// 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/material.dart'; import 'package:flutter_test/flutter_test.dart'; void main() { test('applySurfaceTint with null surface tint returns given color', () { final Color result = ElevationOverlay.applySurfaceTint(const Color(0xff888888), null, 42.0); expect(result, equals(const Color(0xFF888888))); }); test('applySurfaceTint with exact elevation levels uses the right opacity overlay', () { const Color baseColor = Color(0xff888888); const Color surfaceTintColor = Color(0xff44CCFF); Color overlayWithOpacity(double opacity) { return Color.alphaBlend(surfaceTintColor.withOpacity(opacity), baseColor); } // Based on values from the spec: // https://m3.material.io/styles/color/the-color-system/color-roles // Elevation level 0 (0.0) - should have opacity 0.0. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 0.0), equals(overlayWithOpacity(0.0))); // Elevation level 1 (1.0) - should have opacity 0.05. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 1.0), equals(overlayWithOpacity(0.05))); // Elevation level 2 (3.0) - should have opacity 0.08. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 3.0), equals(overlayWithOpacity(0.08))); // Elevation level 3 (6.0) - should have opacity 0.11`. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 6.0), equals(overlayWithOpacity(0.11))); // Elevation level 4 (8.0) - should have opacity 0.12. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 8.0), equals(overlayWithOpacity(0.12))); // Elevation level 5 (12.0) - should have opacity 0.14. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 12.0), equals(overlayWithOpacity(0.14))); }); test('applySurfaceTint with elevation lower than level 0 should have no overlay', () { const Color baseColor = Color(0xff888888); const Color surfaceTintColor = Color(0xff44CCFF); Color overlayWithOpacity(double opacity) { return Color.alphaBlend(surfaceTintColor.withOpacity(opacity), baseColor); } expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, -42.0), equals(overlayWithOpacity(0.0))); }); test('applySurfaceTint with elevation higher than level 5 should have no level 5 overlay', () { const Color baseColor = Color(0xff888888); const Color surfaceTintColor = Color(0xff44CCFF); Color overlayWithOpacity(double opacity) { return Color.alphaBlend(surfaceTintColor.withOpacity(opacity), baseColor); } // Elevation level 5 (12.0) - should have opacity 0.14. expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 42.0), equals(overlayWithOpacity(0.14))); }); test('applySurfaceTint with elevation between two levels should interpolate the opacity', () { const Color baseColor = Color(0xff888888); const Color surfaceTintColor = Color(0xff44CCFF); Color overlayWithOpacity(double opacity) { return Color.alphaBlend(surfaceTintColor.withOpacity(opacity), baseColor); } // Elevation between level 4 (8.0) and level 5 (12.0) should be interpolated // between the opacities 0.12 and 0.14. // One third (0.3): (elevation 9.2) -> (opacity 0.126) expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 9.2), equals(overlayWithOpacity(0.126))); // Half way (0.5): (elevation 10.0) -> (opacity 0.13) expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 10.0), equals(overlayWithOpacity(0.13))); // Two thirds (0.6): (elevation 10.4) -> (opacity 0.132) expect(ElevationOverlay.applySurfaceTint(baseColor, surfaceTintColor, 10.4), equals(overlayWithOpacity(0.132))); }); }