function bp_activity_types_list( $output = 'select', $args = '' ) {

	$args = bp_parse_args( $args, array(
		'checkbox_name' => 'bp_activity_types',
		'selected'      => array(),
	) );

	$activities = bp_activity_get_types();
	natsort( $activities );

	// Loop through the activity types and output markup.
	foreach ( $activities as $type => $description ) {

		// See if we need to preselect the current type.
		$checked  = checked(  true, in_array( $type, (array) $args['selected'] ), false );
		$selected = selected( true, in_array( $type, (array) $args['selected'] ), false );

		// Switch output based on the element.
		switch ( $output ) {
			case 'select' :
				printf( '<option value="%1$s" %2$s>%3$s</option>', esc_attr( $type ), $selected, esc_html( $description ) );
				break;
			case 'checkbox' :
				printf( '<label style="" for="%1$s[]">%2$s<input type="checkbox" id="%1$s[]" name="%1$s[]" value="%3$s" %4$s/></label>', esc_attr( $args['checkbox_name'] ), esc_html( $description ), esc_attr( $args['checkbox_name'] ), esc_attr( $args['checkbox_name'] ), esc_attr( $type ), $checked );
				break;
		}

		/**
		 * Fires at the end of the listing of activity types.
		 *
		 * This is a variable action hook. The actual hook to use will depend on the output type specified.
		 * Two default hooks are bp_activity_types_list_select and bp_activity_types_list_checkbox.
		 *
		 * @since 1.7.0
		 *
		 * @param array  $args        Array of arguments passed into function.
		 * @param string $type        Activity type being rendered in the output.
		 * @param string $description Description of the activity type being rendered.
		 */
		do_action( 'bp_activity_types_list_' . $output, $args, $type, $description );
	}

	// Backpat with BP-Default for dropdown boxes only.
	if ( 'select' === $output ) {
		do_action( 'bp_activity_filter_options' );
	}
}