Fix applying ScrollBarAlways to List

demos/progressbar/main.go

@@ -11,6 +11,7 @@ func main() {
 	app := cview.NewApplication()
 
 	grid := cview.NewGrid().SetColumns(-1, 6, 4, 30, -1).SetRows(-1, 12, 4, 4, -1)
+	grid.SetBackgroundColor(cview.Styles.PrimitiveBackgroundColor)
 
 	verticalProgressBar := cview.NewProgressBar()
 	verticalProgressBar.SetBorder(true)

list.go

@@ -488,9 +488,7 @@ func (l *List) Draw(screen tcell.Screen) {
 			}
 		}
 
-		if l.scrollBarVisibility == ScrollBarAlways || (l.scrollBarVisibility == ScrollBarAuto && len(l.items) > scrollBarHeight) {
-			RenderScrollBar(screen, scrollBarX, y, scrollBarHeight, len(l.items), l.currentItem, index-l.offset, l.hasFocus, l.scrollBarColor)
-		}
+		RenderScrollBar(screen, l.scrollBarVisibility, scrollBarX, y, scrollBarHeight, len(l.items), l.currentItem, index-l.offset, l.hasFocus, l.scrollBarColor)
 
 		y++
 
@@ -502,13 +500,17 @@ func (l *List) Draw(screen tcell.Screen) {
 		if l.showSecondaryText {
 			Print(screen, item.SecondaryText, x, y, width, AlignLeft, l.secondaryTextColor)
 
-			if l.scrollBarVisibility == ScrollBarAlways || (l.scrollBarVisibility == ScrollBarAuto && len(l.items) > scrollBarHeight) {
-				RenderScrollBar(screen, scrollBarX, y, scrollBarHeight, len(l.items), l.currentItem, index-l.offset, l.hasFocus, l.scrollBarColor)
-			}
+			RenderScrollBar(screen, l.scrollBarVisibility, scrollBarX, y, scrollBarHeight, len(l.items), l.currentItem, index-l.offset, l.hasFocus, l.scrollBarColor)
 
 			y++
 		}
 	}
+
+	// Overdraw scroll bar when necessary.
+	for y < bottomLimit {
+		RenderScrollBar(screen, l.scrollBarVisibility, scrollBarX, y, scrollBarHeight, len(l.items), l.currentItem, bottomLimit-y, l.hasFocus, l.scrollBarColor)
+		y++
+	}
 }
 
 // InputHandler returns the handler for this primitive.

table.go

@@ -913,7 +913,7 @@ ColumnLoop:
 		// Draw scroll bar.
 		cursor := int(float64(scrollBarItems) * (float64(t.rowOffset) / float64(((rows-t.fixedRows)-t.visibleRows)+padTotalOffset)))
 		for printed := 0; printed < scrollBarHeight; printed++ {
-			RenderScrollBar(screen, scrollBarX, scrollBarY+printed, scrollBarHeight, scrollBarItems, cursor, printed, t.hasFocus, t.scrollBarColor)
+			RenderScrollBar(screen, t.scrollBarVisibility, scrollBarX, scrollBarY+printed, scrollBarHeight, scrollBarItems, cursor, printed, t.hasFocus, t.scrollBarColor)
 		}
 	}
 

treeview.go

@@ -709,9 +709,7 @@ func (t *TreeView) Draw(screen tcell.Screen) {
 		}
 
 		// Draw scroll bar.
-		if t.scrollBarVisibility == ScrollBarAlways || (t.scrollBarVisibility == ScrollBarAuto && rows > height) {
-			RenderScrollBar(screen, x+(width-1), posY, height, rows, cursor, posY-y, t.hasFocus, tcell.ColorWhite)
-		}
+		RenderScrollBar(screen, t.scrollBarVisibility, x+(width-1), posY, height, rows, cursor, posY-y, t.hasFocus, tcell.ColorWhite)
 
 		// Advance.
 		posY++

util.go

@@ -646,12 +646,16 @@ const (
 )
 
 // RenderScrollBar renders a scroll bar character at the specified position.
-func RenderScrollBar(screen tcell.Screen, x int, y int, height int, items int, cursor int, printed int, focused bool, color tcell.Color) {
-	// Do not render a scroll bar when all items are visible.
-	if items <= height {
+func RenderScrollBar(screen tcell.Screen, visibility ScrollBarVisibility, x int, y int, height int, items int, cursor int, printed int, focused bool, color tcell.Color) {
+	if visibility == ScrollBarNever || (visibility == ScrollBarAuto && items <= height) {
 		return
 	}
 
+	// Place cursor at top when there are no items offscreen.
+	if items <= height {
+		cursor = 0
+	}
+
 	// Handle negative cursor.
 	if cursor < 0 {
 		cursor = 0