}
});
//files drop
tabsAdder = new ClosableTabbedPanelAdder(inputTabbedPanel);
JVisualMultiSelectionDropper dropper = new JVisualMultiSelectionDropper(tabsAdder);
tabbedPanelDropTarget = new DropTarget(inputTabbedPanel,dropper);
openButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JFileChooser fileChooser = SharedJFileChooser.getInstance(SharedJFileChooserType.PDF_FILE, JFileChooser.FILES_ONLY);