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"

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();

    auto content = device->content();
    this->setData(content.get());

    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(SkStreamAsset* content, SkRect bbox,
                                   SkPDFDict* resourceDict) {
    setData(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
    // isolated blending.  Do this conditionally if that changes.
    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));
}

SkPDFFormXObject::~SkPDFFormXObject() {}