Bug 687687 - Log helpful messages to web-console when full-screen is denied/revoked. r=bz

content/base/src/nsDocument.cpp

@@ -8606,6 +8606,8 @@ public:
 void
 nsDocument::AsyncRequestFullScreen(Element* aElement)
 {
+  NS_ASSERTION(aElement,
+    "Must pass non-null element to nsDocument::AsyncRequestFullScreen");
   if (!aElement) {
     return;
   }
@@ -8614,20 +8616,48 @@ nsDocument::AsyncRequestFullScreen(Element* aElement)
   NS_DispatchToCurrentThread(event);
 }
 
+static void
+LogFullScreenDenied(bool aLogFailure, const char* aMessage, nsIDocument* aDoc)
+{
+  if (!aLogFailure) {
+    return;
+  }
+  nsRefPtr<nsPLDOMEvent> e =
+    new nsPLDOMEvent(aDoc,
+                     NS_LITERAL_STRING("mozfullscreenerror"),
+                     true,
+                     false);
+  e->PostDOMEvent();
+  nsContentUtils::ReportToConsole(nsContentUtils::eDOM_PROPERTIES,
+                                  aMessage,
+                                  nsnull, 0, nsnull,
+                                  EmptyString(), 0, 0,
+                                  nsIScriptError::warningFlag,
+                                  "DOM", aDoc);
+}
+
 void
 nsDocument::RequestFullScreen(Element* aElement, bool aWasCallerChrome)
 {
-  if (!aElement ||
-      !aElement->IsInDoc() ||
-      aElement->OwnerDoc() != this ||
-      !IsFullScreenEnabled(aWasCallerChrome) ||
-      !GetWindow()) {
-    nsRefPtr<nsPLDOMEvent> e =
-      new nsPLDOMEvent(this,
-                       NS_LITERAL_STRING("mozfullscreenerror"),
-                       true,
-                       false);
-    e->PostDOMEvent();
+  NS_ASSERTION(aElement,
+    "Must pass non-null element to nsDocument::RequestFullScreen");
+  if (!aElement) {
+    return;
+  }
+  if (!aElement->IsInDoc()) {
+    LogFullScreenDenied(true, "FullScreenDeniedNotInDocument", this);
+    return;
+  }
+  if (aElement->OwnerDoc() != this) {
+    LogFullScreenDenied(true, "FullScreenDeniedMovedDocument", this);
+    return;
+  }
+  if (!GetWindow()) {
+    LogFullScreenDenied(true, "FullScreenDeniedLostWindow", this);
+    return;
+  }
+  if (!IsFullScreenEnabled(aWasCallerChrome, true)) {
+    // IsFullScreenEnabled calls LogFullScreenDenied, no need to log.
     return;
   }
 
@@ -8722,12 +8752,12 @@ NS_IMETHODIMP
 nsDocument::GetMozFullScreenEnabled(bool *aFullScreen)
 {
   NS_ENSURE_ARG_POINTER(aFullScreen);
-  *aFullScreen = IsFullScreenEnabled(nsContentUtils::IsCallerChrome());
+  *aFullScreen = IsFullScreenEnabled(nsContentUtils::IsCallerChrome(), false);
   return NS_OK;
 }
 
 bool
-nsDocument::IsFullScreenEnabled(bool aCallerIsChrome)
+nsDocument::IsFullScreenEnabled(bool aCallerIsChrome, bool aLogFailure)
 {
   if (nsContentUtils::IsFullScreenApiEnabled() && aCallerIsChrome) {
     // Chrome code can always use the full-screen API, provided it's not
@@ -8737,9 +8767,16 @@ nsDocument::IsFullScreenEnabled(bool aCallerIsChrome)
     return true;
   }
 
-  if (!nsContentUtils::IsFullScreenApiEnabled() ||
-      nsContentUtils::HasPluginWithUncontrolledEventDispatch(this) ||
-      !IsVisible()) {
+  if (!nsContentUtils::IsFullScreenApiEnabled()) {
+    LogFullScreenDenied(aLogFailure, "FullScreenDeniedDisabled", this);
+    return false;
+  }
+  if (nsContentUtils::HasPluginWithUncontrolledEventDispatch(this)) {
+    LogFullScreenDenied(aLogFailure, "FullScreenDeniedPlugins", this);
+    return false;
+  }
+  if (!IsVisible()) {
+    LogFullScreenDenied(aLogFailure, "FullScreenDeniedHidden", this);
     return false;
   }
 
@@ -8753,6 +8790,7 @@ nsDocument::IsFullScreenEnabled(bool aCallerIsChrome)
       // The node requesting fullscreen, or one of its crossdoc ancestors,
       // is an iframe which doesn't have the "mozalllowfullscreen" attribute.
       // This request is not authorized by the parent document.
+      LogFullScreenDenied(aLogFailure, "FullScreenDeniedIframeDisallowed", this);
       return false;
     }
     node = nsContentUtils::GetCrossDocParentNode(node);

content/base/src/nsDocument.h

@@ -978,7 +978,9 @@ protected:
   // doc tree, and if the document is visible, and if the api is not
   // disabled by pref. aIsCallerChrome must contain the return value of
   // nsContentUtils::IsCallerChrome() from the context we're checking.
-  bool IsFullScreenEnabled(bool aIsCallerChrome);
+  // If aLogFailure is true, an appropriate warning message is logged to the
+  // console, and a "mozfullscreenerror" event is dispatched to this document.
+  bool IsFullScreenEnabled(bool aIsCallerChrome, bool aLogFailure);
 
