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/cpdf_structelement.h" 12 #include "core/fpdfdoc/cpdf_structtree.h" 13 #include "fpdfsdk/fsdk_define.h" 14 15 namespace { 16 17 CPDF_StructTree* ToStructTree(FPDF_STRUCTTREE struct_tree) { 18 return static_cast<CPDF_StructTree*>(struct_tree); 19 } 20 21 CPDF_StructElement* ToStructTreeElement(FPDF_STRUCTELEMENT struct_element) { 22 return static_cast<CPDF_StructElement*>(struct_element); 23 } 24 25 unsigned long WideStringToBuffer(const WideString& str, 26 void* buffer, 27 unsigned long buflen) { 28 if (str.IsEmpty()) 29 return 0; 30 31 ByteString encodedStr = str.UTF16LE_Encode(); 32 const unsigned long len = encodedStr.GetLength(); 33 if (buffer && len <= buflen) 34 memcpy(buffer, encodedStr.c_str(), len); 35 return len; 36 } 37 38 } // namespace 39 40 FPDF_EXPORT FPDF_STRUCTTREE FPDF_CALLCONV 41 FPDF_StructTree_GetForPage(FPDF_PAGE page) { 42 CPDF_Page* pPage = CPDFPageFromFPDFPage(page); 43 if (!pPage) 44 return nullptr; 45 return CPDF_StructTree::LoadPage(pPage->m_pDocument.Get(), 46 pPage->m_pFormDict.Get()) 47 .release(); 48 } 49 50 FPDF_EXPORT void FPDF_CALLCONV 51 FPDF_StructTree_Close(FPDF_STRUCTTREE struct_tree) { 52 std::unique_ptr<CPDF_StructTree>(ToStructTree(struct_tree)); 53 } 54 55 FPDF_EXPORT int FPDF_CALLCONV 56 FPDF_StructTree_CountChildren(FPDF_STRUCTTREE struct_tree) { 57 CPDF_StructTree* tree = ToStructTree(struct_tree); 58 if (!tree) 59 return -1; 60 61 pdfium::base::CheckedNumeric<int> tmp_size = tree->CountTopElements(); 62 return tmp_size.ValueOrDefault(-1); 63 } 64 65 FPDF_EXPORT FPDF_STRUCTELEMENT FPDF_CALLCONV 66 FPDF_StructTree_GetChildAtIndex(FPDF_STRUCTTREE struct_tree, int index) { 67 CPDF_StructTree* tree = ToStructTree(struct_tree); 68 if (!tree || index < 0 || 69 static_cast<size_t>(index) >= tree->CountTopElements()) { 70 return nullptr; 71 } 72 return tree->GetTopElement(static_cast<size_t>(index)); 73 } 74 75 FPDF_EXPORT unsigned long FPDF_CALLCONV 76 FPDF_StructElement_GetAltText(FPDF_STRUCTELEMENT struct_element, 77 void* buffer, 78 unsigned long buflen) { 79 CPDF_StructElement* elem = ToStructTreeElement(struct_element); 80 return (elem && elem->GetDict()) 81 ? WideStringToBuffer(elem->GetDict()->GetUnicodeTextFor("Alt"), 82 buffer, buflen) 83 : 0; 84 } 85 86 FPDF_EXPORT int FPDF_CALLCONV 87 FPDF_StructElement_GetMarkedContentID(FPDF_STRUCTELEMENT struct_element) { 88 CPDF_StructElement* elem = ToStructTreeElement(struct_element); 89 CPDF_Object* p = 90 (elem && elem->GetDict()) ? elem->GetDict()->GetObjectFor("K") : nullptr; 91 return p && p->IsNumber() ? p->GetInteger() : -1; 92 } 93 94 FPDF_EXPORT unsigned long FPDF_CALLCONV 95 FPDF_StructElement_GetType(FPDF_STRUCTELEMENT struct_element, 96 void* buffer, 97 unsigned long buflen) { 98 CPDF_StructElement* elem = ToStructTreeElement(struct_element); 99 return elem ? WideStringToBuffer(elem->GetType().UTF8Decode(), buffer, buflen) 100 : 0; 101 } 102 103 FPDF_EXPORT unsigned long FPDF_CALLCONV 104 FPDF_StructElement_GetTitle(FPDF_STRUCTELEMENT struct_element, 105 void* buffer, 106 unsigned long buflen) { 107 CPDF_StructElement* elem = ToStructTreeElement(struct_element); 108 return elem 109 ? WideStringToBuffer(elem->GetTitle().UTF8Decode(), buffer, buflen) 110 : 0; 111 } 112 113 FPDF_EXPORT int FPDF_CALLCONV 114 FPDF_StructElement_CountChildren(FPDF_STRUCTELEMENT struct_element) { 115 CPDF_StructElement* elem = ToStructTreeElement(struct_element); 116 if (!elem) 117 return -1; 118 119 pdfium::base::CheckedNumeric<int> tmp_size = elem->CountKids(); 120 return tmp_size.ValueOrDefault(-1); 121 } 122 123 FPDF_EXPORT FPDF_STRUCTELEMENT FPDF_CALLCONV 124 FPDF_StructElement_GetChildAtIndex(FPDF_STRUCTELEMENT struct_element, 125 int index) { 126 CPDF_StructElement* elem = ToStructTreeElement(struct_element); 127 if (!elem || index < 0 || static_cast<size_t>(index) >= elem->CountKids()) 128 return nullptr; 129 130 return elem->GetKidIfElement(static_cast<size_t>(index)); 131 } 132