Merge pull request #7874 from alivedise/bugzilla/833454_v1-train/card…

…s-view-stuck

Bug 833454 - Window manager app switch transition race condition, r=timdream, a=blocking-b2g:tef+

apps/system/js/window.js

@@ -7,6 +7,29 @@
 
   var _ = navigator.mozL10n.get;
 
+  var ENABLE_LOG = false;
+
+  // Use mutation observer to monitor appWindow status change
+  window.AppLog = function AppLog(app) {
+    // select the target node
+    var target = app.frame;
+
+    // create an observer instance
+    var observer = new MutationObserver(function(mutations) {
+      mutations.forEach(function(mutation) {
+        console.log(mutation.target.id,
+                    mutation.target.className,
+                    mutation.attributeName);
+      });
+    });
+
+    // configuration of the observer:
+    var config = { attributes: true };
+
+    // pass in the target node, as well as the observer options
+    observer.observe(target, config);
+  }
+
   window.AppError = function AppError(app) {
     var self = this;
     this.app = app;
@@ -108,6 +131,8 @@
     // we may need to export the error state of AppWindow instance to the other module
     // in the future.
     this.appError = new AppError(this);
+    if (ENABLE_LOG)
+      this.appLog = new AppLog(this);
 
     return this;
   };

apps/system/js/window_manager.js

@@ -337,8 +337,17 @@ var WindowManager = (function() {
         classList.add('closing-card');
 
         if (openFrame) {
-          openFrame.classList.remove('opening-card');
-          openFrame.classList.add('opening-switching');
+          if (openFrame.classList.contains('opening-card')) {
+            openFrame.classList.remove('opening-card');
+            openFrame.classList.add('opening-switching');
+          } else {
+            // Skip the opening-card and opening-switching transition
+            // because the closing-card transition had already finished here.
+            if (openFrame.classList.contains('fullscreen-app')) {
+              screenElement.classList.add('fullscreen-app');
+            }
+            openFrame.classList.add('opening');
+          }
         }
       } else if (classList.contains('closing-card')) {
         windowClosed(frame);
@@ -352,12 +361,7 @@ var WindowManager = (function() {
         }
 
         classList.remove('opening-switching');
-
-        // XXX: without this setTimeout() there will be no opening transition.
-        // See https://bugzilla.mozilla.org/show_bug.cgi?id=780692#c111
-        setTimeout(function continueTransition() {
-          classList.add('opening');
-        });
+        classList.add('opening');
       } else if (classList.contains('opening')) {
         windowOpened(frame);
 
@@ -690,7 +694,7 @@ var WindowManager = (function() {
 
       if (!screenElement.classList.contains('switch-app')) {
         openFrame.classList.add('opening');
-      } else {
+      } else if (!openFrame.classList.contains('opening')) {
         openFrame.classList.add('opening-card');
       }
     };