Bug 777236 - Implement the "fullscreen" app manifest attribute for web apps on desktop. r=myk

webapprt/content/webapp.js

@@ -58,6 +58,10 @@ function onLoad() {
   // This doesn't capture clicks so content can capture them itself and do
   // something different if it doesn't want the default behavior.
   gAppBrowser.addEventListener("click", onContentClick, false, true);
+
+  if (WebappRT.config.app.manifest.fullscreen) {
+    enterFullScreen();
+  }
 }
 window.addEventListener("load", onLoad, false);
 
@@ -66,6 +70,33 @@ function onUnload() {
 }
 window.addEventListener("unload", onUnload, false);
 
+// Fullscreen handling.
+
+function enterFullScreen() {
+  // We call mozRequestFullScreen here so that the app window goes in
+  // fullscreen mode as soon as it's loaded and not after the <browser>
+  // content is loaded.
+  gAppBrowser.mozRequestFullScreen();
+
+  // We need to call mozRequestFullScreen on the document element too,
+  // otherwise the app isn't aware of the fullscreen status.
+  gAppBrowser.addEventListener("load", function onLoad() {
+    gAppBrowser.removeEventListener("load", onLoad, true);
+    gAppBrowser.contentDocument.
+      documentElement.wrappedJSObject.mozRequestFullScreen();
+  }, true);
+}
+
+#ifndef XP_MACOSX
+document.addEventListener('mozfullscreenchange', function() {
+  if (document.mozFullScreenElement) {
+    document.getElementById("main-menubar").style.display = "none";
+  } else {
+    document.getElementById("main-menubar").style.display = "";
+  }
+}, false);
+#endif
+
 /**
  * Direct a click on <a target="_blank"> to the user's default browser.
  *

webapprt/content/webapp.xul

@@ -17,6 +17,7 @@
         id="default"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         width="1024" height="768"
+        fullscreenbutton="true"
         persist="screenX screenY width height sizemode"
         >