Using Smart GWT TreeGrid for Navigation

Question

I'm working on a SmartGWT project where I'd like my main navigation to be done via a treegrid. The treegrid renders proprerly and its DataSource is functioning appropriately as well. The treegrid is correctly situated to the left of the mainView Canvas.

What I can't seem to figure out is how to switch the contents of the mainView Canvas based on what is selected in the NavigationTree. I've mimicked the functionality I'd like by adding new windows to the existing Canvas, but I can't find an example demonstrating how to clear the canvas entirely and replace it with a new Window.

Am I on the right track here? Can anyone point me at an example that shows roughly what I'm trying to accomplish?

public class NavigationTree extends TreeGrid {

    public NavigationTree(Canvas mainView)
    {
        setDataSource(NavigationDataSource.getInstance());
        setAutoFetchData(true);
        setShowHeader(false);

        addNodeClickHandler(new NavClickHandler(mainView));
    }

    // Handler for clicking an item on the Navigation Tree.
    private class NavClickHandler implements NodeClickHandler
    {
        private Canvas mainView;

        public NavClickHandler(Canvas mainView)
        {
            super();
            this.mainView = mainView;
        }

        @Override
        public void onNodeClick(NodeClickEvent event)
        {
            Window window = new Window();

            window.setWidth(300);  
            window.setHeight(230);  
            window.setCanDragReposition(true);  
            window.setCanDragResize(true);  

            window.setTitle(event.getNode().getAttribute("name"));
            window.addItem(new Label("huzzah!"));

            window.setParentElement(mainView);
            window.redraw();
        }
    }
}

Answer 1

I managed to accomplish what I needed with the following change to the event handler code:

public NavClickHandler(UI ui) //UI extends HLayout
{
    this.ui = ui;
}

@Override
public void onNodeClick(NodeClickEvent event) {
    Window window = new Window();

    window.setWidth100();
        window.setHeight100();
        window.setHeaderControls(HeaderControls.HEADER_LABEL);

    window.setTitle(event.getNode().getAttribute("name"));
    window.addItem(new Label("Huzzah!"));

    ui.setMainView(window);
}

...and the following change to my main UI layout:

public void setMainView(Canvas canvas)
{
    mainView.destroy();
    mainView = canvas;
    addMember(mainView);
    this.redraw();
}