Enum RowValue 

#[non_exhaustive]
pub enum RowValue<G: GameData> {
    #[non_exhaustive]
    Toggle {
        get: fn(&Ctx<G>) -> bool,
        set: fn(&mut Ctx<G>, bool) -> bool,
    },
    #[non_exhaustive]
    Choice {
        values: fn(&Ctx<G>) -> Vec<&'static str>,
        get: fn(&Ctx<G>) -> usize,
        set: fn(&mut Ctx<G>, usize) -> bool,
        shown: Option<fn(&Ctx<G>) -> String>,
    },
    #[non_exhaustive]
    Volume {
        get: fn(&Ctx<G>) -> u8,
        set: fn(&mut Ctx<G>, u8) -> bool,
    },
    #[non_exhaustive]
    Action {
        value: fn(&Ctx<G>) -> Option<String>,
        confirm: fn(&mut Ctx<G>) -> RowAction<G>,
        help: fn(&Ctx<G>) -> &'static str,
    },
}

What a row shows beside its label, and what changes it. Build it with RowValue::toggle, choice, volume or action: kinds of row and their fields may come, and never break a game (ADR-0039).

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

#[non_exhaustive]

Toggle

On or off: the cursor’s left key turns it off, the right key on, Confirm the other way.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

get: fn(&Ctx<G>) -> bool

Whether it is on.

set: fn(&mut Ctx<G>, bool) -> bool

Turns it on or off; whether anything changed.

#[non_exhaustive]

Choice

One of several values: the cursor’s keys step through them, stopping at the ends, and Confirm goes round.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

values: fn(&Ctx<G>) -> Vec<&'static str>

The text keys of the values offered, in the order they step.

get: fn(&Ctx<G>) -> usize

Which of them the row shows.

set: fn(&mut Ctx<G>, usize) -> bool

Puts value i in; whether anything changed.

shown: Option<fn(&Ctx<G>) -> String>

What the row shows, if not the text of its value’s key: a value with a number in it (the frame cap’s “60 FPS”).

#[non_exhaustive]

Volume

A volume, 0 to MAX_VOLUME: the keys move its slider by VOLUME_STEP, Confirm opens a box to type the number.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

get: fn(&Ctx<G>) -> u8

The volume.

set: fn(&mut Ctx<G>, u8) -> bool

Sets it; whether anything changed.

#[non_exhaustive]

Action

Something Confirm does.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

value: fn(&Ctx<G>) -> Option<String>

What the row shows beside its label, if anything (the layout in use, say).

confirm: fn(&mut Ctx<G>) -> RowAction<G>

What Confirm on it does.

help: fn(&Ctx<G>) -> &'static str

The text key of the help line while it has the focus.

Implementations

impl<G: GameData> RowValue<G>

pub const fn toggle( get: fn(&Ctx<G>) -> bool, set: fn(&mut Ctx<G>, bool) -> bool, ) -> Self

An on-or-off row: get says whether it is on, set turns it on or off.

pub const fn choice( values: fn(&Ctx<G>) -> Vec<&'static str>, get: fn(&Ctx<G>) -> usize, set: fn(&mut Ctx<G>, usize) -> bool, ) -> Self

A row of one of values: get says which it shows, set puts one in.

pub const fn choice_shown( values: fn(&Ctx<G>) -> Vec<&'static str>, get: fn(&Ctx<G>) -> usize, set: fn(&mut Ctx<G>, usize) -> bool, shown: fn(&Ctx<G>) -> String, ) -> Self

A row of one of values, as choice is, that shows what shown says rather than the text of its value’s key: a value with a number in it.

pub const fn volume( get: fn(&Ctx<G>) -> u8, set: fn(&mut Ctx<G>, u8) -> bool, ) -> Self

A volume row: get reads the volume, set sets it.

pub const fn action( value: fn(&Ctx<G>) -> Option<String>, confirm: fn(&mut Ctx<G>) -> RowAction<G>, help: fn(&Ctx<G>) -> &'static str, ) -> Self

A row Confirm does confirm on, showing value beside its label and help while it has the focus.