SkPdf: SkPDFFormXObject de-class-ified.

src/pdf/SkPDFFormXObject.cpp

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPDFFormXObject.h"
 
-#include "SkMatrix.h"
-#include "SkPDFDevice.h"
-#include "SkPDFUtils.h"
-#include "SkStream.h"
-#include "SkTypes.h"
+sk_sp<SkPDFObject> SkPDFMakeFormXObject(std::unique_ptr<SkStreamAsset> content,
+                                        sk_sp<SkPDFArray> mediaBox,
+                                        sk_sp<SkPDFDict> resourceDict,
+                                        const char* colorSpace) {
+    auto form = sk_make_sp<SkPDFStream>(std::move(content));
+    form->insertName("Type", "XObject");
+    form->insertName("Subtype", "Form");
+    form->insertObject("Resources", std::move(resourceDict));
+    form->insertObject("BBox", std::move(mediaBox));
 
-SkPDFFormXObject::SkPDFFormXObject(SkPDFDevice* device) {
-    // We don't want to keep around device because we'd have two copies
-    // of content, so reference or copy everything we need (content and
-    // resources).
-    auto resourceDict = device->makeResourceDict();
-
-    this->setData(device->content());
-
-    sk_sp<SkPDFArray> bboxArray(device->copyMediaBox());
-    this->init(nullptr, resourceDict.get(), bboxArray.get());
-
-    // We invert the initial transform and apply that to the xobject so that
-    // it doesn't get applied twice. We can't just undo it because it's
-    // embedded in things like shaders and images.
-    if (!device->initialTransform().isIdentity()) {
-        SkMatrix inverse;
-        if (!device->initialTransform().invert(&inverse)) {
-            // The initial transform should be invertible.
-            SkASSERT(false);
-            inverse.reset();
-        }
-        this->insertObject("Matrix", SkPDFUtils::MatrixToArray(inverse));
-    }
-}
-
-/**
- * Creates a FormXObject from a content stream and associated resources.
- */
-SkPDFFormXObject::SkPDFFormXObject(std::unique_ptr<SkStreamAsset> content,
-                                   SkRect bbox,
-                                   SkPDFDict* resourceDict) {
-    this->setData(std::move(content));
-    sk_sp<SkPDFArray> bboxArray(SkPDFUtils::RectToArray(bbox));
-    this->init("DeviceRGB", resourceDict, bboxArray.get());
-}
-
-/**
- * Common initialization code.
- * Note that bbox is unreferenced here, so calling code does not need worry.
- */
-void SkPDFFormXObject::init(const char* colorSpace,
-                            SkPDFDict* resourceDict, SkPDFArray* bbox) {
-    this->insertName("Type", "XObject");
-    this->insertName("Subtype", "Form");
-    this->insertObject("Resources", sk_ref_sp(resourceDict));
-    this->insertObject("BBox", sk_ref_sp(bbox));
-
-    // Right now SkPDFFormXObject is only used for saveLayer, which implies
+    // Right now FormXObject is only used for saveLayer, which implies
     // isolated blending.  Do this conditionally if that changes.
+    // TODO(halcanary): Is this comment obsolete, since we use it for
+    // alpha masks?
     auto group = sk_make_sp<SkPDFDict>("Group");
     group->insertName("S", "Transparency");
-
     if (colorSpace != nullptr) {
         group->insertName("CS", colorSpace);
     }
     group->insertBool("I", true);  // Isolated.
-    this->insertObject("Group", std::move(group));
+    form->insertObject("Group", std::move(group));
+    return form;
 }
-
-SkPDFFormXObject::~SkPDFFormXObject() {}