--- /dev/null
+/**
+ * Implements hook_field_formatter_settings_summary().
+ */
+function {{ machine_name }}_field_formatter_settings_summary($field, $instance, $view_mode) {
+ $display = $instance['display'][$view_mode];
+ $settings = $display['settings'];
+
+ $summary = '';
+
+ if ($display['type'] == 'text_trimmed' || $display['type'] == 'text_summary_or_trimmed') {
+ $summary = t('Length: @chars chars', array('@chars' => $settings['trim_length']));
+ }
+
+ return $summary;
+}