Type Alias SDL_HintCallback 

pub type SDL_HintCallback = Option<unsafe extern "C" fn(userdata: *mut c_void, name: *const c_char, oldValue: *const c_char, newValue: *const c_char)>;

A callback used to send notifications of hint value changes.

This is called an initial time during SDL_AddHintCallback with the hint’s current value, and then again each time the hint’s value changes. In the initial call, the current value is in both oldValue and newValue.

Parameters

• userdata: what was passed as userdata to SDL_AddHintCallback().
• name: what was passed as name to SDL_AddHintCallback().
• oldValue: the previous hint value.
• newValue: the new value hint is to be set to.

Thread safety

This callback is fired from whatever thread is setting a new hint value. SDL holds a lock on the hint subsystem when calling this callback.

Availability

This datatype is available since SDL 3.2.0.

See also

• SDL_AddHintCallback

Aliased Type

pub enum SDL_HintCallback {
    None,
    Some(unsafe extern "C" fn(*mut c_void, *const i8, *const i8, *const i8)),
}

Variants

None

No value.

Some(unsafe extern "C" fn(*mut c_void, *const i8, *const i8, *const i8))

Some value of type T.