- #39674: Scroll fieldsets into view when expanding them

misc/collapse.js

@@ -20,6 +20,9 @@ function collapseAutoAttach() {
     a.href = '#';
     a.onclick = function() {
       toggleClass(this.parentNode.parentNode, 'collapsed');
+      if (!hasClass(this.parentNode.parentNode, 'collapsed')) {
+        collapseScrollIntoView(this.parentNode.parentNode);
+      }
       this.blur();
       return false;
     };
@@ -48,3 +51,16 @@ function collapseEnsureErrorsVisible(fieldset) {
     }
   }
 }
+
+function collapseScrollIntoView(node) {
+  var h = self.innerHeight || document.documentElement.clientHeight || document.body.clientHeight || 0;
+  var offset = self.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
+  var pos = absolutePosition(node);
+  if (pos.y + node.scrollHeight > h + offset) {
+    if (node.scrollHeight > h) {
+      window.scrollTo(0, pos.y);
+    } else {
+      window.scrollTo(0, pos.y + node.scrollHeight - h);
+    }
+  }
+}