make boxes cover anything behind them

ui/ui.go

@@ -185,24 +185,26 @@ func (c *Container) SetContents(con Contents) {
 
 // A Box draws a ASCII box around its contents, with an optional title and footer.
 type Box struct {
-	x, y      int
-	h, w      int
-	title     Drawable
-	menuItems Drawable
-	contents  Contents
-	style     tcell.Style
-	cascade   bool
-	visible   bool
+	x, y        int
+	h, w        int
+	title       Drawable
+	menuItems   Drawable
+	contents    Contents
+	style       tcell.Style
+	cascade     bool
+	visible     bool
+	transparent bool
 }
 
 func NewBox(title string, menuItems []string, contents Contents, initialStyle tcell.Style, cascade bool) *Box {
 	return &Box{
-		title:     NewPaddedText(title),
-		menuItems: NewPaddedText(strings.Join(menuItems, " ")),
-		contents:  contents,
-		style:     initialStyle,
-		cascade:   cascade,
-		visible:   true,
+		title:       NewPaddedText(title),
+		menuItems:   NewPaddedText(strings.Join(menuItems, " ")),
+		contents:    contents,
+		style:       initialStyle,
+		cascade:     cascade,
+		visible:     true,
+		transparent: false,
 	}
 }
 
@@ -223,6 +225,15 @@ func (b *Box) Draw(s tcell.Screen) {
 	if !b.visible {
 		return
 	}
+	// blank out inner area
+	if !b.transparent {
+		for m := b.x + 1; m < b.x+b.w-1; m++ {
+			for n := b.y + 1; n < b.y+b.h-1; n++ {
+				s.SetContent(m, n, ' ', nil, b.style)
+			}
+		}
+	}
+	// draw outside bars
 	for m := b.x + 1; m < b.x+b.w-1; m++ {
 		s.SetContent(m, b.y, tcell.RuneHLine, nil, b.style)
 		s.SetContent(m, b.y+b.h-1, tcell.RuneHLine, nil, b.style)
@@ -262,6 +273,10 @@ func (b *Box) SetVisible(v bool) {
 	b.visible = v
 }
 
+func (b *Box) SetTransparent(v bool) {
+	b.transparent = v
+}
+
 func (b *Box) Contents() Contents {
 	return b.contents
 }