Enum SoftKeyboardSupport 

#[non_exhaustive]
pub enum SoftKeyboardSupport {
    None,
    ViaAccessibility,
    Explicit,
}

What a platform can do about an on-screen keyboard.

Three answers, and the difference between them is what a caller may promise a user, not how much code stands behind them.

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.

None

The framework has no keyboard request to send, and makes no promise that anything will rise on its own. Either the platform has no software keyboard at all, or it has one whose appearance is the platform’s business and not reliable enough to promise. A request is dropped, and a text surface driven by touch needs its own affordance.

ViaAccessibility

A keyboard exists and is guaranteed to rise when a text control takes focus through the accessibility layer, so a touch-driven text surface needs no affordance of its own. There is still nothing to ask: the framework’s ordinary IME-allowance reconcile is what summons it, and an explicit ask would at best duplicate that and at worst re-assert allowance, which cancels a live composition — so a request resolves to “already done”.

The guarantee is what separates this from None, which covers every platform where a keyboard may or may not appear.

Explicit

A keyboard exists and can be shown and hidden on demand. Only a backend that can honour both directions may report this: a toggle whose current state is unknown cannot, because “show” would sometimes hide.

Trait Implementations

impl Clone for SoftKeyboardSupport

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SoftKeyboardSupport

impl Debug for SoftKeyboardSupport

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

Formats the value using the given formatter.

impl Default for SoftKeyboardSupport

fn default() -> Self

Returns the “default value” for a type.

impl Eq for SoftKeyboardSupport

impl Hash for SoftKeyboardSupport

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

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 SoftKeyboardSupport

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SoftKeyboardSupport