gio/gsimpleaction.c

   1 /*
   2  * Copyright © 2010 Codethink Limited
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License as published
   6  * by the Free Software Foundation; either version 2 of the licence or (at
   7  * 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  * Authors: Ryan Lortie <desrt@desrt.ca>
  20  */
  21
  22 #include "config.h"
  23
  24 #include "gsimpleaction.h"
  25
  26 #include "gaction.h"
  27 #include "glibintl.h"
  28
  29 static void g_simple_action_iface_init (GActionInterface *iface);
  30 G_DEFINE_TYPE_WITH_CODE (GSimpleAction, g_simple_action, G_TYPE_OBJECT,
  31   G_IMPLEMENT_INTERFACE (G_TYPE_ACTION, g_simple_action_iface_init))
  32
  33 /**
  34  * SECTION:gsimpleaction
  35  * @title: GSimpleAction
  36  * @short_description: A simple GSimpleAction
  37  *
  38  * A #GSimpleAction is the obvious simple implementation of the #GSimpleAction
  39  * interface.  This is the easiest way to create an action for purposes of
  40  * adding it to a #GSimpleActionGroup.
  41  *
  42  * See also #GtkAction.
  43  **/
  44
  45 struct _GSimpleActionPrivate
  46 {
  47   gchar        *name;
  48   GVariantType *parameter_type;
  49   guint         enabled : 1;
  50   guint         state_set : 1;
  51   GVariant     *state;
  52 };
  53
  54 enum
  55 {
  56   PROP_NONE,
  57   PROP_NAME,
  58   PROP_PARAMETER_TYPE,
  59   PROP_ENABLED,
  60   PROP_STATE_TYPE,
  61   PROP_STATE
  62 };
  63
  64 enum
  65 {
  66   SIGNAL_ACTIVATE,
  67   NR_SIGNALS
  68 };
  69
  70 static guint g_simple_action_signals[NR_SIGNALS];
  71
  72 static const gchar *
  73 g_simple_action_get_name (GAction *action)
  74 {
  75   GSimpleAction *simple = G_SIMPLE_ACTION (action);
  76
  77   return simple->priv->name;
  78 }
  79
  80 const GVariantType *
  81 g_simple_action_get_parameter_type (GAction *action)
  82 {
  83   GSimpleAction *simple = G_SIMPLE_ACTION (action);
  84
  85   return simple->priv->parameter_type;
  86 }
  87
  88 static const GVariantType *
  89 g_simple_action_get_state_type (GAction *action)
  90 {
  91   GSimpleAction *simple = G_SIMPLE_ACTION (action);
  92
  93   if (simple->priv->state != NULL)
  94     return g_variant_get_type (simple->priv->state);
  95   else
  96     return NULL;
  97 }
  98
  99 static GVariant *
 100 g_simple_action_get_state_hint (GAction *action)
 101 {
 102   return NULL;
 103 }
 104
 105 static gboolean
 106 g_simple_action_get_enabled (GAction *action)
 107 {
 108   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 109
 110   return simple->priv->enabled;
 111 }
 112
 113 static void
 114 g_simple_action_set_state (GAction  *action,
 115                            GVariant *value)
 116 {
 117   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 118
 119   g_return_if_fail (value != NULL);
 120
 121   {
 122     const GVariantType *state_type;
 123
 124     state_type = simple->priv->state ?
 125                    g_variant_get_type (simple->priv->state) : NULL;
 126     g_return_if_fail (state_type != NULL);
 127     g_return_if_fail (g_variant_is_of_type (value, state_type));
 128   }
 129
 130   g_variant_ref_sink (value);
 131
 132   if (!g_variant_equal (simple->priv->state, value))
 133     {
 134       if (simple->priv->state)
 135         g_variant_unref (simple->priv->state);
 136
 137       simple->priv->state = g_variant_ref (value);
 138
 139       g_object_notify (G_OBJECT (simple), "state");
 140     }
 141
 142   g_variant_unref (value);
 143 }
 144
 145 static GVariant *
 146 g_simple_action_get_state (GAction *action)
 147 {
 148   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 149
 150   return simple->priv->state ? g_variant_ref (simple->priv->state) : NULL;
 151 }
 152
 153 static void
 154 g_simple_action_activate (GAction  *action,
 155                           GVariant *parameter)
 156 {
 157   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 158
 159   g_return_if_fail (simple->priv->parameter_type == NULL ?
