Bug 189847 [DND] Combo/Text on Linux does not fire Drop event.
examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/dnd/DNDExample.java
data.bottom = new FormAttachment(100, -10);
	data.left = new FormAttachment(0, 10);
	combo.setLayoutData(data);
	
	data = new FormData();
	data.bottom = new FormAttachment(100, -10);
	data.left = new FormAttachment(combo, 10);
	b.setLayoutData(data);
}
private void createDropOperations(Composite parent) {
	parent.setLayout(new RowLayout(SWT.VERTICAL));
	final Button moveButton = new Button(parent, SWT.CHECK);
	moveButton.setText("DND.DROP_MOVE");
	moveButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_MOVE;			
			} else {
				dropOperation = dropOperation & ~DND.DROP_MOVE;
				if (dropOperation == 0 || (dropDefaultOperation & DND.DROP_MOVE) != 0) {
					dropOperation |= DND.DROP_MOVE;
					moveButton.setSelection(true);
				}
			}
			if (dropEnabled) {
				createDropTarget();
			}
		}
	});