const Alignment(0.25, 0.3));
    expect(const AlignmentDirectional(1.25, 0.3).resolve(TextDirection.ltr), const Alignment(1.25, 0.3));
    expect(const AlignmentDirectional(1.25, 0.3).resolve(TextDirection.rtl), const Alignment(-1.25, 0.3));
    expect(const AlignmentDirectional(0.5, -0.3).resolve(TextDirection.ltr), const Alignment(0.5, -0.3));
    expect(const AlignmentDirectional(0.5, -0.3).resolve(TextDirection.rtl), const Alignment(-0.5, -0.3));
110 111 112 113
    expect(AlignmentDirectional.center.resolve(TextDirection.ltr), Alignment.center);
    expect(AlignmentDirectional.center.resolve(TextDirection.rtl), Alignment.center);
    expect(AlignmentDirectional.bottomEnd.resolve(TextDirection.ltr), Alignment.bottomRight);
    expect(AlignmentDirectional.bottomEnd.resolve(TextDirection.rtl), Alignment.bottomLeft);
114
    expect(AlignmentDirectional(nonconst(1.0), 2.0), AlignmentDirectional(nonconst(1.0), 2.0));
115
    expect(const AlignmentDirectional(1.0, 2.0), isNot(const AlignmentDirectional(2.0, 1.0)));
116 117 118 119 120 121 122 123 124 125 126 127
    expect(
      AlignmentDirectional.centerStart.resolve(TextDirection.ltr),
      AlignmentDirectional.centerEnd.resolve(TextDirection.rtl),
    );
    expect(
      AlignmentDirectional.centerStart.resolve(TextDirection.ltr),
      isNot(AlignmentDirectional.centerEnd.resolve(TextDirection.ltr)),
    );
    expect(
      AlignmentDirectional.centerEnd.resolve(TextDirection.ltr),
      isNot(AlignmentDirectional.centerEnd.resolve(TextDirection.rtl)),
    );
128 129 130 131 132 133 134
  });

  test('AlignmentGeometry.lerp ad hoc tests', () {
    final AlignmentGeometry mixed1 = const Alignment(10.0, 20.0).add(const AlignmentDirectional(30.0, 50.0));
    final AlignmentGeometry mixed2 = const Alignment(70.0, 110.0).add(const AlignmentDirectional(130.0, 170.0));
    final AlignmentGeometry mixed3 = const Alignment(25.0, 42.5).add(const AlignmentDirectional(55.0, 80.0));

135
    for (final TextDirection direction in TextDirection.values) {
136 137 138
      expect(AlignmentGeometry.lerp(mixed1, mixed2, 0.0)!.resolve(direction), mixed1.resolve(direction));
      expect(AlignmentGeometry.lerp(mixed1, mixed2, 1.0)!.resolve(direction), mixed2.resolve(direction));
      expect(AlignmentGeometry.lerp(mixed1, mixed2, 0.25)!.resolve(direction), mixed3.resolve(direction));
139 140 141 142
    }
  });

  test('lerp commutes with resolve', () {
143
    final List<AlignmentGeometry?> offsets = <AlignmentGeometry?>[
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177
      Alignment.topLeft,
      Alignment.topCenter,
      Alignment.topRight,
      AlignmentDirectional.topStart,
      AlignmentDirectional.topCenter,
      AlignmentDirectional.topEnd,
      Alignment.centerLeft,
      Alignment.center,
      Alignment.centerRight,
      AlignmentDirectional.centerStart,
      AlignmentDirectional.center,
      AlignmentDirectional.centerEnd,
      Alignment.bottomLeft,
      Alignment.bottomCenter,
      Alignment.bottomRight,
      AlignmentDirectional.bottomStart,
      AlignmentDirectional.bottomCenter,
      AlignmentDirectional.bottomEnd,
      const Alignment(-1.0, 0.65),
      const AlignmentDirectional(-1.0, 0.45),
      const AlignmentDirectional(0.125, 0.625),
      const Alignment(0.25, 0.875),
      const Alignment(0.0625, 0.5625).add(const AlignmentDirectional(0.1875, 0.6875)),
      const AlignmentDirectional(2.0, 3.0),
      const Alignment(2.0, 3.0),
      const Alignment(2.0, 3.0).add(const AlignmentDirectional(5.0, 3.0)),
      const Alignment(10.0, 20.0).add(const AlignmentDirectional(30.0, 50.0)),
      const Alignment(70.0, 110.0).add(const AlignmentDirectional(130.0, 170.0)),
      const Alignment(25.0, 42.5).add(const AlignmentDirectional(55.0, 80.0)),
      null,
    ];

    final List<double> times = <double>[ 0.25, 0.5, 0.75 ];

