[Experimental] Supporting OOPIF printing

skia/ext/SkFutureDrawable.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SKIA_EXT_SK_FUTURE_DRAWABLE_H_
+#define SKIA_EXT_SK_FUTURE_DRAWABLE_H_
+
+#include <memory>
+#include <unordered_map>
+
+#include "third_party/skia/include/core/SkDrawable.h"
+#include "third_party/skia/include/core/SkPicture.h"
+#include "third_party/skia/include/core/SkScalar.h"
+
+class SK_API SkFutureDrawable : public SkDrawable {
+ public:
+  static const char kTypeName[];
+
+  SkFutureDrawable(const SkRect& bounds)
+      : fBounds(bounds), fDrawableRef(nullptr) {}
+  SkFutureDrawable(const SkRect& bounds, int id)
+      : fBounds(bounds), id(id), fDrawableRef(nullptr) {}
+
+  void flatten(SkWriteBuffer& buffer) const override;
+
+  Factory getFactory() const override { return CreateProc; }
+
+  int Id() const { return id; }
+
+  void setDrawableRef(SkDrawable* ref) { fDrawableRef = ref; }
+
+  static sk_sp<SkFlattenable> CreateProc(SkReadBuffer& buffer);
+
+  static void addDrawableRef(int id, std::unique_ptr<SkDrawable> ref) {
+    fDrawableRefMap[id] = std::move(ref);
+  }
+
+  static void resetDrawableRef() { fDrawableRefMap.clear(); }
+
+ protected:
+  SkRect onGetBounds() override { return fBounds; }
+
+  void onDraw(SkCanvas* canvas) override;
+
+  SkPicture* onNewPictureSnapshot() override;
+
+  const char* getTypeName() const override { return kTypeName; }
+
+ private:
+  const SkRect fBounds;
+  int id;
+  SkDrawable* fDrawableRef;
+
+  static std::unordered_map<int, std::unique_ptr<SkDrawable>> fDrawableRefMap;
+};
+
+#endif  // SKIA_EXT_SK_FUTURE_DRAWABLE_H_