mirror of
				https://github.com/RGBCube/serenity
				synced 2025-10-28 11:02:36 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			317 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			317 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * Copyright (c) 2021, Matthew Olsson <mattco@serenityos.org>
 | |
|  *
 | |
|  * SPDX-License-Identifier: BSD-2-Clause
 | |
|  */
 | |
| 
 | |
| #include <LibPDF/CommonNames.h>
 | |
| #include <LibPDF/Document.h>
 | |
| #include <LibPDF/Parser.h>
 | |
| 
 | |
| namespace PDF {
 | |
| 
 | |
| String OutlineItem::to_string(int indent) const
 | |
| {
 | |
|     auto indent_str = String::repeated("  ", indent + 1);
 | |
| 
 | |
|     StringBuilder child_builder;
 | |
|     child_builder.append('[');
 | |
|     for (auto& child : children)
 | |
|         child_builder.appendff("{}\n", child.to_string(indent + 1));
 | |
|     child_builder.appendff("{}]", indent_str);
 | |
| 
 | |
|     StringBuilder builder;
 | |
|     builder.append("OutlineItem {{\n");
 | |
|     builder.appendff("{}title={}\n", indent_str, title);
 | |
|     builder.appendff("{}count={}\n", indent_str, count);
 | |
|     builder.appendff("{}dest={}\n", indent_str, dest);
 | |
|     builder.appendff("{}color={}\n", indent_str, color);
 | |
|     builder.appendff("{}italic={}\n", indent_str, italic);
 | |
|     builder.appendff("{}bold={}\n", indent_str, bold);
 | |
|     builder.appendff("{}children={}\n", indent_str, child_builder.to_string());
 | |
|     builder.appendff("{}}}", String::repeated("  ", indent));
 | |
| 
 | |
|     return builder.to_string();
 | |
| }
 | |
| 
 | |
| RefPtr<Document> Document::create(ReadonlyBytes bytes)
 | |
| {
 | |
|     auto parser = adopt_ref(*new Parser({}, bytes));
 | |
|     auto document = adopt_ref(*new Document(parser));
 | |
| 
 | |
|     if (!parser->initialize())
 | |
|         return {};
 | |
| 
 | |
|     document->m_catalog = parser->trailer()->get_dict(document, CommonNames::Root);
 | |
|     document->build_page_tree();
 | |
|     document->build_outline();
 | |
| 
 | |
|     return document;
 | |
| }
 | |
| 
 | |
| Document::Document(NonnullRefPtr<Parser> const& parser)
 | |
|     : m_parser(parser)
 | |
| {
 | |
|     m_parser->set_document(this);
 | |
| }
 | |
| 
 | |
| Value Document::get_or_load_value(u32 index)
 | |
| {
 | |
|     auto value = get_value(index);
 | |
|     if (!value.has<Empty>()) // FIXME: Use Optional instead?
 | |
|         return value;
 | |
| 
 | |
|     auto object = m_parser->parse_object_with_index(index);
 | |
|     m_values.set(index, object);
 | |
|     return object;
 | |
| }
 | |
| 
 | |
| u32 Document::get_first_page_index() const
 | |
| {
 | |
|     // FIXME: A PDF can have a different default first page, which
 | |
|     // should be fetched and returned here
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| u32 Document::get_page_count() const
 | |
| {
 | |
|     return m_page_object_indices.size();
 | |
| }
 | |
| 
 | |
| Page Document::get_page(u32 index)
 | |
| {
 | |
|     VERIFY(index < m_page_object_indices.size());
 | |
| 
 | |
|     auto cached_page = m_pages.get(index);
 | |
|     if (cached_page.has_value())
 | |
|         return cached_page.value();
 | |
| 
 | |
|     auto page_object_index = m_page_object_indices[index];
 | |
|     auto raw_page_object = resolve_to<DictObject>(get_or_load_value(page_object_index));
 | |
| 
 | |
|     if (!raw_page_object->contains(CommonNames::Resources)) {
 | |
|         // This page inherits its resource dictionary
 | |
|         TODO();
 | |
|     }
 | |
| 
 | |
|     auto resources = raw_page_object->get_dict(this, CommonNames::Resources);
 | |
|     auto contents = raw_page_object->get_object(this, CommonNames::Contents);
 | |
| 
 | |
|     auto media_box_array = raw_page_object->get_array(this, CommonNames::MediaBox);
 | |
|     auto media_box = Rectangle {
 | |
|         media_box_array->at(0).to_float(),
 | |
|         media_box_array->at(1).to_float(),
 | |
|         media_box_array->at(2).to_float(),
 | |
|         media_box_array->at(3).to_float(),
 | |
|     };
 | |
| 
 | |
|     auto crop_box = media_box;
 | |
|     if (raw_page_object->contains(CommonNames::CropBox)) {
 | |
|         auto crop_box_array = raw_page_object->get_array(this, CommonNames::CropBox);
 | |
|         crop_box = Rectangle {
 | |
|             crop_box_array->at(0).to_float(),
 | |
|             crop_box_array->at(1).to_float(),
 | |
|             crop_box_array->at(2).to_float(),
 | |
|             crop_box_array->at(3).to_float(),
 | |
|         };
 | |
|     }
 | |
| 
 | |
|     float user_unit = 1.0f;
 | |
|     if (raw_page_object->contains(CommonNames::UserUnit))
 | |
|         user_unit = raw_page_object->get_value(CommonNames::UserUnit).to_float();
 | |
| 
 | |
|     int rotate = 0;
 | |
|     if (raw_page_object->contains(CommonNames::Rotate)) {
 | |
|         rotate = raw_page_object->get_value(CommonNames::Rotate).get<int>();
 | |
|         VERIFY(rotate % 90 == 0);
 | |
|     }
 | |
| 
 | |
|     Page page { move(resources), move(contents), media_box, crop_box, user_unit, rotate };
 | |
|     m_pages.set(index, page);
 | |
|     return page;
 | |
| }
 | |
| 
 | |
| Value Document::resolve(Value const& value)
 | |
| {
 | |
|     if (value.has<Reference>()) {
 | |
|         // FIXME: Surely indirect PDF objects can't contain another indirect PDF object,
 | |
|         // right? Unsure from the spec, but if they can, these return values would have
 | |
|         // to be wrapped with another resolve() call.
