Trait gio::prelude::InitableExt

source ·
pub trait InitableExt: IsA<Initable> + Sealed + 'static {
    // Provided method
    unsafe fn init(
        cancellable: Option<&impl IsA<Cancellable>>,
    ) -> Result<(), Error> { ... }
Expand description

Provided Methods§


unsafe fn init( &self, cancellable: Option<&impl IsA<Cancellable>>, ) -> Result<(), Error>

Initializes the object implementing the interface.

This method is intended for language bindings. If writing in C, g_initable_new() should typically be used instead.

The object must be initialized before any real use after initial construction, either with this function or g_async_initable_init_async().

Implementations may also support cancellation. If @cancellable is not None, then initialization can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error IOErrorEnum::Cancelled will be returned. If @cancellable is not None and the object doesn’t support cancellable initialization the error IOErrorEnum::NotSupported will be returned.

If the object is not initialized, or initialization returns with an error, then all operations on the object except g_object_ref() and g_object_unref() are considered to be invalid, and have undefined behaviour. See the [introduction][ginitable] for more details.

Callers should not assume that a class which implements #GInitable can be initialized multiple times, unless the class explicitly documents itself as supporting this. Generally, a class’ implementation of init() can assume (and assert) that it will only be called once. Previously, this documentation recommended all #GInitable implementations should be idempotent; that recommendation was relaxed in GLib 2.54.

If a class explicitly supports being initialized multiple times, it is recommended that the method is idempotent: multiple calls with the same arguments should return the same results. Only the first call initializes the object; further calls return the result of the first call.

One reason why a class might need to support idempotent initialization is if it is designed to be used via the singleton pattern, with a #GObjectClass.constructor that sometimes returns an existing instance. In this pattern, a caller would expect to be able to call g_initable_init() on the result of g_object_new(), regardless of whether it is in fact a new instance.


optional #GCancellable object, None to ignore.


true if successful. If an error has occurred, this function will return false and set @error appropriately if present.

Object Safety§

This trait is not object safe.