gomuks/ui/widget/color.go
2019-01-23 00:26:51 +02:00

79 lines
2.2 KiB
Go

// gomuks - A terminal Matrix client written in Go.
// Copyright (C) 2019 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package widget
import (
"fmt"
"hash/fnv"
"sort"
"maunium.net/go/tcell"
)
var colorNames []string
// init initializes the colorNames array.
func init() {
colorNames = make([]string, len(tcell.ColorNames))
i := 0
for name := range tcell.ColorNames {
colorNames[i] = name
i++
}
// In order to have consistent coloring between restarts, we need to sort the array.
sort.Sort(sort.StringSlice(colorNames))
}
// GetHashColorName gets a color name for the given string based on its FNV-1 hash.
//
// The array of possible color names are the alphabetically ordered color
// names specified in tcell.ColorNames.
//
// The algorithm to get the color is as follows:
// colorNames[ FNV1(string) % len(colorNames) ]
//
// With the exception of the three special cases:
// --> = green
// <-- = red
// --- = yellow
func GetHashColorName(s string) string {
switch s {
case "-->":
return "green"
case "<--":
return "red"
case "---":
return "yellow"
default:
h := fnv.New32a()
_, _ = h.Write([]byte(s))
return colorNames[h.Sum32()%uint32(len(colorNames))]
}
}
// GetHashColor gets the tcell Color value for the given string.
//
// GetHashColor calls GetHashColorName() and gets the Color value from the tcell.ColorNames map.
func GetHashColor(s string) tcell.Color {
return tcell.ColorNames[GetHashColorName(s)]
}
// AddColor adds tview color tags to the given string.
func AddColor(s, color string) string {
return fmt.Sprintf("[%s]%s[white]", color, s)
}