wip for drawables

src/core/SkCanvasDrawable.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCanvasDrawable_DEFINED
 #define SkCanvasDrawable_DEFINED
 
 #include "SkRefCnt.h"
 
+class SkBBHFactory;
 class SkCanvas;
 struct SkRect;
 
 /**
  *  Base-class for objects that draw into SkCanvas.
  *
  *  The object has a generation ID, which is guaranteed to be unique across all drawables. To
  *  allow for clients of the drawable that may want to cache the results, the drawable must
  *  change its generation ID whenever its internal state changes such that it will draw differently.
  */
 class SkCanvasDrawable : public SkRefCnt {
 public:
     SkCanvasDrawable();
 
     /**
      *  Draws into the specified content. The drawing sequence will be balanced upon return
      *  (i.e. the saveLevel() on the canvas will match what it was when draw() was called,
      *  and the current matrix and clip settings will not be changed.
      */
     void draw(SkCanvas*);
 
+    SkPicture* newPictureSnapshot(SkBBHFactory* bbhFactory, uint32_t recordFlags);
+    SkPicture* newPictureSnapshot() {
+        return this->newPictureSnapshot(NULL, 0);
+    }
+
     /**
      *  Return a unique value for this instance. If two calls to this return the same value,
      *  it is presumed that calling the draw() method will render the same thing as well.
      *
      *  Subclasses that change their state should call notifyDrawingChanged() to ensure that
      *  a new value will be returned the next time it is called.
      */
     uint32_t getGenerationID();
 
     /**
-     *  If the drawable knows a bounds that will contains all of its drawing, return true and
-     *  set the parameter to that rectangle. If one is not known, ignore the parameter and
-     *  return false.
+     *  Return the (conservative) bounds of what the drawable will draw. If the drawable can
+     *  change what it draws (e.g. animation or in response to some external change), then this
+     *  must return a bounds that is always valid for all possible states.
      */
-    bool getBounds(SkRect*);
+    SkRect getBounds();
 
     /**
      *  Calling this invalidates the previous generation ID, and causes a new one to be computed
      *  the next time getGenerationID() is called. Typically this is called by the object itself,
      *  in response to its internal state changing.
      */
     void notifyDrawingChanged();
 
 protected:
+    virtual SkRect onGetBounds() = 0;
     virtual void onDraw(SkCanvas*) = 0;
-
-    virtual bool onGetBounds(SkRect*) { return false; }
+    virtual SkPicture* onNewPictureSnapshot(SkBBHFactory*, uint32_t recordFlags);
 
 private:
     int32_t fGenerationID;
 };
 
 #endif