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		3f3f45580a
		
	
	
	
	
		
			
			Each of these strings would previously rely on StringView's char const* constructor overload, which would call __builtin_strlen on the string. Since we now have operator ""sv, we can replace these with much simpler versions. This opens the door to being able to remove StringView(char const*). No functional changes.
		
			
				
	
	
		
			258 lines
		
	
	
	
		
			8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			258 lines
		
	
	
	
		
			8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2021-2022, Matthew Olsson <mattco@serenityos.org>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #pragma once
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| 
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| #include <AK/Format.h>
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| #include <AK/HashMap.h>
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| #include <AK/RefCounted.h>
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| #include <AK/Weakable.h>
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| #include <LibGfx/Color.h>
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| #include <LibPDF/Encryption.h>
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| #include <LibPDF/Error.h>
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| #include <LibPDF/ObjectDerivatives.h>
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| #include <LibPDF/Parser.h>
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| 
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| namespace PDF {
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| 
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| struct Rectangle {
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|     float lower_left_x;
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|     float lower_left_y;
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|     float upper_right_x;
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|     float upper_right_y;
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| 
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|     float width() const { return upper_right_x - lower_left_x; }
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|     float height() const { return upper_right_y - lower_left_y; }
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| };
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| 
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| struct Page {
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|     NonnullRefPtr<DictObject> resources;
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|     NonnullRefPtr<Object> contents;
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|     Rectangle media_box;
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|     Rectangle crop_box;
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|     float user_unit;
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|     int rotate;
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| };
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| 
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| struct Destination {
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|     enum class Type {
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|         XYZ,
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|         Fit,
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|         FitH,
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|         FitV,
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|         FitR,
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|         FitB,
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|         FitBH,
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|         FitBV,
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|     };
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| 
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|     Type type;
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|     Value page;
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|     Vector<float> parameters;
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| };
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| 
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| struct OutlineItem final : public RefCounted<OutlineItem> {
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|     RefPtr<OutlineItem> parent;
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|     NonnullRefPtrVector<OutlineItem> children;
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|     String title;
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|     i32 count { 0 };
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|     Destination dest;
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|     Gfx::Color color { Color::NamedColor::Black }; // 'C' in the PDF spec
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|     bool italic { false };                         // bit 0 of 'F' in the PDF spec
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|     bool bold { false };                           // bit 0 of 'F' in the PDF spec
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| 
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|     OutlineItem() = default;
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| 
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|     String to_string(int indent) const;
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| };
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| 
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| struct OutlineDict final : public RefCounted<OutlineDict> {
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|     NonnullRefPtrVector<OutlineItem> children;
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|     u32 count { 0 };
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| 
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|     OutlineDict() = default;
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| };
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| 
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| class Document final
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|     : public RefCounted<Document>
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|     , public Weakable<Document> {
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| public:
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|     static PDFErrorOr<NonnullRefPtr<Document>> create(ReadonlyBytes bytes);
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| 
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|     // If a security handler is present, it is the caller's responsibility to ensure
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|     // this document is unencrypted before calling this function. The user does not
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|     // need to handle the case where the user password is the empty string.
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|     PDFErrorOr<void> initialize();
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| 
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|     ALWAYS_INLINE RefPtr<SecurityHandler> const& security_handler() const { return m_security_handler; }
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| 
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|     ALWAYS_INLINE RefPtr<OutlineDict> const& outline() const { return m_outline; }
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| 
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|     ALWAYS_INLINE RefPtr<DictObject> const& trailer() const { return m_trailer; }
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| 
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|     [[nodiscard]] PDFErrorOr<Value> get_or_load_value(u32 index);
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| 
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|     [[nodiscard]] u32 get_first_page_index() const;
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| 
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|     [[nodiscard]] u32 get_page_count() const;
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| 
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|     [[nodiscard]] PDFErrorOr<Page> get_page(u32 index);
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| 
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|     ALWAYS_INLINE Value get_value(u32 index) const
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|     {
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|         return m_values.get(index).value_or({});
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|     }
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| 
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|     // Strips away the layer of indirection by turning indirect value
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|     // refs into the value they reference, and indirect values into
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|     // the value being wrapped.
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|     PDFErrorOr<Value> resolve(Value const& value);
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| 
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|     // Like resolve, but unwraps the Value into the given type. Accepts
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|     // any object type, and the three primitive Value types.
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|     template<IsValueType T>
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|     PDFErrorOr<UnwrappedValueType<T>> resolve_to(Value const& value)
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|     {
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|         auto resolved = TRY(resolve(value));
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| 
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|         if constexpr (IsSame<T, bool>)
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|             return resolved.get<bool>();
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|         else if constexpr (IsSame<T, int>)
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|             return resolved.get<int>();
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|         else if constexpr (IsSame<T, float>)
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|             return resolved.get<float>();
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|         else if constexpr (IsSame<T, Object>)
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|             return resolved.get<NonnullRefPtr<Object>>();
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|         else if constexpr (IsObject<T>)
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|             return resolved.get<NonnullRefPtr<Object>>()->cast<T>();
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| 
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|         VERIFY_NOT_REACHED();
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|     }
