tweaks for firefox

wagtail/wagtailadmin/static/wagtailadmin/js/page-editor.js

@@ -340,31 +340,55 @@ $(function() {
     });
 
     /* Set up behaviour of preview button */
+    var previewWindow = null;
+    var previewOnloadRun = false;
+
     $('.action-preview').click(function(e) {
         e.preventDefault();
         var $this = $(this);
 
-        var previewWindow = window.open($this.data('placeholder'), $this.data('windowname'));
-        
+        if(!previewWindow || previewWindow.closed){
+            previewOnloadRun = false;
+            previewWindow = window.open($this.data('placeholder'), $this.data('windowname'));
+        }
+
         if(/MSIE/.test(navigator.userAgent)){
+            // If IE, load contents immediately without fancy effects
             submitPreview.call($this, false);
         } else {
-            previewWindow.onload = function(){
+            // If not IE, check if the onload has already fired
+            if(!previewOnloadRun){
+                // This only runs once per new window creation
+                previewWindow.onload = function(){
+                    previewOnloadRun = true;
+                    submitPreview.call($this, true);
+                }
+            }else{
                 submitPreview.call($this, true);
             }
         }
 
         function submitPreview(enhanced){
+            var previewDoc = previewWindow.document;
+
+            // If onload already fired, make window appear like it's loading the content again
+            var spinner = previewDoc.getElementById('loading-spinner-wrapper');
+            previewWindow.focus();
+            
+            if(spinner){
+                spinner.className = spinner.className.replace('remove','');
+            }
+
+           
+
             $.ajax({
                 type: "POST",
                 url: $this.data('action'),
                 data: $('#page-edit-form').serialize(),
                 success: function(data, textStatus, request) {
                     if (request.getResponseHeader('X-Wagtail-Preview') == 'ok') {
-                        var pdoc = previewWindow.document;
-                        
                         if(enhanced){
-                            var frame = pdoc.getElementById('preview-frame');
+                            var frame = previewDoc.getElementById('preview-frame');
 
                             frame = frame.contentWindow || frame.contentDocument.document || frame.contentDocument;
                             frame.document.open();
@@ -372,14 +396,15 @@ $(function() {
                             frame.document.close();
 
                             var hideTimeout = setTimeout(function(){
-                                pdoc.getElementById('loading-spinner-wrapper').className += 'remove';
+                                spinner.className += ' remove';
                                 clearTimeout(hideTimeout);
                             }) // just enough to give effect without adding discernible slowness                       
                         } else {
-                            pdoc.open();
-                            pdoc.write(data);                 
-                            pdoc.close()
+                            previewDoc.open();
+                            previewDoc.write(data);                 
+                            previewDoc.close()
                         }
+
                     } else {
                         previewWindow.close();
                         document.open();
@@ -394,9 +419,9 @@ $(function() {
                     developers can debug template errors. (On a production site, we'd
                     typically be serving a friendly custom 500 page anyhow.) */
 
-                    previewWindow.document.open();
-                    previewWindow.document.write(xhr.responseText);
-                    previewWindow.document.close();
+                    previewDoc.open();
+                    previewDoc.write(xhr.responseText);
+                    previewDoc.close();
                 }
             });
 

wagtail/wagtailadmin/static/wagtailadmin/scss/layouts/preview.scss

@@ -25,9 +25,9 @@ html,body {
     font-size:0em;
     z-index:999999;
     background:white;
-    @include transition(all 0.3s ease);
-
+    
     &.remove{
+        @include transition(all 0.3s ease);
         bottom:-100%;
     }