# HG changeset patch

# Parent fd2da289a3c15b8c96c248df2710d879793f22c9

# User Wolfgang Rosenauer <wr@rosenauer.org>

Bug 526717 - remove non-working "Set as desktop background" from the UI for unsupported desktops

@@ -262,17 +262,17 @@ nsContextMenu.prototype = {

     if (shell)

-      haveSetDesktopBackground = true;

+      haveSetDesktopBackground = shell.canSetDesktopBackground;

     }

diff --git a/browser/components/shell/public/nsIShellService.idl b/browser/components/shell/public/nsIShellService.idl

--- a/browser/components/shell/public/nsIShellService.idl

+++ b/browser/components/shell/public/nsIShellService.idl

@@ -69,16 +69,25 @@ interface nsIShellService : nsISupports

   /** 

    * Used to determine whether or not to show a "Set Default Browser"

    * query dialog. This attribute is true if the application is starting

    * up and "browser.shell.checkDefaultBrowser" is true, otherwise it

    * is false.

    */

   attribute boolean shouldCheckDefaultBrowser;

+  /**

+   * Used to determine whether or not to offer "Set as desktop background"

+   * context menu item. Even if shell service is available it is not

+   * guaranteed that it is able to set the background for every desktop

+   * which is especially true for Linux with its many different desktop

+   * environments.

+   */

+  readonly attribute boolean canSetDesktopBackground;

+

   /** 

    * Flags for positioning/sizing of the Desktop Background image.

    */

   const long BACKGROUND_TILE      = 1;

   const long BACKGROUND_STRETCH   = 2;

   const long BACKGROUND_CENTER    = 3;

   const long BACKGROUND_FILL      = 4;

   const long BACKGROUND_FIT       = 5;

diff --git a/browser/components/shell/src/nsGNOMEShellService.cpp b/browser/components/shell/src/nsGNOMEShellService.cpp

--- a/browser/components/shell/src/nsGNOMEShellService.cpp

+++ b/browser/components/shell/src/nsGNOMEShellService.cpp

@@ -377,16 +377,31 @@ nsGNOMEShellService::SetShouldCheckDefau

     pserve->GetBranch("", getter_AddRefs(prefs));

   if (prefs)

     prefs->SetBoolPref(PREF_CHECKDEFAULTBROWSER, aShouldCheck);

   return NS_OK;

 }

+NS_IMETHODIMP

+nsGNOMEShellService::GetCanSetDesktopBackground(bool* aResult)

+{

+  // setting desktop background is currently only supported

+  // for Gnome or desktops using the same GSettings and GConf keys

+  const char* gnomeSession = getenv("GNOME_DESKTOP_SESSION_ID");

+  if (gnomeSession) {

+    *aResult = true;

+  } else {

+    *aResult = false;

+  }

+

+  return NS_OK;

+}

+

 static nsresult

 WriteImage(const nsCString& aPath, imgIContainer* aImage)

 {

 #ifndef MOZ_WIDGET_GTK2

   return NS_ERROR_NOT_AVAILABLE;

 #else

   nsCOMPtr<nsIImageToPixbuf> imgToPixbuf =

     do_GetService("@mozilla.org/widget/image-to-gdk-pixbuf;1");