| // Copyright 2014 The PDFium Authors |
| // 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 "public/fpdf_flatten.h" |
| |
| #include <limits.h> |
| |
| #include <algorithm> |
| #include <sstream> |
| #include <utility> |
| #include <vector> |
| |
| #include "constants/annotation_common.h" |
| #include "constants/annotation_flags.h" |
| #include "constants/font_encodings.h" |
| #include "constants/page_object.h" |
| #include "core/fpdfapi/edit/cpdf_contentstream_write_utils.h" |
| #include "core/fpdfapi/page/cpdf_page.h" |
| #include "core/fpdfapi/page/cpdf_pageobject.h" |
| #include "core/fpdfapi/parser/cpdf_array.h" |
| #include "core/fpdfapi/parser/cpdf_dictionary.h" |
| #include "core/fpdfapi/parser/cpdf_document.h" |
| #include "core/fpdfapi/parser/cpdf_name.h" |
| #include "core/fpdfapi/parser/cpdf_number.h" |
| #include "core/fpdfapi/parser/cpdf_reference.h" |
| #include "core/fpdfapi/parser/cpdf_stream.h" |
| #include "core/fpdfapi/parser/cpdf_stream_acc.h" |
| #include "core/fpdfapi/parser/fpdf_parser_utility.h" |
| #include "core/fpdfdoc/cpdf_annot.h" |
| #include "core/fxcrt/fx_string_wrappers.h" |
| #include "core/fxcrt/notreached.h" |
| #include "fpdfsdk/cpdfsdk_helpers.h" |
| |
| enum FPDF_TYPE { MAX, MIN }; |
| enum FPDF_VALUE { TOP, LEFT, RIGHT, BOTTOM }; |
| |
| namespace { |
| |
| bool IsValidRect(const CFX_FloatRect& rect, const CFX_FloatRect& rcPage) { |
| constexpr float kMinSize = 0.000001f; |
| if (rect.IsEmpty() || rect.Width() < kMinSize || rect.Height() < kMinSize) |
| return false; |
| |
| if (rcPage.IsEmpty()) |
| return true; |
| |
| constexpr float kMinBorderSize = 10.000001f; |
| return rect.left - rcPage.left >= -kMinBorderSize && |
| rect.right - rcPage.right <= kMinBorderSize && |
| rect.top - rcPage.top <= kMinBorderSize && |
| rect.bottom - rcPage.bottom >= -kMinBorderSize; |
| } |
| |
| void GetContentsRect(CPDF_Document* pDoc, |
| RetainPtr<CPDF_Dictionary> pDict, |
| std::vector<CFX_FloatRect>* pRectArray) { |
| auto pPDFPage = pdfium::MakeRetain<CPDF_Page>(pDoc, pDict); |
| pPDFPage->ParseContent(); |
| |
| for (const auto& pPageObject : *pPDFPage) { |
| const CFX_FloatRect& rc = pPageObject->GetRect(); |
| if (IsValidRect(rc, pDict->GetRectFor(pdfium::page_object::kMediaBox))) |
| pRectArray->push_back(rc); |
| } |
| } |
| |
| void ParserStream(const CPDF_Dictionary* pPageDic, |
| CPDF_Dictionary* pStream, |
| std::vector<CFX_FloatRect>* pRectArray, |
| std::vector<CPDF_Dictionary*>* pObjectArray) { |
| if (!pStream) |
| return; |
| CFX_FloatRect rect; |
| if (pStream->KeyExist("Rect")) |
| rect = pStream->GetRectFor("Rect"); |
| else if (pStream->KeyExist("BBox")) |
| rect = pStream->GetRectFor("BBox"); |
| |
| if (IsValidRect(rect, pPageDic->GetRectFor(pdfium::page_object::kMediaBox))) |
| pRectArray->push_back(rect); |
| |
| pObjectArray->push_back(pStream); |
| } |
| |
| int ParserAnnots(CPDF_Document* pSourceDoc, |
| RetainPtr<CPDF_Dictionary> pPageDic, |
| std::vector<CFX_FloatRect>* pRectArray, |
| std::vector<CPDF_Dictionary*>* pObjectArray, |
