core/fpdfapi/page/cpdf_imageobject.cpp

// Copyright 2016 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#include "core/fpdfapi/page/cpdf_imageobject.h"

#include <memory>

#include "core/fpdfapi/page/cpdf_docpagedata.h"
#include "core/fpdfapi/page/cpdf_image.h"
#include "core/fpdfapi/parser/cpdf_document.h"
#include "core/fpdfapi/parser/cpdf_stream.h"
#include "core/fxge/dib/cfx_dibbase.h"
#include "core/fxge/dib/cfx_dibitmap.h"

CPDF_ImageObject::CPDF_ImageObject(int32_t content_stream)
    : CPDF_PageObject(content_stream) {}

CPDF_ImageObject::CPDF_ImageObject() : CPDF_ImageObject(kNoContentStream) {}

CPDF_ImageObject::~CPDF_ImageObject() {
  MaybePurgeCache();
}

CPDF_PageObject::Type CPDF_ImageObject::GetType() const {
  return IMAGE;
}

void CPDF_ImageObject::Transform(const CFX_Matrix& matrix) {
  m_Matrix.Concat(matrix);
  CalcBoundingBox();
  SetDirty(true);
}

bool CPDF_ImageObject::IsImage() const {
  return true;
}

CPDF_ImageObject* CPDF_ImageObject::AsImage() {
  return this;
}

const CPDF_ImageObject* CPDF_ImageObject::AsImage() const {
  return this;
}

void CPDF_ImageObject::CalcBoundingBox() {
  static constexpr CFX_FloatRect kRect(0.0f, 0.0f, 1.0f, 1.0f);
  SetRect(m_Matrix.TransformRect(kRect));
}

void CPDF_ImageObject::SetImage(const RetainPtr<CPDF_Image>& pImage) {
  MaybePurgeCache();
  m_pImage = pImage;
}

RetainPtr<CPDF_Image> CPDF_ImageObject::GetImage() const {
  return m_pImage;
}

RetainPtr<CFX_DIBitmap> CPDF_ImageObject::GetIndependentBitmap() const {
  RetainPtr<CFX_DIBBase> pSource = GetImage()->LoadDIBBase();

  // Clone() is non-virtual, and can't be overloaded by CPDF_DIB to
  // return a clone of the subclass as one would typically expect from a
  // such a method. Instead, it only clones the CFX_DIBBase, none of whose
  // members point to objects owned by |this| or the form containing |this|.
  // As a result, the clone may outlive them.
  return pSource ? pSource->Clone(nullptr) : nullptr;
}

void CPDF_ImageObject::MaybePurgeCache() {
  if (!m_pImage)
    return;

  auto* pPageData = CPDF_DocPageData::FromDocument(m_pImage->GetDocument());
  if (!pPageData)
    return;

  CPDF_Stream* pStream = m_pImage->GetStream();
  if (!pStream)
    return;

  uint32_t objnum = pStream->GetObjNum();
  if (!objnum)
    return;

  m_pImage.Reset();  // Clear my reference before asking the cache.
  pPageData->MaybePurgeImage(objnum);
}