178
    for (final TextDirection direction in TextDirection.values) {
179
      final Alignment defaultValue = AlignmentDirectional.center.resolve(direction);
180
      for (final AlignmentGeometry? a in offsets) {
181
        final Alignment resolvedA = a?.resolve(direction) ?? defaultValue;
182
        for (final AlignmentGeometry? b in offsets) {
183
          final Alignment resolvedB = b?.resolve(direction) ?? defaultValue;
184 185
          approxExpect(Alignment.lerp(resolvedA, resolvedB, 0.0)!, resolvedA);
          approxExpect(Alignment.lerp(resolvedA, resolvedB, 1.0)!, resolvedB);
186 187
          approxExpect((AlignmentGeometry.lerp(a, b, 0.0) ?? defaultValue).resolve(direction), resolvedA);
          approxExpect((AlignmentGeometry.lerp(a, b, 1.0) ?? defaultValue).resolve(direction), resolvedB);
188
          for (final double t in times) {
189 190 191
            assert(t > 0.0);
            assert(t < 1.0);
            final Alignment value = (AlignmentGeometry.lerp(a, b, t) ?? defaultValue).resolve(direction);
192
            approxExpect(value, Alignment.lerp(resolvedA, resolvedB, t)!);
193 194 195 196 197 198 199 200 201 202 203 204 205
            final double minDX = math.min(resolvedA.x, resolvedB.x);
            final double maxDX = math.max(resolvedA.x, resolvedB.x);
            final double minDY = math.min(resolvedA.y, resolvedB.y);
            final double maxDY = math.max(resolvedA.y, resolvedB.y);
            expect(value.x, inInclusiveRange(minDX, maxDX));
            expect(value.y, inInclusiveRange(minDY, maxDY));
          }
        }
      }
    }
  });

  test('AlignmentGeometry add/subtract', () {
206 207
    const AlignmentGeometry directional = AlignmentDirectional(1.0, 2.0);
    const AlignmentGeometry normal = Alignment(3.0, 5.0);
208 209 210 211 212 213 214 215 216
    expect(directional.add(normal).resolve(TextDirection.ltr), const Alignment(4.0, 7.0));
    expect(directional.add(normal).resolve(TextDirection.rtl), const Alignment(2.0, 7.0));
    expect(normal.add(normal), normal * 2.0);
    expect(directional.add(directional), directional * 2.0);
  });

  test('AlignmentGeometry operators', () {
    expect(const AlignmentDirectional(1.0, 2.0) * 2.0, const AlignmentDirectional(2.0, 4.0));
    expect(const AlignmentDirectional(1.0, 2.0) / 2.0, const AlignmentDirectional(0.5, 1.0));
217 218
    expect(const AlignmentDirectional(1.0, 2.0) % 2.0, AlignmentDirectional.centerEnd);
    expect(const AlignmentDirectional(1.0, 2.0) ~/ 2.0, AlignmentDirectional.bottomCenter);
219
    for (final TextDirection direction in TextDirection.values) {
220 221
      expect(Alignment.center.add(const AlignmentDirectional(1.0, 2.0) * 2.0).resolve(direction), const AlignmentDirectional(2.0, 4.0).resolve(direction));
      expect(Alignment.center.add(const AlignmentDirectional(1.0, 2.0) / 2.0).resolve(direction), const AlignmentDirectional(0.5, 1.0).resolve(direction));
222 223
      expect(Alignment.center.add(const AlignmentDirectional(1.0, 2.0) % 2.0).resolve(direction), AlignmentDirectional.centerEnd.resolve(direction));
      expect(Alignment.center.add(const AlignmentDirectional(1.0, 2.0) ~/ 2.0).resolve(direction), AlignmentDirectional.bottomCenter.resolve(direction));
224 225 226
    }
    expect(const Alignment(1.0, 2.0) * 2.0, const Alignment(2.0, 4.0));
    expect(const Alignment(1.0, 2.0) / 2.0, const Alignment(0.5, 1.0));
227 228
    expect(const Alignment(1.0, 2.0) % 2.0, Alignment.centerRight);
    expect(const Alignment(1.0, 2.0) ~/ 2.0, Alignment.bottomCenter);
229 230 231 232 233 234 235 236 237 238 239
  });

  test('AlignmentGeometry operators', () {
    expect(const Alignment(1.0, 2.0) + const Alignment(3.0, 5.0), const Alignment(4.0, 7.0));
    expect(const Alignment(1.0, 2.0) - const Alignment(3.0, 5.0), const Alignment(-2.0, -3.0));
    expect(const AlignmentDirectional(1.0, 2.0) + const AlignmentDirectional(3.0, 5.0), const AlignmentDirectional(4.0, 7.0));
    expect(const AlignmentDirectional(1.0, 2.0) - const AlignmentDirectional(3.0, 5.0), const AlignmentDirectional(-2.0, -3.0));
  });

  test('AlignmentGeometry toString', () {
    expect(const Alignment(1.0001, 2.0001).toString(), 'Alignment(1.0, 2.0)');
240 241
    expect(Alignment.center.toString(), 'Alignment.center');
    expect(Alignment.bottomLeft.add(AlignmentDirectional.centerEnd).toString(), 'Alignment.bottomLeft + AlignmentDirectional.centerEnd');
242
    expect(const Alignment(0.0001, 0.0001).toString(), 'Alignment(0.0, 0.0)');
243 244 245
    expect(Alignment.center.toString(), 'Alignment.center');
    expect(AlignmentDirectional.center.toString(), 'AlignmentDirectional.center');
    expect(Alignment.bottomRight.add(AlignmentDirectional.bottomEnd).toString(), 'Alignment(1.0, 2.0) + AlignmentDirectional.centerEnd');
246 247
  });
}