58 lines
1.8 KiB
Dart
58 lines
1.8 KiB
Dart
/*
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* fluro
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* Created by Yakka
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* https://theyakka.com
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*
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* Copyright (c) 2019 Yakka, LLC. All rights reserved.
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* See LICENSE for distribution and usage details.
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*/
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import 'package:flutter/material.dart';
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enum ContrastPreference {
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none,
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light,
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dark,
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}
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class ColorHelpers {
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static int fromHexString(String argbHexString) {
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String useString = argbHexString;
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if (useString.startsWith("#")) {
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useString = useString.substring(1); // trim the starting '#'
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}
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if (useString.length < 8) {
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useString = "FF" + useString;
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}
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if (!useString.startsWith("0x")) {
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useString = "0x" + useString;
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}
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return int.parse(useString);
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}
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static final double _kMinContrastModifierRange = 0.35;
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static final double _kMaxContrastModifierRange = 0.65;
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/// Returns black or white depending on whether the source color is darker
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/// or lighter. If darker, will return white. If lighter, will return
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/// black. If the color is within 35-65% of the spectrum and a prefer
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/// value is specified, then white or black will be preferred.
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static Color blackOrWhiteContrastColor(Color sourceColor,
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{ContrastPreference prefer = ContrastPreference.none}) {
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// Will return a value between 0.0 (black) and 1.0 (white)
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double value = (((sourceColor.red * 299.0) +
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(sourceColor.green * 587.0) +
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(sourceColor.blue * 114.0)) /
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1000.0) /
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255.0;
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if (prefer != ContrastPreference.none) {
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if (value >= _kMinContrastModifierRange &&
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value <= _kMaxContrastModifierRange) {
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return prefer == ContrastPreference.light
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? new Color(0xFFFFFFFF)
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: new Color(0xFF000000);
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}
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}
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return value > 0.6 ? new Color(0xFF000000) : new Color(0xFFFFFFFF);
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}
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}
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