1 files changed, 25 insertions, 0 deletions
diff --git a/Source/WebCore/platform/graphics/cairo/PlatformContextCairo.h b/Source/WebCore/platform/graphics/cairo/PlatformContextCairo.h
index c6cceda..937417a 100644
--- a/Source/WebCore/platform/graphics/cairo/PlatformContextCairo.h
+++ b/Source/WebCore/platform/graphics/cairo/PlatformContextCairo.h
@@ -31,6 +31,25 @@
 
 namespace WebCore {
 
+// In Cairo image masking is immediate, so to emulate image clipping we must save masking
+// details as part of the context state and apply them during platform restore.
+class ImageMaskInformation {
+public:
+    void update(cairo_surface_t* maskSurface, const FloatRect& maskRect)
+    {
+        m_maskSurface = maskSurface;
+        m_maskRect = maskRect;
+    }
+
+    bool isValid() const { return m_maskSurface; }
+    cairo_surface_t* maskSurface() const { return m_maskSurface.get(); }
+    const FloatRect& maskRect() const { return m_maskRect; }
+
+private:
+    RefPtr<cairo_surface_t> m_maskSurface;
+    FloatRect m_maskRect;
+};
+
 // Much like PlatformContextSkia in the Skia port, this class holds information that
 // would normally be private to GraphicsContext, except that we want to allow access
 // to it in Font and Image code. This allows us to separate the concerns of Cairo-specific
@@ -40,11 +59,17 @@ class PlatformContextCairo {
     WTF_MAKE_NONCOPYABLE(PlatformContextCairo);
 public:
     PlatformContextCairo(cairo_t*);
+
     cairo_t* cr() { return m_cr.get(); }
     void setCr(cairo_t* cr) { m_cr = cr; }
 
+    void save();
+    void restore();
+    void pushImageMask(cairo_surface_t*, const FloatRect&);
+
 private:
     RefPtr<cairo_t> m_cr;
+    Vector<ImageMaskInformation> m_maskImageStack;
 };
 
 } // namespace WebCore