79 lines
2.9 KiB
Go
79 lines
2.9 KiB
Go
package common
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import (
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"regexp"
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"strings"
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"github.com/lucasb-eyer/go-colorful"
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)
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// the values in colors must be lowercase so it matches with the color input
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// this saves from having to call strings.ToLower(color) every time to check
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var colors = []string{
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"aliceblue", "antiquewhite", "aqua", "aquamarine", "azure",
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"beige", "bisque", "black", "blanchedalmond", "blue",
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"blueviolet", "brown", "burlywood", "cadetblue", "chartreuse",
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"chocolate", "coral", "cornflowerblue", "cornsilk", "crimson",
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"cyan", "darkblue", "darkcyan", "darkgoldenrod", "darkgray",
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"darkgrey", "darkgreen", "darkkhaki", "darkmagenta", "darkolivegreen",
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"darkorange", "darkorchid", "darkred", "darksalmon", "darkseagreen",
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"darkslateblue", "darkslategray", "darkslategrey", "darkturquoise", "darkviolet",
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"deeppink", "deepskyblue", "dimgray", "dimgrey", "dodgerblue",
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"firebrick", "floralwhite", "forestgreen", "fuchsia", "gainsboro",
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"ghostwhite", "gold", "goldenrod", "gray", "grey",
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"green", "greenyellow", "honeydew", "hotpink", "indianred",
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"indigo", "ivory", "khaki", "lavender", "lavenderblush",
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"lawngreen", "lemonchiffon", "lightblue", "lightcoral", "lightcyan",
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"lightgoldenrodyellow", "lightgray", "lightgrey", "lightgreen", "lightpink",
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"lightsalmon", "lightseagreen", "lightskyblue", "lightslategray", "lightslategrey",
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"lightsteelblue", "lightyellow", "lime", "limegreen", "linen",
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"magenta", "maroon", "mediumaquamarine", "mediumblue", "mediumorchid",
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"mediumpurple", "mediumseagreen", "mediumslateblue", "mediumspringgreen", "mediumturquoise",
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"mediumvioletred", "midnightblue", "mintcream", "mistyrose", "moccasin",
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"navajowhite", "navy", "oldlace", "olive", "olivedrab",
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"orange", "orangered", "orchid", "palegoldenrod", "palegreen",
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"paleturquoise", "palevioletred", "papayawhip", "peachpuff", "peru",
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"pink", "plum", "powderblue", "purple", "rebeccapurple",
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"red", "rosybrown", "royalblue", "saddlebrown", "salmon",
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"sandybrown", "seagreen", "seashell", "sienna", "silver",
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"skyblue", "slateblue", "slategray", "slategrey", "snow",
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"springgreen", "steelblue", "tan", "teal", "thistle",
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"tomato", "turquoise", "violet", "wheat", "white",
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"whitesmoke", "yellow", "yellowgreen",
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}
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var (
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regexColor = regexp.MustCompile(`^#([0-9A-Fa-f]{3}){1,2}$`)
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)
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// IsValidColor takes a string s and compares it against a list of css color names.
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// It also accepts hex codes in the form of #000 (RGB), to #00000000 (RRGGBBAA), with A
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// being the alpha value
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func IsValidColor(s string) bool {
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s = strings.ToLower(s)
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for _, c := range colors {
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if s == c {
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return true
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}
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}
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if regexColor.MatchString(s) {
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c, err := colorful.Hex(s)
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if err != nil {
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return false
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}
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total := c.R + c.G + c.B
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return total > 0.7 && c.B/total < 0.7
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}
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return false
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}
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// RandomColor returns a hex color code
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func RandomColor() string {
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var color colorful.Color
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for !IsValidColor(color.Hex()) {
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color = colorful.FastHappyColor()
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}
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return color.Hex()
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}
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