Remove node from TreeView

Question

I want to create this simple example of javaFX TreeView with context menu which can remove nodes from the tree:

public class TreeViewSample extends Application {

    private final Node rootIcon = new ImageView(
        new Image(getClass().getResourceAsStream("folder_16.png"))
    );

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Tree View Sample");        

        TreeItem<String> rootItem = new TreeItem<String> ("Inbox", rootIcon);
        rootItem.setExpanded(true);
        for (int i = 1; i < 6; i++) {
            TreeItem<String> item = new TreeItem<String> ("Message" + i);            
            rootItem.getChildren().add(item);
        }        
        TreeView<String> tree = new TreeView<String> (rootItem);        
        StackPane root = new StackPane();
        root.getChildren().add(tree);
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();
    }
}

I tested this context menu to remove right click selected node:

final ContextMenu contextMenu = new ContextMenu();
        MenuItem item1 = new MenuItem("About");
        item1.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent e)
            {
                System.out.println("About");
            }
        });
        MenuItem item2 = new MenuItem("Preferences");
        item2.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent e)
            {
                System.out.println("Preferences");
            }
        });
        MenuItem item3 = new MenuItem("Remove");
        item3.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent e)
            {

                DynamicTreeNodeModel c = treeView.getSelectionModel().getSelectedItem().getValue();
                boolean remove = treeView.getSelectionModel().getSelectedItem().getChildren().remove(c);
                System.out.println("Remove");
            }
        });
        contextMenu.getItems().addAll(item1, item2, item3);

        treeView.setContextMenu(contextMenu);

For some reason the code is not working. Can you help me to fix this issue?

Answer 1

You're trying to remove the selected node from it's own children. Since it doesn't exist there, nothing happens. You need to remove the selected node from it's parent's children.

    MenuItem item3 = new MenuItem("Remove");
    item3.setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent e) {
            TreeItem c = (TreeItem)treeView.getSelectionModel().getSelectedItem();
            boolean remove = c.getParent().getChildren().remove(c);
            System.out.println("Remove");
        }
    });