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
b = new Button(parent, SWT.CHECK);
	b.setText("File Transfer");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				addDropTransfer(FileTransfer.getInstance());			
			} else {
				removeDropTransfer(FileTransfer.getInstance());
			}
		}
	});
	
	
	textButton.setSelection(true);
	addDropTransfer(TextTransfer.getInstance());
}
private void createDropWidget(Composite parent) {
	parent.setLayout(new FormLayout());
	Combo combo = new Combo(parent, SWT.READ_ONLY);
	combo.setItems(new String[] {"Toggle Button", "Radio Button", "Checkbox", "Canvas", "Label", "List", "Table", "Tree", "Text", "StyledText"});
	combo.select(LABEL);
	dropControlType = combo.getSelectionIndex();
	dropControl = createWidget(dropControlType, parent, "Drop Target");
	combo.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Object data = dropControl.getLayoutData();
			Composite parent = dropControl.getParent();
			dropControl.dispose();
			Combo c = (Combo)e.widget;