 | |
|         return get_or_load_value(value.as_ref_index());
 | |
|     }
 | |
| 
 | |
|     if (!value.has<NonnullRefPtr<Object>>())
 | |
|         return value;
 | |
| 
 | |
|     auto& obj = value.get<NonnullRefPtr<Object>>();
 | |
| 
 | |
|     if (obj->is_indirect_value())
 | |
|         return static_ptr_cast<IndirectValue>(obj)->value();
 | |
| 
 | |
|     return value;
 | |
| }
 | |
| 
 | |
| bool Document::build_page_tree()
 | |
| {
 | |
|     if (!m_catalog->contains(CommonNames::Pages))
 | |
|         return false;
 | |
|     auto page_tree = m_catalog->get_dict(this, CommonNames::Pages);
 | |
|     return add_page_tree_node_to_page_tree(page_tree);
 | |
| }
 | |
| 
 | |
| bool Document::add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> const& page_tree)
 | |
| {
 | |
|     if (!page_tree->contains(CommonNames::Kids) || !page_tree->contains(CommonNames::Count))
 | |
|         return false;
 | |
| 
 | |
|     auto kids_array = page_tree->get_array(this, CommonNames::Kids);
 | |
|     auto page_count = page_tree->get(CommonNames::Count).value().get<int>();
 | |
| 
 | |
|     if (static_cast<size_t>(page_count) != kids_array->elements().size()) {
 | |
|         // This page tree contains child page trees, so we recursively add
 | |
|         // these pages to the overall page tree
 | |
| 
 | |
|         for (auto& value : *kids_array) {
 | |
|             auto reference_index = value.as_ref_index();
 | |
|             bool ok;
 | |
|             auto maybe_page_tree_node = m_parser->conditionally_parse_page_tree_node(reference_index, ok);
 | |
|             if (!ok)
 | |
|                 return false;
 | |
|             if (maybe_page_tree_node) {
 | |
|                 if (!add_page_tree_node_to_page_tree(maybe_page_tree_node.release_nonnull()))
 | |
|                     return false;
 | |
|             } else {
 | |
|                 m_page_object_indices.append(reference_index);
 | |
|             }
 | |
|         }
 | |
|     } else {
 | |
|         // We know all of the kids are leaf nodes
 | |
|         for (auto& value : *kids_array)
 | |
|             m_page_object_indices.append(value.as_ref_index());
 | |
|     }
 | |
| 
 | |
|     return true;
 | |
| }
 | |
| 
 | |
| void Document::build_outline()
 | |
| {
 | |
|     if (!m_catalog->contains(CommonNames::Outlines))
 | |
|         return;
 | |
| 
 | |
|     auto outline_dict = m_catalog->get_dict(this, CommonNames::Outlines);
 | |
|     if (!outline_dict->contains(CommonNames::First))
 | |
|         return;
 | |
|     if (!outline_dict->contains(CommonNames::Last))
 | |
|         return;
 | |
| 
 | |
|     auto first_ref = outline_dict->get_value(CommonNames::First);
 | |
|     auto last_ref = outline_dict->get_value(CommonNames::Last);
 | |
| 
 | |
|     auto children = build_outline_item_chain(first_ref, last_ref);
 | |
| 
 | |
|     m_outline = adopt_ref(*new OutlineDict());
 | |
|     m_outline->children = move(children);
 | |
| 
 | |
|     if (outline_dict->contains(CommonNames::Count))
 | |
|         m_outline->count = outline_dict->get_value(CommonNames::Count).get<int>();
 | |
| }
 | |
| 
 | |
| NonnullRefPtr<OutlineItem> Document::build_outline_item(NonnullRefPtr<DictObject> const& outline_item_dict)
 | |
| {
 | |
|     auto outline_item = adopt_ref(*new OutlineItem {});
 | |
| 
 | |
|     if (outline_item_dict->contains(CommonNames::First)) {
 | |
|         VERIFY(outline_item_dict->contains(CommonNames::Last));
 | |
|         auto first_ref = outline_item_dict->get_value(CommonNames::First);
 | |
|         auto last_ref = outline_item_dict->get_value(CommonNames::Last);
 | |
| 
 | |
|         auto children = build_outline_item_chain(first_ref, last_ref);
 | |
|         outline_item->children = move(children);
 | |
|     }
 | |
| 
 | |
|     outline_item->title = outline_item_dict->get_string(this, CommonNames::Title)->string();
 | |
