Deserialize pictures with custom image-deserializer

include/core/SkPicture.h

 /*
  * Copyright 2007 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 SkPicture_DEFINED
 #define SkPicture_DEFINED
 
 #include "SkRefCnt.h"
 #include "SkRect.h"
 #include "SkTypes.h"
 
 class GrContext;
 class SkBigPicture;
 class SkBitmap;
 class SkCanvas;
+class SkData;
+class SkImage;
+class SkImageDeserializer;
 class SkPath;
 class SkPictureData;
 class SkPixelSerializer;
 class SkReadBuffer;
 class SkRefCntSet;
 class SkStream;
 class SkTypefacePlayback;
 class SkWStream;
 class SkWriteBuffer;
 struct SkPictInfo;
@@ skipping 13 matching lines @@
      *  If the installed pixelref has decoded the data into pixels, then the src buffer need not be
      *  copied. If the pixelref defers the actual decode until its lockPixels() is called, then it
      *  must make a copy of the src buffer.
      *  @param src Encoded data.
      *  @param length Size of the encoded data, in bytes.
      *  @param dst SkBitmap to install the pixel ref on.
      *  @param bool Whether or not a pixel ref was successfully installed.
      */
     typedef bool (*InstallPixelRefProc)(const void* src, size_t length, SkBitmap* dst);
 
+#ifdef SK_SUPPORT_LEGACY_PICTUREINSTALLPIXELREF
     /**
      *  Recreate a picture that was serialized into a stream.
      *  @param SkStream Serialized picture data. Ownership is unchanged by this call.
      *  @param proc Function pointer for installing pixelrefs on SkBitmaps representing the
      *              encoded bitmap data from the stream.
      *  @return A new SkPicture representing the serialized data, or NULL if the stream is
      *          invalid.
      */
     static sk_sp<SkPicture> MakeFromStream(SkStream*, InstallPixelRefProc proc);
+#endif
+
+    static sk_sp<SkPicture> MakeFromStream(SkStream*, SkImageDeserializer*);
 
     /**
      *  Recreate a picture that was serialized into a stream.
      *
      *  Any serialized images in the stream will be passed to
      *  SkImageGenerator::NewFromEncoded.
      *
      *  @param SkStream Serialized picture data. Ownership is unchanged by this call.
      *  @return A new SkPicture representing the serialized data, or NULL if the stream is
      *          invalid.
      */
     static sk_sp<SkPicture> MakeFromStream(SkStream*);
+    static sk_sp<SkPicture> MakeFromStream(SkStream* stream, std::nullptr_t) {

[mtklein, 2016/08/10 21:48:31]

Confused.  Are you sure we need two MakeFromStream() methods, and do we care
which one MakeFromStream(stream, nullptr) goes to?

Do we want these two pieces of code to behave differently?
   SkPicture::MakeFromStream(stream, nullptr);
vs.
   SkImageDeserializer* deserializer = nullptr;
   SkPicture::MakeFromStream(stream, deserializer);

[reed1, 2016/08/10 23:43:19]

This is needed as chrome has callers today that pass nullptr and that pass
InstallPixelRef. When I've updated the caller after this lands (and removed the
InstallPixelRef variant) the other variants can also go away.

+        return MakeFromStream(stream);
+    }
 
     /**
      *  Recreate a picture that was serialized into a buffer. If the creation requires bitmap
      *  decoding, the decoder must be set on the SkReadBuffer parameter by calling
      *  SkReadBuffer::setBitmapDecoder() before calling SkPicture::CreateFromBuffer().
      *  @param SkReadBuffer Serialized picture data.
      *  @return A new SkPicture representing the serialized data, or NULL if the buffer is
      *          invalid.
      */
     static sk_sp<SkPicture> MakeFromBuffer(SkReadBuffer&);
@@ skipping 98 matching lines @@
 #endif
 
 private:
     // Subclass whitelist.
     SkPicture();
     friend class SkBigPicture;
     friend class SkEmptyPicture;
     template <typename> friend class SkMiniPicture;
 
     void serialize(SkWStream*, SkPixelSerializer*, SkRefCntSet* typefaces) const;
-    static sk_sp<SkPicture> MakeFromStream(SkStream*, InstallPixelRefProc, SkTypefacePlayback*);
+//    static sk_sp<SkPicture> MakeFromStream(SkStream*, InstallPixelRefProc, SkTypefacePlayback*);
+    static sk_sp<SkPicture> MakeFromStream(SkStream*, SkImageDeserializer*, SkTypefacePlayback*);
     friend class SkPictureData;
 
     virtual int numSlowPaths() const = 0;
     friend class SkPictureGpuAnalyzer;
     friend struct SkPathCounter;
 
     // V35: Store SkRect (rather then width & height) in header
     // V36: Remove (obsolete) alphatype from SkColorTable
     // V37: Added shadow only option to SkDropShadowImageFilter (last version to record CLEAR)
     // V38: Added PictureResolution option to SkPictureImageFilter
@@ skipping 27 matching lines @@
                                         const SkPictureData*,
                                         const SkReadBuffer* buffer);
 
     SkPictInfo createHeader() const;
     SkPictureData* backport() const;
 
     mutable uint32_t fUniqueID;
 };
 
 #endif