_complex_widget_installed_instances()

gistfile1.php

<?php
/**
 * Return a structured array defining the instances for this content type.
 *
 * This is provided as a function so that it can be used in both hook_install()
 * and hook_uninstall().
 */
function _complex_widget_installed_instances() {
  $types = array(t('number'), t('string'));
  return array(
    'source_variable' => array(
      'field_name' => 'source_variable',
      'label' => t('Variables'),
      'widget' => array(
        'type' => 'source_variable',
        'settings' => array(
          'summary_rows' => 2,
          'types' => implode('|', $types),
        ),
        'weight' => -4,
        'module' => 'source',
      ),
      'settings' => array('display_summary' => FALSE),
      'display' => array(
        'default' => array(
          'label' => 'hidden',
          'type' => 'source_default',
        ),
        'teaser' => array(
          'label' => 'hidden',
          'type' => 'source_default',
        ),
      ),
    ),
  );
}