clean up SkPicture include

Get SkPicture.h ready for documenting.

- remove private methods
- move private forward declarations
- name parameters

R=reed@google.com, bsalomon@google.com

Bug: skia:6898
Change-Id: I28829111203d8ae2a4661cf02c99023403aa0df0
Reviewed-on: https://skia-review.googlesource.com/134120
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@google.com>

7 files changed, 58 insertions, 17 deletions

diff --git a/src/core/SkPicture.cpp b/src/core/SkPicture.cpp
index 2325fde864..34fa558ef5 100644
--- a/src/core/SkPicture.cpp
+++ b/src/core/SkPicture.cpp
@@ -8,10 +8,10 @@
 #include "SkAtomics.h"
 #include "SkImageGenerator.h"
 #include "SkMathPriv.h"
-#include "SkPicture.h"
 #include "SkPictureCommon.h"
 #include "SkPictureData.h"
 #include "SkPicturePlayback.h"
+#include "SkPicturePriv.h"
 #include "SkPictureRecord.h"
 #include "SkPictureRecorder.h"
 #include "SkSerialProcs.h"
@@ -198,9 +198,9 @@ sk_sp<SkPicture> SkPicture::MakeFromStream(SkStream* stream, const SkDeserialPro
     return nullptr;
 }
 
-sk_sp<SkPicture> SkPicture::MakeFromBuffer(SkReadBuffer& buffer) {
+sk_sp<SkPicture> SkPicturePriv::MakeFromBuffer(SkReadBuffer& buffer) {
     SkPictInfo info;
-    if (!BufferIsSKP(&buffer, &info)) {
+    if (!SkPicture::BufferIsSKP(&buffer, &info)) {
         return nullptr;
     }
     // size should be 0, 1, or negative
@@ -218,7 +218,7 @@ sk_sp<SkPicture> SkPicture::MakeFromBuffer(SkReadBuffer& buffer) {
         return nullptr;
     }
    std::unique_ptr<SkPictureData> data(SkPictureData::CreateFromBuffer(buffer, info));
-    return Forwardport(info, data.get(), &buffer);
+    return SkPicture::Forwardport(info, data.get(), &buffer);
 }
 
 SkPictureData* SkPicture::backport() const {
@@ -296,15 +296,15 @@ void SkPicture::serialize(SkWStream* stream, const SkSerialProcs* procsPtr,
     }
 }
 
-void SkPicture::flatten(SkWriteBuffer& buffer) const {
-    SkPictInfo info = this->createHeader();
-    std::unique_ptr<SkPictureData> data(this->backport());
+void SkPicturePriv::Flatten(const sk_sp<const SkPicture> picture, SkWriteBuffer& buffer) {
+    SkPictInfo info = picture->createHeader();
+    std::unique_ptr<SkPictureData> data(picture->backport());
 
     buffer.writeByteArray(&info.fMagic, sizeof(info.fMagic));
     buffer.writeUInt(info.getVersion());
     buffer.writeRect(info.fCullRect);
 
-    if (auto custom = custom_serialize(this, buffer.fProcs)) {
+    if (auto custom = custom_serialize(picture.get(), buffer.fProcs)) {
         int32_t size = SkToS32(custom->size());
         buffer.write32(-size);    // negative for custom format
         buffer.writePad32(custom->data(), size);
diff --git a/src/core/SkPictureData.cpp b/src/core/SkPictureData.cpp
index 4d927380cc..3d34b27bf6 100644
--- a/src/core/SkPictureData.cpp
+++ b/src/core/SkPictureData.cpp
@@ -12,6 +12,7 @@
 #include "SkMakeUnique.h"
 #include "SkPictureData.h"
 #include "SkPictureRecord.h"
+#include "SkPicturePriv.h"
 #include "SkReadBuffer.h"
 #include "SkTextBlob.h"
 #include "SkTypeface.h"
@@ -232,7 +233,7 @@ void SkPictureData::flatten(SkWriteBuffer& buffer) const {
     if (!fPictures.empty()) {
         write_tag_size(buffer, SK_PICT_PICTURE_TAG, fPictures.count());
         for (const auto& pic : fPictures) {
-            pic->flatten(buffer);
+            SkPicturePriv::Flatten(pic, buffer);
         }
     }
 
