DEV: Add composer-open class to body element when compsoer is open (#15420)

app/assets/javascripts/discourse/app/controllers/composer.js

@@ -1401,6 +1401,7 @@ export default Controller.extend({
 
     const elem = document.querySelector("html");
     elem.classList.remove("fullscreen-composer");
+    elem.classList.remove("composer-open");
 
     document.activeElement && document.activeElement.blur();
     this.setProperties({ model: null, lastValidatedAt: null });

app/assets/javascripts/discourse/app/models/composer.js

@@ -211,12 +211,14 @@ const Composer = RestModel.extend({
 
     if (this.composeState === OPEN) {
       this.set("composerOpened", oldOpen || new Date());
+      elem.classList.add("composer-open");
     } else {
       if (oldOpen) {
         const oldTotal = this.composerTotalOpened || 0;
         this.set("composerTotalOpened", oldTotal + (new Date() - oldOpen));
       }
       this.set("composerOpened", null);
+      elem.classList.remove("composer-open");
     }
   },