From d3ac703b45231d5a2addc641bd156e70244864be Mon Sep 17 00:00:00 2001
From: Adam Butterworth <abutterworth@edx.org>
Date: Wed, 29 Jan 2020 11:51:46 -0500
Subject: [PATCH 1/2] Report iframed courseware content dimensions to parent
 window

---
 .../courseware/courseware-chromeless.html     | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/lms/templates/courseware/courseware-chromeless.html b/lms/templates/courseware/courseware-chromeless.html
index c9a9cb2e43ad..0b9134077e40 100644
--- a/lms/templates/courseware/courseware-chromeless.html
+++ b/lms/templates/courseware/courseware-chromeless.html
@@ -106,3 +106,46 @@
       % endif
     </nav>
 % endif
+
+<script type="text/javascript">
+  (function() {
+    // If this view is rendered in an iframe within the learning microfrontend app
+    // it will report the height of its contents to the parent window when the
+    // document loads, window resizes, or DOM mutates.
+    if (window !== window.parent) {
+      var learningAppReferrer = "${settings.LEARNING_MICROFRONTEND_URL | n, js_escaped_string}";
+      if (document.referrer === learningAppReferrer) {
+
+        var lastHeight = window.offsetHeight;
+        var lastWidth = window.offsetWidth;
+        var contentElement = document.getElementById('content');
+
+        function dispatchResizeMessage() {
+          if (contentElement.offsetHeight === lastHeight && contentElement.offsetWidth === lastWidth) {
+            return;
+          }
+
+          window.parent.postMessage({
+              type: 'plugin.resize',
+              payload: {
+                width: contentElement.offsetWidth,
+                height: contentElement.offsetHeight,
+              }
+            }, document.referrer
+          );
+          lastHeight = contentElement.offsetHeight;
+          lastWidth = contentElement.offsetWidth;
+        }
+
+        // Create an observer instance linked to the callback function
+        const observer = new MutationObserver(dispatchResizeMessage);
+
+        // Start observing the target node for configured mutations
+        observer.observe(document.body, { attributes: true, childList: true, subtree: true });
+
+        window.addEventListener('load', dispatchResizeMessage);
+        window.addEventListener('resize', dispatchResizeMessage);
+      }
+    }
+  }());
+</script>

From 912a622065f90c59bb00e3c6f73838a1fbc773ee Mon Sep 17 00:00:00 2001
From: Adam Butterworth <abutterworth@edx.org>
Date: Wed, 29 Jan 2020 11:56:58 -0500
Subject: [PATCH 2/2] Update courseware-chromeless.html

---
 .../courseware/courseware-chromeless.html          | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/lms/templates/courseware/courseware-chromeless.html b/lms/templates/courseware/courseware-chromeless.html
index 0b9134077e40..466b99bfe132 100644
--- a/lms/templates/courseware/courseware-chromeless.html
+++ b/lms/templates/courseware/courseware-chromeless.html
@@ -121,20 +121,24 @@
         var contentElement = document.getElementById('content');
 
         function dispatchResizeMessage() {
-          if (contentElement.offsetHeight === lastHeight && contentElement.offsetWidth === lastWidth) {
+          var newHeight = contentElement.offsetHeight;
+          var newWidth = contentElement.offsetWidth;
+
+          if (newWidth === lastWidth && newHeight === lastHeight) {
             return;
           }
 
           window.parent.postMessage({
               type: 'plugin.resize',
               payload: {
-                width: contentElement.offsetWidth,
-                height: contentElement.offsetHeight,
+                width: newWidth,
+                height: newHeight,
               }
             }, document.referrer
           );
-          lastHeight = contentElement.offsetHeight;
-          lastWidth = contentElement.offsetWidth;
+
+          lastHeight = newHeight;
+          lastWidth = newWidth;
         }
 
         // Create an observer instance linked to the callback function