ladybird/Userland/Libraries/LibPDF/Document.h
2023-03-25 16:27:30 -06:00

270 lines
9.2 KiB
C++

/*
* Copyright (c) 2021-2022, 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 <AK/Weakable.h>
#include <LibGfx/Color.h>
#include <LibPDF/DocumentParser.h>
#include <LibPDF/Encryption.h>
#include <LibPDF/Error.h>
#include <LibPDF/ObjectDerivatives.h>
namespace PDF {
struct Rectangle {
float lower_left_x;
float lower_left_y;
float upper_right_x;
float upper_right_y;
float width() const { return upper_right_x - lower_left_x; }
float height() const { return upper_right_y - lower_left_y; }
};
struct Page {
NonnullRefPtr<DictObject> resources;
RefPtr<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;
Optional<u32> page;
Vector<Optional<float>> parameters;
};
struct OutlineItem final : public RefCounted<OutlineItem> {
RefPtr<OutlineItem> parent;
Vector<NonnullRefPtr<OutlineItem>> children;
DeprecatedString 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;
DeprecatedString to_deprecated_string(int indent) const;
};
struct OutlineDict final : public RefCounted<OutlineDict> {
Vector<NonnullRefPtr<OutlineItem>> children;
u32 count { 0 };
OutlineDict() = default;
};
class Document final
: public RefCounted<Document>
, public Weakable<Document> {
public:
static PDFErrorOr<NonnullRefPtr<Document>> create(ReadonlyBytes bytes);
// If a security handler is present, it is the caller's responsibility to ensure
// this document is unencrypted before calling this function. The user does not
// need to handle the case where the user password is the empty string.
PDFErrorOr<void> initialize();
ALWAYS_INLINE RefPtr<SecurityHandler> const& security_handler() const { return m_security_handler; }
ALWAYS_INLINE RefPtr<OutlineDict> const& outline() const { return m_outline; }
ALWAYS_INLINE RefPtr<DictObject> const& trailer() const { return m_trailer; }
[[nodiscard]] PDFErrorOr<Value> get_or_load_value(u32 index);
[[nodiscard]] u32 get_first_page_index() const;
[[nodiscard]] u32 get_page_count() const;
[[nodiscard]] PDFErrorOr<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.
PDFErrorOr<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>
PDFErrorOr<UnwrappedValueType<T>> resolve_to(Value const& value)
{
return cast_to<T>(TRY(resolve(value)));
}
/// Whether this Document is reasdy to resolve references, which is usually
/// true, except just before the XRef table is parsed (and while the linearization
/// dict is being read).
bool can_resolve_refefences() { return m_parser->can_resolve_references(); }
private:
explicit Document(NonnullRefPtr<DocumentParser> 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.
PDFErrorOr<void> build_page_tree();
PDFErrorOr<void> add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> const& page_tree);
PDFErrorOr<void> build_outline();
PDFErrorOr<NonnullRefPtr<OutlineItem>> build_outline_item(NonnullRefPtr<DictObject> const& outline_item_dict, HashMap<u32, u32> const&);
PDFErrorOr<Vector<NonnullRefPtr<OutlineItem>>> build_outline_item_chain(Value const& first_ref, HashMap<u32, u32> const&);
PDFErrorOr<Destination> create_destination_from_parameters(NonnullRefPtr<ArrayObject>, HashMap<u32, u32> const&);
PDFErrorOr<Destination> create_destination_from_dictionary_entry(NonnullRefPtr<Object> const& entry, HashMap<u32, u32> const& page_number_by_index_ref);
PDFErrorOr<Optional<NonnullRefPtr<Object>>> get_inheritable_object(DeprecatedFlyString const& name, NonnullRefPtr<DictObject>);
