Add generation ID to SkPicture

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
@@ skipping 41 matching lines @@
 
         // This entry point allows user's to get a unique domain prefix
         // for their keys
         static Domain GenerateDomain();
     private:
         Key fKey;
 
         typedef SkRefCnt INHERITED;
     };
 
-    /** The constructor prepares the picture to record.
-        @param width the width of the virtual device the picture records.
-        @param height the height of the virtual device the picture records.
-    */
     SkPicture();
     /** Make a copy of the contents of src. If src records more drawing after
         this call, those elements will not appear in this picture.
     */
     SkPicture(const SkPicture& src);
 
     /**  PRIVATE / EXPERIMENTAL -- do not call */
     void EXPERIMENTAL_addAccelData(const AccelData* data) {
         SkRefCnt_SafeAssign(fAccelData, data);
     }
@@ skipping 122 matching lines @@
     */
     int width() const { return fWidth; }
 
     /** Return the height of the picture's recording canvas. This
         value reflects what was passed to setSize(), and does not necessarily
         reflect the bounds of what has been recorded into the picture.
         @return the height of the picture's recording canvas
     */
     int height() const { return fHeight; }
 
+    static const uint32_t kInvalidGenID = 0;

[reed1, 2014/04/07 13:16:59]

Seems like this should be in some larger/global header, since we have the same
convention for all of our classes that use genIDs

+
+    /** Return a non-zero, unique value representing the picture. This call is 
+        only valid when not recording. Between a beginRecording/endRecording 
+        pair it will just return 0 (the invalid gen ID). Each beginRecording/
+        endRecording pair will cause a different generation ID to be returned.
+    */
+    uint32_t getGenerationID() const;

[reed1, 2014/04/07 13:16:59]

Why not call it uniqueID() as we do in typeface?

+
     /**
      *  Function to encode an SkBitmap to an SkData. A function with this
      *  signature can be passed to serialize() and SkWriteBuffer.
      *  Returning NULL will tell the SkWriteBuffer to use
      *  SkBitmap::flatten() to store the bitmap.
      *
      *  @param pixelRefOffset DEPRECATED -- caller assumes it will return 0.
      *  @return SkData If non-NULL, holds encoded data representing the passed
      *      in bitmap. The caller is responsible for calling unref().
      */
@@ skipping 62 matching lines @@
     // V7 : changed drawBitmapRect(IRect) to drawBitmapRectToRect(Rect)
     // V8 : Add an option for encoding bitmaps
     // V9 : Allow the reader and writer of an SKP disagree on whether to support
     //      SK_SUPPORT_HINTING_SCALE_FACTOR
     // V10: add drawRRect, drawOval, clipRRect
     // V11: modify how readBitmap and writeBitmap store their info.
     // V12: add conics to SkPath, use new SkPathRef flattening
     // V13: add flag to drawBitmapRectToRect
     //      parameterize blurs by sigma rather than radius
     // V14: Add flags word to PathRef serialization
-    // V15: Remove A1 bitmpa config (and renumber remaining configs)
+    // V15: Remove A1 bitmap config (and renumber remaining configs)
     // V16: Move SkPath's isOval flag to SkPathRef
     // V17: SkPixelRef now writes SkImageInfo
     // V18: SkBitmap now records x,y for its pixelref origin, instead of offset.
     // V19: encode matrices and regions into the ops stream
     // V20: added bool to SkPictureImageFilter's serialization (to allow SkPicture serialization)
     // V21: add pushCull, popCull
     // V22: SK_PICT_FACTORY_TAG's size is now the chunk size in bytes
 
     // Note: If the picture version needs to be increased then please follow the
     // steps to generate new SKPs in (only accessible to Googlers): http://goo.gl/qATVcw
 
     // Only SKPs within the min/current picture version range (inclusive) can be read.
     static const uint32_t MIN_PICTURE_VERSION = 19;
     static const uint32_t CURRENT_PICTURE_VERSION = 22;
 
+    mutable uint32_t      fGenerationID;
+
     // fPlayback, fRecord, fWidth & fHeight are protected to allow derived classes to
     // install their own SkPicturePlayback-derived players,SkPictureRecord-derived
     // recorders and set the picture size
     SkPicturePlayback*    fPlayback;
     SkPictureRecord*      fRecord;
     int                   fWidth, fHeight;
     const AccelData*      fAccelData;
 
+    void needsNewGenID() { fGenerationID = kInvalidGenID; }
+
     // Create a new SkPicture from an existing SkPicturePlayback. Ref count of
     // playback is unchanged.
     SkPicture(SkPicturePlayback*, int width, int height);
 
     // For testing. Derived classes may instantiate an alternate
     // SkBBoxHierarchy implementation
     virtual SkBBoxHierarchy* createBBoxHierarchy() const;
 private:
     // An OperationList encapsulates a set of operation offsets into the picture byte
     // stream along with the CTMs needed for those operation.
@@ skipping 54 matching lines @@
  */
 class SK_API SkDrawPictureCallback {
 public:
     SkDrawPictureCallback() {}
     virtual ~SkDrawPictureCallback() {}
 
     virtual bool abortDrawing() = 0;
 };
 
 #endif