--- /dev/null
+/**
+ * Implements hook_field_formatter_settings_form().
+ */
+function {{ machine_name }}_field_formatter_settings_form($field, $instance, $view_mode, $form, &$form_state) {
+ $display = $instance['display'][$view_mode];
+ $settings = $display['settings'];
+
+ $element = array();
+
+ if ($display['type'] == 'text_trimmed' || $display['type'] == 'text_summary_or_trimmed') {
+ $element['trim_length'] = array(
+ '#title' => t('Length'),
+ '#type' => 'textfield',
+ '#size' => 20,
+ '#default_value' => $settings['trim_length'],
+ '#element_validate' => array('element_validate_integer_positive'),
+ '#required' => TRUE,
+ );
+ }
+
+ return $element;
+
+}