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/*
* Copyright (c) 2021, Matthew Olsson <mattco@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Format.h>
#include <AK/HashMap.h>
#include <AK/RefCounted.h>
#include <LibGfx/Color.h>
#include <LibPDF/Object.h>
#include <LibPDF/Parser.h>
namespace PDF {
struct Rectangle {
float lower_left_x;
float lower_left_y;
float upper_right_x;
float upper_right_y;
};
struct Page {
NonnullRefPtr<DictObject> resources;
NonnullRefPtr<Object> contents;
Rectangle media_box;
Rectangle crop_box;
float user_unit;
int rotate;
};
struct Destination {
enum class Type {
XYZ,
Fit,
FitH,
FitV,
FitR,
FitB,
FitBH,
FitBV,
};
Type type;
Value page;
Vector<float> parameters;
};
struct OutlineItem final : public RefCounted<OutlineItem> {
RefPtr<OutlineItem> parent;
NonnullRefPtrVector<OutlineItem> children;
String title;
i32 count { 0 };
Destination dest;
Gfx::Color color { Color::NamedColor::Black }; // 'C' in the PDF spec
bool italic { false }; // bit 0 of 'F' in the PDF spec
bool bold { false }; // bit 0 of 'F' in the PDF spec
OutlineItem() = default;
String to_string(int indent) const;
};
struct OutlineDict final : public RefCounted<OutlineDict> {
NonnullRefPtrVector<OutlineItem> children;
u32 count { 0 };
OutlineDict() = default;
};
class Document final : public RefCounted<Document> {
public:
static RefPtr<Document> create(ReadonlyBytes const& bytes);
ALWAYS_INLINE RefPtr<OutlineDict> const& outline() const { return m_outline; }
[[nodiscard]] Value get_or_load_value(u32 index);
[[nodiscard]] u32 get_first_page_index() const;
[[nodiscard]] u32 get_page_count() const;
[[nodiscard]] Page get_page(u32 index);
ALWAYS_INLINE Value get_value(u32 index) const
{
return m_values.get(index).value_or({});
}
// Strips away the layer of indirection by turning indirect value
// refs into the value they reference, and indirect values into
// the value being wrapped.
Value resolve(Value const& value);
// Like resolve, but unwraps the Value into the given type. Accepts
// any object type, and the three primitive Value types.
template<IsValueType T>
UnwrappedValueType<T> resolve_to(Value const& value)
{
auto resolved = resolve(value);
if constexpr (IsSame<T, bool>)
return resolved.as_bool();
if constexpr (IsSame<T, int>)
return resolved.as_int();
if constexpr (IsSame<T, float>)
return resolved.as_float();
if constexpr (IsObject<T>)
return object_cast<T>(resolved.as_object());
VERIFY_NOT_REACHED();
}
private:
explicit Document(NonnullRefPtr<Parser> const& parser);
// FIXME: Currently, to improve performance, we don't load any pages at Document
// construction, rather we just load the page structure and populate
// m_page_object_indices. However, we can be even lazier and defer page tree node
// parsing, as good PDF writers will layout the page tree in a balanced tree to
// improve lookup time. This would reduce the initial overhead by not loading
// every page tree node of, say, a 1000+ page PDF file.
bool build_page_tree();
bool add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> const& page_tree);
void build_outline();
NonnullRefPtr<OutlineItem> build_outline_item(NonnullRefPtr<DictObject> const& outline_item_dict);
NonnullRefPtrVector<OutlineItem> build_outline_item_chain(Value const& first_ref, Value const& last_ref);
NonnullRefPtr<Parser> m_parser;
RefPtr<DictObject> m_catalog;
Vector<u32> m_page_object_indices;
HashMap<u32, Page> m_pages;
HashMap<u32, Value> m_values;
RefPtr<OutlineDict> m_outline;
};
}
namespace AK {
template<>
struct Formatter<PDF::Rectangle> : Formatter<StringView> {
void format(FormatBuilder& builder, PDF::Rectangle const& rectangle)
{
Formatter<StringView>::format(builder,
String::formatted("Rectangle {{ ll=({}, {}), ur=({}, {}) }}",
rectangle.lower_left_x,
rectangle.lower_left_y,
rectangle.upper_right_x,
rectangle.upper_right_y));
}
};
template<>
struct Formatter<PDF::Page> : Formatter<StringView> {
void format(FormatBuilder& builder, PDF::Page const& page)
{
constexpr auto fmt_string = "Page {{\n resources={}\n contents={}\n media_box={}\n crop_box={}\n user_unit={}\n rotate={}\n}}";
auto str = String::formatted(fmt_string,
page.resources->to_string(1),
page.contents->to_string(1),
page.media_box,
page.crop_box,
page.user_unit,
page.rotate);
Formatter<StringView>::format(builder, str);
}
};
template<>
struct Formatter<PDF::Destination> : Formatter<StringView> {
void format(FormatBuilder& builder, PDF::Destination const& destination)
{
String type_str;
switch (destination.type) {
case PDF::Destination::Type::XYZ:
type_str = "XYZ";
break;
case PDF::Destination::Type::Fit:
type_str = "Fit";
break;
case PDF::Destination::Type::FitH:
type_str = "FitH";
break;
case PDF::Destination::Type::FitV:
type_str = "FitV";
break;
case PDF::Destination::Type::FitR:
type_str = "FitR";
break;
case PDF::Destination::Type::FitB:
type_str = "FitB";
break;
case PDF::Destination::Type::FitBH:
type_str = "FitBH";
break;
case PDF::Destination::Type::FitBV:
type_str = "FitBV";
break;
}
StringBuilder param_builder;
for (auto& param : destination.parameters)
param_builder.appendff("{} ", param);
auto str = String::formatted("{{ type={} page={} params={} }}", type_str, destination.page, param_builder.to_string());
Formatter<StringView>::format(builder, str);
}
};
template<>
struct Formatter<PDF::OutlineItem> : Formatter<StringView> {
void format(FormatBuilder& builder, PDF::OutlineItem const& item)
{
Formatter<StringView>::format(builder, item.to_string(0));
}
};
template<>
struct Formatter<PDF::OutlineDict> : Formatter<StringView> {
void format(FormatBuilder& builder, PDF::OutlineDict const& dict)
{
StringBuilder child_builder;
child_builder.append('[');
for (auto& child : dict.children)
child_builder.appendff("{}\n", child.to_string(2));
child_builder.append(" ]");
Formatter<StringView>::format(builder,
String::formatted("OutlineDict {{\n count={}\n children={}\n}}", dict.count, child_builder.to_string()));
}
};
}
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