Struct glib::closure::Closure

#[repr(transparent)]
pub struct Closure { /* private fields */ }

Implementations

impl Closure

pub fn new<F: Fn(&[Value]) -> Option<Value> + Send + Sync + 'static>(
    callback: F
) -> Self

Creates a new closure around a Rust closure.

Note that RustClosure provides more convenient and non-unsafe API for invoking closures. This type mostly exists for FFI interop.

Panics

Invoking the closure with wrong argument types or returning the wrong return value type will panic.

Example

use glib::prelude::*;

let closure = glib::Closure::new(|values| {
    let x = values[0].get::<i32>().unwrap();
    Some((x + 1).to_value())
});

// Invoking non-Rust closures is unsafe because of possibly missing
// argument and return value type checks.
let res = unsafe {
    closure
        .invoke_with_values(glib::Type::I32, &[1i32.to_value()])
        .and_then(|v| v.get::<i32>().ok())
        .expect("Invalid return value")
};

assert_eq!(res, 2);

pub fn new_local<F: Fn(&[Value]) -> Option<Value> + 'static>(
    callback: F
) -> Self

Creates a new closure around a Rust closure.

Note that RustClosure provides more convenient and non-unsafe API for invoking closures. This type mostly exists for FFI interop.

Panics

Invoking the closure with wrong argument types or returning the wrong return value type will panic.

Invoking the closure from a different thread than this one will panic.

pub unsafe fn new_unsafe<F: Fn(&[Value]) -> Option<Value>>(callback: F) -> Self

Creates a new closure around a Rust closure.

Safety

The captured variables of the closure must stay valid as long as the return value of this constructor does, and it must be valid to call the closure from any thread that is used by callers.

pub unsafe fn invoke_with_values(
    &self,
    return_type: Type,
    values: &[Value]
) -> Option<Value>

Invokes the closure with the given arguments.

For invalidated closures this returns the “default” value of the return type.

Safety

The argument types and return value type must match the ones expected by the closure or otherwise the behaviour is undefined.

Closures created from Rust via e.g. Closure::new will panic on type mismatches but this is not guaranteed for closures created from other languages.

pub fn invalidate(&self)

Invalidates the closure.

Invoking an invalidated closure has no effect.

Trait Implementations

impl AsRef<Closure> for RustClosure

fn as_ref(&self) -> &Closure

Performs the conversion.

impl AsRef<Closure> for Closure

fn as_ref(&self) -> &Closure

Performs the conversion.

impl Clone for Closure

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Closure

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

Formats the value using the given formatter.

impl From<RustClosure> for Closure

fn from(c: RustClosure) -> Self

Performs the conversion.

impl Hash for Closure

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, 

Feeds a slice of this type into the given Hasher.

impl Ord for Closure

fn cmp(&self, other: &Closure) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Closure> for Closure

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Closure> for Closure

fn partial_cmp(&self, other: &Closure) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for Closure

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for Closure

impl Send for Closure

impl StructuralEq for Closure

impl StructuralPartialEq for Closure

impl Sync for Closure