bug 78273, r=ftang/jbetak, sr=blizzard

for the embedding API add "get font list"

gfx/idl/nsIFontList.idl

@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 2001 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s): 
+ *   Brian Stell <bstell@netscape.com>
+ */
+
+#include "nsISupports.idl"
+
+interface nsISimpleEnumerator;
+
+/**
+ * The nsIFontList interface provides an application the  
+ * necessary information so that the user can select the font to use 
+ * as the default style sheet. This is used if the style sheet is 
+ * missing or does not specify a font.
+ * <P>Font lists are specified per language group.
+ *
+ */
+
+[scriptable, uuid(702909c6-1dd2-11b2-b833-8a740f643539)]
+interface nsIFontList : nsISupports
+{
+    
+  /**
+   * Get the list of available fonts for a language group
+   * and for use as the given CSS generic font.
+   *
+   * @param aLangGroup limits the fonts to fonts in a language 
+   *          group; eg: x-western (American/Western European), 
+   *          ar (Arabic), el (Greek), he (Hebrew), ja (Japanese),
+   *          ko (Korean), th (Thai), tr (Turkish),
+   *          x-baltic (Baltic), x-central-euro (Eastern European),
+   *          x-cyrillic (Russian), zh-CN (China), zh-TW (Taiwan)
+   *
+   * @param aFontType limits the fonts to the fonts with this CSS 
+   *          generic font type; eg: serif, sans-serif, cursive,
+   *          fantasy, monospace.
+   *
+   * @return a simple enumerator of the available fonts for a 
+   *          language group / generic type.  These strings are
+   *          the text supplied by the operating system's font 
+   *          system.
+   */
+  nsISimpleEnumerator availableFonts(in wstring aLangGroup, 
+                                     in wstring aFontType);
+};
+