CODEWITHSUNDEEP
javajavafx-2javafx-8
Joey Tyson
Joey Tyson

Reputation: 1

JavaFX 8 - Adding Components to TreeTable Cells

So I have this TreeTableView and I can get text to display properly but buttons and images don't want to display. I'm currently using the method of overriding the TreeTableCell class and its update method.

 TreeTableColumn<Application, Application> installed = new TreeTableColumn<Application, Application>("Installed?");
    installed.setResizable(false);
    installed.setPrefWidth(308.9);
    installed.setCellFactory(new Callback<TreeTableColumn<Application, Application>, TreeTableCell<Application, Application>>()
    {
        @Override
        public TreeTableCell<Application, Application> call(TreeTableColumn<Application, Application> param)
        {
            TreeTableCell<Application, Application> cell = new TreeTableCell<Application, Application>()
            {                   
                @Override
                public void updateItem(Application app, boolean empty)
                {
                    if(app != null)
                    {
                        setGraphic(app.getInstalledImage());
                    }
                }
            };            
            return cell;
        }

    });
    appTree.getColumns().add(installed);

However, "app" throws a NullPointerException when not checking for app != null so I'm thinking that may fix my problem. Any ideas why a valid Application is not getting passed?

Upvotes: 0

Views: 720

Answers (1)

James_D
James_D

Reputation: 209319

The TreeTableView contains empty cells; cells in the space below the last populated row and, perhaps, cells in some columns for collapsed rows. Empty cells always have updateItem(...) called with a null item.

Note that it's always essential to call super.updateItem(...) in your implementation:

            @Override
            public void updateItem(Application app, boolean empty)
            {
                super.updateItem(app, empty);
                if(app != null)
                {
                    setGraphic(app.getInstalledImage());
                }
            }

See the Javadocs for Cell for details.

Upvotes: 1

Related Questions