v0.1.0 initial commit

tui/input.go

@@ -0,0 +1,78 @@
+package tui
+
+import (
+	"github.com/lixenwraith/terminal"
+)
+
+// InputOpts configures single-line input field
+type InputOpts struct {
+	Label    string
+	LabelFg  terminal.RGB
+	Text     string
+	Cursor   int // Cursor position in text (rune index)
+	CursorBg terminal.RGB
+	TextFg   terminal.RGB
+	Bg       terminal.RGB
+}
+
+// Input renders labeled text input field on row y, handling cursor display and horizontal scrolling
+func (r Region) Input(y int, opts InputOpts) {
+	if y < 0 || y >= r.H || r.W < 5 {
+		return
+	}
+
+	x := 0
+
+	// Label
+	if opts.Label != "" {
+		for _, ch := range opts.Label {
+			if x >= r.W {
+				break
+			}
+			r.Cell(x, y, ch, opts.LabelFg, opts.Bg, terminal.AttrNone)
+			x++
+		}
+	}
+
+	// Available width for input text
+	inputW := r.W - x
+	if inputW < 3 {
+		return
+	}
+
+	runes := []rune(opts.Text)
+	cursor := opts.Cursor
+	if cursor > len(runes) {
+		cursor = len(runes)
+	}
+	if cursor < 0 {
+		cursor = 0
+	}
+
+	// Horizontal scroll to keep cursor visible
+	scroll := 0
+	if cursor >= inputW-1 {
+		scroll = cursor - inputW + 2
+	}
+
+	// Render visible portion
+	for i := 0; i < inputW; i++ {
+		runeIdx := scroll + i
+		ch := ' '
+		if runeIdx < len(runes) {
+			ch = runes[runeIdx]
+		}
+
+		bg := opts.Bg
+		if runeIdx == cursor {
+			bg = opts.CursorBg
+		}
+
+		r.Cell(x+i, y, ch, opts.TextFg, bg, terminal.AttrNone)
+	}
+
+	// Cursor at end if past text
+	if cursor == len(runes) && cursor-scroll < inputW {
+		r.Cell(x+cursor-scroll, y, ' ', opts.TextFg, opts.CursorBg, terminal.AttrNone)
+	}
+}