| int nUsage) { |
| if (!pSourceDoc) |
| return FLATTEN_FAIL; |
| |
| GetContentsRect(pSourceDoc, pPageDic, pRectArray); |
| RetainPtr<const CPDF_Array> pAnnots = pPageDic->GetArrayFor("Annots"); |
| if (!pAnnots) |
| return FLATTEN_NOTHINGTODO; |
| |
| CPDF_ArrayLocker locker(pAnnots); |
| for (const auto& pAnnot : locker) { |
| RetainPtr<CPDF_Dictionary> pAnnotDict = |
| ToDictionary(pAnnot->GetMutableDirect()); |
| if (!pAnnotDict) |
| continue; |
| |
| ByteString sSubtype = |
| pAnnotDict->GetByteStringFor(pdfium::annotation::kSubtype); |
| if (sSubtype == "Popup") |
| continue; |
| |
| int nAnnotFlag = pAnnotDict->GetIntegerFor("F"); |
| if (nAnnotFlag & pdfium::annotation_flags::kHidden) |
| continue; |
| |
| bool bParseStream; |
| if (nUsage == FLAT_NORMALDISPLAY) |
| bParseStream = !(nAnnotFlag & pdfium::annotation_flags::kInvisible); |
| else |
| bParseStream = !!(nAnnotFlag & pdfium::annotation_flags::kPrint); |
| if (bParseStream) |
| ParserStream(pPageDic.Get(), pAnnotDict.Get(), pRectArray, pObjectArray); |
| } |
| return FLATTEN_SUCCESS; |
| } |
| |
| float GetMinMaxValue(const std::vector<CFX_FloatRect>& array, |
| FPDF_TYPE type, |
| FPDF_VALUE value) { |
| if (array.empty()) |
| return 0.0f; |
| |
| size_t nRects = array.size(); |
| std::vector<float> pArray(nRects); |
| switch (value) { |
| case LEFT: |
| for (size_t i = 0; i < nRects; i++) |
| pArray[i] = array[i].left; |
| break; |
| case TOP: |
| for (size_t i = 0; i < nRects; i++) |
| pArray[i] = array[i].top; |
| break; |
| case RIGHT: |
| for (size_t i = 0; i < nRects; i++) |
| pArray[i] = array[i].right; |
| break; |
| case BOTTOM: |
| for (size_t i = 0; i < nRects; i++) |
| pArray[i] = array[i].bottom; |
| break; |
| } |
| |
| float fRet = pArray[0]; |
| if (type == MAX) { |
| for (size_t i = 1; i < nRects; i++) |
| fRet = std::max(fRet, pArray[i]); |
| } else { |
| for (size_t i = 1; i < nRects; i++) |
| fRet = std::min(fRet, pArray[i]); |
| } |
| return fRet; |
| } |
| |
| CFX_FloatRect CalculateRect(std::vector<CFX_FloatRect>* pRectArray) { |
| CFX_FloatRect rcRet; |
| |
| rcRet.left = GetMinMaxValue(*pRectArray, MIN, LEFT); |
| rcRet.top = GetMinMaxValue(*pRectArray, MAX, TOP); |
| rcRet.right = GetMinMaxValue(*pRectArray, MAX, RIGHT); |
| rcRet.bottom = GetMinMaxValue(*pRectArray, MIN, BOTTOM); |
| |
| return rcRet; |
| } |
| |
| ByteString GenerateFlattenedContent(const ByteString& key) { |
| return "q 1 0 0 1 0 0 cm /" + key + " Do Q"; |
| } |
| |
| RetainPtr<CPDF_Reference> NewIndirectContentsStreamReference( |
| CPDF_Document* pDocument, |
| const ByteString& contents) { |
| auto pNewContents = |
| pDocument->NewIndirect<CPDF_Stream>(pDocument->New<CPDF_Dictionary>()); |
| pNewContents->SetData(contents.unsigned_span()); |
| return pNewContents->MakeReference(pDocument); |
| } |
| |
| void SetPageContents(const ByteString& key, |
| CPDF_Dictionary* pPage, |
| CPDF_Document* pDocument) { |
| RetainPtr<CPDF_Array> pContentsArray = |
| pPage->GetMutableArrayFor(pdfium::page_object::kContents); |
