Bug 1135933 - Make nsContextMenu.setDesktopBackground() use a message to get the image as a dataURL and make a new element with it to pass to the setDesktopBackground dialog. r=gabor

Also perform the disableSetDesktopBackground() check in content

--HG--
extra : commitid : KxHNPz0K0D3
extra : rebase_source : d5f8876a2f3bc58fd4ce133c2eca9b18ce70f282

browser/base/content/content.js

@@ -102,12 +102,15 @@ let handleContentContextMenu = function (event) {
                                           .getInterface(Ci.nsIDOMWindowUtils)
                                           .outerWindowID;
 
+  let disableSetDesktopBg = null;
   // Media related cache info parent needs for saving
   let contentType = null;
   let contentDisposition = null;
   if (event.target.nodeType == Ci.nsIDOMNode.ELEMENT_NODE &&
       event.target instanceof Ci.nsIImageLoadingContent &&
       event.target.currentURI) {
+    disableSetDesktopBg = disableSetDesktopBackground(event.target);
+
     try {
       let imageCache = 
         Cc["@mozilla.org/image/tools;1"].getService(Ci.imgITools)
@@ -148,7 +151,7 @@ let handleContentContextMenu = function (event) {
                     { editFlags, spellInfo, customMenuItems, addonInfo,
                       principal, docLocation, charSet, baseURI, referrer,
                       referrerPolicy, contentType, contentDisposition,
-                      frameOuterWindowID, selectionInfo },
+                      frameOuterWindowID, selectionInfo, disableSetDesktopBg },
                     { event, popupNode: event.target });
   }
   else {
@@ -169,6 +172,7 @@ let handleContentContextMenu = function (event) {
       contentType: contentType,
       contentDisposition: contentDisposition,
       selectionInfo: selectionInfo,
+      disableSetDesktopBackground: disableSetDesktopBg,
     };
   }
 }
@@ -753,3 +757,52 @@ addMessageListener("ContextMenu:SearchFieldBookmarkData", (message) => {
   sendAsyncMessage("ContextMenu:SearchFieldBookmarkData:Result",
                    { spec, title, description, postData, charset });
 });
+
+function disableSetDesktopBackground(aTarget) {
+  // Disable the Set as Desktop Background menu item if we're still trying
+  // to load the image or the load failed.
+  if (!(aTarget instanceof Ci.nsIImageLoadingContent))
+    return true;
+
+  if (("complete" in aTarget) && !aTarget.complete)
+    return true;
+
+  if (aTarget.currentURI.schemeIs("javascript"))
+    return true;
+
+  let request = aTarget.QueryInterface(Ci.nsIImageLoadingContent)
+                       .getRequest(Ci.nsIImageLoadingContent.CURRENT_REQUEST);
+  if (!request)
+    return true;
+
+  return false;
+}
+
+addMessageListener("ContextMenu:SetAsDesktopBackground", (message) => {
+  let target = message.objects.target;
+
+  // Paranoia: check disableSetDesktopBackground again, in case the
+  // image changed since the context menu was initiated.
+  let disable = disableSetDesktopBackground(target);
+
+  if (!disable) {
+    try {
+      BrowserUtils.urlSecurityCheck(target.currentURI.spec, target.ownerDocument.nodePrincipal);
+      let canvas = content.document.createElement("canvas");
+      canvas.width = target.naturalWidth;
+      canvas.height = target.naturalHeight;
+      let ctx = canvas.getContext("2d");
+      ctx.drawImage(target, 0, 0);
+      let dataUrl = canvas.toDataURL();
+      sendAsyncMessage("ContextMenu:SetAsDesktopBackground:Result",
+                       { dataUrl });
+    }
+    catch (e) {
+      Cu.reportError(e);
+      disable = true;
+    }
+  }
+
+  if (disable)
+    sendAsyncMessage("ContextMenu:SetAsDesktopBackground:Result", { disable });
+});

browser/base/content/nsContextMenu.js

@@ -241,7 +241,7 @@ nsContextMenu.prototype = {
 
     if (haveSetDesktopBackground && this.onLoadedImage) {
       document.getElementById("context-setDesktopBackground")
-              .disabled = this.disableSetDesktopBackground();
+              .disabled = gContextMenuContentData.disableSetDesktopBackground;
     }
 
