Enum Rotation 

pub enum Rotation {
    None,
    Quarter,
    Half,
    ThreeQuarter,
}

A widget’s rotation, normalized to one of the four quadrants.

The appearance builder reads the same key, so this is its type rather than a second one that could fold /MK /R differently: routing and the generator must agree about which box a click lands in. A widget annotation’s /MK /R, normalized to one of the four quadrants.

ISO 32000-1 Table 189 defines /R as “the number of degrees by which the widget annotation shall be rotated counterclockwise relative to the page”, and says it “shall be a multiple of 90”. Neither clause is a guarantee about real files, so WidgetRotation::from_degrees rules on both: a negative or out-of-range angle is the same quadrant it names modulo a full turn, and an angle that is not a multiple of 90 names no quadrant at all and is upright.

This is the one normalization both readers of the key share — the appearance builder, which needs the box, and pdfrum-form’s routing, which needs the map. They used to fold it separately and disagreed.

Variants

None

Upright.

Quarter

A quarter turn counterclockwise.

Half

A half turn.

ThreeQuarter

Three quarters counterclockwise.

Implementations

impl WidgetRotation

pub fn from_degrees(degrees: i64) -> WidgetRotation

The quadrant /MK /R n names, or WidgetRotation::None when it names none.

The fold is rem_euclid(360), so -90 is 270 — a quarter turn clockwise is three quarters counterclockwise, which is what a counterclockwise angle of -90 means. A value that is not a multiple of 90 is upright.

[oracle-bug] A negative multiple of 90 keeps its sign through the fold, so /R -90 draws and hit-tests as a three-quarter turn — the specification’s “counterclockwise” reading, and pdf.js’s.

use pdfrum_doc::geom::WidgetRotation;

assert_eq!(WidgetRotation::from_degrees(90), WidgetRotation::Quarter);
// `-90` counterclockwise is three quarters, and folds there.
assert_eq!(WidgetRotation::from_degrees(-90), WidgetRotation::ThreeQuarter);
// Not a multiple of 90: no quadrant at all.
assert_eq!(WidgetRotation::from_degrees(45), WidgetRotation::None);

pub fn swaps_axes(self) -> bool

Whether this rotation exchanges the widget’s width and height.

use pdfrum_doc::geom::WidgetRotation;

assert!(WidgetRotation::Quarter.swaps_axes());
assert!(!WidgetRotation::Half.swaps_axes());

Trait Implementations

impl Clone for WidgetRotation

fn clone(&self) -> WidgetRotation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for WidgetRotation

impl Debug for WidgetRotation

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

Formats the value using the given formatter.

impl Default for WidgetRotation

fn default() -> WidgetRotation

Returns the “default value” for a type.

impl Eq for WidgetRotation

impl Hash for WidgetRotation

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for WidgetRotation

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for WidgetRotation