diff --git a/src/rich_text_editor/index.js b/src/rich_text_editor/index.js
index 934fa0569..3b01f368e 100644
--- a/src/rich_text_editor/index.js
+++ b/src/rich_text_editor/index.js
@@ -1,10 +1,4 @@
 /**
- * * [add](#add)
- * * [get](#get)
- * * [getAll](#getall)
- * * [remove](#remove)
- * * [getToolbarEl](#gettoolbarel)
- *
  * This module allows to customize the toolbar of the Rich Text Editor and use commands from the HTML Editing APIs.
  * For more info about HTML Editing APIs check here:
  * https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand
@@ -130,12 +124,28 @@ module.exports = () => {
      * });
      * rte.add('link', {
      *   icon: document.getElementById('t'),
-     *   // Bind the 'result' on 'onclick' listener
-     *   event: 'click',
      *   attributes: {title: 'Link',}
      *   // Example on it's easy to wrap a selected content
      *   result: rte => rte.insertHTML(`<a href="#">${rte.selection()}</a>`)
      * });
+     * // An example with fontSize
+     * rte.add('fontSize', {
+     *   icon: `<select class="gjs-field">
+     *         <option>1</option>
+     *         <option>4</option>
+     *         <option>7</option>
+     *       </select>`,
+     *     // Bind the 'result' on 'change' listener
+     *   event: 'change',
+     *   result: (rte, action) => rte.exec('fontSize', action.btn.firstChild.value),
+     *   // Callback on any input change (mousedown, keydown, etc..)
+     *   update: (rte, action) => {
+     *     const value = rte.doc.queryCommandValue(action.name);
+     *     if (value != 'false') { // value is a string
+     *       action.btn.firstChild.value = value;
+     *     }
+     *    }
+     *   })
      */
     add(name, action = {}) {
       action.name = name;
diff --git a/src/rich_text_editor/model/RichTextEditor.js b/src/rich_text_editor/model/RichTextEditor.js
index 565376b63..11631fcc5 100644
--- a/src/rich_text_editor/model/RichTextEditor.js
+++ b/src/rich_text_editor/model/RichTextEditor.js
@@ -102,12 +102,18 @@ export default class RichTextEditor {
   updateActiveActions() {
     this.getActions().forEach(action => {
       const btn = action.btn;
+      const update = action.update;
       const active = this.classes.active;
+      const name = action.name;
+      const doc = this.doc;
       btn.className = btn.className.replace(active, '').trim();
 
-      if (this.doc.queryCommandState(action.name)) {
+      // doc.queryCommandValue(name) != 'false'
+      if (doc.queryCommandState(name)) {
         btn.className += ` ${active}`;
       }
+
+      update && update(this, action);
     })
   }
 
@@ -141,7 +147,7 @@ export default class RichTextEditor {
     this.getActions().forEach(action => {
       const event = action.event || 'click';
       action.btn[`on${event}`] = e => {
-        action.result(this);
+        action.result(this, action);
         this.updateActiveActions();
       };
     })