fnx_web/webcontroller/user_style.go

package webcontroller

import (
	"fmt"
	"html/template"
	"net/http"
)

func userStyle(r *http.Request) (style template.CSS) {
	var selectedStyle pixeldrainStyleSheet

	if cookie, err := r.Cookie("style"); err != nil {
		selectedStyle = defaultPixeldrainStyle
	} else {
		switch cookie.Value {
		case "solarized_dark":
			selectedStyle = solarizedDarkStyle
		case "maroon":
			selectedStyle = maroonStyle
		case "hacker":
			selectedStyle = hackerStyle
		case "default":
			fallthrough // use default case
		default:
			selectedStyle = defaultPixeldrainStyle
		}
	}

	return template.CSS(fmt.Sprintf(
		`:root {
	--text_color:            %s;
	--input_color:           %s;
	--input_color_dark:      %s;
	--input_text_color:      %s;
	--highlight_color:       %s;
	--highlight_color_dark:  %s;
	--highlight_text_color:  %s;
	--danger_color:          %s;
	--danger_color_dark:     %s;
	--file_background_color: %s;

	--background_color:           %s;
	--body_color:                 %s;
	--accent_color_dark:          %s;
	--accent_color_dark_border:   %s;
	--accent_color_medium:        %s;
	--accent_color_medium_border: %s;
	--accent_color_light:         %s;
	--accent_color_light_border:  %s;

	--shadow_color:     %s;
	--shadow_spread:    %s;
	--shadow_intensity: %s;
}`,
		selectedStyle.TextColor.cssString(),
		selectedStyle.InputColor.cssString(),
		selectedStyle.InputColor.add(0, 0, -.08).cssString(),
		selectedStyle.InputTextColor.cssString(),
		selectedStyle.HighlightColor.cssString(),
		selectedStyle.HighlightColor.add(0, 0, -.08).cssString(),
		selectedStyle.HighlightTextColor.cssString(),
		selectedStyle.DangerColor.cssString(),
		selectedStyle.DangerColorDark.cssString(),
		selectedStyle.FileBackgroundColor.cssString(),
		selectedStyle.BackgroundColor.cssString(),
		selectedStyle.BodyColor.cssString(),
		selectedStyle.AccentColorDark.cssString(),
		selectedStyle.AccentColorDark.add(0, 0, .15).cssString(),
		selectedStyle.AccentColorMedium.cssString(),
		selectedStyle.AccentColorMedium.add(0, 0, .15).cssString(),
		selectedStyle.AccentColorLight.cssString(),
		selectedStyle.AccentColorLight.add(0, 0, .15).cssString(),
		selectedStyle.ShadowColor.cssString(),
		fmt.Sprintf("%dpx", selectedStyle.ShadowSpread),
		fmt.Sprintf("%dpx", selectedStyle.ShadowIntensity),
	))
}

type pixeldrainStyleSheet struct {
	TextColor           hsl
	InputColor          hsl // Buttons, text fields
	InputTextColor      hsl
	HighlightColor      hsl // Links, highlighted buttons, list navigation
	HighlightTextColor  hsl // Text on buttons
	DangerColor         hsl
	DangerColorDark     hsl
	FileBackgroundColor hsl

	BackgroundColor   hsl
	BodyColor         hsl
	AccentColorDark   hsl
	AccentColorMedium hsl
	AccentColorLight  hsl

	ShadowColor     hsl
	ShadowSpread    int // Pixels
	ShadowIntensity int // Pixels
}
type hsl struct {
	Hue        int
	Saturation float64
	Lightness  float64
}

func (h hsl) cssString() string {
	return fmt.Sprintf(
		"hsl(%d, %.3f%%, %.3f%%)",
		h.Hue,
		h.Saturation*100,
		h.Lightness*100,
	)
}

