Added Combobox.Append() and Combobox.InsertBefore().

combobox.go

@@ -26,7 +26,34 @@ func NewCombobox(editable bool, items ...string) (c *Combobox) {
 	return c
 }
 
-// TODO Append, InsertBefore, Delete
+// Append adds an item to the end of the Combobox's list.
+func (c *Combobox) Append(what string) (err error) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if c.created {
+		return c.sysData.append(what)
+	}
+	c.initItems = append(c.initItems, what)
+	return nil
+}
+
+// InsertBefore inserts a new item in the Combobox before the item at the given position.
+func (c *Combobox) InsertBefore(what string, before int) (err error) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if c.created {
+		return c.sysData.insertBefore(what, before)
+	}
+	m := make([]string, 0, len(c.initItems) + 1)
+	m = append(m, c.initItems[:before]...)
+	m = append(m, what)
+	c.initItems = append(m, c.initItems[before:]...)
+	return nil
+}
+
+// TODO Delete
 
 // Selection returns the current selection.
 func (c *Combobox) Selection() string {

main.go

@@ -12,6 +12,13 @@ func main() {
 	c := NewCheckbox("Check Me")
 	cb1 := NewCombobox(true, "You can edit me!", "Yes you can!", "Yes you will!")
 	cb2 := NewCombobox(false, "You can't edit me!", "No you can't!", "No you won't!")
+	i := 0
+	doAdjustments := func() {
+		cb1.Append("append")
+		cb2.InsertBefore(fmt.Sprintf("before %d", i), 1)
+		i++
+	}
+	doAdjustments()
 	e := NewLineEdit("Enter text here too")
 	l := NewLabel("This is a label")
 	s0 := NewStack(Vertical, b, c, cb1, cb2, e, l)
@@ -38,6 +45,7 @@ mainloop:
 			if err != nil {
 				panic(err)
 			}
+			doAdjustments()
 		}
 	}
 	w.Hide()