@@ -440,7 +441,7 @@ void SkPictureData::parseBufferTag(SkReadBuffer& buffer, uint32_t tag, uint32_t
             fOpData = std::move(data);
         } break;
         case SK_PICT_PICTURE_TAG:
-            new_array_from_buffer(buffer, size, fPictures, SkPicture::MakeFromBuffer);
+            new_array_from_buffer(buffer, size, fPictures, SkPicturePriv::MakeFromBuffer);
             break;
         case SK_PICT_DRAWABLE_TAG:
             new_array_from_buffer(buffer, size, fDrawables, create_drawable_from_buffer);
diff --git a/src/core/SkPicturePriv.h b/src/core/SkPicturePriv.h
new file mode 100644
index 0000000000..5c772fc9df
--- /dev/null
+++ b/src/core/SkPicturePriv.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkPicturePriv_DEFINED
+#define SkPicturePriv_DEFINED
+
+#include "SkPicture.h"
+
+class SkReadBuffer;
+class SkWriteBuffer;
+
+class SkPicturePriv {
+public:
+    /**
+     *  Recreate a picture that was serialized into a buffer. If the creation requires bitmap
+     *  decoding, the decoder must be set on the SkReadBuffer parameter by calling
+     *  SkReadBuffer::setBitmapDecoder() before calling SkPicture::MakeFromBuffer().
+     *  @param buffer Serialized picture data.
+     *  @return A new SkPicture representing the serialized data, or NULL if the buffer is
+     *          invalid.
+     */
+    static sk_sp<SkPicture> MakeFromBuffer(SkReadBuffer& buffer);
+
+    /**
+     *  Serialize to a buffer.
+     */
+    static void Flatten(const sk_sp<const SkPicture> , SkWriteBuffer& buffer);
+
+    // Returns NULL if this is not an SkBigPicture.
+    static const SkBigPicture* AsSkBigPicture(const sk_sp<const SkPicture> picture) {
+        return picture->asSkBigPicture();
+    }
+};
+
+#endif
diff --git a/src/core/SkReadBuffer.h b/src/core/SkReadBuffer.h
index 5f459cecef..baf8ea143f 100644
--- a/src/core/SkReadBuffer.h
+++ b/src/core/SkReadBuffer.h
@@ -292,7 +292,7 @@ private:
     SkTHashMap<SkString, SkFlattenable::Factory> fCustomFactory;
 
     SkDeserialProcs fProcs;
-    friend class SkPicture;
+    friend class SkPicturePriv;
 
 #ifdef DEBUG_NON_DETERMINISTIC_ASSERT
     // Debugging counter to keep track of how many bitmaps we
diff --git a/src/core/SkWriteBuffer.h b/src/core/SkWriteBuffer.h
index c3d6f570bf..7be1794c2d 100644
--- a/src/core/SkWriteBuffer.h
+++ b/src/core/SkWriteBuffer.h
@@ -67,7 +67,7 @@ protected:
     SkDeduper*      fDeduper = nullptr;
     SkSerialProcs   fProcs;
 
-    friend class SkPicture; // fProcs
+    friend class SkPicturePriv; // fProcs
 };
 
 /**
diff --git a/src/effects/SkPictureImageFilter.cpp b/src/effects/SkPictureImageFilter.cpp
index df11e6c0df..b9c298dbac 100644
--- a/src/effects/SkPictureImageFilter.cpp
+++ b/src/effects/SkPictureImageFilter.cpp
@@ -12,6 +12,7 @@
 #include "SkColorSpaceXformer.h"
 #include "SkFlattenablePriv.h"
 #include "SkImageSource.h"
+#include "SkPicturePriv.h"
 #include "SkReadBuffer.h"
 #include "SkSpecialImage.h"
 #include "SkSpecialSurface.h"
@@ -58,7 +59,7 @@ sk_sp<SkFlattenable> SkPictureImageFilter::CreateProc(SkReadBuffer& buffer) {
     SkRect cropRect;
 
     if (buffer.readBool()) {
-        picture = SkPicture::MakeFromBuffer(buffer);
+        picture = SkPicturePriv::MakeFromBuffer(buffer);
     }
     buffer.readRect(&cropRect);
 
@@ -77,7 +78,7 @@ void SkPictureImageFilter::flatten(SkWriteBuffer& buffer) const {
     bool hasPicture = (fPicture != nullptr);
     buffer.writeBool(hasPicture);
     if (hasPicture) {
-        fPicture->flatten(buffer);
+        SkPicturePriv::Flatten(fPicture, buffer);
     }
     buffer.writeRect(fCropRect);
 }
diff --git a/src/shaders/SkPictureShader.cpp b/src/shaders/SkPictureShader.cpp
index 576598bfe6..6ff4a0eb12 100644
--- a/src/shaders/SkPictureShader.cpp
+++ b/src/shaders/SkPictureShader.cpp
@@ -15,7 +15,7 @@
 #include "SkImage.h"
 #include "SkImageShader.h"
 #include "SkMatrixUtils.h"
-#include "SkPicture.h"
+#include "SkPicturePriv.h"
 #include "SkPictureImageGenerator.h"
 #include "SkReadBuffer.h"
 #include "SkResourceCache.h"
@@ -157,7 +157,7 @@ sk_sp<SkFlattenable> SkPictureShader::CreateProc(SkReadBuffer& buffer) {
 
     bool didSerialize = buffer.readBool();
     if (didSerialize) {
-        picture = SkPicture::MakeFromBuffer(buffer);
+        picture = SkPicturePriv::MakeFromBuffer(buffer);
     }
     return SkPictureShader::Make(picture, mx, my, &lm, &tile);
 }
@@ -169,7 +169,7 @@ void SkPictureShader::flatten(SkWriteBuffer& buffer) const {
     buffer.writeRect(fTile);
 
     buffer.writeBool(true);
-    fPicture->flatten(buffer);
+    SkPicturePriv::Flatten(fPicture, buffer);
 }
 
 // Returns a cached image shader, which wraps a single picture tile at the given