* @param elem the element
* @param focusable true to make focusable, false to make unfocusable
*/
protected void setFocusable(Element elem, boolean focusable) {
if (focusable) {
FocusImpl focusImpl = FocusImpl.getFocusImplForWidget();
com.google.gwt.user.client.Element rowElem = elem.cast();
focusImpl.setTabIndex(rowElem, getTabIndex());
if (accessKey != 0) {
focusImpl.setAccessKey(rowElem, accessKey);
}
} else {
// Chrome: Elements remain focusable after removing the tabIndex, so set
// it to -1 first.
elem.setTabIndex(-1);