split SkPictureRecorder out of SkPicture

include/core/SkPicture.h

Index: include/core/SkPicture.h
===================================================================
--- include/core/SkPicture.h	(revision 13963)
+++ include/core/SkPicture.h	(working copy)
@@ -164,6 +164,13 @@
         kOptimizeForClippedPlayback_RecordingFlag = 0x02,
     };
 
+#ifndef SK_SUPPORT_LEGACY_PICTURE_CAN_RECORD
+private:
+    friend class SkPictureRecorder;
+    friend class SkImage_Picture;
+    friend class SkSurface_Picture;
+#endif
+
     /** Returns the canvas that records the drawing commands.
         @param width the base width for the picture, as if the recording
                      canvas' bitmap had this width.
@@ -185,6 +192,10 @@
     */
     void endRecording();
 
+#ifndef SK_SUPPORT_LEGACY_PICTURE_CAN_RECORD
+public:
+#endif
+
     /** Replays the drawing commands on the specified canvas. This internally
         calls endRecording() if that has not already been called.
         @param canvas the canvas receiving the drawing commands.
@@ -384,4 +395,81 @@
     virtual bool abortDrawing() = 0;
 };
 
+class SkPictureFactory : public SkRefCnt {
+public:
+    /**
+     *  Allocate a new SkPicture. Return NULL on failure.
+     */
+    virtual SkPicture* create(int width, int height) = 0;

[mtklein, 2014/04/07 15:18:12]

If you keep factories, it might be less obtrusive to pass this around as an
SkPicture* (*SkPictureFactory)(int w, int h)?  No need to deal with refcounting
then.

[robertphillips, 2014/04/07 16:26:56]

The TileGrid ctor requires extra parameters.

[mtklein, 2014/04/07 16:29:43]

OK then, pass as a functor?

+};
+
+class SK_API SkPictureRecorder : public SkNoncopyable {

[mtklein, 2014/04/07 15:18:12]

For SkNoncopyable to work, it's got to be private inheritance, no?  : private
SkNoncopyable or : SkNoncopyable?

[mtklein, 2014/04/07 15:18:12]

I'm still somewhat surprised that SkPictureRecorder isn't an SkCanvas itself. 
What's the extra step between the constructor and beginRecording() get us?

[robertphillips, 2014/04/07 16:26:56]

If that's true we're doing it wrong all over the place.

[mtklein, 2014/04/07 16:29:43]

Gross.

+public:
+    SkPictureRecorder(SkPictureFactory* factory = NULL) {

[reed1, 2014/04/07 14:49:57]

icky icky factory. why is this here? Is it just for bbox stuff?

[robertphillips, 2014/04/07 15:05:37]

Yes. Ultimately this should change to "SkAccelFactory" though. That way
SkPicture doesn't have to be sub-classed just to get a different acceleration
structure.

+        fFactory.reset(factory);
+        if (NULL != fFactory.get()) {
+            fFactory.get()->ref();
+        }
+    }
+
+    /** Returns the canvas that records the drawing commands.
+        @param width the base width for the picture, as if the recording
+                     canvas' bitmap had this width.
+        @param height the base width for the picture, as if the recording
+                     canvas' bitmap had this height.
+        @param recordFlags optional flags that control recording.
+        @return the canvas.
+    */
+    SkCanvas* beginRecording(int width, int height, uint32_t recordFlags = 0) {

[mtklein, 2014/04/07 15:18:12]

Can we just pass in the SkPicture to record into?
    SkCanvas* beginRecording(SkPicture*, int w, int h, uint32_t flags = 0);
Then there's no need for SkPictureRecorder to know about these factories at all;
it'll never make its own SkPicture.

+        if (NULL != fFactory) {
+            fPicture.reset(fFactory->create(width, height));
+        } else {
+            fPicture.reset(SkNEW(SkPicture));
+        }
+
+        return fPicture->beginRecording(width, height, recordFlags);
+    }
+
+    /** Returns the recording canvas if one is active, or NULL if recording is
+        not active. This does not alter the refcnt on the canvas (if present).
+    */
+    SkCanvas* getRecordingCanvas() {
+        if (NULL != fPicture.get()) {
+            return fPicture->getRecordingCanvas();
+        }
+        return NULL;
+    }
+
+    /** Signal that the caller is done recording. This invalidates the canvas
+        returned by beginRecording/getRecordingCanvas, and returns the 
+        created SkPicture. Note that the returned picture has its creation
+        ref which the caller must take ownership of. 
+    */
+    SkPicture* endRecording() {
+        if (NULL != fPicture.get()) {
+            fPicture->endRecording();
+            return fPicture.detach();
+        }
+        return NULL;
+    }
+
+    /** Enable/disable all the picture recording optimizations (i.e.,
+        those in SkPictureRecord). It is mainly intended for testing the
+        existing optimizations (i.e., to actually have the pattern
+        appear in an .skp we have to disable the optimization). Call right
+        after 'beginRecording'.
+    */
+    void internalOnly_EnableOpts(bool enableOpts) {
+        if (NULL != fPicture.get()) {
+            fPicture->internalOnly_EnableOpts(enableOpts);
+        }
+    }
+
+private:
+    SkAutoTUnref<SkPictureFactory> fFactory;
+    SkAutoTUnref<SkPicture>        fPicture;
+
+    typedef SkNoncopyable INHERITED;
+};
+
 #endif