add optional SkAlphaType parameter to notifyPixelsChanged

include/core/SkPixelRef.h

-
 /*
  * 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.
  */
 
-
 #ifndef SkPixelRef_DEFINED
 #define SkPixelRef_DEFINED
 
 #include "SkBitmap.h"
 #include "SkRefCnt.h"
 #include "SkString.h"
 #include "SkFlattenable.h"
 #include "SkImageInfo.h"
 #include "SkTDArray.h"
 
@@ skipping 101 matching lines @@
      *  modifications will be lost when unlockPixels() is called.)
      */
     bool lockPixelsAreWritable() const;
 
     /** Returns a non-zero, unique value corresponding to the pixels in this
         pixelref. Each time the pixels are changed (and notifyPixelsChanged is
         called), a different generation ID will be returned.
     */
     uint32_t getGenerationID() const;
 
-    /** Call this if you have changed the contents of the pixels. This will in-
-        turn cause a different generation ID value to be returned from
-        getGenerationID().
-    */
-    void notifyPixelsChanged();
+    /**
+     *  Call this if you have changed the contents of the pixels. This will in-
+     *  turn cause a different generation ID value to be returned from
+     *  getGenerationID().
+     *
+     *  If the alphatype has also changed, specify its new value as well. If
+     *  the new pixels' alphatype is the same, this can be called with no
+     *  parameter.
+     */
+    void notifyPixelsChanged(SkAlphaType);
+    void notifyPixelsChanged() {
+        this->notifyPixelsChanged(fInfo.fAlphaType);
+    }
 
     /** Returns true if this pixelref is marked as immutable, meaning that the
         contents of its pixels will not change for the lifetime of the pixelref.
     */
     bool isImmutable() const { return fIsImmutable; }
 
     /** Marks this pixelref is immutable, meaning that the contents of its
         pixels will not change for the lifetime of the pixelref. This state can
         be set on a pixelref, but it cannot be cleared once it is set.
     */
@@ skipping 180 matching lines @@
     virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
 
     // only call from constructor. Flags this to always be locked, removing
     // the need to grab the mutex and call onLockPixels/onUnlockPixels.
     // Performance tweak to avoid those calls (esp. in multi-thread use case).
     void setPreLocked(void*, size_t rowBytes, SkColorTable*);
 
 private:
     SkBaseMutex*    fMutex; // must remain in scope for the life of this object
 
+    // mostly const. fInfo.fAlpahType can be changed at runtime.
     const SkImageInfo fInfo;
 
     // LockRec is only valid if we're in a locked state (isLocked())
     LockRec         fRec;
     int             fLockCount;
 
     mutable uint32_t fGenerationID;
     mutable bool     fUniqueGenerationID;
 
     SkTDArray<GenIDChangeListener*> fGenIDChangeListeners;  // pointers are owned
@@ skipping 23 matching lines @@
     /**
      *  Allocate a new pixelref matching the specified ImageInfo, allocating
      *  the memory for the pixels. If the ImageInfo requires a ColorTable,
      *  the pixelref will ref() the colortable.
      *  On failure return NULL.
      */
     virtual SkPixelRef* create(const SkImageInfo&, SkColorTable*) = 0;
 };
 
 #endif