Jface TreeViewer add right click menu, depending on clicked node

问题

There is a good thread on how to correctly hook up a right-click menu to a Jface TreeViewer depending on the selected item.

I would like to show the right click menu depending on: if the right-click was on a node or into "empty space". The problem is that TreeViewer does not automatically clear the selection if you click into empty space. Is there any clean way how to achieve this?

My current approach would be to simply hook up a MouseListener to the tree with the following mouseDown method:

@Override
public void mouseDown(MouseEvent e) {
    TreeItem item = treeViewer.getTree().getItem(new Point(e.x, e.y));
    if (item == null) {
        treeViewer.getTree().deselectAll();
    }
}

This seems to work quite well. What do you think of this?

回答1:

Ok, I found a dirty workaround. So if you really want to do it, here is a possible solution:

final Tree tree = viewer.getTree();

final Menu menu = new Menu(tree);
tree.setMenu(menu);
menu.addMenuListener(new MenuAdapter()
{
    @Override
    public void menuShown(MenuEvent e)
    {
        Point point = tree.toControl(Display.getDefault().getCursorLocation());
        boolean found = false;
        for (TreeItem item : tree.getItems())
        {
            for (int i = 0; i < tree.getColumnCount(); i++)
                if (item.getBounds(i).contains(point))
                    found = true;
        }

        System.out.println(found);
    }
});

回答2:

How to add popup menu to your SWT/JFace TreeViewer
Hi, in your applications main class (that extends ApplicationWindow) in protected Control createContents(Composite parent) method you should add code like this:
//Author: Darius Kucinskas (c) 2008-2009
//Email: d[dot]kucinskas[eta]gmail[dot]com
//Blog: http://blog-of-darius.blogspot.com/
//License: GPL

// Create the popup menu
  MenuManager menuMgr = new MenuManager();
  Menu menu = menuMgr.createContextMenu(mTreeViewer.getControl());
  menuMgr.addMenuListener(new IMenuListener() {
    @Override
    public void menuAboutToShow(IMenuManager manager) {
      if(mTreeViewer.getSelection().isEmpty()) {
        return;
      }

      if(mTreeViewer.getSelection() instanceof IStructuredSelection) {
        IStructuredSelection selection = (IStructuredSelection)mTreeViewer.getSelection();
        DatabaseModelObject object = (DatabaseModelObject)selection.getFirstElement();

        if (object.getType() == DATABASE_OBJECT_TYPE.TABLE){
          manager.add(new ShowTableDataAction(SWTApp.this));
        }
      }
    }
  });

  menuMgr.setRemoveAllWhenShown(true);
  mTreeViewer.getControl().setMenu(menu);
DatabaseModelObject - is class from my problem domain (specific to my program). mTreeViewer - is object of TreeViewer class (JFace). Thanks, have a nice day!

来源：https://stackoverflow.com/questions/25682081/jface-treeviewer-add-right-click-menu-depending-on-clicked-node

标签

java

swt

jface

treeviewer