v0.1.0 initial commit

tui/tab.go

@@ -0,0 +1,131 @@
+package tui
+
+import "github.com/lixenwraith/terminal"
+
+// TabBounds stores position and size of a rendered tab
+type TabBounds struct {
+	X, W int
+}
+
+// TabBarOpts configures tab bar rendering
+type TabBarOpts struct {
+	ActiveStyle   Style
+	InactiveStyle Style
+	Separator     string // Between tabs, default " │ "
+	Padding       int    // Horizontal padding inside each tab, default 1
+}
+
+// DefaultTabBarOpts returns sensible defaults
+func DefaultTabBarOpts() TabBarOpts {
+	return TabBarOpts{
+		ActiveStyle:   Style{Attr: terminal.AttrBold | terminal.AttrReverse},
+		InactiveStyle: Style{Attr: terminal.AttrNone},
+		Separator:     " │ ",
+		Padding:       1,
+	}
+}
+
+// TabBar renders horizontal tab strip at row y
+// Returns bounds of each tab for hit testing / navigation
+func (r Region) TabBar(y int, titles []string, active int, opts TabBarOpts) []TabBounds {
+	if y < 0 || y >= r.H || len(titles) == 0 {
+		return nil
+	}
+
+	if opts.Separator == "" {
+		opts.Separator = " │ "
+	}
+
+	bounds := make([]TabBounds, len(titles))
+	x := 0
+	sepLen := RuneLen(opts.Separator)
+
+	for i, title := range titles {
+		if x >= r.W {
+			break
+		}
+
+		// Calculate tab width
+		tabW := RuneLen(title) + opts.Padding*2
+		if x+tabW > r.W {
+			tabW = r.W - x
+		}
+
+		bounds[i] = TabBounds{X: x, W: tabW}
+
+		// Select style
+		style := opts.InactiveStyle
+		if i == active {
+			style = opts.ActiveStyle
+		}
+
+		// Render padding + title + padding
+		for j := 0; j < opts.Padding && x+j < r.W; j++ {
+			r.Cell(x+j, y, ' ', style.Fg, style.Bg, style.Attr)
+		}
+
+		titleStart := x + opts.Padding
+		for j, ch := range title {
+			if titleStart+j >= r.W {
+				break
+			}
+			r.Cell(titleStart+j, y, ch, style.Fg, style.Bg, style.Attr)
+		}
+
+		for j := 0; j < opts.Padding; j++ {
+			pos := x + opts.Padding + RuneLen(title) + j
+			if pos < r.W {
+				r.Cell(pos, y, ' ', style.Fg, style.Bg, style.Attr)
+			}
+		}
+
+		x += tabW
+
+		// Separator between tabs
+		if i < len(titles)-1 && x+sepLen <= r.W {
+			for j, ch := range opts.Separator {
+				r.Cell(x+j, y, ch, opts.InactiveStyle.Fg, opts.InactiveStyle.Bg, terminal.AttrDim)
+			}
+			x += sepLen
+		}
+	}
+
+	return bounds
+}
+
+// TabBarCentered renders tab bar centered horizontally
+func (r Region) TabBarCentered(y int, titles []string, active int, opts TabBarOpts) []TabBounds {
+	if len(titles) == 0 {
+		return nil
+	}
+
+	if opts.Separator == "" {
+		opts.Separator = " │ "
+	}
+
+	// Calculate total width
+	totalW := 0
+	sepLen := RuneLen(opts.Separator)
+	for i, title := range titles {
+		totalW += RuneLen(title) + opts.Padding*2
+		if i < len(titles)-1 {
+			totalW += sepLen
+		}
+	}
+
+	// Create sub-region for centering
+	startX := (r.W - totalW) / 2
+	if startX < 0 {
+		startX = 0
+	}
+
+	subR := r.Sub(startX, y, totalW, 1)
+	bounds := subR.TabBar(0, titles, active, opts)
+
+	// Adjust bounds to parent coordinates
+	for i := range bounds {
+		bounds[i].X += startX
+	}
+
+	return bounds
+}