| RetainPtr<CPDF_Stream> pContentsStream = |
| pPage->GetMutableStreamFor(pdfium::page_object::kContents); |
| if (!pContentsStream && !pContentsArray) { |
| if (!key.IsEmpty()) { |
| pPage->SetFor(pdfium::page_object::kContents, |
| NewIndirectContentsStreamReference( |
| pDocument, GenerateFlattenedContent(key))); |
| } |
| return; |
| } |
| |
| pPage->ConvertToIndirectObjectFor(pdfium::page_object::kContents, pDocument); |
| if (pContentsArray) { |
| pContentsArray->InsertAt( |
| 0, NewIndirectContentsStreamReference(pDocument, "q")); |
| pContentsArray->Append(NewIndirectContentsStreamReference(pDocument, "Q")); |
| } else { |
| ByteString sStream = "q\n"; |
| { |
| auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(pContentsStream); |
| pAcc->LoadAllDataFiltered(); |
| sStream += ByteStringView(pAcc->GetSpan()); |
| sStream += "\nQ"; |
| } |
| pContentsStream->SetDataAndRemoveFilter(sStream.unsigned_span()); |
| pContentsArray = pDocument->NewIndirect<CPDF_Array>(); |
| pContentsArray->AppendNew<CPDF_Reference>(pDocument, |
| pContentsStream->GetObjNum()); |
| pPage->SetNewFor<CPDF_Reference>(pdfium::page_object::kContents, pDocument, |
| pContentsArray->GetObjNum()); |
| } |
| if (!key.IsEmpty()) { |
| pContentsArray->Append(NewIndirectContentsStreamReference( |
| pDocument, GenerateFlattenedContent(key))); |
| } |
| } |
| |
| CFX_Matrix GetMatrix(const CFX_FloatRect& rcAnnot, |
| const CFX_FloatRect& rcStream, |
| const CFX_Matrix& matrix) { |
| if (rcStream.IsEmpty()) |
| return CFX_Matrix(); |
| |
| CFX_FloatRect rcTransformed = matrix.TransformRect(rcStream); |
| rcTransformed.Normalize(); |
| |
| float a = rcAnnot.Width() / rcTransformed.Width(); |
| float d = rcAnnot.Height() / rcTransformed.Height(); |
| |
| float e = rcAnnot.left - rcTransformed.left * a; |
| float f = rcAnnot.bottom - rcTransformed.bottom * d; |
| return CFX_Matrix(a, 0.0f, 0.0f, d, e, f); |
| } |
| |
| bool IsValidBaseEncoding(ByteString base_encoding) { |
| // ISO 32000-1:2008 spec, table 114. |
| // ISO 32000-2:2020 spec, table 112. |
| return base_encoding == pdfium::font_encodings::kWinAnsiEncoding || |
| base_encoding == pdfium::font_encodings::kMacRomanEncoding || |
| base_encoding == pdfium::font_encodings::kMacExpertEncoding; |
| } |
| |
| void SanitizeFont(RetainPtr<CPDF_Dictionary> font_dict) { |
| if (!font_dict) { |
| return; |
| } |
| |
| RetainPtr<CPDF_Dictionary> encoding_dict = |
| font_dict->GetMutableDictFor("Encoding"); |
| if (encoding_dict) { |
| if (!IsValidBaseEncoding(encoding_dict->GetNameFor("BaseEncoding"))) { |
| font_dict->RemoveFor("Encoding"); |
| } |
| } |
| } |
| |
| void SanitizeFontResources(RetainPtr<CPDF_Dictionary> font_resource_dict) { |
| if (!font_resource_dict) { |
| return; |
| } |
| |
| CPDF_DictionaryLocker locker(font_resource_dict); |
| for (auto it : locker) { |
| SanitizeFont(ToDictionary(it.second->GetMutableDirect())); |
| } |
| } |
| |
| void SanitizeResources(RetainPtr<CPDF_Dictionary> resources_dict) { |
| if (!resources_dict) { |
| return; |
| } |
| |
