Bug 702517 - Add SupportsAzure function to decide which backend to use. r=jrmuizel

gfx/thebes/gfxAndroidPlatform.cpp

@@ -79,12 +79,6 @@ gfxAndroidPlatform::CreateOffscreenSurface(const gfxIntSize& size,
     return newSurface.forget();
 }
 
-RefPtr<DrawTarget>
-gfxAndroidPlatform::CreateOffscreenDrawTarget(const IntSize& aSize, SurfaceFormat aFormat)
-{
-  return Factory::CreateDrawTarget(BACKEND_SKIA, aSize, aFormat);
-}
-
 nsresult
 gfxAndroidPlatform::GetFontList(nsIAtom *aLangGroup,
                                 const nsACString& aGenericFamily,

gfx/thebes/gfxAndroidPlatform.h

@@ -66,8 +66,7 @@ public:
     CreateOffscreenSurface(const gfxIntSize& size,
                            gfxASurface::gfxContentType contentType);
     
-    virtual mozilla::RefPtr<mozilla::gfx::DrawTarget>
-      CreateOffscreenDrawTarget(const mozilla::gfx::IntSize& aSize, mozilla::gfx::SurfaceFormat aFormat);
+    virtual bool SupportsAzure(mozilla::gfx::BackendType& aBackend) { aBackend = mozilla::gfx::BACKEND_SKIA; return true; }
 
     virtual gfxImageFormat GetOffscreenFormat() { return gfxASurface::ImageFormatRGB16_565; }
     

gfx/thebes/gfxPlatform.cpp

@@ -546,7 +546,11 @@ gfxPlatform::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
 RefPtr<DrawTarget>
 gfxPlatform::CreateOffscreenDrawTarget(const IntSize& aSize, SurfaceFormat aFormat)
 {
-  return NULL;
+  BackendType backend;
+  if (!SupportsAzure(backend)) {
+    return NULL;
+  }
+  return Factory::CreateDrawTarget(backend, aSize, aFormat); 
 }
 
 nsresult

gfx/thebes/gfxPlatform.h

@@ -188,6 +188,8 @@ public:
     virtual mozilla::RefPtr<mozilla::gfx::DrawTarget>
       CreateOffscreenDrawTarget(const mozilla::gfx::IntSize& aSize, mozilla::gfx::SurfaceFormat aFormat);
 
+    virtual bool SupportsAzure(mozilla::gfx::BackendType& aBackend) { return false; }
+
     /*
      * Font bits
      */

gfx/thebes/gfxPlatformMac.cpp

@@ -139,12 +139,6 @@ gfxPlatformMac::CreateOffscreenSurface(const gfxIntSize& size,
     return newSurface;
 }
     
-RefPtr<DrawTarget>
-gfxPlatformMac::CreateOffscreenDrawTarget(const IntSize& aSize, SurfaceFormat aFormat)
-{
-  return Factory::CreateDrawTarget(BACKEND_SKIA, aSize, aFormat);
-}
-
 already_AddRefed<gfxASurface>
 gfxPlatformMac::OptimizeImage(gfxImageSurface *aSurface,
                               gfxASurface::gfxImageFormat format)
@@ -179,6 +173,13 @@ gfxPlatformMac::GetScaledFontForFont(gfxFont *aFont)
     return scaledFont;
 }
 
+bool
+gfxPlatformMac::SupportsAzure(BackendType& aBackend)
+{
+  aBackend = BACKEND_SKIA;
+  return true;
+}
+
 nsresult
 gfxPlatformMac::ResolveFontName(const nsAString& aFontName,
                                 FontResolverCallback aCallback,

gfx/thebes/gfxPlatformMac.h

@@ -63,15 +63,14 @@ public:
     already_AddRefed<gfxASurface> CreateOffscreenSurface(const gfxIntSize& size,
                                                          gfxASurface::gfxContentType contentType);
     
-    virtual mozilla::RefPtr<mozilla::gfx::DrawTarget>
-      CreateOffscreenDrawTarget(const mozilla::gfx::IntSize& aSize, mozilla::gfx::SurfaceFormat aFormat);
-
     already_AddRefed<gfxASurface> OptimizeImage(gfxImageSurface *aSurface,
                                                 gfxASurface::gfxImageFormat format);
     
     mozilla::RefPtr<mozilla::gfx::ScaledFont>
       GetScaledFontForFont(gfxFont *aFont);
 
+    virtual bool SupportsAzure(mozilla::gfx::BackendType& aBackend);
+
     nsresult ResolveFontName(const nsAString& aFontName,
                              FontResolverCallback aCallback,
                              void *aClosure, bool& aAborted);

gfx/thebes/gfxWindowsPlatform.cpp

@@ -474,22 +474,6 @@ gfxWindowsPlatform::CreateOffscreenSurface(const gfxIntSize& size,
     return surf;
 }
 
-RefPtr<DrawTarget>
-gfxWindowsPlatform::CreateOffscreenDrawTarget(const IntSize& aSize, SurfaceFormat aFormat)
-{
-#ifdef CAIRO_HAS_D2D_SURFACE
-  if (mRenderMode == RENDER_DIRECT2D) {
-      return Factory::CreateDrawTarget(BACKEND_DIRECT2D, aSize, aFormat); 
-  }
-#endif
-
-  if (Preferences::GetBool("gfx.canvas.azure.prefer-skia", false)) {
-    return Factory::CreateDrawTarget(BACKEND_SKIA, aSize, aFormat);
-  }
-
-  return NULL;
-}
-
 RefPtr<ScaledFont>
 gfxWindowsPlatform::GetScaledFontForFont(gfxFont *aFont)
 {
@@ -540,6 +524,23 @@ gfxWindowsPlatform::GetThebesSurfaceForDrawTarget(DrawTarget *aTarget)
   return gfxPlatform::GetThebesSurfaceForDrawTarget(aTarget);
 }
 
+bool
+gfxWindowsPlatform::SupportsAzure(BackendType& aBackend)
+{
+#ifdef CAIRO_HAS_D2D_SURFACE
+  if (mRenderMode == RENDER_DIRECT2D) {
+      aBackend = BACKEND_DIRECT2D;
+      return true;
+  }
+#endif
+  
+  if (Preferences::GetBool("gfx.canvas.azure.prefer-skia", false)) {
+    aBackend = BACKEND_SKIA;
+    return true;
+  }
+  return false;
+}
+
 nsresult
 gfxWindowsPlatform::GetFontList(nsIAtom *aLangGroup,
                                 const nsACString& aGenericFamily,

gfx/thebes/gfxWindowsPlatform.h

@@ -131,8 +131,8 @@ public:
       GetScaledFontForFont(gfxFont *aFont);
     virtual already_AddRefed<gfxASurface>
       GetThebesSurfaceForDrawTarget(mozilla::gfx::DrawTarget *aTarget);
-    virtual mozilla::RefPtr<mozilla::gfx::DrawTarget>
-      CreateOffscreenDrawTarget(const mozilla::gfx::IntSize& aSize, mozilla::gfx::SurfaceFormat aFormat);
+    
+    virtual bool SupportsAzure(mozilla::gfx::BackendType& aBackend);
 
     enum RenderMode {
         /* Use GDI and windows surfaces */