v0.1.0 initial commit

tui/scrollbar.go

@@ -0,0 +1,73 @@
+package tui
+
+import (
+	"github.com/lixenwraith/terminal"
+)
+
+// ScrollBar draws vertical scrollbar track with thumb
+func (r Region) ScrollBar(x int, offset, visible, total int, fg terminal.RGB) {
+	if x < 0 || x >= r.W || r.H < 1 {
+		return
+	}
+
+	trackH := r.H
+	if total <= visible || trackH < 3 {
+		// No scrolling needed or track too small
+		for y := range trackH {
+			r.Cell(x, y, '│', fg, terminal.RGB{}, terminal.AttrDim)
+		}
+		return
+	}
+
+	// Calculate thumb size and position
+	thumbH := min(max((visible*trackH)/total, 1), trackH)
+
+	maxScroll := total - visible
+	thumbY := 0
+	if maxScroll > 0 {
+		thumbY = (offset * (trackH - thumbH)) / maxScroll
+	}
+	if thumbY < 0 {
+		thumbY = 0
+	}
+	if thumbY+thumbH > trackH {
+		thumbY = trackH - thumbH
+	}
+
+	// Draw track and thumb
+	for y := range trackH {
+		var ch rune
+		if y >= thumbY && y < thumbY+thumbH {
+			ch = '█'
+		} else {
+			ch = '░'
+		}
+		r.Cell(x, y, ch, fg, terminal.RGB{}, terminal.AttrNone)
+	}
+}
+
+// ScrollIndicator draws compact indicator text (Top/Bot/XX%)
+func (r Region) ScrollIndicator(y int, offset, visible, total int, fg terminal.RGB) {
+	if y < 0 || y >= r.H {
+		return
+	}
+
+	var text string
+	if total <= visible || offset <= 0 {
+		text = "Top"
+	} else if offset+visible >= total {
+		text = "Bot"
+	} else {
+		pct := ScrollPercent(offset, visible, total)
+		if pct >= 100 {
+			text = "99%"
+		} else if pct >= 10 {
+			text = string(rune('0'+pct/10)) + string(rune('0'+pct%10)) + "%"
+		} else {
+			text = " " + string(rune('0'+pct)) + "%"
+		}
+	}
+
+	r.TextRight(y, text, fg, terminal.RGB{}, terminal.AttrDim)
+}
+