From 024d8acf0d75a91179b6ec1245da53e2836e500a Mon Sep 17 00:00:00 2001
From: Jeff Muizelaar <jmuizelaar@mozilla.com>
Date: Mon, 16 Aug 2010 09:15:03 +0200
Subject: [PATCH] Bug 587395: Expose whether DWrite is enabled through
 nsIGfxInfo. r=joedrew

---
 gfx/thebes/gfxWindowsPlatform.h | 3 +++
 widget/public/nsIGfxInfo.idl    | 3 +++
 widget/src/windows/GfxInfo.cpp  | 6 ++++++
 3 files changed, 12 insertions(+)

diff --git a/gfx/thebes/gfxWindowsPlatform.h b/gfx/thebes/gfxWindowsPlatform.h
index 9b8d6230de3..364c05524a4 100644
--- a/gfx/thebes/gfxWindowsPlatform.h
+++ b/gfx/thebes/gfxWindowsPlatform.h
@@ -213,6 +213,9 @@ public:
 
 #ifdef CAIRO_HAS_DWRITE_FONT
     IDWriteFactory *GetDWriteFactory() { return mDWriteFactory; }
+    inline PRBool DWriteEnabled() { return !!mDWriteFactory; }
+#else
+    inline PRBool DWriteEnabled() { return PR_FALSE; }
 #endif
 #ifdef CAIRO_HAS_D2D_SURFACE
     cairo_device_t *GetD2DDevice() { return mD2DDevice; }
diff --git a/widget/public/nsIGfxInfo.idl b/widget/public/nsIGfxInfo.idl
index e2dc9b9812e..74eebf2bda6 100644
--- a/widget/public/nsIGfxInfo.idl
+++ b/widget/public/nsIGfxInfo.idl
@@ -38,9 +38,12 @@
 
 #include "nsISupports.idl"
 
+/* NOTE: this interface is completely undesigned, not stable and likely to change */
+
 [scriptable, uuid(5C05E5B7-0FCC-4070-BF6B-58BC33ECA427)]
 interface nsIGfxInfo : nsISupports
 {
   readonly attribute boolean D2DEnabled;
+  readonly attribute boolean DWriteEnabled;
 };
 
diff --git a/widget/src/windows/GfxInfo.cpp b/widget/src/windows/GfxInfo.cpp
index 2bc2bd064c0..c5aefd8aeca 100644
--- a/widget/src/windows/GfxInfo.cpp
+++ b/widget/src/windows/GfxInfo.cpp
@@ -47,3 +47,9 @@ nsresult GfxInfo::GetD2DEnabled(PRBool *aEnabled)
   *aEnabled = gfxWindowsPlatform::GetPlatform()->GetRenderMode() == gfxWindowsPlatform::RENDER_DIRECT2D;
   return NS_OK;
 }
+
+nsresult GfxInfo::GetDWriteEnabled(PRBool *aEnabled)
+{
+  *aEnabled = gfxWindowsPlatform::GetPlatform()->DWriteEnabled();
+  return NS_OK;
+}