add optional SkAlphaType parameter to notifyPixelsChanged

src/core/SkBitmap.cpp

 
 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkBitmap.h"
@@ skipping 304 matching lines @@
 bool SkBitmap::setConfig(const SkImageInfo& info, size_t rowBytes) {
     return this->setConfig(SkImageInfoToBitmapConfig(info), info.fWidth,
                            info.fHeight, rowBytes, info.fAlphaType);
 }
 
 bool SkBitmap::setAlphaType(SkAlphaType alphaType) {
     if (!validate_alphaType(this->config(), alphaType, &alphaType)) {
         return false;
     }
     fAlphaType = SkToU8(alphaType);
+    if (fPixelRef) {
+        fPixelRef->notifyAlphaTypeChanged(alphaType);

[scroggo, 2014/01/24 20:50:52]

One downside is that if a bitmap representing an opaque subset calls this, the
full set has its alpha type changed. I think we all agreed we don't care about
such a use case, so that's fine.

Maybe we could put a comment in the doc that it will affect all bitmaps pointing
to the same pixel ref (which I assume Hal won't like because it means more
exposure for pixel refs). I'm fine with or without the added comment.

[reed1, 2014/01/27 13:46:14]

Done.

+    }
     return true;
 }
 
 void SkBitmap::updatePixelsFromRef() const {
     if (NULL != fPixelRef) {
         if (fPixelLockCount > 0) {
             SkASSERT(fPixelRef->isLocked());
 
             void* p = fPixelRef->pixels();
             if (NULL != p) {
@@ skipping 1368 matching lines @@
         if (NULL != uri) {
             str->appendf(" uri:\"%s\"", uri);
         } else {
             str->appendf(" pixelref:%p", pr);
         }
     }
 
     str->append(")");
 }
 #endif