Struct ChoiceState 

pub struct ChoiceState {
    pub options: Vec<ChoiceOption>,
    pub selected: BTreeSet<usize>,
    pub caret_index: Option<usize>,
    pub anchor: Option<usize>,
    pub top_visible: usize,
    pub popup_open: bool,
    pub hovered: Option<usize>,
    pub config: ChoiceConfig,
    pub edit_text: String,
    pub edit: Option<Box<TextEdit>>,
}

A combo box or list box’s interaction state.

use pdfrum_form::field::{ChoiceConfig, ChoiceOption, ChoiceState, choice};

let rows = ["Apple", "Banana"]
    .map(|l| ChoiceOption { label: l.to_string(), value: l.to_string() })
    .to_vec();
let mut state = ChoiceState::new(rows, ChoiceConfig::default());
choice::select_only(&mut state, 1);
assert_eq!(state.focused_text(), "Banana");
assert!(!state.popup_open, "nothing a file says opens a dropdown");

Fields

options: Vec<ChoiceOption>

The rows.

selected: BTreeSet<usize>

Which rows are selected.

caret_index: Option<usize>

The row last acted upon.

Not a description of the selection: a multi-select list box reports this row’s text as its focused text, and a call that selects nothing — deselecting an already-deselected row — still moves it. That is the asserted behaviour, however odd it reads.

anchor: Option<usize>

The pivot a shift-click ranges from. Successive shift-clicks all pivot on the same row, so this is not updated by one.

top_visible: usize

The first row currently visible.

popup_open: bool

Whether a combo box’s dropdown is open.

Meaningless on a list box, which has no second window to open, and never set on one.

Open is a session fact and not a document one: nothing a file can say opens a dropdown, and the only thing that does is a click on the drop button, a Return, or a Space on a gated combo. What it changes is where a click lands — a point below the widget is inside the list rather than a miss — and what a host is told to draw (crate::popup::PopupView).

hovered: Option<usize>

The row the pointer is over while the dropdown is open.

Hovering a row selects it. Kept beside the selection rather than folded into it, so that closing the list without clicking leaves the stored selection alone.

config: ChoiceConfig

How the field is configured.

edit_text: String

What an editable combo box has in its text box.

Kept as a string beside the control rather than only inside it, so a combo that has never been typed into still answers its text without a layout — and so the control itself can be dropped and rebuilt when the font or the plate changes.

edit: Option<Box<TextEdit>>

The editable combo’s live edit control, once one has been typed into.

None until the first character: a non-editable combo never has one, and an editable one that has only been clicked does not need one. It is boxed because it is much larger than the rest of this record and absent in the common case.

Implementations

impl ChoiceState

pub fn new( options: impl IntoIterator<Item = ChoiceOption>, config: ChoiceConfig, ) -> ChoiceState

A choice field with the given rows and configuration.

Nothing is selected and nothing has been acted upon yet, so the field reports no focused text at all.

use pdfrum_form::{ChoiceConfig, ChoiceState};

let state = ChoiceState::new(Vec::new(), ChoiceConfig::default());
assert!(state.selected.is_empty());
assert_eq!(state.caret_index, None);
assert_eq!(state.focused_text(), "");

pub fn focused_text(&self) -> String

The text this field reports as its focused text.

The row last acted upon for a choice field, which for a single-select field is the same thing as “the selected row” and for a multi-select one deliberately is not.

use pdfrum_form::field::{ChoiceConfig, ChoiceOption, ChoiceState};

let rows = ["Apple", "Banana", "Cherry", "Date"]
    .map(|l| ChoiceOption { label: l.to_string(), value: l.to_string() })
    .to_vec();
let mut state = ChoiceState::new(rows, ChoiceConfig::default());
state.selected.insert(0);
state.selected.insert(2);

// With nothing acted upon, the first selected row answers.
assert_eq!(state.focused_text(), "Apple");

// Acting on a row moves it — even to a row that is not selected.
state.caret_index = Some(3);
assert_eq!(state.focused_text(), "Date");

Trait Implementations

impl Clone for ChoiceState

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 ChoiceState

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

Formats the value using the given formatter.

impl Default for ChoiceState

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for ChoiceState

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ChoiceState