| 
 | |
|     if (outline_item_dict->contains(CommonNames::Count))
 | |
|         outline_item->count = outline_item_dict->get_value(CommonNames::Count).get<int>();
 | |
| 
 | |
|     if (outline_item_dict->contains(CommonNames::Dest)) {
 | |
|         auto dest_arr = outline_item_dict->get_array(this, CommonNames::Dest);
 | |
|         auto page_ref = dest_arr->at(0);
 | |
|         auto type_name = dest_arr->get_name_at(this, 1)->name();
 | |
| 
 | |
|         Vector<float> parameters;
 | |
|         for (size_t i = 2; i < dest_arr->size(); i++)
 | |
|             parameters.append(dest_arr->at(i).to_float());
 | |
| 
 | |
|         Destination::Type type;
 | |
|         if (type_name == CommonNames::XYZ) {
 | |
|             type = Destination::Type::XYZ;
 | |
|         } else if (type_name == CommonNames::Fit) {
 | |
|             type = Destination::Type::Fit;
 | |
|         } else if (type_name == CommonNames::FitH) {
 | |
|             type = Destination::Type::FitH;
 | |
|         } else if (type_name == CommonNames::FitV) {
 | |
|             type = Destination::Type::FitV;
 | |
|         } else if (type_name == CommonNames::FitR) {
 | |
|             type = Destination::Type::FitR;
 | |
|         } else if (type_name == CommonNames::FitB) {
 | |
|             type = Destination::Type::FitB;
 | |
|         } else if (type_name == CommonNames::FitBH) {
 | |
|             type = Destination::Type::FitBH;
 | |
|         } else if (type_name == CommonNames::FitBV) {
 | |
|             type = Destination::Type::FitBV;
 | |
|         } else {
 | |
|             VERIFY_NOT_REACHED();
 | |
|         }
 | |
| 
 | |
|         outline_item->dest = Destination { type, page_ref, parameters };
 | |
|     }
 | |
| 
 | |
|     if (outline_item_dict->contains(CommonNames::C)) {
 | |
|         auto color_array = outline_item_dict->get_array(this, CommonNames::C);
 | |
|         auto r = static_cast<int>(255.0f * color_array->at(0).get<float>());
 | |
|         auto g = static_cast<int>(255.0f * color_array->at(1).get<float>());
 | |
|         auto b = static_cast<int>(255.0f * color_array->at(2).get<float>());
 | |
|         outline_item->color = Color(r, g, b);
 | |
|     }
 | |
| 
 | |
|     if (outline_item_dict->contains(CommonNames::F)) {
 | |
|         auto bitfield = outline_item_dict->get_value(CommonNames::F).get<int>();
 | |
|         outline_item->italic = bitfield & 0x1;
 | |
|         outline_item->bold = bitfield & 0x2;
 | |
|     }
 | |
| 
 | |
|     return outline_item;
 | |
| }
 | |
| 
 | |
| NonnullRefPtrVector<OutlineItem> Document::build_outline_item_chain(Value const& first_ref, Value const& last_ref)
 | |
| {
 | |
|     VERIFY(first_ref.has<Reference>());
 | |
|     VERIFY(last_ref.has<Reference>());
 | |
| 
 | |
|     NonnullRefPtrVector<OutlineItem> children;
 | |
| 
 | |
|     auto first_dict = object_cast<DictObject>(
 | |
|         get_or_load_value(first_ref.as_ref_index()).get<NonnullRefPtr<Object>>());
 | |
|     auto first = build_outline_item(first_dict);
 | |
|     children.append(first);
 | |
| 
 | |
|     auto current_child_dict = first_dict;
 | |
|     u32 current_child_index = first_ref.as_ref_index();
 | |
| 
 | |
|     while (current_child_dict->contains(CommonNames::Next)) {
 | |
|         auto next_child_dict_ref = current_child_dict->get_value(CommonNames::Next);
 | |
|         current_child_index = next_child_dict_ref.as_ref_index();
 | |
|         auto next_child_dict = object_cast<DictObject>(get_or_load_value(current_child_index).get<NonnullRefPtr<Object>>());
 | |
|         auto next_child = build_outline_item(next_child_dict);
 | |
|         children.append(next_child);
 | |
| 
 | |
|         current_child_dict = move(next_child_dict);
 | |
|     }
 | |
| 
 | |
|     VERIFY(last_ref.as_ref_index() == current_child_index);
 | |
| 
 | |
|     return children;
 | |
| }
 | |
| 
 | |
| }
 | 
