// this.comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
// it probably breaks various things
// hitting enter in the combo box should stop cellediting
JComponent editorComponent = (JComponent) comboBox.getEditor().getEditorComponent();
editorComponent.addKeyListener(handler);
// remove the editor's border - the cell itself already has one
editorComponent.setBorder(null);
// editor component might change (e.g. a look&feel change)
// the new editor component needs to be modified then (keyListener, border)