| SanitizeFontResources(resources_dict->GetMutableDictFor("Font")); |
| } |
| |
| } // namespace |
| |
| FPDF_EXPORT int FPDF_CALLCONV FPDFPage_Flatten(FPDF_PAGE page, int nFlag) { |
| CPDF_Page* pPage = CPDFPageFromFPDFPage(page); |
| if (!page) |
| return FLATTEN_FAIL; |
| |
| CPDF_Document* pDocument = pPage->GetDocument(); |
| RetainPtr<CPDF_Dictionary> pPageDict = pPage->GetMutableDict(); |
| if (!pDocument) |
| return FLATTEN_FAIL; |
| |
| std::vector<CPDF_Dictionary*> ObjectArray; |
| std::vector<CFX_FloatRect> RectArray; |
| int iRet = |
| ParserAnnots(pDocument, pPageDict, &RectArray, &ObjectArray, nFlag); |
| if (iRet == FLATTEN_NOTHINGTODO || iRet == FLATTEN_FAIL) |
| return iRet; |
| |
| CFX_FloatRect rcMerger = CalculateRect(&RectArray); |
| CFX_FloatRect rcOriginalMB = |
| pPageDict->GetRectFor(pdfium::page_object::kMediaBox); |
| if (pPageDict->KeyExist(pdfium::page_object::kCropBox)) |
| rcOriginalMB = pPageDict->GetRectFor(pdfium::page_object::kCropBox); |
| |
| rcOriginalMB.Normalize(); |
| if (rcOriginalMB.IsEmpty()) |
| rcOriginalMB = CFX_FloatRect(0.0f, 0.0f, 612.0f, 792.0f); |
| |
| CFX_FloatRect rcOriginalCB; |
| if (pPageDict->KeyExist(pdfium::page_object::kCropBox)) { |
| rcOriginalCB = pPageDict->GetRectFor(pdfium::page_object::kCropBox); |
| rcOriginalCB.Normalize(); |
| } |
| if (rcOriginalCB.IsEmpty()) |
| rcOriginalCB = rcOriginalMB; |
| |
| rcMerger.left = std::max(rcMerger.left, rcOriginalMB.left); |
| rcMerger.right = std::min(rcMerger.right, rcOriginalMB.right); |
| rcMerger.bottom = std::max(rcMerger.bottom, rcOriginalMB.bottom); |
| rcMerger.top = std::min(rcMerger.top, rcOriginalMB.top); |
| |
| pPageDict->SetRectFor(pdfium::page_object::kMediaBox, rcOriginalMB); |
| pPageDict->SetRectFor(pdfium::page_object::kCropBox, rcOriginalCB); |
| |
| RetainPtr<CPDF_Dictionary> pRes = |
| pPageDict->GetOrCreateDictFor(pdfium::page_object::kResources); |
| auto pNewXObject = |
| pDocument->NewIndirect<CPDF_Stream>(pDocument->New<CPDF_Dictionary>()); |
| RetainPtr<CPDF_Dictionary> pPageXObject = pRes->GetOrCreateDictFor("XObject"); |
| |
| ByteString key; |
| if (!ObjectArray.empty()) { |
| int i = 0; |
| while (i < INT_MAX) { |
| ByteString sKey = ByteString::Format("FFT%d", i); |
| if (!pPageXObject->KeyExist(sKey)) { |
| key = std::move(sKey); |
| break; |
| } |
| ++i; |
| } |
| } |
| |
| SetPageContents(key, pPageDict.Get(), pDocument); |
| |
| RetainPtr<CPDF_Dictionary> pNewXORes; |
| if (!key.IsEmpty()) { |
| pPageXObject->SetNewFor<CPDF_Reference>(key, pDocument, |
| pNewXObject->GetObjNum()); |
| |
| RetainPtr<CPDF_Dictionary> pNewOXbjectDic = pNewXObject->GetMutableDict(); |
| pNewXORes = pNewOXbjectDic->SetNewFor<CPDF_Dictionary>("Resources"); |
| pNewOXbjectDic->SetNewFor<CPDF_Name>("Type", "XObject"); |
| pNewOXbjectDic->SetNewFor<CPDF_Name>("Subtype", "Form"); |
| pNewOXbjectDic->SetNewFor<CPDF_Number>("FormType", 1); |
| pNewOXbjectDic->SetRectFor("BBox", rcOriginalCB); |
| } |
| |
| for (size_t i = 0; i < ObjectArray.size(); ++i) { |
| CPDF_Dictionary* pAnnotDict = ObjectArray[i]; |
