2011-04-06 Martin Robinson <mrobinson@igalia.com>

        Reviewed by Xan Lopez.

        [Cairo] Hide the details of image masking in PlatformContextCairo
        https://bugs.webkit.org/show_bug.cgi?id=57878

        No new tests. This is just a refactor.

        * platform/graphics/GraphicsContext.h:
        * platform/graphics/cairo/GraphicsContextCairo.cpp:
        (WebCore::GraphicsContext::savePlatformState): Call into PlatformContextCairo now to
        do the actual cairo_save. Remove information about image masking.
        (WebCore::GraphicsContext::restorePlatformState): Call into PlatformContextCairo now to
        do the actual cairo_restore. Remove information about image masking.
        * platform/graphics/cairo/GraphicsContextPlatformPrivateCairo.h:
        * platform/graphics/cairo/ImageBufferCairo.cpp:
        (WebCore::ImageBuffer::clip): Use PlatformContextCairo here now.
        * platform/graphics/cairo/PlatformContextCairo.cpp:
        (WebCore::PlatformContextCairo::restore): Added.
        (WebCore::PlatformContextCairo::save): Added.
        (WebCore::PlatformContextCairo::pushImageMask): Added.
        * platform/graphics/cairo/PlatformContextCairo.h:
        (WebCore::ImageMaskInformation::update): Moved from GraphicsContextPlatformPrivateCairo.h.
        (WebCore::ImageMaskInformation::isValid): Ditto.
        (WebCore::ImageMaskInformation::maskSurface): Ditto.
        (WebCore::ImageMaskInformation::maskRect): Ditto.

git-svn-id: svn://svn.chromium.org/blink/trunk@83044 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/WebCore/ChangeLog

+2011-04-06  Martin Robinson  <mrobinson@igalia.com>
+
+        Reviewed by Xan Lopez.
+
+        [Cairo] Hide the details of image masking in PlatformContextCairo
+        https://bugs.webkit.org/show_bug.cgi?id=57878
+
+        No new tests. This is just a refactor.
+
+        * platform/graphics/GraphicsContext.h:
+        * platform/graphics/cairo/GraphicsContextCairo.cpp:
+        (WebCore::GraphicsContext::savePlatformState): Call into PlatformContextCairo now to
+        do the actual cairo_save. Remove information about image masking.
+        (WebCore::GraphicsContext::restorePlatformState): Call into PlatformContextCairo now to
+        do the actual cairo_restore. Remove information about image masking.
+        * platform/graphics/cairo/GraphicsContextPlatformPrivateCairo.h:
+        * platform/graphics/cairo/ImageBufferCairo.cpp:
+        (WebCore::ImageBuffer::clip): Use PlatformContextCairo here now.
+        * platform/graphics/cairo/PlatformContextCairo.cpp:
+        (WebCore::PlatformContextCairo::restore): Added.
+        (WebCore::PlatformContextCairo::save): Added.
+        (WebCore::PlatformContextCairo::pushImageMask): Added.
+        * platform/graphics/cairo/PlatformContextCairo.h:
+        (WebCore::ImageMaskInformation::update): Moved from GraphicsContextPlatformPrivateCairo.h.
+        (WebCore::ImageMaskInformation::isValid): Ditto.
+        (WebCore::ImageMaskInformation::maskSurface): Ditto.
+        (WebCore::ImageMaskInformation::maskRect): Ditto.
+
 2011-04-02  Diego Gonzalez  <diegohcg@webkit.org>
 
         Reviewed by Csaba Osztrogonác.

third_party/WebKit/Source/WebCore/platform/graphics/GraphicsContext.h

@@ -492,7 +492,6 @@ namespace WebCore {
 
 #if PLATFORM(CAIRO)
         GraphicsContext(cairo_t*);
-        void pushImageMask(cairo_surface_t*, const FloatRect&);
 #endif
 
 #if PLATFORM(GTK)

third_party/WebKit/Source/WebCore/platform/graphics/cairo/GraphicsContextCairo.cpp

@@ -235,24 +235,13 @@ PlatformContextCairo* GraphicsContext::platformContext() const
 
 void GraphicsContext::savePlatformState()
 {
-    cairo_save(platformContext()->cr());
+    platformContext()->save();
     m_data->save();
     m_data->shadowStack.append(m_data->shadow);
-    m_data->maskImageStack.append(ImageMaskInformation());
 }
 
 void GraphicsContext::restorePlatformState()
 {
-    cairo_t* cr = platformContext()->cr();
-
-    const ImageMaskInformation& maskInformation = m_data->maskImageStack.last();
-    if (maskInformation.isValid()) {
-        const FloatRect& maskRect = maskInformation.maskRect();
-        cairo_pop_group_to_source(cr);
-        cairo_mask_surface(cr, maskInformation.maskSurface(), maskRect.x(), maskRect.y());
-    }
-    m_data->maskImageStack.removeLast();
-
     if (m_data->shadowStack.isEmpty())
         m_data->shadow = ContextShadow();
     else {
@@ -260,7 +249,7 @@ void GraphicsContext::restorePlatformState()
         m_data->shadowStack.removeLast();
     }
 
