Struct ToggleState 

pub struct ToggleState {
    pub state: String,
    pub on_state: String,
    pub checked_control: Option<AnnotId>,
}

A check box or radio button’s interaction state.

One fact: which appearance state the control is showing.

use pdfrum_form::field::{ToggleKind, ToggleState, activate, toggle::OFF_STATE};

let mut state = ToggleState::new(OFF_STATE, "On");
assert!(!state.is_checked());
activate(&mut state, ToggleKind::Check, false);
assert_eq!(state.state, "On");

Fields

state: String

The appearance state name currently selected — the “on” name when the control is checked, OFF_STATE when it is not.

on_state: String

The name this control shows when checked, from its appearance dictionary. Empty when the control offers no on state at all.

checked_control: Option<AnnotId>

Which control of the field is the checked one, by its raw /Annots index, once one has been chosen.

A field’s controls share one state here, which is right for a check box (a field with one kid) and not enough for a radio group, where the clicked control shows its own on state and every other control of the field shows Off. This records the half of that a shared state can express — which control is on — so a sibling’s appearance can be answered Off without a second state record.

None before any control has been activated, which is the state a group loaded from a file with no /V is in.

Implementations

impl ToggleState

pub fn new(state: impl Into<String>, on_state: impl Into<String>) -> ToggleState

A control showing state, whose checked appearance is on_state.

An empty on_state means the control offers no checked appearance at all, and it can then never be checked.

use pdfrum_form::field::{ToggleState, toggle::OFF_STATE};

let state = ToggleState::new(OFF_STATE, "On");
assert!(!state.is_checked());
assert_eq!(state.checked_control, None, "nothing has been clicked yet");

pub fn is_checked(&self) -> bool

Whether the control is currently checked.

An empty state reads as clear rather than as ambiguous: a widget with no appearance state at all is not checked.

use pdfrum_form::field::ToggleState;

assert!(ToggleState::new("On", "On").is_checked());
assert!(!ToggleState::new("Off", "On").is_checked());
assert!(!ToggleState::new("", "On").is_checked());

pub fn state_for_control(&self, control: AnnotId) -> Option<&str>

The appearance state one control of this field should draw.

The per-control answer a shared ToggleState can give: the clicked control shows its own on state and every other control of the same field shows Off.

Three cases, and the middle one is why this is not simply Self::state:

• Nothing has been clicked (Self::checked_control is None): None, meaning “read the widget’s own /AS” — a group loaded from a file must render exactly as the file wrote it, kid by kid.
• This control is the chosen one: its own on state, which for a radio group is a name only this kid carries.
• A sibling was chosen: OFF_STATE, whatever the file’s /AS still says.

use pdfrum_form::AnnotId;
use pdfrum_form::field::{ToggleState, toggle::OFF_STATE};

let clicked = AnnotId::new(0u32, 1);
let sibling = AnnotId::new(0u32, 2);

let mut state = ToggleState::new(OFF_STATE, "Choice1");
// Nothing clicked yet: read each widget's own `/AS`.
assert_eq!(state.state_for_control(clicked), None);

state.set_checked(true);
state.checked_control = Some(clicked);
assert_eq!(state.state_for_control(clicked), Some("Choice1"));
assert_eq!(state.state_for_control(sibling), Some(OFF_STATE));

pub fn set_checked(&mut self, checked: bool)

Sets the control checked or clear.

Checking a control with no on state leaves it clear: there is no appearance to show.

use pdfrum_form::field::{ToggleState, toggle::OFF_STATE};

let mut none = ToggleState::new(OFF_STATE, "");
none.set_checked(true);
assert!(!none.is_checked());

pub fn toggle(&mut self)

Flips the control. What a click on a check box does.

use pdfrum_form::field::{ToggleState, toggle::OFF_STATE};

let mut state = ToggleState::new(OFF_STATE, "On");
state.toggle();
assert!(state.is_checked());
state.toggle();
assert!(!state.is_checked());

Trait Implementations

impl Clone for ToggleState

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 ToggleState

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

Formats the value using the given formatter.

impl Default for ToggleState

fn default() -> Self

Returns the “default value” for a type.

impl Eq for ToggleState

impl PartialEq for ToggleState

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ToggleState