| if (!pAnnotDict) |
| continue; |
| |
| CFX_FloatRect rcAnnot = pAnnotDict->GetRectFor(pdfium::annotation::kRect); |
| rcAnnot.Normalize(); |
| |
| ByteString sAnnotState = pAnnotDict->GetByteStringFor("AS"); |
| RetainPtr<CPDF_Dictionary> pAnnotAP = |
| pAnnotDict->GetMutableDictFor(pdfium::annotation::kAP); |
| if (!pAnnotAP) |
| continue; |
| |
| RetainPtr<CPDF_Stream> original_ap_stream = |
| pAnnotAP->GetMutableStreamFor("N"); |
| if (!original_ap_stream) { |
| RetainPtr<CPDF_Dictionary> original_ap_dict = |
| pAnnotAP->GetMutableDictFor("N"); |
| if (!original_ap_dict) { |
| continue; |
| } |
| |
| if (!sAnnotState.IsEmpty()) { |
| original_ap_stream = original_ap_dict->GetMutableStreamFor(sAnnotState); |
| } else { |
| if (original_ap_dict->size() > 0) { |
| CPDF_DictionaryLocker locker(original_ap_dict); |
| RetainPtr<CPDF_Object> pFirstObj = locker.begin()->second; |
| if (pFirstObj) { |
| if (pFirstObj->IsReference()) |
| pFirstObj = pFirstObj->GetMutableDirect(); |
| if (!pFirstObj->IsStream()) |
| continue; |
| original_ap_stream.Reset(pFirstObj->AsMutableStream()); |
| } |
| } |
| } |
| } |
| if (!original_ap_stream) { |
| continue; |
| } |
| |
| RetainPtr<const CPDF_Dictionary> original_ap_stream_dict = |
| original_ap_stream->GetDict(); |
| CFX_FloatRect rcStream; |
| if (original_ap_stream_dict->KeyExist("Rect")) { |
| rcStream = original_ap_stream_dict->GetRectFor("Rect"); |
| } else if (original_ap_stream_dict->KeyExist("BBox")) { |
| rcStream = original_ap_stream_dict->GetRectFor("BBox"); |
| } |
| rcStream.Normalize(); |
| |
| if (rcStream.IsEmpty()) |
| continue; |
| |
| RetainPtr<CPDF_Stream> ap_stream; |
| if (original_ap_stream->IsInline()) { |
| ap_stream = ToStream(original_ap_stream->Clone()); |
| pDocument->AddIndirectObject(ap_stream); |
| } else { |
| ap_stream = original_ap_stream; |
| } |
| |
| RetainPtr<CPDF_Dictionary> ap_stream_dict = ap_stream->GetMutableDict(); |
| ap_stream_dict->SetNewFor<CPDF_Name>("Type", "XObject"); |
| ap_stream_dict->SetNewFor<CPDF_Name>("Subtype", "Form"); |
| SanitizeResources(ap_stream_dict->GetMutableDictFor("Resources")); |
| |
| RetainPtr<CPDF_Dictionary> pXObject = |
| pNewXORes->GetOrCreateDictFor("XObject"); |
| ByteString sFormName = ByteString::Format("F%d", i); |
| pXObject->SetNewFor<CPDF_Reference>(sFormName, pDocument, |
| ap_stream->GetObjNum()); |
| |
| ByteString sStream; |
| { |
| auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(pNewXObject); |
| pAcc->LoadAllDataFiltered(); |
| sStream = ByteString(ByteStringView(pAcc->GetSpan())); |
| } |
| CFX_Matrix matrix = original_ap_stream_dict->GetMatrixFor("Matrix"); |
| CFX_Matrix m = GetMatrix(rcAnnot, rcStream, matrix); |
| m.b = 0; |
| m.c = 0; |
| fxcrt::ostringstream buf; |
| WriteMatrix(buf, m); |
| ByteString str(buf); |
| sStream += ByteString::Format("q %s cm /%s Do Q\n", str.c_str(), |
| sFormName.c_str()); |
| pNewXObject->SetDataAndRemoveFilter(sStream.unsigned_span()); |
| } |
| pPageDict->RemoveFor("Annots"); |
| return FLATTEN_SUCCESS; |
| } |