   /**
    * Check that aId is not empty and log a message to the console

content/base/src/nsGenericElement.cpp

@@ -3067,6 +3067,12 @@ nsGenericElement::UnbindFromTree(bool aDeep, bool aNullParent)
     if (IsFullScreenAncestor(this)) {
       // The element being removed is an ancestor of the full-screen element,
       // exit full-screen state.
+      nsContentUtils::ReportToConsole(nsContentUtils::eDOM_PROPERTIES,
+                                      "RemovedFullScreenElement",
+                                      nsnull, 0, nsnull,
+                                      EmptyString(), 0, 0,
+                                      nsIScriptError::warningFlag,
+                                      "DOM", OwnerDoc());      
       OwnerDoc()->CancelFullScreen();
     }
     if (GetParent()) {

content/html/content/src/nsGenericHTMLElement.cpp

@@ -118,6 +118,7 @@
 #include "nsHTMLFieldSetElement.h"
 #include "nsHTMLMenuElement.h"
 #include "nsPLDOMEvent.h"
+#include "nsIScriptError.h"
 
 #include "mozilla/Preferences.h"
 #include "mozilla/dom/FromParser.h"
@@ -3468,6 +3469,12 @@ nsresult nsGenericHTMLElement::MozRequestFullScreen()
   // and it also makes it harder for bad guys' script to go full-screen and
   // spoof the browser chrome/window and phish logins etc.
   if (!nsContentUtils::IsRequestFullScreenAllowed()) {
+    nsContentUtils::ReportToConsole(nsContentUtils::eDOM_PROPERTIES,
+                                    "FullScreenDeniedNotInputDriven",
+                                    nsnull, 0, nsnull,
+                                    EmptyString(), 0, 0,
+                                    nsIScriptError::warningFlag,
+                                    "DOM", OwnerDoc());
     nsRefPtr<nsPLDOMEvent> e =
       new nsPLDOMEvent(OwnerDoc(),
                        NS_LITERAL_STRING("mozfullscreenerror"),

content/html/content/src/nsHTMLSharedObjectElement.cpp

@@ -49,6 +49,7 @@
 #include "nsThreadUtils.h"
 #include "nsIDOMGetSVGDocument.h"
 #include "nsIDOMSVGDocument.h"
+#include "nsIScriptError.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -297,6 +298,12 @@ nsHTMLSharedObjectElement::BindToTree(nsIDocument *aDocument,
     // to prevent phishing attacks.
     NS_DispatchToCurrentThread(
       NS_NewRunnableMethod(aDocument, &nsIDocument::CancelFullScreen));
+    nsContentUtils::ReportToConsole(nsContentUtils::eDOM_PROPERTIES,
+                                    "AddedWindowedPluginWhileFullScreen",
+                                    nsnull, 0, nsnull,
+                                    EmptyString(), 0, 0,
+                                    nsIScriptError::warningFlag,
+                                    "DOM", aDocument);           
   }
 #endif
   return NS_OK;

dom/locales/en-US/chrome/dom/dom.properties

@@ -115,5 +115,15 @@ nsIJSONEncodeDeprecatedWarning=nsIJSON.encode is deprecated.  Please use JSON.st
 nsIDOMWindowInternalWarning=Use of nsIDOMWindowInternal is deprecated. Use nsIDOMWindow instead.
 InputEncodingWarning=Use of inputEncoding is deprecated.
 GlobalStorageWarning=Use of globalStorage is deprecated. Please use localStorage instead.
+FullScreenDeniedDisabled=Request for full-screen was denied because full-screen API is disabled by user preference.
+FullScreenDeniedPlugins=Request for full-screen was denied because a document on this page contains a windowed plugin.
+FullScreenDeniedHidden=Request for full-screen was denied because the document is no longer visible.
+FullScreenDeniedIframeDisallowed=Request for full-screen was denied because at least one of the document's containing iframes does not have a "mozallowfullscreen" attribute.
+FullScreenDeniedNotInputDriven=Request for full-screen was denied because Element.mozRequestFullScreen() was not called from inside a short running user-generated event handler.
+FullScreenDeniedNotInDocument=Request for full-screen was denied because requesting element is no longer in its document.
+FullScreenDeniedMovedDocument=Request for full-screen was denied because requesting element has moved document.
+FullScreenDeniedLostWindow=Request for full-screen was denied because we no longer have a window.
+RemovedFullScreenElement=Exited full-screen because full-screen element was removed from document.
+AddedWindowedPluginWhileFullScreen=Exited full-screen because windowed plugin was added to document.
 HTMLMultipartXHRWarning=HTML parsing in XMLHttpRequest is not supported for multipart responses.
 HTMLSyncXHRWarning=HTML parsing in XMLHttpRequest is not supported in the synchronous mode.