v0.2.0 16 colors, default colors, /dev/tty, bracketed paste, themed form controls

tui/theme.go

@@ -2,65 +2,100 @@ package tui
 
 import (
 	"github.com/lixenwraith/color"
+	"github.com/lixenwraith/terminal"
 )
 
-// Theme defines semantic colors for TUI components
+// Theme styles the widgets that take one. Each role is a Style whose Attr may
+// carry color bits (a palette index, the terminal's own color), so one theme
+// per color tier, mono included, draws every widget alike. A role with a zero
+// Bg and no Bg bits draws on whatever is beneath it.
 type Theme struct {
-	Bg       color.RGB
-	Fg       color.RGB
-	FocusBg  color.RGB
-	CursorBg color.RGB
-
-	Selected   color.RGB
-	Unselected color.RGB
-	Partial    color.RGB
-	Error      color.RGB
-	Warning    color.RGB
-
-	Border   color.RGB
-	HeaderBg color.RGB
-	HeaderFg color.RGB
-	StatusFg color.RGB
-	HintFg   color.RGB
-	InputBg  color.RGB
-
-	DirFg    color.RGB
-	FileFg   color.RGB
-	SymbolFg color.RGB
-
-	SyntaxComment color.RGB
-	SyntaxString  color.RGB
-	SyntaxKeyword color.RGB
-	SyntaxType    color.RGB
-	SyntaxNumber  color.RGB
-	SyntaxSymbol  color.RGB
+	Text     Style // values and body text; its Bg is the panel's
+	Muted    Style // labels, hints, placeholders and defaults, help lines
+	Accent   Style // marks: focus, the chosen option, a required field
+	Selected Style // the cursor row of a list
+	Input    Style // the background of the field being edited
+	Cursor   Style // the text cursor
+	Error    Style // errors
+	Border   Style // boxes and rules
+	Glyphs   Glyphs
 }
 
-// DefaultTheme provides reasonable defaults
+// Glyphs are the marks widgets draw; a selection always changes a glyph, so
+// it reads without color. A text console's font takes GlyphsCP437, a
+// terminal outside UTF-8 GlyphsASCII.
+type Glyphs struct {
+	Focus    rune // beside the focused control
+	Pointer  rune // the cursor row of a list
+	Folded   rune // a closed group
+	Unfolded rune // an open group
+	On, Off  rune // a toggle
+	Required rune // after a required field's label
+}
+
+var (
+	GlyphsUnicode = Glyphs{Focus: '▌', Pointer: '▸', Folded: '▸', Unfolded: '▾', On: '●', Off: '○', Required: '*'}
+	GlyphsCP437   = Glyphs{Focus: '▌', Pointer: '►', Folded: '►', Unfolded: '▼', On: '•', Off: '○', Required: '*'}
+	GlyphsASCII   = Glyphs{Focus: '>', Pointer: '>', Folded: '+', Unfolded: '-', On: '*', Off: '-', Required: '*'}
+)
+
+// DefaultTheme is a dark theme for true color and 256-color terminals
 var DefaultTheme = Theme{
-	Bg:            color.RGB{R: 20, G: 20, B: 30},
-	Fg:            color.RGB{R: 200, G: 200, B: 200},
-	FocusBg:       color.RGB{R: 30, G: 35, B: 45},
-	CursorBg:      color.RGB{R: 50, G: 50, B: 70},
-	Selected:      color.RGB{R: 80, G: 200, B: 80},
-	Unselected:    color.RGB{R: 100, G: 100, B: 100},
-	Partial:       color.RGB{R: 80, G: 160, B: 220},
-	Error:         color.RGB{R: 255, G: 80, B: 80},
-	Warning:       color.RGB{R: 255, G: 80, B: 80},
-	Border:        color.RGB{R: 60, G: 80, B: 100},
-	HeaderBg:      color.RGB{R: 40, G: 60, B: 90},
-	HeaderFg:      color.RGB{R: 255, G: 255, B: 255},
-	StatusFg:      color.RGB{R: 140, G: 140, B: 140},
-	HintFg:        color.RGB{R: 100, G: 180, B: 200},
-	InputBg:       color.RGB{R: 30, G: 30, B: 50},
-	DirFg:         color.RGB{R: 130, G: 170, B: 220},
-	FileFg:        color.RGB{R: 200, G: 200, B: 200},
-	SymbolFg:      color.RGB{R: 180, G: 220, B: 220},
-	SyntaxComment: color.RGB{R: 100, G: 110, B: 120},
-	SyntaxString:  color.RGB{R: 180, G: 220, B: 140},
-	SyntaxKeyword: color.RGB{R: 180, G: 140, B: 220},
-	SyntaxType:    color.RGB{R: 80, G: 200, B: 200},
-	SyntaxNumber:  color.RGB{R: 220, G: 180, B: 120},
-	SyntaxSymbol:  color.RGB{R: 220, G: 180, B: 80},
+	Text:     Style{Fg: color.RGB{R: 200, G: 200, B: 200}, Bg: color.RGB{R: 20, G: 20, B: 30}},
+	Muted:    Style{Fg: color.RGB{R: 120, G: 125, B: 140}},
+	Accent:   Style{Fg: color.RGB{R: 80, G: 160, B: 220}, Attr: terminal.AttrBold},
+	Selected: Style{Bg: color.RGB{R: 40, G: 45, B: 65}},
+	Input:    Style{Bg: color.RGB{R: 30, G: 30, B: 50}},
+	Cursor:   Style{Fg: color.RGB{R: 20, G: 20, B: 30}, Bg: color.RGB{R: 200, G: 200, B: 200}},
+	Error:    Style{Fg: color.RGB{R: 255, G: 80, B: 80}},
+	Border:   Style{Fg: color.RGB{R: 60, G: 80, B: 100}},
+	Glyphs:   GlyphsUnicode,
 }
 
