php/widgets/ButtonWidget.php
public function setActive( $active = null ) {
		$this->active = (bool)$active;
		$this->toggleClasses( [ 'oo-ui-buttonElement-active' ], $this->active );
		return $this;
	}
public function setActive( $active = null ) {
		$this->active = (bool)$active;
		$this->toggleClasses( [ 'oo-ui-buttonElement-active' ], $this->active );
		return $this;
	}
public function setActive ( $ active = null ) { $ this -> active = ( bool ) $ active ; $ this -> toggleClasses ( [ 'oo-ui-buttonElement-active' ] , $ this -> active ) ; return $ this ; }
Toggle active state.

A button should be marked as active when clicking it would only refresh the page.

@param bool|null $active Make button active
@return $this
Toggle active state .