Complete Option Form

gistfile1.php

<?php
/**
   * Define the options form to enable selection of flags.
   */
function options_form(&$form, &$form_state) {
 
    // Load all flags and types of each flag.
    $flags = flag_get_flags('taxonomy_term');
    // Combine all types (=vocabs) into one option array.
    $flag_types = array();
    $flag_options = array();
    foreach ($flags as $flagname => $value) {
      // $flag_types is the array storing all vocabs.
      $flag_types = array_merge($flag_types, $value->types);
      // $flag_options is the array storing all possible Flags.
      $flag_options[$flagname] = $flagname;
    }
    $form['flags'] = array(
      '#type' => 'checkboxes',
      '#title' => t('Choose the Flags'),
      '#options' => $flag_options,
      '#process' => array('form_process_checkboxes'),
      '#default_value' => $this->options['flags'],
    );
    $form['vocabularies'] = array(
      '#type' => 'checkboxes',
      '#title' => t('Choose the Vocabularies'),
      '#options' => drupal_map_assoc($flag_types),
      '#process' => array('form_process_checkboxes'),
      '#default_value' => $this->options['vocabularies'],
    );
    $form['fallback'] = array(
      '#type' => 'textfield',
      '#title' => t('Fallback value'),
      '#description' => t('Value to use, when no item is flagged'),
      '#default_value' => $this->options['fallback'],
    );
    $form['multiple_operator'] = array(
      '#type' => 'select',
      '#options' => array(
        '+' => 'OR',
        ',' => 'AND',
      ),
      '#title' => t('Operator for multiple values'),
      '#default_value' => $this->options['multiple_operator'],
    );
  }