// Add returns a NEW HSL struct, it doesn't modify the current one
func (h hsl) add(hue int, saturation float64, lightness float64) hsl {
	var new = hsl{
		h.Hue + hue,
		h.Saturation + saturation,
		h.Lightness + lightness,
	}
	// Hue bounds correction
	if new.Hue < 0 {
		new.Hue += 360
	} else if new.Hue > 360 {
		new.Hue -= 360
	}
	// Saturation bounds check
	if new.Saturation < 0 {
		new.Saturation = 0
	} else if new.Saturation > 1 {
		new.Saturation = 1
	}
	// Lightness bounds check
	if new.Lightness < 0 {
		new.Lightness = 0
	} else if new.Lightness > 1 {
		new.Lightness = 1
	}

	return new
}

// Following are all the available styles

var defaultPixeldrainStyle = pixeldrainStyleSheet{
	TextColor:           hsl{0, 0, .75},
	InputColor:          hsl{0, 0, .38},
	InputTextColor:      hsl{0, 0, 1},
	HighlightColor:      hsl{89, .51, .5},
	HighlightTextColor:  hsl{0, 0, 0},
	DangerColor:         hsl{339, .65, .31},
	DangerColorDark:     hsl{339, .64, .23},
	FileBackgroundColor: hsl{0, 0, 0},

	BackgroundColor:   hsl{0, 0, .05},
	BodyColor:         hsl{20, .05, .14},
	AccentColorDark:   hsl{0, 0, .19},
	AccentColorMedium: hsl{0, 0, .23},
	AccentColorLight:  hsl{0, 0, .28},

	ShadowColor:     hsl{0, 0, 0},
	ShadowSpread:    50,
	ShadowIntensity: 5,
}

var solarizedDarkStyle = pixeldrainStyleSheet{
	TextColor:           hsl{0, 0, .75},
	InputColor:          hsl{192, .95, .30},
	InputTextColor:      hsl{0, 0, 1},
	HighlightColor:      hsl{145, .63, .42},
	HighlightTextColor:  hsl{0, 0, 1},
	DangerColor:         hsl{343, .63, .42},
	DangerColorDark:     hsl{343, .63, .36},
	FileBackgroundColor: hsl{192, .87, .05},

	BackgroundColor:   hsl{192, 1, .05},
	BodyColor:         hsl{192, 1, .11},
	AccentColorDark:   hsl{192, .87, .09},
	AccentColorMedium: hsl{192, .81, .14},
	AccentColorLight:  hsl{192, .95, .17},

	ShadowColor:     hsl{192, .87, 0},
	ShadowSpread:    50,
	ShadowIntensity: 5,
}

var maroonStyle = pixeldrainStyleSheet{
	TextColor:           hsl{0, 0, .7},
	InputColor:          hsl{0, .75, .2},
	InputTextColor:      hsl{0, 0, 1},
	HighlightColor:      hsl{0, 1, .4},
	HighlightTextColor:  hsl{0, 0, 1},
	DangerColor:         hsl{0, .1, .1},
	DangerColorDark:     hsl{0, 0, 0},
	FileBackgroundColor: hsl{0, 1, .03},

	BackgroundColor:   hsl{0, 1, .05},
	BodyColor:         hsl{0, .6, .1},
	AccentColorDark:   hsl{0, .5, .07},
	AccentColorMedium: hsl{0, .8, .15},
	AccentColorLight:  hsl{0, .9, .2},

	ShadowColor:     hsl{192, .87, 0},
	ShadowSpread:    50,
	ShadowIntensity: 5,
}

var hackerStyle = pixeldrainStyleSheet{
	TextColor:           hsl{0, 0, .8},
	InputColor:          hsl{0, 0, .25},
	InputTextColor:      hsl{0, 0, 1},
	HighlightColor:      hsl{120, 1, .5},
	HighlightTextColor:  hsl{0, 0, 0},
	DangerColor:         hsl{0, .65, .31},
	DangerColorDark:     hsl{0, .64, .23},
	FileBackgroundColor: hsl{120, .8, .06},

	BackgroundColor:   hsl{0, 0, 0},
	BodyColor:         hsl{0, 0, 0},
	AccentColorDark:   hsl{120, .1, .05},
	AccentColorMedium: hsl{120, .2, .10},
	AccentColorLight:  hsl{120, .3, .15},

	ShadowColor:     hsl{120, 1, .08},
	ShadowSpread:    50,
	ShadowIntensity: 5,
}