tui: truncate title to width

pkg/tui/tui.go

@@ -123,6 +123,8 @@ var (
 			PaddingLeft(2).
 			PaddingRight(2)
 	headerStyle = lipgloss.NewStyle().
+			PaddingLeft(1).
+			PaddingRight(1).
 			Background(lipgloss.Color("0"))
 	footerStyle = lipgloss.NewStyle().
 			BorderTop(true).
@@ -327,6 +329,22 @@ func height(str string) int {
 	return strings.Count(str, "\n") + 1
 }
 
+func truncateToCellWidth(str string, width int, tail string) string {
+	cellWidth := ansi.PrintableRuneWidth(str)
+	if cellWidth <= width {
+		return str
+	}
+	tailWidth := ansi.PrintableRuneWidth(tail)
+	for {
+		str = str[:len(str)-((cellWidth+tailWidth)-width)]
+		cellWidth = ansi.PrintableRuneWidth(str)
+		if cellWidth+tailWidth <= max(width, 0) {
+			break
+		}
+	}
+	return str + tail
+}
+
 func (m model) View() string {
 	if m.width == 0 {
 		// this is the case upon initial startup, but it's also a safe bet that
@@ -351,18 +369,15 @@ func (m model) View() string {
 }
 
 func (m *model) headerView() string {
-	titleStyle := lipgloss.NewStyle().
+	titleStyle := lipgloss.NewStyle().Bold(true)
-		PaddingLeft(1).
-		PaddingRight(1).
-		Bold(true)
 	var title string
 	if m.conversation != nil && m.conversation.Title != "" {
 		title = m.conversation.Title
 	} else {
 		title = "Untitled"
 	}
+	title = truncateToCellWidth(title, m.width-headerStyle.GetHorizontalPadding(), "...")
 	part := titleStyle.Render(title)
-
 	return headerStyle.Width(m.width).Render(part)
 }
 
@@ -424,16 +439,7 @@ func (m *model) footerView() string {
 
 	footer := left + padding + right
 	if remaining < 0 {
-		ellipses := "... "
+		footer = truncateToCellWidth(footer, m.width, "...")
-		for {
-			truncWidth := ansi.PrintableRuneWidth(footer) + len(ellipses)
-			if truncWidth <= m.width {
-				break
-			}
-			// truncate the minimum amount, not accounting for printed width
-			footer = footer[:len(footer)-(truncWidth-m.width)]
-		}
-		footer += ellipses
 	}
 	return footerStyle.Width(m.width).Render(footer)
 }