added font existence API.

gfx/src/motif/nsDeviceContextUnix.h

@@ -97,6 +97,8 @@ public:
                            PRInt32              aId,
                            nsIImage*&           aImage);
 
+  NS_IMETHOD CheckFontExistence(const char * aFontName);
+
 protected:
   ~nsDeviceContextUnix();
   nsresult CreateFontCache();

gfx/src/nsIDeviceContext.h

@@ -108,6 +108,7 @@ public:
                            PRInt32              aId,
                            nsIImage*&           aImage) = 0;
 
+  NS_IMETHOD CheckFontExistence(const char * aFontName) = 0;
 };
 
 #endif /* nsIDeviceContext_h___ */

gfx/src/windows/nsDeviceContextWin.cpp

@@ -59,4 +59,28 @@ nsDrawingSurface nsDeviceContextWin :: GetDrawingSurface(nsIRenderingContext &aC
   return mSurface;
 }
 
+int CALLBACK fontcallback(ENUMLOGFONT FAR *lpelf, NEWTEXTMETRIC FAR *lpntm,
+                          int FontType, LPARAM lParam)  
+{
+  if (NULL != lpelf)
+    *((PRBool *)lParam) = PR_TRUE;
+
+  return 0;
+}
+
+NS_IMETHODIMP nsDeviceContextWin :: CheckFontExistence(const char * aFontName)
+{
+  HWND    hwnd = (HWND)GetNativeWidget();
+  HDC     hdc = ::GetDC(hwnd);
+  PRBool  isthere = PR_FALSE;
+
+  ::EnumFontFamilies(hdc, aFontName, (FONTENUMPROC)fontcallback, (LPARAM)&isthere);
+
+  ::ReleaseDC(hwnd, hdc);
+
+  if (PR_TRUE == isthere)
+    return NS_OK;
+  else
+    return NS_ERROR_FAILURE;
+}
 

gfx/src/windows/nsDeviceContextWin.h

@@ -36,6 +36,8 @@ public:
   //in the device context for re-use.
   virtual nsDrawingSurface GetDrawingSurface(nsIRenderingContext &aContext);
 
+  NS_IMETHOD CheckFontExistence(const char * aFontName);
+
 protected:
   virtual ~nsDeviceContextWin();