/* * Licensed under the GNU Lesser General Public License Version 3 * * This library is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the license, or * (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library. If not, see . */ // generated automatically - do not change module gio.AsyncResultT; public import gio.c.functions; public import gio.c.types; public import glib.ErrorG; public import glib.GException; public import gobject.ObjectG; /** * Provides a base class for implementing asynchronous function results. * * Asynchronous operations are broken up into two separate operations * which are chained together by a #GAsyncReadyCallback. To begin * an asynchronous operation, provide a #GAsyncReadyCallback to the * asynchronous function. This callback will be triggered when the * operation has completed, and will be passed a #GAsyncResult instance * filled with the details of the operation's success or failure, the * object the asynchronous function was started for and any error codes * returned. The asynchronous callback function is then expected to call * the corresponding "_finish()" function, passing the object the * function was called for, the #GAsyncResult instance, and (optionally) * an @error to grab any error conditions that may have occurred. * * The "_finish()" function for an operation takes the generic result * (of type #GAsyncResult) and returns the specific result that the * operation in question yields (e.g. a #GFileEnumerator for a * "enumerate children" operation). If the result or error status of the * operation is not needed, there is no need to call the "_finish()" * function; GIO will take care of cleaning up the result and error * information after the #GAsyncReadyCallback returns. You can pass * %NULL for the #GAsyncReadyCallback if you don't need to take any * action at all after the operation completes. Applications may also * take a reference to the #GAsyncResult and call "_finish()" later; * however, the "_finish()" function may be called at most once. * * Example of a typical asynchronous operation flow: * |[ * void _theoretical_frobnitz_async (Theoretical *t, * GCancellable *c, * GAsyncReadyCallback cb, * gpointer u); * * gboolean _theoretical_frobnitz_finish (Theoretical *t, * GAsyncResult *res, * GError **e); * * static void * frobnitz_result_func (GObject *source_object, * GAsyncResult *res, * gpointer user_data) * { * gboolean success = FALSE; * * success = _theoretical_frobnitz_finish (source_object, res, NULL); * * if (success) * g_printf ("Hurray!\n"); * else * g_printf ("Uh oh!\n"); * * ... * * } * * int main (int argc, void *argv[]) * { * ... * * _theoretical_frobnitz_async (theoretical_data, * NULL, * frobnitz_result_func, * NULL); * * ... * } * ]| * * The callback for an asynchronous operation is called only once, and is * always called, even in the case of a cancelled operation. On cancellation * the result is a %G_IO_ERROR_CANCELLED error. * * ## I/O Priority # {#io-priority} * * Many I/O-related asynchronous operations have a priority parameter, * which is used in certain cases to determine the order in which * operations are executed. They are not used to determine system-wide * I/O scheduling. Priorities are integers, with lower numbers indicating * higher priority. It is recommended to choose priorities between * %G_PRIORITY_LOW and %G_PRIORITY_HIGH, with %G_PRIORITY_DEFAULT * as a default. */ public template AsyncResultT(TStruct) { /** Get the main Gtk struct */ public GAsyncResult* getAsyncResultStruct(bool transferOwnership = false) { if (transferOwnership) ownedRef = false; return cast(GAsyncResult*)getStruct(); } /** * Gets the source object from a #GAsyncResult. * * Returns: a new reference to the source object for the @res, * or %NULL if there is none. */ public ObjectG getSourceObject() { auto p = g_async_result_get_source_object(getAsyncResultStruct()); if(p is null) { return null; } return ObjectG.getDObject!(ObjectG)(cast(GObject*) p, true); } /** * Gets the user data from a #GAsyncResult. * * Returns: the user data for @res. */ public void* getUserData() { return g_async_result_get_user_data(getAsyncResultStruct()); } /** * Checks if @res has the given @source_tag (generally a function * pointer indicating the function @res was created by). * * Params: * sourceTag = an application-defined tag * * Returns: %TRUE if @res has the indicated @source_tag, %FALSE if * not. * * Since: 2.34 */ public bool isTagged(void* sourceTag) { return g_async_result_is_tagged(getAsyncResultStruct(), sourceTag) != 0; } /** * If @res is a #GSimpleAsyncResult, this is equivalent to * g_simple_async_result_propagate_error(). Otherwise it returns * %FALSE. * * This can be used for legacy error handling in async *_finish() * wrapper functions that traditionally handled #GSimpleAsyncResult * error returns themselves rather than calling into the virtual method. * This should not be used in new code; #GAsyncResult errors that are * set by virtual methods should also be extracted by virtual methods, * to enable subclasses to chain up correctly. * * Returns: %TRUE if @error is has been filled in with an error from * @res, %FALSE if not. * * Since: 2.34 * * Throws: GException on failure. */ public bool legacyPropagateError() { GError* err = null; auto p = g_async_result_legacy_propagate_error(getAsyncResultStruct(), &err) != 0; if (err !is null) { throw new GException( new ErrorG(err) ); } return p; } }