-    cairo_restore(cr);
+    platformContext()->restore();
     m_data->restore();
 }
 
@@ -1191,33 +1180,6 @@ InterpolationQuality GraphicsContext::imageInterpolationQuality() const
     return InterpolationDefault;
 }
 
-void GraphicsContext::pushImageMask(cairo_surface_t* surface, const FloatRect& rect)
-{
-    // We must call savePlatformState at least once before we can use image masking,
-    // since we actually apply the mask in restorePlatformState.
-    ASSERT(!m_data->maskImageStack.isEmpty());
-    m_data->maskImageStack.last().update(surface, rect);
-
-    // Cairo doesn't support the notion of an image clip, so we push a group here
-    // and then paint it to the surface with an image mask (which is an immediate
-    // operation) during restorePlatformState.
-
-    // We want to allow the clipped elements to composite with the surface as it
-    // is now, but they are isolated in another group. To make this work, we're
-    // going to blit the current surface contents onto the new group once we push it.
-    cairo_t* cr = platformContext()->cr();
-    cairo_surface_t* currentTarget = cairo_get_target(cr);
-    cairo_surface_flush(currentTarget);
-
-    // Pushing a new group ensures that only things painted after this point are clipped.
-    cairo_push_group(cr);
-    cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
-
-    cairo_set_source_surface(cr, currentTarget, 0, 0);
-    cairo_rectangle(cr, rect.x(), rect.y(), rect.width(), rect.height());
-    cairo_fill(cr);
-}
-
 } // namespace WebCore
 
 #endif // PLATFORM(CAIRO)

third_party/WebKit/Source/WebCore/platform/graphics/cairo/GraphicsContextPlatformPrivateCairo.h

@@ -47,25 +47,6 @@ typedef struct _GdkExposeEvent GdkExposeEvent;
 
 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 it 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;
-};
-
 class GraphicsContextPlatformPrivate {
 public:
     GraphicsContextPlatformPrivate(PlatformContextCairo* newPlatformContext)
@@ -121,7 +102,6 @@ public:
     Vector<float> layers;
     ContextShadow shadow;
     Vector<ContextShadow> shadowStack;
-    Vector<ImageMaskInformation> maskImageStack;
 
 #if PLATFORM(GTK)
     GdkEventExpose* expose;

third_party/WebKit/Source/WebCore/platform/graphics/cairo/ImageBufferCairo.cpp

@@ -117,7 +117,7 @@ PassRefPtr<Image> ImageBuffer::copyImage() const
 
 void ImageBuffer::clip(GraphicsContext* context, const FloatRect& maskRect) const
 {
-    context->pushImageMask(m_data.m_surface, maskRect);
+    context->platformContext()->pushImageMask(m_data.m_surface, maskRect);
 }
 
 void ImageBuffer::draw(GraphicsContext* context, ColorSpace styleColorSpace, const FloatRect& destRect, const FloatRect& srcRect,

third_party/WebKit/Source/WebCore/platform/graphics/cairo/PlatformContextCairo.cpp

@@ -35,4 +35,51 @@ PlatformContextCairo::PlatformContextCairo(cairo_t* cr)
 {
 }
 
+void PlatformContextCairo::restore()
+{
+    const ImageMaskInformation& maskInformation = m_maskImageStack.last();
+    if (maskInformation.isValid()) {
+        const FloatRect& maskRect = maskInformation.maskRect();
+        cairo_pop_group_to_source(m_cr.get());
+        cairo_mask_surface(m_cr.get(), maskInformation.maskSurface(), maskRect.x(), maskRect.y());
+    }
+    m_maskImageStack.removeLast();
+
+    cairo_restore(m_cr.get());
+}
+
+void PlatformContextCairo::save()
+{
+    m_maskImageStack.append(ImageMaskInformation());
+
+    cairo_save(m_cr.get());
+}
+
+void PlatformContextCairo::pushImageMask(cairo_surface_t* surface, const FloatRect& rect)
+{
+    // We must call savePlatformState at least once before we can use image masking,
+    // since we actually apply the mask in restorePlatformState.
+    ASSERT(!m_data->maskImageStack.isEmpty());
+    m_maskImageStack.last().update(surface, rect);
+
+    // Cairo doesn't support the notion of an image clip, so we push a group here
+    // and then paint it to the surface with an image mask (which is an immediate
+    // operation) during restorePlatformState.
+
+    // We want to allow the clipped elements to composite with the surface as it
+    // is now, but they are isolated in another group. To make this work, we're
+    // going to blit the current surface contents onto the new group once we push it.
+    cairo_surface_t* currentTarget = cairo_get_target(m_cr.get());
+    cairo_surface_flush(currentTarget);
+
+    // Pushing a new group ensures that only things painted after this point are clipped.
+    cairo_push_group(m_cr.get());
+    cairo_set_operator(m_cr.get(), CAIRO_OPERATOR_SOURCE);
+
+    cairo_set_source_surface(m_cr.get(), currentTarget, 0, 0);
+    cairo_rectangle(m_cr.get(), rect.x(), rect.y(), rect.width(), rect.height());
+    cairo_fill(m_cr.get());
+}
+
+
 } // namespace WebCore

third_party/WebKit/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