在SWT.Tree中选择SWT.TreeItem

Question

So, I have the following code

tree.addSelectionListener(new SelectionAdapter() {
    public void widgetSelected(SelectionEvent e) {
        System.out.println("Clicked Item>>" + tree.getSelection()[0].toString());
    }
});`

How can I change it so that it fires only when I select an TreeItem within that Tree but on on expand or any other events?

Answer 1

You could use JFace to handle it:

TreeViewer viewer = new TreeViewer(tree);
viewer.addSelectionChangedListener(new ISelectionChangedListener() {
    @Override
    public void selectionChanged(SelectionChangedEvent event) {
        IStructuredSelection selection = (IStructuredSelection) event.getSelection();
        System.out.println("Clicked Item>>" + selection.getFirstElement());
    }
});

You will not be working with TreeItems though. Pass your model to the viewer using setInput(). Set a content provider to handle your model and set a label provider to handle what is displayed.

viewer.setLabelProvider(labelProvider);
viewer.setContentProvider(provider);
viewer.setInput(input);

Here is an example: http://www.vogella.com/tutorials/EclipseJFaceTree/article.html

Edit according to comment:

Depending on the model you use, you might find out if the selected element has children from the model element. (eg a TreeNode object having a getChildren() or hasChilrden() method)
If you are using a ITreeContentProvider as content provider (which is probably true), you can do the following:

IStructuredSelection selection = (IStructuredSelection) event.getSelection();
Object element = selection.getFirstElement();
System.out.println("Clicked Item>>" + element);
((ITreeContentProvider)viewer.getContentProvider()).hasChildren(element);