Simplify flattening to just write enough to call the factory

include/core/SkFlattenable.h

-
 /*
  * Copyright 2006 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 SkFlattenable_DEFINED
 #define SkFlattenable_DEFINED
 
 #include "SkRefCnt.h"
 
+//#define SK_SUPPORT_LEGACY_DEEPFLATTENING
+
 class SkReadBuffer;
 class SkWriteBuffer;
 
 #define SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(flattenable) \
         SkFlattenable::Registrar(#flattenable, flattenable::CreateProc, \
                                  flattenable::GetFlattenableType());
 
 #define SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP() static void InitializeFlattenables();
 
 #define SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(flattenable) \
     void flattenable::InitializeFlattenables() {
 
 #define SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END \
     }
 
 #define SK_DECLARE_UNFLATTENABLE_OBJECT() \
     virtual Factory getFactory() const SK_OVERRIDE { return NULL; }
 
-#define SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(flattenable) \
-    virtual Factory getFactory() const SK_OVERRIDE { return CreateProc; } \
-    static SkFlattenable* CreateProc(SkReadBuffer& buffer) { \
-        return SkNEW_ARGS(flattenable, (buffer)); \
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+#define SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(flattenable)    \
+    static SkFlattenable* CreateProc(SkReadBuffer&);                        \
+    virtual Factory getFactory() const SK_OVERRIDE {return DeepCreateProc;} \
+    static SkFlattenable* DeepCreateProc(SkReadBuffer& buffer) {            \
+        if (NeedsDeepUnflatten(buffer)) {                                   \
+            return SkNEW_ARGS(flattenable, (buffer));                       \
+        }                                                                   \
+        return CreateProc(buffer);                                          \
     }
+#else
+#define SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(flattenable)    \
+    static SkFlattenable* CreateProc(SkReadBuffer&);                        \
+    virtual Factory getFactory() const SK_OVERRIDE { return CreateProc; }
+#endif
+
+// If your subclass will *never* need to be unflattened, declar this.
+#define SK_DECLARE_NOT_FLATTENABLE_PROCS(flattenable)   \
+    virtual Factory getFactory() const SK_OVERRIDE { return ReturnNullCreateProc; }
 
 /** For SkFlattenable derived objects with a valid type
     This macro should only be used in base class objects in core
   */
 #define SK_DEFINE_FLATTENABLE_TYPE(flattenable) \
     static Type GetFlattenableType() { \
         return k##flattenable##_Type; \
     }
 
 /** \class SkFlattenable
@@ skipping 46 matching lines @@
         }
     };
 
     /** Override this to write data specific to your subclass into the buffer,
      being sure to call your super-class' version first. This data will later
      be passed to your Factory function, returned by getFactory().
      */
     virtual void flatten(SkWriteBuffer&) const;
 
 protected:
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+    enum {
+        kNewFlattenVersion = 27
+    };
+    static bool NeedsDeepUnflatten(const SkReadBuffer&);
     SkFlattenable(SkReadBuffer&) {}
+#endif
+
+    static SkFlattenable* ReturnNullCreateProc(SkReadBuffer&) {
+        return NULL;
+    }
 
 private:
     static void InitializeFlattenablesIfNeeded();
 
     friend class SkGraphics;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif