C++ (Cpp) RetainPtr::Clone示例

示例#1

bool CPDF_Type3Char::LoadBitmap(CPDF_RenderContext* pContext) {
  if (m_pBitmap || !m_pForm)
    return true;

  if (m_pForm->GetPageObjectList()->size() != 1 || m_bColored)
    return false;

  auto& pPageObj = m_pForm->GetPageObjectList()->front();
  if (!pPageObj->IsImage())
    return false;

  m_ImageMatrix = pPageObj->AsImage()->matrix();
  {
    // |pSource| actually gets assigned a CPDF_DIBBase, which has pointers
    // into objects owned by |m_pForm|. Make sure it is out of scope before
    // clearing the form.
    RetainPtr<CFX_DIBBase> pSource =
        pPageObj->AsImage()->GetImage()->LoadDIBBase();

    // Clone() is non-virtual, and can't be overloaded by CPDF_DIBBase 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 the form. As a result, |m_pBitmap|
    // may outlive |m_pForm|.
    if (pSource)
      m_pBitmap = pSource->Clone(nullptr);
  }
  m_pForm.reset();
  return true;
}