Struct ViewerPrefs 

pub struct ViewerPrefs {
    pub dict: Option<Dict>,
}

A document’s viewer preferences.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

assert!(prefs.is_direction_r2l(&NoResolve));
// A catalog with no `/ViewerPreferences` has no dictionary at all,
// which is not the same as an empty one.
assert!(ViewerPrefs::read(&Dict::default(), &NoResolve).dict.is_none());

Fields

dict: Option<Dict>

The /ViewerPreferences dictionary, absent when the catalog has none.

Implementations

impl ViewerPrefs

pub fn read<R: Resolve>(catalog: &Dict, r: &R) -> ViewerPrefs

Reads the catalog’s preferences.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

assert!(prefs.dict.is_some());

pub fn is_direction_r2l<R: Resolve>(&self, r: &R) -> bool

Whether the reading order is right-to-left.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

assert!(prefs.is_direction_r2l(&NoResolve));
assert!(!ViewerPrefs::default().is_direction_r2l(&NoResolve));

pub fn print_scaling<R: Resolve>(&self, r: &R) -> bool

Whether the print dialog offers page scaling. True with no dictionary.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

// True with no dictionary, and true unless the key says `None`.
assert!(prefs.print_scaling(&NoResolve));
assert!(ViewerPrefs::default().print_scaling(&NoResolve));

pub fn num_copies<R: Resolve>(&self, r: &R) -> i64

The default number of copies.

One with no dictionary, zero with a dictionary that omits the key — the two paths genuinely differ.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

assert_eq!(prefs.num_copies(&NoResolve), 3);
// One with no dictionary; a dictionary omitting the key answers zero.
assert_eq!(ViewerPrefs::default().num_copies(&NoResolve), 1);

pub fn print_page_range<R: Resolve>(&self, r: &R) -> Option<Array>

The default printed page range, as raw index pairs. Duplicates are kept.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

assert!(prefs.print_page_range(&NoResolve).is_none());

pub fn duplex<R: Resolve>(&self, r: &R) -> Vec<u8>

The duplex handling. None — the string — with no dictionary.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

// The *string* `None` is the default, not an absent value.
assert_eq!(prefs.duplex(&NoResolve), b"None");

pub fn generic_name(&self, key: &Name) -> Option<Vec<u8>>

Any preference whose value is a name.

The type filter is the point: a Boolean /HideToolbar and an integer /NumCopies both answer nothing here even when present. Keys are case-sensitive.

use pdfrum_doc::ViewerPrefs;
use pdfrum_object::{Dict, Name, NoResolve, Object};

let catalog = Dict::from_pairs([(
    Name::from("ViewerPreferences"),
    Object::Dict(Dict::from_pairs([
        (Name::from("Direction"), Object::Name(Name::from("R2L"))),
        (Name::from("NumCopies"), Object::Int(3)),
    ])),
)]);
let prefs = ViewerPrefs::read(&catalog, &NoResolve);

assert_eq!(prefs.generic_name(&Name::from("Direction")), Some(b"R2L".to_vec()));
// Name-typed: the integer `/NumCopies` answers nothing here.
assert_eq!(prefs.generic_name(&Name::from("NumCopies")), None);

Trait Implementations

impl Clone for ViewerPrefs

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ViewerPrefs

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ViewerPrefs

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for ViewerPrefs

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ViewerPrefs