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
final Button copyButton = new Button(parent, SWT.CHECK);
	copyButton.setText("DND.DROP_COPY");
	copyButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_COPY;			
			} else {
				dropOperation = dropOperation & ~DND.DROP_COPY;
				if (dropOperation == 0 || (dropDefaultOperation & DND.DROP_COPY) != 0) {
					dropOperation = DND.DROP_COPY;
					copyButton.setSelection(true);
				}
			}
			if (dropEnabled) {
				createDropTarget();
			}
		}
	});
	final Button linkButton = new Button(parent, SWT.CHECK);
	linkButton.setText("DND.DROP_LINK");
	linkButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_LINK;			
			} else {
				dropOperation = dropOperation & ~DND.DROP_LINK;
				if (dropOperation == 0 || (dropDefaultOperation & DND.DROP_LINK) != 0) {