navstack: close the top model when on push

examples/deeper/artistpaintings/model.go

@@ -42,6 +42,11 @@ func (m Model) Init() tea.Cmd {
 	return nil
 }
 
+func (m Model) Close() error {
+	// This is called when the model is pushed and popped from the navigation stack.
+	return nil
+}
+
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 	switch msg := msg.(type) {

navstack/model.go

@@ -48,9 +48,17 @@ func (m Model) Init() tea.Cmd {
 // Push pushes a new navigation item onto the stack.
 // The new navigation item is given a tea.WindowSizeMsg to ensure it's view can be presented correctly.
 // The item's Init method is called and resulting command is processed by [BubbleTea].
+// If top item's model implements the Closable interface the Close method is called.
 // This new item will be the top most item on the stack and thus will be rendered.
 func (m *Model) Push(item NavigationItem) tea.Cmd {
 
+	top := m.Top()
+	if top != nil {
+		if c, ok := top.Model.(Closable); ok {
+			c.Close()
+		}
+	}
+
 	wmsg := m.window.GetWindowSizeMsg()
 	nim, cmd := item.Model.Update(wmsg)
 	item.Model = nim