+// MonoTheme draws with attributes alone in the terminal's own colors: the
+// theme for ColorModeNone, and one that reads on any terminal
+var MonoTheme = Theme{
+	Text:     Style{Attr: own | terminal.AttrBgDefault},
+	Muted:    Style{Attr: own | terminal.AttrDim},
+	Accent:   Style{Attr: own | terminal.AttrBold},
+	Selected: Style{Attr: own | terminal.AttrReverse},
+	Input:    Style{Attr: own | terminal.AttrUnderline},
+	Cursor:   Style{Attr: own | terminal.AttrReverse},
+	Error:    Style{Attr: own | terminal.AttrBold | terminal.AttrUnderline},
+	Border:   Style{Attr: own},
+	Glyphs:   GlyphsUnicode,
+}
+
+// Theme16 uses the ANSI 16 colors alone, in the terminal's own shades, on
+// its own background: the theme for ColorMode16, a text console's
+var Theme16 = Theme{
+	Text:     Style{Attr: own | terminal.AttrBgDefault},
+	Muted:    ansi(color.ANSIBrightBlack, 0),
+	Accent:   ansi(color.ANSICyan, terminal.AttrBold),
+	Selected: Style{Attr: own | terminal.AttrReverse},
+	Input:    Style{Attr: own | terminal.AttrUnderline},
+	Cursor:   Style{Attr: own | terminal.AttrReverse},
+	Error:    ansi(color.ANSIRed, terminal.AttrBold),
+	Border:   Style{Attr: own},
+	Glyphs:   GlyphsUnicode,
+}
+
+// ThemeFor returns the theme for a color mode: DefaultTheme with 256 colors
+// or more, Theme16 with 16, MonoTheme with none
+func ThemeFor(mode terminal.ColorMode) Theme {
+	switch mode {
+	case terminal.ColorMode16:
+		return Theme16
+	case terminal.ColorModeNone:
+		return MonoTheme
+	}
+	return DefaultTheme
+}
+
+// own is the terminal's own foreground
+const own = terminal.AttrFgDefault
+
+// ansi is a foreground of the ANSI 16, in the terminal's shade of it
+func ansi(i uint8, attr terminal.Attr) Style {
+	return Style{Fg: color.RGB{R: i}, Attr: terminal.AttrFg256 | attr}
+}