Enum Appearance 

pub enum Appearance {
    Untouched,
    Generated(GeneratedAp),
    Suppressed,
}

What an overlay says about one annotation.

Three states, not two, and the third is why this is an enum rather than an Option. “Nothing was generated” and “this annotation draws nothing” are different instructions: the first falls through to whatever /AP the file carries, the second suppresses it. A field whose appearance has been cleared — focus left it and it went back to drawing nothing — needs the second, and expressing it as the absence of an entry would make it indistinguishable from the first.

use pdfrum_doc::{AnnotOverlay, ap::Appearance};

let mut overlay = AnnotOverlay::with_capacity(2);
assert_eq!(overlay.appearance(0), &Appearance::Untouched);

// Suppressed is not the same as untouched: it says "draw nothing",
// even for an annotation the file gave an `/AP`.
overlay.set_appearance(0, Appearance::Suppressed);
assert!(overlay.get(0).is_none());

Variants

Untouched

Nothing to say. The file’s own /AP is used, if it has one.

Generated(GeneratedAp)

Draw this instead of the file’s /AP.

Suppressed

Draw nothing at all, even if the file carries an /AP.

Nothing sets this yet. It exists so a cleared appearance has a spelling that is not “absent”, which is what keeps the merge below able to express one later without changing shape.

Trait Implementations

impl Clone for Appearance

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 Appearance

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

Formats the value using the given formatter.

impl Default for Appearance

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for Appearance

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Appearance