store SkAlphaType inside SkBitmap, on road to support unpremul

samplecode/SampleXfermodesBlur.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SampleCode.h"
 #include "SkView.h"
 #include "SkBlurMask.h"
@@ skipping 59 matching lines @@
         p.setColor(0x00AA6633 | alpha << 24);
         r.set(ww/3, hh/3, ww*19/20, hh*19/20);
         r.offset(x, y);
         canvas->drawRect(r, p);
     }
 
 public:
     const static int W = 64;
     const static int H = 64;
     XfermodesBlurView() {
-        fBG.setConfig(SkBitmap::kARGB_4444_Config, 2, 2, 4);
+        fBG.setConfig(SkBitmap::kARGB_4444_Config, 2, 2, 4, kOpaque_SkAlphaType);
         fBG.setPixels(gBG);
-        fBG.setIsOpaque(true);
     }
 
 protected:
     // overrides from SkEventSink
     virtual bool onQuery(SkEvent* evt) {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "XfermodesBlur");
             return true;
         }
         return this->INHERITED::onQuery(evt);
@@ skipping 111 matching lines @@
     }
 
 private:
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new XfermodesBlurView; }
 static SkViewRegister reg(MyFactory);