1 // Copyright 2016 PDFium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "public/fpdf_structtree.h" 6 7 #include <memory> 8 9 #include "core/fpdfapi/page/cpdf_page.h" 10 #include "core/fpdfapi/parser/cpdf_dictionary.h" 11 #include "core/fpdfdoc/fpdf_tagged.h" 12 #include "fpdfsdk/fsdk_define.h" 13 14 namespace { 15 16 IPDF_StructTree* ToStructTree(FPDF_STRUCTTREE struct_tree) { 17 return reinterpret_cast<IPDF_StructTree*>(struct_tree); 18 } 19 20 IPDF_StructElement* ToStructTreeElement(FPDF_STRUCTELEMENT struct_element) { 21 return reinterpret_cast<IPDF_StructElement*>(struct_element); 22 } 23 24 } // namespace 25 26 DLLEXPORT FPDF_STRUCTTREE STDCALL FPDF_StructTree_GetForPage(FPDF_PAGE page) { 27 CPDF_Page* pPage = CPDFPageFromFPDFPage(page); 28 if (!pPage) 29 return nullptr; 30 return IPDF_StructTree::LoadPage(pPage->m_pDocument, pPage->m_pFormDict) 31 .release(); 32 } 33 34 DLLEXPORT void STDCALL FPDF_StructTree_Close(FPDF_STRUCTTREE struct_tree) { 35 std::unique_ptr<IPDF_StructTree>(ToStructTree(struct_tree)); 36 } 37 38 DLLEXPORT int STDCALL 39 FPDF_StructTree_CountChildren(FPDF_STRUCTTREE struct_tree) { 40 IPDF_StructTree* tree = ToStructTree(struct_tree); 41 return tree ? tree->CountTopElements() : -1; 42 } 43 44 DLLEXPORT FPDF_STRUCTELEMENT STDCALL 45 FPDF_StructTree_GetChildAtIndex(FPDF_STRUCTTREE struct_tree, int index) { 46 IPDF_StructTree* tree = ToStructTree(struct_tree); 47 if (!tree || index < 0 || index >= tree->CountTopElements()) 48 return nullptr; 49 return tree->GetTopElement(index); 50 } 51 52 DLLEXPORT unsigned long STDCALL 53 FPDF_StructElement_GetAltText(FPDF_STRUCTELEMENT struct_element, 54 void* buffer, 55 unsigned long buflen) { 56 IPDF_StructElement* elem = ToStructTreeElement(struct_element); 57 if (!elem) 58 return 0; 59 60 CPDF_Dictionary* dict = elem->GetDict(); 61 if (!dict) 62 return 0; 63 64 CFX_WideString str = elem->GetDict()->GetUnicodeTextFor("Alt"); 65 if (str.IsEmpty()) 66 return 0; 67 68 CFX_ByteString encodedStr = str.UTF16LE_Encode(); 69 const unsigned long len = encodedStr.GetLength(); 70 if (buffer && len <= buflen) 71 FXSYS_memcpy(buffer, encodedStr.c_str(), len); 72 return len; 73 } 74 75 DLLEXPORT int STDCALL 76 FPDF_StructElement_CountChildren(FPDF_STRUCTELEMENT struct_element) { 77 IPDF_StructElement* elem = ToStructTreeElement(struct_element); 78 return elem ? elem->CountKids() : -1; 79 } 80 81 DLLEXPORT FPDF_STRUCTELEMENT STDCALL 82 FPDF_StructElement_GetChildAtIndex(FPDF_STRUCTELEMENT struct_element, 83 int index) { 84 IPDF_StructElement* elem = ToStructTreeElement(struct_element); 85 if (!elem || index < 0 || index >= elem->CountKids()) 86 return nullptr; 87 88 return elem->GetKidIfElement(index); 89 } 90