Enable flattening of SkRecordedDrawable

tests/FlattenDrawableTest.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkDrawable.h"
 #include "SkOnce.h"
@@ skipping 229 matching lines @@
     // Note that we can still recognize the generic drawable as an IntDrawable
     SkDrawable* generic = rootOut->drawable();
     REPORTER_ASSERT(r, !strcmp("IntDrawable", generic->getTypeName()));
     IntDrawable* integer = (IntDrawable*) generic;
     REPORTER_ASSERT(r, 1 == integer->a());
     REPORTER_ASSERT(r, 2 == integer->b());
     REPORTER_ASSERT(r, 3 == integer->c());
     REPORTER_ASSERT(r, 4 == integer->d());
 }
 
+DEF_TEST(FlattenRecordedDrawable, r) {
+    register_test_drawables_once();
+
+    // Record a set of canvas draw commands
+    SkPictureRecorder recorder;
+    SkCanvas* canvas = recorder.beginRecording(1000.0f, 1000.0f);
+    canvas->drawPoint(42.0f, 17.0f, SK_ColorGREEN);
+    SkPaint paint;
+    paint.setColor(SK_ColorRED);
+    canvas->drawPaint(paint);
+    SkPaint textPaint;
+    textPaint.setColor(SK_ColorBLUE);
+    canvas->drawText("TEXT", 354.0f, 467.0f, 100.0f, textPaint);
+
+    // Draw some drawables as well
+    SkAutoTUnref<SkDrawable> drawable(new IntDrawable(1, 2, 3, 4));
+    SkAutoTUnref<RootDrawable> root(new RootDrawable(5, 6, 7, 8, paint, 9, 10, 11, 12, drawable));
+    canvas->drawDrawable(root, 747.0f, 242.0f);
+    SkAutoTUnref<PaintDrawable> paintDrawable(new PaintDrawable(paint));
+    canvas->drawDrawable(paintDrawable, 500.0, 500.0f);
+    SkAutoTUnref<CompoundDrawable> comDrawable(new CompoundDrawable(13, 14, 15, 16, textPaint));
+    canvas->drawDrawable(comDrawable, 10.0f, 10.0f);
+
+    // Serialize the recorded drawable
+    sk_sp<SkDrawable> recordedDrawable = recorder.finishRecordingAsDrawable();
+    SkWriteBuffer writeBuffer;
+    writeBuffer.writeFlattenable(recordedDrawable.get());
+
+    // Copy the contents of the write buffer into a read buffer
+    sk_sp<SkData> data = SkData::MakeUninitialized(writeBuffer.bytesWritten());
+    writeBuffer.writeToMemory(data->writable_data());
+    SkReadBuffer readBuffer(data->data(), data->size());
+    readBuffer.initDrawableFactories();

[djsollen, 2016/04/27 13:05:40]

seems awkward that I need to need to register factories for classes that already
live in Skia.  Why not have SkRecordedDrawable in the global registry?

[msarett, 2016/04/27 13:24:17]

That was original approach in Patch Sets 1 and 2.  I think this is a good
solution, I'm happy with it as well.

The idea behind Patch Set 3 is that we don't need to depend on the global
registry now that we have another way to register unflatten procs.  And I think
we ought to prefer the new approach to using the global registry when we can. 
Though I'm not sure we'll be able to drop the global registry completely.

Another alternative would be to register SkRecordedDrawable on construction of
the SkReadBuffer.  This has the advantage that you don't have to make a function
call to register anything, but it means that all users of SkReadBuffer
(including those that don't care about SkDrawable) will get SkRecordedDrawable's
create proc.

+
+    // Deserialize and verify the drawable
+    SkAutoTUnref<SkDrawable> out((SkDrawable*)
+            readBuffer.readFlattenable(SkFlattenable::kSkDrawable_Type));
+    REPORTER_ASSERT(r, out);
+    REPORTER_ASSERT(r, !strcmp("SkRecordedDrawable", out->getTypeName()));
+}
+
 static sk_sp<SkFlattenable> custom_create_proc(SkReadBuffer& buffer) {
     sk_sp<SkFlattenable> drawable = IntDrawable::CreateProc(buffer);
     IntDrawable* intDrawable = (IntDrawable*) drawable.get();
     return sk_sp<IntDrawable>(new IntDrawable(intDrawable->a() + 1, intDrawable->b() + 1,
                                               intDrawable->c() + 1, intDrawable->d() + 1));
 }
 
 DEF_TEST(FlattenCustomDrawable, r) {
     // No need to register the drawables since we will be using a custom proc.
 
@@ skipping 12 matching lines @@
 
     // Deserialize and verify the drawable
     SkAutoTUnref<IntDrawable> out((IntDrawable*)
             readBuffer.readFlattenable(SkFlattenable::kSkDrawable_Type));
     REPORTER_ASSERT(r, out);
     REPORTER_ASSERT(r, 2 == out->a());
     REPORTER_ASSERT(r, 3 == out->b());
     REPORTER_ASSERT(r, 4 == out->c());
     REPORTER_ASSERT(r, 5 == out->d());
 }