protected void initGUI() {
    getGridLayout().numColumns = 2;
    //		fileExtList = new List(this, SWT.BORDER);
    //		fileExtList.setLayoutData(new GridData(GridData.FILL_BOTH));

    fileExtListViewer = new ListViewer(this, SWT.BORDER | SWT.V_SCROLL);
    fileExtListViewer.setContentProvider(new ListViewerContentProvider());
    fileExtListViewer.setLabelProvider(new ListViewerLabelProvider());
    fileExtListViewer.getControl().setLayoutData(new GridData(GridData.FILL_BOTH));

    buttonWrapper = new XComposite(this, SWT.NONE, LayoutMode.TIGHT_WRAPPER, LayoutDataMode.NONE);
    buttonWrapper.setLayoutData(new GridData(GridData.FILL_VERTICAL));

    addDelegation = new Button(buttonWrapper, SWT.PUSH);
    addDelegation.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    addDelegation.setText(
        Messages.getString(
            "org.nightlabs.base.ui.print.pref.EditDocumentPrinterTypeRegsComposite.addDelegation.text")); //$NON-NLS-1$
    addDelegation.addSelectionListener(
        new SelectionListener() {
          public void widgetDefaultSelected(SelectionEvent arg0) {}

          public void widgetSelected(SelectionEvent arg0) {
            String fileExt = openFileExtDlg();
            if (fileExt != null && !"".equals(fileExt)) { // $NON-NLS-1$
              addTypeReg(fileExt);
              // TODO: Removed, as the SelectionListener does not get notified. Why not?
              //					fileExtList.setSelection(new String[]{fileExt});
            }
          }
        });

    removeDelegation = new Button(buttonWrapper, SWT.PUSH);
    removeDelegation.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    removeDelegation.setText(
        Messages.getString(
            "org.nightlabs.base.ui.print.pref.EditDocumentPrinterTypeRegsComposite.removeDelegation.text")); //$NON-NLS-1$
    removeDelegation.addSelectionListener(
        new SelectionListener() {
          public void widgetDefaultSelected(SelectionEvent arg0) {}

          public void widgetSelected(SelectionEvent arg0) {
            removeTypeReg(getSelectedFileExt());
          }
        });
  }