Menu/MenuItem work

menu_item.go

@@ -36,12 +36,15 @@ type MenuItem struct {
 	w, h    int
 
 	menuType  MenuType
+	cursor    int
 	items     []*MenuItem
 	onPressed func() bool
 
 	manualExpand bool
 	expanded     bool
 	disabled     bool
+
+	keyMap KeyMap
 }
 
 func NewMenuItem(id string, style tcell.Style) *MenuItem {
@@ -54,6 +57,21 @@ func (w *MenuItem) Init(id string, style tcell.Style) {
 	w.id = id
 	w.style = style
 	w.visible = true
+	w.keyMap = NewKeyMap(map[tcell.Key]func(ev *tcell.EventKey) bool{
+		tcell.KeyUp:   w.MoveUp,
+		tcell.KeyDown: w.MoveDown,
+		tcell.KeyEnter: func(ev *tcell.EventKey) bool {
+			if w.onPressed != nil {
+				return w.onPressed()
+			} else if len(w.items) > w.cursor && w.items[w.cursor].HandleKey(ev) {
+				return true
+			}
+			return false
+		},
+	})
+	for i := range w.items {
+		w.items[i].SetActive(i == w.cursor)
+	}
 }
 func (w *MenuItem) Id() string                         { return w.id }
 func (w *MenuItem) HandleResize(ev *tcell.EventResize) {}
@@ -61,12 +79,8 @@ func (w *MenuItem) HandleKey(ev *tcell.EventKey) bool {
 	if !w.active {
 		return false
 	}
-	if ev.Key() == tcell.KeyEnter {
-		if w.onPressed != nil {
-			return w.onPressed()
-		}
-	}
-	return false
+	// Look for a sub-item that's selected
+	return w.keyMap.Handle(ev)
 }
 func (w *MenuItem) HandleTime(ev *tcell.EventTime) {}
 func (w *MenuItem) Draw(screen tcell.Screen) {
@@ -77,10 +91,15 @@ func (w *MenuItem) Draw(screen tcell.Screen) {
 	if w.active {
 		st = w.style.Reverse(true)
 	}
+	if w.disabled {
+		st = st.Dim(true)
+		st = st.Italic(true)
+	}
 
 	x, y := w.x, w.y
 	wd := w.w
 	h.DrawText(x, y, h.PadR(w.label, wd), st, screen)
+	y += 1
 	if w.expanded {
 		x += 2
 		for i := range w.items {
@@ -140,10 +159,47 @@ func (w *MenuItem) Expand(e bool) {
 	}
 }
 
+func (w *MenuItem) updateActive() {
+	for i := range w.items {
+		w.items[i].SetActive(i == w.cursor)
+	}
+}
+
+func (w *MenuItem) MoveUp(ev *tcell.EventKey) bool {
+	// Look for a previous enabled item
+	st := w.cursor
+	i := (w.cursor - 1 + len(w.items)) % len(w.items)
+	for ; i != st; i = (i - 1 + len(w.items)) % len(w.items) {
+		if !w.items[i].IsDisabled() {
+			break
+		}
+	}
+	w.cursor = i
+	w.updateActive()
+	return true
+}
+
+func (w *MenuItem) MoveDown(ev *tcell.EventKey) bool {
+	// Look for next enabled item
+	st := w.cursor
+	i := (st + 1) % len(w.items)
+	for ; i != st; i = (i + 1) % len(w.items) {
+		if !w.items[i].IsDisabled() {
+			break
+		}
+	}
+	w.cursor = i
+	w.updateActive()
+	return true
+}
 func (w *MenuItem) SetLabel(lbl string) { w.label = lbl }
 func (w *MenuItem) SetDisabled(d bool)  { w.disabled = d }
+func (w *MenuItem) IsDisabled() bool    { return w.disabled }
 
 func (w *MenuItem) AddItems(iL ...*MenuItem) {
 	w.items = append(w.items, iL...)
+	for i := range w.items {
+		w.items[i].SetActive(i == w.cursor)
+	}
 }
 func (w *MenuItem) SetOnPressed(p func() bool) { w.onPressed = p }