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| 
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| private:
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|     explicit Document(NonnullRefPtr<Parser> const& parser);
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| 
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|     // FIXME: Currently, to improve performance, we don't load any pages at Document
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|     // construction, rather we just load the page structure and populate
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|     // m_page_object_indices. However, we can be even lazier and defer page tree node
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|     // parsing, as good PDF writers will layout the page tree in a balanced tree to
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|     // improve lookup time. This would reduce the initial overhead by not loading
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|     // every page tree node of, say, a 1000+ page PDF file.
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|     PDFErrorOr<void> build_page_tree();
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|     PDFErrorOr<void> add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> const& page_tree);
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| 
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|     PDFErrorOr<void> build_outline();
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|     PDFErrorOr<NonnullRefPtr<OutlineItem>> build_outline_item(NonnullRefPtr<DictObject> const& outline_item_dict);
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|     PDFErrorOr<NonnullRefPtrVector<OutlineItem>> build_outline_item_chain(Value const& first_ref, Value const& last_ref);
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| 
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|     PDFErrorOr<Destination> create_destination_from_parameters(NonnullRefPtr<ArrayObject>);
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| 
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|     NonnullRefPtr<Parser> m_parser;
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|     RefPtr<DictObject> m_catalog;
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|     RefPtr<DictObject> m_trailer;
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|     Vector<u32> m_page_object_indices;
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|     HashMap<u32, Page> m_pages;
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|     HashMap<u32, Value> m_values;
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|     RefPtr<OutlineDict> m_outline;
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|     RefPtr<SecurityHandler> m_security_handler;
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| };
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| 
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| }
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| 
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| namespace AK {
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| 
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| template<>
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| struct Formatter<PDF::Rectangle> : Formatter<FormatString> {
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|     ErrorOr<void> format(FormatBuilder& builder, PDF::Rectangle const& rectangle)
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|     {
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|         return Formatter<FormatString>::format(builder,
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|             "Rectangle {{ ll=({}, {}), ur=({}, {}) }}"sv,
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|             rectangle.lower_left_x,
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|             rectangle.lower_left_y,
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|             rectangle.upper_right_x,
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|             rectangle.upper_right_y);
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|     }
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| };
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| 
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| template<>
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| struct Formatter<PDF::Page> : Formatter<FormatString> {
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|     ErrorOr<void> format(FormatBuilder& builder, PDF::Page const& page)
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|     {
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|         return Formatter<FormatString>::format(builder,
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|             "Page {{\n  resources={}\n  contents={}\n  media_box={}\n  crop_box={}\n  user_unit={}\n  rotate={}\n}}"sv,
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|             page.resources->to_string(1),
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|             page.contents->to_string(1),
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|             page.media_box,
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|             page.crop_box,
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|             page.user_unit,
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|             page.rotate);
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|     }
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| };
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| 
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| template<>
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| struct Formatter<PDF::Destination> : Formatter<FormatString> {
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|     ErrorOr<void> format(FormatBuilder& builder, PDF::Destination const& destination)
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|     {
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|         StringView type_str;
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|         switch (destination.type) {
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|         case PDF::Destination::Type::XYZ:
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|             type_str = "XYZ"sv;
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|             break;
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|         case PDF::Destination::Type::Fit:
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|             type_str = "Fit"sv;
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|             break;
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|         case PDF::Destination::Type::FitH:
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|             type_str = "FitH"sv;
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|             break;
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|         case PDF::Destination::Type::FitV:
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|             type_str = "FitV"sv;
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|             break;
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|         case PDF::Destination::Type::FitR:
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|             type_str = "FitR"sv;
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|             break;
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|         case PDF::Destination::Type::FitB:
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|             type_str = "FitB"sv;
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|             break;
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|         case PDF::Destination::Type::FitBH:
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|             type_str = "FitBH"sv;
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|             break;
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|         case PDF::Destination::Type::FitBV:
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|             type_str = "FitBV"sv;
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|             break;
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|         }
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| 
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|         StringBuilder param_builder;
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|         for (auto& param : destination.parameters)
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|             param_builder.appendff("{} ", param);
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| 
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|         return Formatter<FormatString>::format(builder, "{{ type={} page={} params={} }}"sv, type_str, destination.page, param_builder.to_string());
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|     }
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| };
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| 
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| template<>
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| struct Formatter<PDF::OutlineItem> : Formatter<FormatString> {
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|     ErrorOr<void> format(FormatBuilder& builder, PDF::OutlineItem const& item)
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|     {
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|         return builder.put_string(item.to_string(0));
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|     }
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| };
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| 
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| template<>
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| struct Formatter<PDF::OutlineDict> : Formatter<FormatString> {
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|     ErrorOr<void> format(FormatBuilder& builder, PDF::OutlineDict const& dict)
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|     {
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|         StringBuilder child_builder;
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|         child_builder.append('[');
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|         for (auto& child : dict.children)
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|             child_builder.appendff("{}\n", child.to_string(2));
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|         child_builder.append("  ]"sv);
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| 
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|         return Formatter<FormatString>::format(builder,
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|             "OutlineDict {{\n  count={}\n  children={}\n}}"sv, dict.count, child_builder.to_string());
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|     }
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| };
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| 
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| }
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