Bug 507032 - "Set As Desktop Background..." doesn't work on Windows CE, r=robert.bugzilla

browser/components/shell/content/setDesktopBackground.xul

@@ -77,7 +77,9 @@
         <menupopup>
           <menuitem label="&center.label;"  value="CENTER"/>
           <menuitem label="&tile.label;"    value="TILE"/>
+#ifndef WINCE
           <menuitem label="&stretch.label;" value="STRETCH"/>
+#endif
         </menupopup>
       </menulist>
       <spacer flex="1"/>

browser/components/shell/src/nsWindowsShellService.cpp

@@ -26,6 +26,7 @@
  *  Robert Strong  <robert.bugzilla@gmail.com>
  *  Asaf Romano    <mano@mozilla.com>
  *  Ryan Jones     <sciguyryan@gmail.com>
+ *  Paul O'Shannessy <paul@oshannessy.com>
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or
@@ -215,9 +216,11 @@ typedef struct {
 #define APP_REG_NAME L"Firefox"
 #define CLS_HTML "FirefoxHTML"
 #define CLS_URL "FirefoxURL"
+#define CPL_DESKTOP L"\\Control Panel\\Desktop"
 #define VAL_OPEN "\"%APPPATH%\" -requestPending -osint -url \"%1\""
 #define VAL_FILE_ICON "%APPPATH%,1"
 #else
+#define CPL_DESKTOP L"\\ControlPanel\\Desktop"
 #define VAL_OPEN "\"%APPPATH%\" -osint -url \"%1\""
 #define VAL_FILE_ICON "%APPPATH%,-2"
 #endif
@@ -656,12 +659,12 @@ nsWindowsShellService::SetDesktopBackground(nsIDOMElement* aElement,
      PRBool result = PR_FALSE;
      DWORD  dwDisp = 0;
      HKEY   key;
-     // Try to create/open a subkey under HKLM.
-     DWORD res = ::RegCreateKeyExW(HKEY_CURRENT_USER,
-                                   L"Control Panel\\Desktop",
+     // Try to create/open a subkey under HKCU.
+     DWORD res = ::RegCreateKeyExW(HKEY_CURRENT_USER, CPL_DESKTOP,
                                    0, NULL, REG_OPTION_NON_VOLATILE,
                                    KEY_WRITE, NULL, &key, &dwDisp);
     if (REG_SUCCEEDED(res)) {
+#ifndef WINCE
       PRUnichar tile[2], style[2];
       switch (aPosition) {
         case BACKGROUND_TILE:
@@ -688,8 +691,25 @@ nsWindowsShellService::SetDesktopBackground(nsIDOMElement* aElement,
                        0, REG_SZ, (const BYTE *)style, size);
       ::SystemParametersInfoW(SPI_SETDESKWALLPAPER, 0, (PVOID)path.get(),
                               SPIF_UPDATEINIFILE | SPIF_SENDCHANGE);
+#else
+      DWORD tile = (aPosition == BACKGROUND_TILE);
+      ::RegSetValueExW(key, L"Tile",
+                       0, REG_DWORD, (const BYTE *)&tile, sizeof(DWORD));
+      // On WinCE SPI_SETDESKWALLPAPER isn't available, so set the registry
+      // entry ourselves and then broadcast UI change
+      PRInt32 size = (path.Length() + 1) * sizeof(PRUnichar);
+      ::RegSetValueExW(key, L"Wallpaper",
+                       0, REG_SZ, (const BYTE *)path.get(), size);
+      ::SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, NULL, 0);
+#endif
+
       // Close the key we opened.
       ::RegCloseKey(key);
+
+#ifdef WINCE
+      // Ensure that the writes are flushed in case of hard reboot
+      ::RegFlushKey(HKEY_CURRENT_USER);
+#endif
     }
   }
   return rv;
@@ -815,10 +835,13 @@ nsWindowsShellService::SetDesktopBackgroundColor(PRUint32 aColor)
 
   ::SetSysColors(sizeof(aParameters) / sizeof(int), aParameters, colors);
 
+  // SetSysColors is persisting across sessions on Windows CE, so no need to
+  // write to registry
+#ifndef WINCE
   PRBool result = PR_FALSE;
   DWORD  dwDisp = 0;
   HKEY   key;
-  // Try to create/open a subkey under HKLM.
+  // Try to create/open a subkey under HKCU.
   DWORD rv = ::RegCreateKeyExW(HKEY_CURRENT_USER,
                                L"Control Panel\\Colors", 0, NULL,
                                REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL,
@@ -836,6 +859,7 @@ nsWindowsShellService::SetDesktopBackgroundColor(PRUint32 aColor)
   
   // Close the key we opened.
   ::RegCloseKey(key);
+#endif
   return NS_OK;
 }