* @param styleName Dictates what the button should look like.
* @param tooltip The tooltip for this button.
*/
private void initDirect(String styleName, String tooltip, ButtonStateCss stateCss) {
internalStateCss = stateCss;
buttonStateClassName = new StyleAxis(getElement());
iconStyleClassName = new StyleAxis(getElement());
iconStyleClassName.setStyle(styleName);
setTitle(tooltip);
}