Fix SkXfermode deserialization.

tests/SerializationTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Resources.h"
 #include "SkBitmapSource.h"
 #include "SkCanvas.h"
@@ skipping 243 matching lines @@
         bitmap.allocN32Pixels(24, 24);
         SkCanvas canvas(bitmap);
         canvas.clear(0x00000000);
         SkPaint paint;
         paint.setImageFilter(deserializedFilter);
         canvas.clipRect(SkRect::MakeXYWH(0, 0, SkIntToScalar(24), SkIntToScalar(24)));
         canvas.drawBitmap(bitmap, 0, 0, &paint);
     }
 }
 
+static void TestXfermodeSerialization(skiatest::Reporter* reporter) {

[reed1, 2014/09/24 15:58:46]

Ensuring that this list matches the enum in SkXfermode seems hard.
Do you think just a loop that ends with <= kLastMode would works just as well
(with an escape-hatch for SrcOver)?

[Stephen White, 2014/09/24 16:38:39]

Good idea. Done.

+    const SkXfermode::Mode gModes[] = {
+        SkXfermode::kClear_Mode,
+        SkXfermode::kSrc_Mode,
+        SkXfermode::kDst_Mode,
+        // Don't test SrcOver_Mode, since this (correctly) deserializes as NULL
+//        SkXfermode::kSrcOver_Mode,
+        SkXfermode::kDstOver_Mode,
+        SkXfermode::kSrcIn_Mode,
+        SkXfermode::kDstIn_Mode,
+        SkXfermode::kSrcOut_Mode,
+        SkXfermode::kDstOut_Mode,
+        SkXfermode::kSrcATop_Mode,
+        SkXfermode::kDstATop_Mode,
+        SkXfermode::kXor_Mode,
+
+        SkXfermode::kPlus_Mode,
+        SkXfermode::kModulate_Mode,
+        SkXfermode::kScreen_Mode,
+        SkXfermode::kOverlay_Mode,
+        SkXfermode::kDarken_Mode,
+        SkXfermode::kLighten_Mode,
+        SkXfermode::kColorDodge_Mode,
+        SkXfermode::kColorBurn_Mode,
+        SkXfermode::kHardLight_Mode,
+        SkXfermode::kSoftLight_Mode,
+        SkXfermode::kDifference_Mode,
+        SkXfermode::kExclusion_Mode,
+        SkXfermode::kMultiply_Mode,
+        SkXfermode::kHue_Mode,
+        SkXfermode::kSaturation_Mode,
+        SkXfermode::kColor_Mode,
+        SkXfermode::kLuminosity_Mode,
+    };
+
+    for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); i++) {
+        SkAutoTUnref<SkXfermode> mode(SkXfermode::Create(gModes[i]));
+        REPORTER_ASSERT(reporter, mode.get());
+        TestFlattenableSerialization<SkXfermode>(mode.get(), true, reporter);
+    }
+}
+
 static SkBitmap draw_picture(SkPicture& picture) {
      SkBitmap bitmap;
      bitmap.allocN32Pixels(SkScalarCeilToInt(picture.cullRect().width()), 
                            SkScalarCeilToInt(picture.cullRect().height()));
      SkCanvas canvas(bitmap);
      picture.playback(&canvas);
      return bitmap;
 }
 
 static void compare_bitmaps(skiatest::Reporter* reporter,
@@ skipping 125 matching lines @@
         SkPath path;
         TestObjectSerialization(&path, reporter);
     }
 
     // Test region serialization
     {
         SkRegion region;
         TestObjectSerialization(&region, reporter);
     }
 
+    // Test xfermode serialization
+    {
+        TestXfermodeSerialization(reporter);
+    }
+
     // Test string serialization
     {
         SkString string("string");
         TestObjectSerializationNoAlign<SkString, false>(&string, reporter);
         TestObjectSerializationNoAlign<SkString, true>(&string, reporter);
     }
 
     // Test rrect serialization
     {
         // SkRRect does not initialize anything.
@@ skipping 69 matching lines @@
 
         // Deserialize picture
         SkValidatingReadBuffer reader(static_cast<void*>(data.get()), size);
         SkAutoTUnref<SkPicture> readPict(
             SkPicture::CreateFromBuffer(reader));
         REPORTER_ASSERT(reporter, readPict.get());
     }
 
     TestPictureTypefaceSerialization(reporter);
 }