DragDropLayout - Drop Deletes Component

Flow
1

I am trying to use the DragDropLayout Addon. Using the grid layout demo from John Ahlroos, I find that when you drop a component on another component it gets deleted from the layout. I would have thought that the other components on the layout would have gotten reordered.

Please advise if there is a way around this.

Regards,
Eric

2

In the addon, I was just using the DefaultGridLayoutDropHandler(). I ended up just creating my own drop handler that would not allow a drop ontop of another component.

grid.setDropHandler(new DropHandler()
{
    private static final long serialVersionUID = 1L;

    /*
     * Don't allow a drop onto another component
     * 
     */
    @Override
    public void drop(DragAndDropEvent event)
    {
        GridLayoutTargetDetails details = (GridLayoutTargetDetails) event.getTargetDetails();
                
        // If there is no component there already drop it there or else don't do anything
        if (((DDGridLayout)details.getTarget()).getComponent(details.getOverColumn(), details.getOverRow()) == null)
        {
            LayoutBoundTransferable transferable = (LayoutBoundTransferable)event.getTransferable();
            Component c = transferable.getComponent();
                    
            ((ComponentContainer)c.getParent()).removeComponent(c);

            ((DDGridLayout)details.getTarget()).addComponent(c,details.getOverColumn(),details.getOverRow());
        } 
                
    }

    @Override
    public AcceptCriterion getAcceptCriterion()
    {
        return AcceptAll.get();
    }
});

It can be taken much further where the components are then shifted to allow for the drop if a component is aready present.

Best Regards,

Eric