we have all basic ansi text color codes and attributes now. we can also

convert a string to a corresponding code (e.g. from a config file).

1 files changed, 164 insertions, 0 deletions

diff --git a/internal/color/color.go b/internal/color/color.go
new file mode 100644
index 0000000..c6760d5
--- /dev/null
+++ b/internal/color/color.go
@@ -0,0 +1,164 @@
+// Package color contains all terminal color codes we know of.
+package color
+
+import (
+	"fmt"
+	"strings"
+)
+
+// FgColor is the text foreground color.
+type FgColor string
+
+// BgColor is the text background color.
+type BgColor string
+
+// Attribute of text.
+type Attribute string
+
+// The possible color variations.
+const (
+	escape        = "\x1b"
+	seq    string = "%s%s%s"
+
+	FgBlack   FgColor = escape + "[30m"
+	FgRed     FgColor = escape + "[31m"
+	FgGreen   FgColor = escape + "[32m"
+	FgYellow  FgColor = escape + "[33m"
+	FgBlue    FgColor = escape + "[34m"
+	FgMagenta FgColor = escape + "[35m"
+	FgCyan    FgColor = escape + "[36m"
+	FgWhite   FgColor = escape + "[37m"
+	FgDefault FgColor = escape + "[39m"
+
+	BgBlack   BgColor = escape + "[40m"
+	BgRed     BgColor = escape + "[41m"
+	BgGreen   BgColor = escape + "[42m"
+	BgYellow  BgColor = escape + "[43m"
+	BgBlue    BgColor = escape + "[44m"
+	BgMagenta BgColor = escape + "[45m"
+	BgCyan    BgColor = escape + "[46m"
+	BgWhite   BgColor = escape + "[47m"
+	BgDefault BgColor = escape + "[49m"
+
+	AttReset      Attribute = escape + "[0m"
+	AttBold       Attribute = escape + "[1m"
+	AttDim        Attribute = escape + "[2m"
+	AttItalic     Attribute = escape + "[3m"
+	AttUnderline  Attribute = escape + "[4m"
+	AttBlink      Attribute = escape + "[5m"
+	AttSlowBlink  Attribute = escape + "[5m"
+	AttRapidBlink Attribute = escape + "[6m"
+	AttReverse    Attribute = escape + "[7m"
+	AttHidden     Attribute = escape + "[8m"
+
+	// Internal (manual) testing.
+	FgTest  FgColor   = FgBlue
+	BgTest  BgColor   = BgYellow
+	AttTest Attribute = AttBold
+)
+
+// Colored DTail client output enabled.
+var Colored bool
+
+// Paint paints a given text in a given foreground/background color combination.
+func Paint(fg FgColor, bg FgColor, text string) string {
+	return fmt.Sprintf(seq, fg, bg, text, BgDefault, FgDefault)
+}
+
+// PaintWithAttr paints a given text in a given foreground/background/attribute combination
+func PaintWithAtt(fg FgColor, bg FgColor, att Attribute, text string) string {
+	return fmt.Sprintf(seq, fg, bg, att, text, AttReset, BgDefault, FgDefault)
+}
+
+// PaintFg paints a given text in a given foreground color.
+func PaintFg(fg FgColor, text string) string {
+	return fmt.Sprintf(seq, fg, text, FgDefault)
+}
+
+// PaintBg paints a given text in a given background color.
+func PaintBg(bg BgColor, text string) string {
+	return fmt.Sprintf(seq, bg, text, BgDefault)
+}
+
+// PaintAtt adds a given attribute to a given text, such as "bold" or "italic".
+func PaintAtt(att Attribute, text string) string {
+	return fmt.Sprintf(seq, att, text, AttReset)
+}
+
+// ToFgColor converts a given string (e.g. from a config file) into a foreground color code.
+func ToFgColor(s string) (FgColor, error) {
+	switch strings.ToLower(s) {
+	case "black":
+		return FgBlack, nil
+	case "red":
+		return FgRed, nil
+	case "green":
+		return FgGreen, nil
+	case "yellow":
+		return FgYellow, nil
+	case "blue":
+		return FgBlue, nil
+	case "magenta":
+		return FgMagenta, nil
+	case "cyan":
+		return FgCyan, nil
+	case "white":
+		return FgWhite, nil
+	case "default":
+		return FgDefault, nil
+	default:
+		return FgDefault, fmt.Errorf("unknown foreground text color '" + s + "'")
+	}
+}
+
+// ToBgColor converts a given string (e.g. from a config file) into a background color code.
+func ToBgColor(s string) (BgColor, error) {
+	switch strings.ToLower(s) {
+	case "black":
+		return BgBlack, nil
+	case "red":
+		return BgRed, nil
+	case "green":
+		return BgGreen, nil
+	case "yellow":
+		return BgYellow, nil
+	case "blue":
+		return BgBlue, nil
+	case "magenta":
+		return BgMagenta, nil
+	case "cyan":
+		return BgCyan, nil
+	case "white":
+		return BgWhite, nil
+	case "default":
+		return BgDefault, nil
+	default:
+		return BgDefault, fmt.Errorf("unknown background text color '" + s + "'")
+	}
+}
+
+// ToAttribute converts a given string (e.g. from a config file) into a text attribute.
+func ToAttColor(s string) (Attribute, error) {
+	switch strings.ToLower(s) {
+	case "bold":
+		return AttBold, nil
+	case "dim":
+		return AttDim, nil
+	case "italic":
+		return AttItalic, nil
+	case "underline":
+		return AttUnderline, nil
+	case "blink":
+		return AttBlink, nil
+	case "slowblink":
+		return AttSlowBlink, nil
+	case "rapidblink":
+		return AttRapidBlink, nil
+	case "reverse":
+		return AttReverse, nil
+	case "hidden":
+		return AttHidden, nil
+	default:
+		return AttReset, fmt.Errorf("unknown text attribute '" + s + "'")
+	}
+}