// Copyright 2015 The Chromium 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 'dart:ui' show Color, Offset; import 'package:flutter/painting.dart'; // Based on http://www.google.com/design/spec/what-is-material/elevation-shadows.html // Currently, only the elevation values that are bound to one or more widgets are // defined here. /// Map of elevation offsets used by material design to [BoxShadow] definitions. /// /// The following elevations have defined shadows: 1, 2, 3, 4, 6, 8, 9, 12, 16, 24 /// /// Each entry has three shadows which must be combined to obtain the defined /// effect for that elevation. /// /// See also: /// /// * [Material] /// * <https://www.google.com/design/spec/what-is-material/elevation-shadows.html> const Map<int, List<BoxShadow>> kElevationToShadow = _elevationToShadow; // to hide the literal from the docs const Color _kKeyUmbraOpacity = const Color(0x33000000); // alpha = 0.2 const Color _kKeyPenumbraOpacity = const Color(0x24000000); // alpha = 0.14 const Color _kAmbientShadowOpacity = const Color(0x1F000000); // alpha = 0.12 const Map<int, List<BoxShadow>> _elevationToShadow = const <int, List<BoxShadow>>{ 1: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 2.0), blurRadius: 1.0, spreadRadius: -1.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 1.0), blurRadius: 1.0, spreadRadius: 0.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 1.0), blurRadius: 3.0, spreadRadius: 0.0, color: _kAmbientShadowOpacity), ], 2: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 3.0), blurRadius: 1.0, spreadRadius: -2.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 2.0), blurRadius: 2.0, spreadRadius: 0.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 1.0), blurRadius: 5.0, spreadRadius: 0.0, color: _kAmbientShadowOpacity), ], 3: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 3.0), blurRadius: 3.0, spreadRadius: -2.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 3.0), blurRadius: 4.0, spreadRadius: 0.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 1.0), blurRadius: 8.0, spreadRadius: 0.0, color: _kAmbientShadowOpacity), ], 4: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 2.0), blurRadius: 4.0, spreadRadius: -1.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 4.0), blurRadius: 5.0, spreadRadius: 0.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 1.0), blurRadius: 10.0, spreadRadius: 0.0, color: _kAmbientShadowOpacity), ], 6: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 3.0), blurRadius: 5.0, spreadRadius: -1.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 6.0), blurRadius: 10.0, spreadRadius: 0.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 1.0), blurRadius: 18.0, spreadRadius: 0.0, color: _kAmbientShadowOpacity), ], 8: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 5.0), blurRadius: 5.0, spreadRadius: -3.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 8.0), blurRadius: 10.0, spreadRadius: 1.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 3.0), blurRadius: 14.0, spreadRadius: 2.0, color: _kAmbientShadowOpacity), ], 9: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 5.0), blurRadius: 6.0, spreadRadius: -3.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 9.0), blurRadius: 12.0, spreadRadius: 1.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 3.0), blurRadius: 16.0, spreadRadius: 2.0, color: _kAmbientShadowOpacity), ], 12: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 7.0), blurRadius: 8.0, spreadRadius: -4.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 12.0), blurRadius: 17.0, spreadRadius: 2.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 5.0), blurRadius: 22.0, spreadRadius: 4.0, color: _kAmbientShadowOpacity), ], 16: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 8.0), blurRadius: 10.0, spreadRadius: -5.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 16.0), blurRadius: 24.0, spreadRadius: 2.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 6.0), blurRadius: 30.0, spreadRadius: 5.0, color: _kAmbientShadowOpacity), ], 24: const <BoxShadow>[ const BoxShadow(offset: const Offset(0.0, 11.0), blurRadius: 15.0, spreadRadius: -7.0, color: _kKeyUmbraOpacity), const BoxShadow(offset: const Offset(0.0, 24.0), blurRadius: 38.0, spreadRadius: 3.0, color: _kKeyPenumbraOpacity), const BoxShadow(offset: const Offset(0.0, 9.0), blurRadius: 46.0, spreadRadius: 8.0, color: _kAmbientShadowOpacity), ], };