Adding a Settings metabox tab (in 1.8+)

add-metabox-tab.php

<?php

/**
 * Example of adding a metabox used in GravityView Maps metabox
 * You can also add a filter to `gravityview/metaboxes/default` and modify the default metaboxes, but
 * that will only work for 1.8+
 */
function example_register_metabox() {

	$m = array(
		'id' => 'maps_settings',
		'title' => __( 'Maps', 'gravityview-maps' ),
		'callback' => array( $this, 'render_metabox' ),
		'icon-class' => 'dashicons-location-alt',
		'file' => '',
		'callback_args' => '',
		'screen' => 'gravityview',
		'context' => 'side',
		'priority' => 'default',
	);

	if( class_exists('GravityView_Metabox_Tab') ) {

		$metabox = new GravityView_Metabox_Tab( $m['id'], $m['title'], $m['file'], $m['icon-class'], $m['callback'], $m['callback_args'] );

		GravityView_Metabox_Tabs::add( $metabox );

	} else {

		add_meta_box( 'gravityview_'.$m['id'], $m['title'], $m['callback'], $m['screen'], $m['context'], $m['priority'] );

	}
}