table: fix center padding

When a column has ALIGN_CENTER and the number of white space character
of padding is not a multiple of two, the last cell(character) is not
padded and that can cause coloring glitches. Make sure to pad all the
way.

Fixes: 49de9b09cacc ("ui: parse strings for ansi styles")
Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Tim Culverhouse <tim@timculverhouse.com>

2 files changed, 29 insertions, 14 deletions

diff --git a/lib/parse/ansi.go b/lib/parse/ansi.go
index a9a46fdd..94f0c4fc 100644
--- a/lib/parse/ansi.go
+++ b/lib/parse/ansi.go
@@ -67,9 +67,30 @@ func (rb *RuneBuffer) Write(r rune, style tcell.Style) {
 }
 
 // Prepend inserts the rune at the beginning of the rune buffer
-func (rb *RuneBuffer) Prepend(r rune, style tcell.Style) {
-	w := runewidth.RuneWidth(r)
-	rb.buf = append([]*StyledRune{{r, w, style}}, rb.buf...)
+func (rb *RuneBuffer) PadLeft(width int, r rune, style tcell.Style) {
+	w := rb.Len()
+	if w >= width {
+		return
+	}
+	w = width - w
+	for w > 0 {
+		ww := runewidth.RuneWidth(r)
+		w -= ww
+		rb.buf = append([]*StyledRune{{r, ww, style}}, rb.buf...)
+	}
+}
+
+func (rb *RuneBuffer) PadRight(width int, r rune, style tcell.Style) {
+	w := rb.Len()
+	if w >= width {
+		return
+	}
+	w = width - w
+	for w > 0 {
+		ww := runewidth.RuneWidth(r)
+		w -= ww
+		rb.buf = append(rb.buf, &StyledRune{r, ww, style})
+	}
 }
 
 // String outputs a styled-string using TERM=xterm-256color
diff --git a/lib/ui/table.go b/lib/ui/table.go
index 704dd2be..9cb96bd9 100644
--- a/lib/ui/table.go
+++ b/lib/ui/table.go
@@ -166,29 +166,23 @@ func (col *Column) alignCell(cell string) string {
 	switch {
 	case col.Def.Flags.Has(config.ALIGN_LEFT):
 		if width < col.Width {
-			for i := 0; i < (col.Width - width); i += 1 {
-				buf.Write(' ', tcell.StyleDefault)
-			}
+			buf.PadRight(col.Width, ' ', tcell.StyleDefault)
 			cell = buf.String()
 		} else if width > col.Width {
 			cell = buf.Truncate(col.Width, '…')
 		}
 	case col.Def.Flags.Has(config.ALIGN_CENTER):
 		if width < col.Width {
-			pad := (col.Width - width) / 2
-			for i := 0; i < pad; i += 1 {
-				buf.Prepend(' ', tcell.StyleDefault)
-				buf.Write(' ', tcell.StyleDefault)
-			}
+			pad := col.Width - width
+			buf.PadLeft(col.Width-(pad/2), ' ', tcell.StyleDefault)
+			buf.PadRight(col.Width, ' ', tcell.StyleDefault)
 			cell = buf.String()
 		} else if width > col.Width {
 			cell = buf.Truncate(col.Width, '…')
 		}
 	case col.Def.Flags.Has(config.ALIGN_RIGHT):
 		if width < col.Width {
-			for i := 0; i < (col.Width - width); i += 1 {
-				buf.Prepend(' ', tcell.StyleDefault)
-			}
+			buf.PadLeft(col.Width, ' ', tcell.StyleDefault)
 			cell = buf.String()
 		} else if width > col.Width {
 			cell = buf.TruncateHead(col.Width, '…')