module Gio::AsyncInitable

Overview

This is the asynchronous version of #GInitable; it behaves the same in all ways except that initialization is asynchronous. For more details see the descriptions on #GInitable.

A class may implement both the #GInitable and #GAsyncInitable interfaces.

Users of objects implementing this are not intended to use the interface method directly; instead it will be used automatically in various ways. For C applications you generally just call g_async_initable_new_async() directly, or indirectly via a foo_thing_new_async() wrapper. This will call g_async_initable_init_async() under the cover, calling back with nil and a set %GError on failure.

A typical implementation might look something like this:

|[ enum { NOT_INITIALIZED, INITIALIZING, INITIALIZED };

static void _foo_ready_cb (Foo *self) { GList *l;

self->priv->state = INITIALIZED;

for (l = self->priv->init_results; l != NULL; l = l->next) { GTask *task = l->data;

  if (self->priv->success)
    g_task_return_boolean (task, TRUE);
  else
    g_task_return_new_error (task, ...);
  g_object_unref (task);
}

g_list_free (self->priv->init_results); self->priv->init_results = NULL; }

static void foo_init_async (GAsyncInitable *initable, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { Foo *self = FOO (initable); GTask *task;

task = g_task_new (initable, cancellable, callback, user_data); g_task_set_name (task, G_STRFUNC);

switch (self->priv->state) { case NOT_INITIALIZED: _foo_get_ready (self); self->priv->init_results = g_list_append (self->priv->init_results, task); self->priv->state = INITIALIZING; break; case INITIALIZING: self->priv->init_results = g_list_append (self->priv->init_results, task); break; case INITIALIZED: if (!self->priv->success) g_task_return_new_error (task, ...); else g_task_return_boolean (task, TRUE); g_object_unref (task); break; } }

static gboolean foo_init_finish (GAsyncInitable *initable, GAsyncResult *result, GError **error) { g_return_val_if_fail (g_task_is_valid (result, initable), FALSE);

return g_task_propagate_boolean (G_TASK (result), error); }

static void foo_async_initable_iface_init (gpointer g_iface, gpointer data) { GAsyncInitableIface *iface = g_iface;

iface->init_async = foo_init_async; iface->init_finish = foo_init_finish; } ]|

Direct including types

Defined in:

lib/gi-crystal/src/auto/gio-2.0/async_initable.cr

Constructors

Class Method Summary

Instance Method Summary

Constructor Detail

def self.cast(obj : GObject::Object) : self #

Cast a GObject::Object to self, throws a TypeCastError if the cast can't be made.


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Class Method Detail

def self.cast?(obj : GObject::Object) : self | Nil #

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def self.g_type : UInt64 #

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def self.newv_async(object_type : UInt64, n_parameters : UInt32, parameters : GObject::Parameter, io_priority : Int32, cancellable : Gio::Cancellable | Nil, callback : Gio::AsyncReadyCallback | Nil, user_data : Pointer(Void) | Nil) : Nil #

DEPRECATED


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Instance Method Detail

def init_async(io_priority : Int32, cancellable : Gio::Cancellable | Nil, callback : Gio::AsyncReadyCallback | Nil, user_data : Pointer(Void) | Nil) : Nil #

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def init_finish(res : Gio::AsyncResult) : Bool #

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def new_finish(res : Gio::AsyncResult) : GObject::Object #

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abstract def to_unsafe #

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