     // Reload image depends on an image that's not fully loaded
@@ -1134,60 +1134,49 @@ nsContextMenu.prototype = {
                                      referrerURI: gContextMenuContentData.documentURIObject });
   },
 
-  disableSetDesktopBackground: function() {
-    // Disable the Set as Desktop Background menu item if we're still trying
-    // to load the image or the load failed.
-    if (!(this.target instanceof Ci.nsIImageLoadingContent))
-      return true;
-
-    if (("complete" in this.target) && !this.target.complete)
-      return true;
-
-    if (this.target.currentURI.schemeIs("javascript"))
-      return true;
-
-    var request = this.target
-                      .QueryInterface(Ci.nsIImageLoadingContent)
-                      .getRequest(Ci.nsIImageLoadingContent.CURRENT_REQUEST);
-    if (!request)
-      return true;
-
-    return false;
-  },
-
   setDesktopBackground: function() {
-    // Paranoia: check disableSetDesktopBackground again, in case the
-    // image changed since the context menu was initiated.
-    if (this.disableSetDesktopBackground())
-      return;
+    let mm = this.browser.messageManager;
 
-    var doc = this.target.ownerDocument;
-    urlSecurityCheck(this.target.currentURI.spec, this.principal);
+    mm.sendAsyncMessage("ContextMenu:SetAsDesktopBackground", null,
+                        { target: this.target });
 
-    // Confirm since it's annoying if you hit this accidentally.
-    const kDesktopBackgroundURL =
-                  "chrome://browser/content/setDesktopBackground.xul";
+    let onMessage = (message) => {
+      mm.removeMessageListener("ContextMenu:SetAsDesktopBackground:Result",
+                               onMessage);
+
+      if (message.data.disable)
+        return;
+
+      let image = document.createElementNS('http://www.w3.org/1999/xhtml', 'img');
+      image.src = message.data.dataUrl;
+
+      // Confirm since it's annoying if you hit this accidentally.
+      const kDesktopBackgroundURL =
+                    "chrome://browser/content/setDesktopBackground.xul";
 #ifdef XP_MACOSX
-    // On Mac, the Set Desktop Background window is not modal.
-    // Don't open more than one Set Desktop Background window.
-    var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]
-                       .getService(Components.interfaces.nsIWindowMediator);
-    var dbWin = wm.getMostRecentWindow("Shell:SetDesktopBackground");
-    if (dbWin) {
-      dbWin.gSetBackground.init(this.target);
-      dbWin.focus();
-    }
-    else {
-      openDialog(kDesktopBackgroundURL, "",
-                 "centerscreen,chrome,dialog=no,dependent,resizable=no",
-                 this.target);
-    }
+      // On Mac, the Set Desktop Background window is not modal.
+      // Don't open more than one Set Desktop Background window.
+      const wm = Cc["@mozilla.org/appshell/window-mediator;1"].
+                 getService(Ci.nsIWindowMediator);
+      let dbWin = wm.getMostRecentWindow("Shell:SetDesktopBackground");
+      if (dbWin) {
+        dbWin.gSetBackground.init(image);
+        dbWin.focus();
+      }
+      else {
+        openDialog(kDesktopBackgroundURL, "",
+                   "centerscreen,chrome,dialog=no,dependent,resizable=no",
+                   image);
+      }
 #else
-    // On non-Mac platforms, the Set Wallpaper dialog is modal.
-    openDialog(kDesktopBackgroundURL, "",
-               "centerscreen,chrome,dialog,modal,dependent",
-               this.target);
+      // On non-Mac platforms, the Set Wallpaper dialog is modal.
+      openDialog(kDesktopBackgroundURL, "",
+                 "centerscreen,chrome,dialog,modal,dependent",
+                 image);
 #endif
+    };
+
+    mm.addMessageListener("ContextMenu:SetAsDesktopBackground:Result", onMessage);
   },
 
   // Save URL of clicked-on frame.

browser/base/content/tabbrowser.xml

@@ -3890,6 +3890,7 @@
                                           contentDisposition: aMessage.data.contentDisposition,
                                           frameOuterWindowID: aMessage.data.frameOuterWindowID,
                                           selectionInfo: aMessage.data.selectionInfo,
+                                          disableSetDesktopBackground: aMessage.data.disableSetDesktopBg,
                                         };
               let popup = browser.ownerDocument.getElementById("contentAreaContextMenu");
               let event = gContextMenuContentData.event;