1 /* 2 * This file is part of gtkD. 3 * 4 * gtkD is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU Lesser General Public License 6 * as published by the Free Software Foundation; either version 3 7 * of the License, or (at your option) any later version, with 8 * some exceptions, please read the COPYING file. 9 * 10 * gtkD is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public License 16 * along with gtkD; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA 18 */ 19 20 // generated automatically - do not change 21 // find conversion definition on APILookup.txt 22 // implement new conversion functionalities on the wrap.utils pakage 23 24 25 module gio.AsyncResultT; 26 27 public import gio.c.functions; 28 public import gio.c.types; 29 public import glib.ErrorG; 30 public import glib.GException; 31 public import gobject.ObjectG; 32 public import gtkc.giotypes; 33 34 35 /** 36 * Provides a base class for implementing asynchronous function results. 37 * 38 * Asynchronous operations are broken up into two separate operations 39 * which are chained together by a #GAsyncReadyCallback. To begin 40 * an asynchronous operation, provide a #GAsyncReadyCallback to the 41 * asynchronous function. This callback will be triggered when the 42 * operation has completed, and must be run in a later iteration of 43 * the [thread-default main context][g-main-context-push-thread-default] 44 * from where the operation was initiated. It will be passed a 45 * #GAsyncResult instance filled with the details of the operation's 46 * success or failure, the object the asynchronous function was 47 * started for and any error codes returned. The asynchronous callback 48 * function is then expected to call the corresponding "_finish()" 49 * function, passing the object the function was called for, the 50 * #GAsyncResult instance, and (optionally) an @error to grab any 51 * error conditions that may have occurred. 52 * 53 * The "_finish()" function for an operation takes the generic result 54 * (of type #GAsyncResult) and returns the specific result that the 55 * operation in question yields (e.g. a #GFileEnumerator for a 56 * "enumerate children" operation). If the result or error status of the 57 * operation is not needed, there is no need to call the "_finish()" 58 * function; GIO will take care of cleaning up the result and error 59 * information after the #GAsyncReadyCallback returns. You can pass 60 * %NULL for the #GAsyncReadyCallback if you don't need to take any 61 * action at all after the operation completes. Applications may also 62 * take a reference to the #GAsyncResult and call "_finish()" later; 63 * however, the "_finish()" function may be called at most once. 64 * 65 * Example of a typical asynchronous operation flow: 66 * |[<!-- language="C" --> 67 * void _theoretical_frobnitz_async (Theoretical *t, 68 * GCancellable *c, 69 * GAsyncReadyCallback cb, 70 * gpointer u); 71 * 72 * gboolean _theoretical_frobnitz_finish (Theoretical *t, 73 * GAsyncResult *res, 74 * GError **e); 75 * 76 * static void 77 * frobnitz_result_func (GObject *source_object, 78 * GAsyncResult *res, 79 * gpointer user_data) 80 * { 81 * gboolean success = FALSE; 82 * 83 * success = _theoretical_frobnitz_finish (source_object, res, NULL); 84 * 85 * if (success) 86 * g_printf ("Hurray!\n"); 87 * else 88 * g_printf ("Uh oh!\n"); 89 * 90 * ... 91 * 92 * } 93 * 94 * int main (int argc, void *argv[]) 95 * { 96 * ... 97 * 98 * _theoretical_frobnitz_async (theoretical_data, 99 * NULL, 100 * frobnitz_result_func, 101 * NULL); 102 * 103 * ... 104 * } 105 * ]| 106 * 107 * The callback for an asynchronous operation is called only once, and is 108 * always called, even in the case of a cancelled operation. On cancellation 109 * the result is a %G_IO_ERROR_CANCELLED error. 110 * 111 * ## I/O Priority # {#io-priority} 112 * 113 * Many I/O-related asynchronous operations have a priority parameter, 114 * which is used in certain cases to determine the order in which 115 * operations are executed. They are not used to determine system-wide 116 * I/O scheduling. Priorities are integers, with lower numbers indicating 117 * higher priority. It is recommended to choose priorities between 118 * %G_PRIORITY_LOW and %G_PRIORITY_HIGH, with %G_PRIORITY_DEFAULT 119 * as a default. 120 */ 121 public template AsyncResultT(TStruct) 122 { 123 /** Get the main Gtk struct */ 124 public GAsyncResult* getAsyncResultStruct(bool transferOwnership = false) 125 { 126 if (transferOwnership) 127 ownedRef = false; 128 return cast(GAsyncResult*)getStruct(); 129 } 130 131 132 /** 133 * Gets the source object from a #GAsyncResult. 134 * 135 * Returns: a new reference to the source 136 * object for the @res, or %NULL if there is none. 137 */ 138 public ObjectG getSourceObject() 139 { 140 auto p = g_async_result_get_source_object(getAsyncResultStruct()); 141 142 if(p is null) 143 { 144 return null; 145 } 146 147 return ObjectG.getDObject!(ObjectG)(cast(GObject*) p, true); 148 } 149 150 /** 151 * Gets the user data from a #GAsyncResult. 152 * 153 * Returns: the user data for @res. 154 */ 155 public void* getUserData() 156 { 157 return g_async_result_get_user_data(getAsyncResultStruct()); 158 } 159 160 /** 161 * Checks if @res has the given @source_tag (generally a function 162 * pointer indicating the function @res was created by). 163 * 164 * Params: 165 * sourceTag = an application-defined tag 166 * 167 * Returns: %TRUE if @res has the indicated @source_tag, %FALSE if 168 * not. 169 * 170 * Since: 2.34 171 */ 172 public bool isTagged(void* sourceTag) 173 { 174 return g_async_result_is_tagged(getAsyncResultStruct(), sourceTag) != 0; 175 } 176 177 /** 178 * If @res is a #GSimpleAsyncResult, this is equivalent to 179 * g_simple_async_result_propagate_error(). Otherwise it returns 180 * %FALSE. 181 * 182 * This can be used for legacy error handling in async *_finish() 183 * wrapper functions that traditionally handled #GSimpleAsyncResult 184 * error returns themselves rather than calling into the virtual method. 185 * This should not be used in new code; #GAsyncResult errors that are 186 * set by virtual methods should also be extracted by virtual methods, 187 * to enable subclasses to chain up correctly. 188 * 189 * Returns: %TRUE if @error is has been filled in with an error from 190 * @res, %FALSE if not. 191 * 192 * Since: 2.34 193 * 194 * Throws: GException on failure. 195 */ 196 public bool legacyPropagateError() 197 { 198 GError* err = null; 199 200 auto p = g_async_result_legacy_propagate_error(getAsyncResultStruct(), &err) != 0; 201 202 if (err !is null) 203 { 204 throw new GException( new ErrorG(err) ); 205 } 206 207 return p; 208 } 209 }