PDFErrorOr<Optional<Value>> get_inheritable_value(DeprecatedFlyString const& name, NonnullRefPtr<DictObject>);
PDFErrorOr<NonnullRefPtr<Object>> find_in_name_tree(NonnullRefPtr<DictObject> root, DeprecatedFlyString name);
PDFErrorOr<NonnullRefPtr<Object>> find_in_name_tree_nodes(NonnullRefPtr<ArrayObject> siblings, DeprecatedFlyString name);
PDFErrorOr<NonnullRefPtr<Object>> find_in_key_value_array(NonnullRefPtr<ArrayObject> key_value_array, DeprecatedFlyString name);
NonnullRefPtr<DocumentParser> m_parser;
RefPtr<DictObject> m_catalog;
RefPtr<DictObject> m_trailer;
Vector<u32> m_page_object_indices;
HashMap<u32, Page> m_pages;
HashMap<u32, Value> m_values;
RefPtr<OutlineDict> m_outline;
RefPtr<SecurityHandler> m_security_handler;
};
}
namespace AK {
template<>
struct Formatter<PDF::Rectangle> : Formatter<FormatString> {
ErrorOr<void> format(FormatBuilder& builder, PDF::Rectangle const& rectangle)
{
return Formatter<FormatString>::format(builder,
"Rectangle {{ ll=({}, {}), ur=({}, {}) }}"sv,
rectangle.lower_left_x,
rectangle.lower_left_y,
rectangle.upper_right_x,
rectangle.upper_right_y);
}
};
template<>
struct Formatter<PDF::Page> : Formatter<FormatString> {
ErrorOr<void> format(FormatBuilder& builder, PDF::Page const& page)
{
return Formatter<FormatString>::format(builder,
"Page {{\n resources={}\n contents={}\n media_box={}\n crop_box={}\n user_unit={}\n rotate={}\n}}"sv,
page.resources->to_deprecated_string(1),
page.contents->to_deprecated_string(1),
page.media_box,
page.crop_box,
page.user_unit,
page.rotate);
}
};
template<>
struct Formatter<PDF::Destination> : Formatter<FormatString> {
ErrorOr<void> format(FormatBuilder& builder, PDF::Destination const& destination)
{
StringView type_str;
switch (destination.type) {
case PDF::Destination::Type::XYZ:
type_str = "XYZ"sv;
break;
case PDF::Destination::Type::Fit:
type_str = "Fit"sv;
break;
case PDF::Destination::Type::FitH:
type_str = "FitH"sv;
break;
case PDF::Destination::Type::FitV:
type_str = "FitV"sv;
break;
case PDF::Destination::Type::FitR:
type_str = "FitR"sv;
break;
case PDF::Destination::Type::FitB:
type_str = "FitB"sv;
break;
case PDF::Destination::Type::FitBH:
type_str = "FitBH"sv;
break;
case PDF::Destination::Type::FitBV:
type_str = "FitBV"sv;
break;
}
StringBuilder param_builder;
builder.builder().appendff("{{ type={} page="sv, type_str);
if (!destination.page.has_value())
TRY(builder.put_literal("{{}}"sv));
else
TRY(builder.put_u64(destination.page.value()));
if (!destination.parameters.is_empty()) {
TRY(builder.put_literal(" parameters="sv));
for (auto const& param : destination.parameters) {
if (param.has_value())
TRY(builder.put_f64(double(param.value())));
else
TRY(builder.put_literal("{{}}"sv));
TRY(builder.put_literal(" "sv));
}
}
return builder.put_literal(" }}"sv);
}
};
template<>
struct Formatter<PDF::OutlineItem> : Formatter<FormatString> {
ErrorOr<void> format(FormatBuilder& builder, PDF::OutlineItem const& item)
{
return builder.put_string(item.to_deprecated_string(0));
}
};
template<>
struct Formatter<PDF::OutlineDict> : Formatter<FormatString> {
ErrorOr<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_deprecated_string(2));
child_builder.append(" ]"sv);
return Formatter<FormatString>::format(builder,
"OutlineDict {{\n count={}\n children={}\n}}"sv, dict.count, child_builder.to_deprecated_string());
}
};
}