Bug 134754; add scriptiable API to get Win32 registry value; r=sgehani, sr=dveditz

xpfe/components/winhooks/nsIWindowsHooks.idl

@@ -200,6 +200,29 @@ interface nsIWindowsHooks : nsISupports {
     void setImageAsWallpaper(in nsIDOMElement aImageElement, in boolean useBackground);
 };
 
+/* nsIWindowsRegistry
+ *
+ * This interface describes the service that you can use to
+ * get/set Win32 registry entries.
+ * 
+ * Notice: This interface is incomplete and should be used at your own risk!
+ */
+[scriptable, uuid(e07e7430-8d11-417c-83ee-c994400c452f)]
+interface nsIWindowsRegistry : nsISupports {
+    /**
+     * Returns a Win32 registry entry value.  The returned string will be truncated
+     * at 4096 bytes.  The constants define the set of valid starting keys.  You
+     * pass in the subkey name and a value identifier (an empty string returns
+     * the "default" value for that subkey).
+     */
+    const long HKCR = 0; // HKEY_CLASSES_ROOT
+    const long HKCC = 1; // HKEY_CURRENT_CONFIG
+    const long HKCU = 2; // HKEY_CURRENT_USER
+    const long HKLM = 3; // HKEY_LOCAL_MACHINE
+    const long HKU  = 4; // HKEY_USERS
+    string getRegistryEntry( in long aHKeyConstant, in string aSubKeyName, in string aValueName );
+};
+
 %{C++
 #define NS_IWINDOWSHOOKS_CONTRACTID    "@mozilla.org/winhooks;1"
 #define NS_IWINDOWSHOOKS_CLASSNAME "Mozilla Windows Integration Hooks"

xpfe/components/winhooks/nsWindowsHooks.cpp

@@ -172,7 +172,7 @@ DEFINE_GETTER_AND_SETTER( HaveBeenSet,      mHaveBeenSet  )
 
 // Implementation of the nsIWindowsHooks interface.
 // Use standard implementation of nsISupports stuff.
-NS_IMPL_ISUPPORTS1( nsWindowsHooks, nsIWindowsHooks );
+NS_IMPL_ISUPPORTS2( nsWindowsHooks, nsIWindowsHooks, nsIWindowsRegistry );
 
 nsWindowsHooks::nsWindowsHooks() {
   NS_INIT_ISUPPORTS();
@@ -647,6 +647,40 @@ nsWindowsHooks::SetRegistry() {
     return NS_OK;
 }
 
+NS_IMETHODIMP nsWindowsHooks::GetRegistryEntry( PRInt32 aHKEYConstant, const char *aSubKeyName, const char *aValueName, char **aResult ) {
+    NS_ENSURE_ARG( aResult );
+    *aResult = 0;
+    // Calculate HKEY_* starting point based on input nsIWindowsHooks constant.
+    HKEY hKey;
+    switch ( aHKEYConstant ) {
+        case HKCR:
+            hKey = HKEY_CLASSES_ROOT;
+            break;
+        case HKCC:
+            hKey = HKEY_CURRENT_CONFIG;
+            break;
+        case HKCU:
+            hKey = HKEY_CURRENT_USER;
+            break;
+        case HKLM:
+            hKey = HKEY_LOCAL_MACHINE;
+            break;
+        case HKU:
+            hKey = HKEY_USERS;
+            break;
+        default:
+            return NS_ERROR_INVALID_ARG;
+    }
+
+    // Get requested registry entry.
+    nsCAutoString entry( RegistryEntry( hKey, aSubKeyName, aValueName, 0 ).currentSetting() );
+
+    // Copy to result.
+    *aResult = PL_strdup( entry.get() );
+
+    return *aResult ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
+}
+
 // nsIWindowsHooks.idl for documentation
 
 /*
@@ -742,6 +776,7 @@ NS_IMETHODIMP nsWindowsHooks::StartupAddOption(const char* option) {
     newsetting.Append(option);
     startup.setting = newsetting;
     startup.set();    
+    return NS_OK;
 }
 
 /*
@@ -944,9 +979,3 @@ nsWindowsHooks::SetImageAsWallpaper(nsIDOMElement* aElement, PRBool aUseBackgrou
 
   return rv;
 }
-
-#if (_MSC_VER == 1100)
-#define INITGUID
-#include "objbase.h"
-DEFINE_OLEGUID(IID_IPersistFile, 0x0000010BL, 0, 0);
-#endif

xpfe/components/winhooks/nsWindowsHooks.h

@@ -102,7 +102,7 @@ private:
     friend class nsWindowsHooks;
 }; // nsWindowsHooksSettings
 
-class nsWindowsHooks : public nsIWindowsHooks {
+class nsWindowsHooks : public nsIWindowsHooks, public nsIWindowsRegistry {
 public:
     // ctor/dtor
     nsWindowsHooks();
@@ -111,6 +111,7 @@ public:
     // Declare all interface methods we must implement.
     NS_DECL_ISUPPORTS
     NS_DECL_NSIWINDOWSHOOKS
+    NS_DECL_NSIWINDOWSREGISTRY
 
 protected:
     // Internal flavor of GetPreferences.