gobject/gsourceclosure.c

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 2001 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General
  15  * Public License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include "config.h"
  21
  22 #include "gsourceclosure.h"
  23 #include "gboxed.h"
  24 #include "genums.h"
  25 #include "gmarshal.h"
  26 #include "gvalue.h"
  27 #include "gvaluetypes.h"
  28
  29 G_DEFINE_BOXED_TYPE (GIOChannel, g_io_channel, g_io_channel_ref, g_io_channel_unref)
  30
  31 GType
  32 g_io_condition_get_type (void)
  33 {
  34   static GType etype = 0;
  35   if (etype == 0)
  36     {
  37       static const GFlagsValue values[] = {
  38         { G_IO_IN,   "G_IO_IN",   "in" },
  39         { G_IO_OUT,  "G_IO_OUT",  "out" },
  40         { G_IO_PRI,  "G_IO_PRI",  "pri" },
  41         { G_IO_ERR,  "G_IO_ERR",  "err" },
  42         { G_IO_HUP,  "G_IO_HUP",  "hup" },
  43         { G_IO_NVAL, "G_IO_NVAL", "nval" },
  44         { 0, NULL, NULL }
  45       };
  46       etype = g_flags_register_static ("GIOCondition", values);
  47     }
  48   return etype;
  49 }
  50
  51 /* We need to hand-write this marshaler, since it doesn't have an
  52  * instance object.
  53  */
  54 static void
  55 source_closure_marshal_BOOLEAN__VOID (GClosure     *closure,
  56                                       GValue       *return_value,
  57                                       guint         n_param_values,
  58                                       const GValue *param_values,
  59                                       gpointer      invocation_hint,
  60                                       gpointer      marshal_data)
  61 {
  62   GSourceFunc callback;
  63   GCClosure *cc = (GCClosure*) closure;
  64   gboolean v_return;
  65
  66   g_return_if_fail (return_value != NULL);
  67   g_return_if_fail (n_param_values == 0);
  68
  69   callback = (GSourceFunc) (marshal_data ? marshal_data : cc->callback);
  70
  71   v_return = callback (closure->data);
  72
  73   g_value_set_boolean (return_value, v_return);
  74 }
  75
  76 static gboolean
  77 io_watch_closure_callback (GIOChannel   *channel,
  78                            GIOCondition  condition,
  79                            gpointer      data)
  80 {
  81   GClosure *closure = data;
  82
  83   GValue params[2] = { G_VALUE_INIT, G_VALUE_INIT };
  84   GValue result_value = G_VALUE_INIT;
  85   gboolean result;
  86
  87   g_value_init (&result_value, G_TYPE_BOOLEAN);
  88   g_value_init (&params[0], G_TYPE_IO_CHANNEL);
  89   g_value_set_boxed (&params[0], channel);
  90
  91   g_value_init (&params[1], G_TYPE_IO_CONDITION);
  92   g_value_set_flags (&params[1], condition);
  93
  94   g_closure_invoke (closure, &result_value, 2, params, NULL);
  95
  96   result = g_value_get_boolean (&result_value);
  97   g_value_unset (&result_value);
  98   g_value_unset (&params[0]);
  99   g_value_unset (&params[1]);
 100
 101   return result;
 102 }
 103
 104 static gboolean
 105 source_closure_callback (gpointer data)
 106 {
 107   GClosure *closure = data;
 108   GValue result_value = G_VALUE_INIT;
 109   gboolean result;
 110
 111   g_value_init (&result_value, G_TYPE_BOOLEAN);
 112
 113   g_closure_invoke (closure, &result_value, 0, NULL, NULL);
 114
 115   result = g_value_get_boolean (&result_value);
 116   g_value_unset (&result_value);
 117
 118   return result;
 119 }
 120
 121 static void
 122 closure_callback_get (gpointer     cb_data,
 123                       GSource     *source,
 124                       GSourceFunc *func,
 125                       gpointer    *data)
 126 {
 127   GSourceFunc closure_callback = source->source_funcs->closure_callback;
 128
 129   if (!closure_callback)
 130     {
 131       if (source->source_funcs == &g_io_watch_funcs)
 132         closure_callback = (GSourceFunc)io_watch_closure_callback;
 133       else if (source->source_funcs == &g_timeout_funcs ||
 134                source->source_funcs == &g_idle_funcs)
 135         closure_callback = source_closure_callback;
 136     }
 137
 138   *func = closure_callback;
 139   *data = cb_data;
 140 }
 141
 142 static GSourceCallbackFuncs closure_callback_funcs = {
 143   (void (*) (gpointer)) g_closure_ref,
 144   (void (*) (gpointer)) g_closure_unref,
 145   closure_callback_get
 146 };
 147
 148 /**
 149  * g_source_set_closure:
 150  * @source: the source
 151  * @closure: a #GClosure
 152  *
 153  * Set the callback for a source as a #GClosure.
