When printing a page containing alpha blending on a printer which doesn't support alpha blending, post-process the

metafile to replace the AlphaBlend calls with BitBlts from a software-composited rendering of the page so far.

BUG=7434
TEST=see bug

Review URL: http://codereview.chromium.org/5362002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71177 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 8 insertions, 1 deletions

diff --git a/skia/ext/vector_platform_device_win.cc b/skia/ext/vector_platform_device_win.cc
index 31ac722..6ec4e39 100644
--- a/skia/ext/vector_platform_device_win.cc
+++ b/skia/ext/vector_platform_device_win.cc
@@ -104,7 +104,8 @@ VectorPlatformDevice::VectorPlatformDevice(HDC dc, const SkBitmap& bitmap)
     : PlatformDevice(bitmap),
       hdc_(dc),
       previous_brush_(NULL),
-      previous_pen_(NULL) {
+      previous_pen_(NULL),
+      alpha_blend_used_(false) {
   transform_.reset();
 }
 
@@ -698,6 +699,8 @@ void VectorPlatformDevice::InternalDrawBitmap(const SkBitmap& bitmap,
     result = SetStretchBltMode(dc, previous_mode);
     SkASSERT(result);
 
+    alpha_blend_used_ = true;
+
     ::SelectObject(bitmap_dc, static_cast<HBITMAP>(old_bitmap));
     DeleteObject(hbitmap);
     DeleteDC(bitmap_dc);
diff --git a/skia/ext/vector_platform_device_win.h b/skia/ext/vector_platform_device_win.h
index 2a5057e..3050a90 100644
--- a/skia/ext/vector_platform_device_win.h
+++ b/skia/ext/vector_platform_device_win.h
@@ -81,6 +81,7 @@ class VectorPlatformDevice : public PlatformDevice {
   virtual bool IsVectorial() { return true; }
 
   void LoadClipRegion();
+  bool alpha_blend_used() const { return alpha_blend_used_; }
 
  private:
   // Applies the SkPaint's painting properties in the current GDI context, if
@@ -129,6 +130,9 @@ class VectorPlatformDevice : public PlatformDevice {
   // Previously selected pen before the current drawing.
   HGDIOBJ previous_pen_;
 
+  // True if AlphaBlend() was called during this print.
+  bool alpha_blend_used_;
+
   // Copy & assign are not supported.
   VectorPlatformDevice(const VectorPlatformDevice&);
   const VectorPlatformDevice& operator=(const VectorPlatformDevice&);