better horizontal scroll draw support

canvas.go

@@ -286,15 +286,19 @@ func (fb *FrameBuffer) DrawScroll(x, y, w, h, pos int, fgScroll, bgScroll, fgThu
 	}
 
 	if scrollChars == "" {
-		scrollChars = "░■▲▼"
+		scrollChars = "░■▲▼◄►"
 	}
 
 	parts := []rune(scrollChars)
 	chLine, chCursor, chUp, chDown := parts[0], parts[1], parts[2], parts[3]
+	chLeft, chRight := '◄', '►'
+	if len(parts) > 4 {
+		chLeft, chRight = parts[4], parts[5]
+	}
 
 	if h == 1 {
-		fb.PutChar(x, y, chUp, fgScroll, bgScroll)
-		fb.PutChar(x+w-1, y, chDown, fgScroll, bgScroll)
+		fb.PutChar(x, y, chLeft, fgScroll, bgScroll)
+		fb.PutChar(x+w-1, y, chRight, fgScroll, bgScroll)
 
 		if w > 2 {
 			for xx := 1; xx < w-1; xx++ {

demos/themes/acsii.theme

@@ -16,7 +16,7 @@ ProgressActiveText = white
 SingleBorder=-|++++
 DoubleBorder==|++++
 Edit=<>V
-ScrollBar=|O^V
+ScrollBar=|O^V<>
 ViewButtons=^_X[]
 CheckBox=[] X?
 Radio=() *

demos/themes/turbovision.theme

@@ -58,7 +58,7 @@ ButtonDisabledBack=white
 SingleBorder=─│┌┐└┘
 DoubleBorder=═║╔╗╚╝
 Edit=←→V
-ScrollBar=░■▲▼
+ScrollBar=░■▲▼◄►
 ViewButtons=^↓○[]
 CheckBox=[] X?
 Radio=() *

textutil.go

@@ -134,7 +134,7 @@ func SliceColorized(str string, start, end int) string {
 	parser := NewColorParser(str, term.ColorBlack, term.ColorBlack)
 	var out string
 	for {
-		if curr >= end {
+		if end != -1 && curr >= end {
 			break
 		}
 		elem := parser.NextElement()

theme.go

@@ -130,7 +130,7 @@ func (s *ThemeManager) Reset() {
 	defTheme.objects[ObjSingleBorder] = "─│┌┐└┘"
 	defTheme.objects[ObjDoubleBorder] = "═║╔╗╚╝"
 	defTheme.objects[ObjEdit] = "←→V"
-	defTheme.objects[ObjScrollBar] = "░■▲▼"
+	defTheme.objects[ObjScrollBar] = "░■▲▼◄►"
 	defTheme.objects[ObjViewButtons] = "^↓○[]"
 	defTheme.objects[ObjCheckBox] = "[] X?"
 	defTheme.objects[ObjRadio] = "() *"

themes/turbovision.theme

@@ -59,7 +59,7 @@ ButtonDisabledBack=white
 SingleBorder=─│┌┐└┘
 DoubleBorder=═║╔╗╚╝
 Edit=←→V
-ScrollBar=░■▲▼
+ScrollBar=░■▲▼◄►
 ViewButtons=^↓○[]
 CheckBox=[] X?
 Radio=() *