public void showMatchingList() {

		//
		//  We temporarily enable this list to show for empty text, even if the text is not empty.
		// This handles the default setting, which has this feature off.  We can refactor this class
		// to allow us to make a direct call instead of using this temporary setting.  This seems
		// simple enough for now.
		//
		boolean restore = showMachingListOnEmptyText;
		try {
			showMachingListOnEmptyText = true;
			pendingTextUpdate = pendingTextUpdate != null ? pendingTextUpdate : getText();
			updateManager.updateNow();
		}
		finally {
			showMachingListOnEmptyText = restore;
		}
	}
Shows the matching list.  This can be used to show all data when the user has not typed any
text.
Ghidra/Framework/Docking/src/main/java/docking/widgets/DropDownTextField.java