add a function to traverse in nodes (#3)

sway_test.go

@@ -148,3 +148,17 @@ func processFocus(ctx context.Context, client sway.Client, node *sway.Node) {
 		log.Println(err)
 	}
 }
+
+func TestFocused(t *testing.T) {
+	ctx := context.Background()
+	client, err := sway.New(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+	tree, err := client.GetTree(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+	f := tree.FocusedNode()
+	printJSON(f)
+}

types.go

@@ -124,6 +124,14 @@ type Node struct {
 
 // FocusedNode traverses the node tree and returns the focused node
 func (n *Node) FocusedNode() *Node {
+	focusedNode := n.TraverseNodes(func(n *Node) bool {
+		return n.Focused
+	})
+	return focusedNode
+}
+
+// TraverseNodes returns the first Node matching the predicate
+func (n *Node) TraverseNodes(predicate func(*Node) bool) *Node {
 	queue := []*Node{n}
 	for len(queue) > 0 {
 		n = queue[0]
@@ -133,7 +141,7 @@ func (n *Node) FocusedNode() *Node {
 			continue
 		}
 
-		if n.Focused {
+		if predicate(n) {
 			return n
 		}