 154  *
 155  * If the source is not one of the standard GLib types, the @closure_callback
 156  * and @closure_marshal fields of the #GSourceFuncs structure must have been
 157  * filled in with pointers to appropriate functions.
 158  */
 159 void
 160 g_source_set_closure (GSource  *source,
 161                       GClosure *closure)
 162 {
 163   g_return_if_fail (source != NULL);
 164   g_return_if_fail (closure != NULL);
 165
 166   if (!source->source_funcs->closure_callback &&
 167       source->source_funcs != &g_io_watch_funcs &&
 168       source->source_funcs != &g_timeout_funcs &&
 169       source->source_funcs != &g_idle_funcs)
 170     {
 171       g_critical (G_STRLOC ": closure can not be set on closure without GSourceFuncs::closure_callback\n");
 172       return;
 173     }
 174
 175   g_closure_ref (closure);
 176   g_closure_sink (closure);
 177   g_source_set_callback_indirect (source, closure, &closure_callback_funcs);
 178
 179   if (G_CLOSURE_NEEDS_MARSHAL (closure))
 180     {
 181       GClosureMarshal marshal = (GClosureMarshal)source->source_funcs->closure_marshal;
 182       if (!marshal)
 183         {
 184           if (source->source_funcs == &g_idle_funcs ||
 185               source->source_funcs == &g_timeout_funcs)
 186             marshal = source_closure_marshal_BOOLEAN__VOID;
 187           else if (source->source_funcs == &g_io_watch_funcs)
 188             marshal = g_cclosure_marshal_BOOLEAN__FLAGS;
 189         }
 190       if (marshal)
 191         g_closure_set_marshal (closure, marshal);
 192     }
 193 }
 194
 195 static void
 196 dummy_closure_marshal (GClosure     *closure,
 197                        GValue       *return_value,
 198                        guint         n_param_values,
 199                        const GValue *param_values,
 200                        gpointer      invocation_hint,
 201                        gpointer      marshal_data)
 202 {
 203   if (G_VALUE_HOLDS_BOOLEAN (return_value))
 204     g_value_set_boolean (return_value, TRUE);
 205 }
 206
 207 /**
 208  * g_source_set_dummy_callback:
 209  * @source: the source
 210  *
 211  * Sets a dummy callback for @source. The callback will do nothing, and
 212  * if the source expects a #gboolean return value, it will return %TRUE.
 213  * (If the source expects any other type of return value, it will return
 214  * a 0/%NULL value; whatever g_value_init() initializes a #GValue to for
 215  * that type.)
 216  *
 217  * If the source is not one of the standard GLib types, the
 218  * @closure_callback and @closure_marshal fields of the #GSourceFuncs
 219  * structure must have been filled in with pointers to appropriate
 220  * functions.
 221  */
 222 void
 223 g_source_set_dummy_callback (GSource *source)
 224 {
 225   GClosure *closure;
 226
 227   closure = g_closure_new_simple (sizeof (GClosure), NULL);
 228   g_closure_set_meta_marshal (closure, NULL, dummy_closure_marshal);
 229   g_source_set_closure (source, closure);
 230 }