| // Copyright 2019 The PDFium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "public/fpdf_thumbnail.h" |
| |
| #include <utility> |
| |
| #include "core/fpdfapi/page/cpdf_dib.h" |
| #include "core/fpdfapi/page/cpdf_page.h" |
| #include "core/fpdfapi/parser/cpdf_dictionary.h" |
| #include "core/fpdfapi/parser/cpdf_stream.h" |
| #include "core/fpdfapi/parser/cpdf_stream_acc.h" |
| #include "core/fxcrt/compiler_specific.h" |
| #include "core/fxcrt/span.h" |
| #include "core/fxge/dib/cfx_dibitmap.h" |
| #include "fpdfsdk/cpdfsdk_helpers.h" |
| #include "public/fpdfview.h" |
| |
| namespace { |
| |
| RetainPtr<const CPDF_Stream> CPDFStreamForThumbnailFromPage(FPDF_PAGE page) { |
| const CPDF_Page* pdf_page = CPDFPageFromFPDFPage(page); |
| if (!pdf_page) |
| return nullptr; |
| |
| RetainPtr<const CPDF_Dictionary> page_dict = pdf_page->GetDict(); |
| if (!page_dict->KeyExist("Type")) |
| return nullptr; |
| |
| return page_dict->GetStreamFor("Thumb"); |
| } |
| |
| } // namespace |
| |
| FPDF_EXPORT unsigned long FPDF_CALLCONV |
| FPDFPage_GetDecodedThumbnailData(FPDF_PAGE page, |
| void* buffer, |
| unsigned long buflen) { |
| RetainPtr<const CPDF_Stream> thumb_stream = |
| CPDFStreamForThumbnailFromPage(page); |
| if (!thumb_stream) |
| return 0u; |
| |
| // SAFETY: caller ensures `buffer` points to at least `buflen` bytes. |
| return DecodeStreamMaybeCopyAndReturnLength( |
| std::move(thumb_stream), |
| UNSAFE_BUFFERS(pdfium::make_span(static_cast<uint8_t*>(buffer), |
| static_cast<size_t>(buflen)))); |
| } |
| |
| FPDF_EXPORT unsigned long FPDF_CALLCONV |
| FPDFPage_GetRawThumbnailData(FPDF_PAGE page, |
| void* buffer, |
| unsigned long buflen) { |
| RetainPtr<const CPDF_Stream> thumb_stream = |
| CPDFStreamForThumbnailFromPage(page); |
| if (!thumb_stream) |
| return 0u; |
| |
| // SAFETY: caller ensures `buffer` points to at least `buflen` bytes. |
| return GetRawStreamMaybeCopyAndReturnLength( |
| std::move(thumb_stream), |
| UNSAFE_BUFFERS(pdfium::make_span(static_cast<uint8_t*>(buffer), |
| static_cast<size_t>(buflen)))); |
| } |
| |
| FPDF_EXPORT FPDF_BITMAP FPDF_CALLCONV |
| FPDFPage_GetThumbnailAsBitmap(FPDF_PAGE page) { |
| RetainPtr<const CPDF_Stream> thumb_stream = |
| CPDFStreamForThumbnailFromPage(page); |
| if (!thumb_stream) |
| return nullptr; |
| |
| const CPDF_Page* pdf_page = CPDFPageFromFPDFPage(page); |
| auto dib_source = pdfium::MakeRetain<CPDF_DIB>(pdf_page->GetDocument(), |
| std::move(thumb_stream)); |
| const CPDF_DIB::LoadState start_status = dib_source->StartLoadDIBBase( |
| false, nullptr, pdf_page->GetPageResources().Get(), false, |
| CPDF_ColorSpace::Family::kUnknown, false, {0, 0}); |
| if (start_status == CPDF_DIB::LoadState::kFail) |
| return nullptr; |
| |
| auto thumb_bitmap = pdfium::MakeRetain<CFX_DIBitmap>(); |
| if (!thumb_bitmap->Copy(std::move(dib_source))) { |
| return nullptr; |
| } |
| |
| CHECK(!thumb_bitmap->IsPremultiplied()); |
| return FPDFBitmapFromCFXDIBitmap(thumb_bitmap.Leak()); |
| } |