 160                       parameter == NULL :
 161                     (parameter != NULL &&
 162                      g_variant_is_of_type (parameter,
 163                                            simple->priv->parameter_type)));
 164
 165   if (parameter != NULL)
 166     g_variant_ref_sink (parameter);
 167
 168   if (simple->priv->enabled)
 169     g_signal_emit (simple, g_simple_action_signals[SIGNAL_ACTIVATE], 0, parameter);
 170
 171   if (parameter != NULL)
 172     g_variant_unref (parameter);
 173 }
 174
 175 static void
 176 g_simple_action_set_property (GObject      *object,
 177                               guint         prop_id,
 178                               const GValue *value,
 179                               GParamSpec   *pspec)
 180 {
 181   GSimpleAction *simple = G_SIMPLE_ACTION (object);
 182
 183   switch (prop_id)
 184     {
 185     case PROP_NAME:
 186       g_assert (simple->priv->name == NULL);
 187       simple->priv->name = g_value_dup_string (value);
 188       break;
 189
 190     case PROP_PARAMETER_TYPE:
 191       g_assert (simple->priv->parameter_type == NULL);
 192       simple->priv->parameter_type = g_value_dup_boxed (value);
 193       break;
 194
 195     case PROP_ENABLED:
 196       g_simple_action_set_enabled (simple, g_value_get_boolean (value));
 197       break;
 198
 199     case PROP_STATE:
 200       /* PROP_STATE is marked as G_PARAM_CONSTRUCT so we always get a
 201        * call during object construction, even if it is NULL.  We treat
 202        * that first call differently, for a number of reasons.
 203        *
 204        * First, we don't want the value to be rejected by the
 205        * possibly-overridden .set_state() function.  Second, we don't
 206        * want to be tripped by the assertions in g_simple_action_set_state()
 207        * that would enforce the catch22 that we only provide a value of
 208        * the same type as the existing value (when there is not yet an
 209        * existing value).
 210        */
 211       if (simple->priv->state_set)
 212         g_simple_action_set_state (G_ACTION (simple),
 213                                    g_value_get_variant (value));
 214
 215       else /* this is the special case */
 216         {
 217           /* only do it the first time. */
 218           simple->priv->state_set = TRUE;
 219
 220           /* blindly set it. */
 221           simple->priv->state = g_value_dup_variant (value);
 222         }
 223       break;
 224
 225     default:
 226       g_assert_not_reached ();
 227     }
 228 }
 229
 230 static void
 231 g_simple_action_get_property (GObject    *object,
 232                               guint       prop_id,
 233                               GValue     *value,
 234                               GParamSpec *pspec)
 235 {
 236   GAction *action = G_ACTION (object);
 237
 238   switch (prop_id)
 239     {
 240     case PROP_NAME:
 241       g_value_set_string (value, g_simple_action_get_name (action));
 242       break;
 243
 244     case PROP_PARAMETER_TYPE:
 245       g_value_set_boxed (value, g_simple_action_get_parameter_type (action));
 246       break;
 247
 248     case PROP_ENABLED:
 249       g_value_set_boolean (value, g_simple_action_get_enabled (action));
 250       break;
 251
 252     case PROP_STATE_TYPE:
 253       g_value_set_boxed (value, g_simple_action_get_state_type (action));
 254       break;
 255
 256     case PROP_STATE:
 257       g_value_take_variant (value, g_simple_action_get_state (action));
 258       break;
 259
 260     default:
 261       g_assert_not_reached ();
 262     }
 263 }
 264
 265 static void
 266 g_simple_action_finalize (GObject *object)
 267 {
 268   GSimpleAction *simple = G_SIMPLE_ACTION (object);
 269
 270   g_free (simple->priv->name);
 271   if (simple->priv->parameter_type)
 272     g_variant_type_free (simple->priv->parameter_type);
 273   if (simple->priv->state)
 274     g_variant_unref (simple->priv->state);
 275
 276   G_OBJECT_CLASS (g_simple_action_parent_class)
 277     ->finalize (object);
 278 }
 279
 280 void
 281 g_simple_action_init (GSimpleAction *simple)
 282 {
 283   simple->priv = G_TYPE_INSTANCE_GET_PRIVATE (simple,
 284                                               G_TYPE_SIMPLE_ACTION,
 285                                               GSimpleActionPrivate);
 286 }
 287
 288 void
 289 g_simple_action_iface_init (GActionInterface *iface)
 290 {
 291   iface->get_name = g_simple_action_get_name;
 292   iface->get_parameter_type = g_simple_action_get_parameter_type;
 293   iface->get_state_type = g_simple_action_get_state_type;
 294   iface->get_state_hint = g_simple_action_get_state_hint;
 295   iface->get_enabled = g_simple_action_get_enabled;
 296   iface->get_state = g_simple_action_get_state;
 297   iface->set_state = g_simple_action_set_state;
 298   iface->activate = g_simple_action_activate;
 299 }
 300
 301 void
 302 g_simple_action_class_init (GSimpleActionClass *class)
 303 {
 304   GObjectClass *object_class = G_OBJECT_CLASS (class);
 305
 306
 307   object_class->get_property = g_simple_action_get_property;
 308   object_class->set_property = g_simple_action_set_property;
 309   object_class->finalize = g_simple_action_finalize;
 310
 311   /**
 312    * GSimpleAction::activate:
 313    * @simple: the #GSimpleAction
 314    * @parameter: (allow-none): the parameter to the activation
 315    *
 316    * Indicates that the action was just activated.
 317    *
 318    * @parameter will always be of the expected type.  In the event that
 319    * an incorrect type was given, no signal will be emitted.
 320    *
 321    * Since: 2.28
 322    */
 323   g_simple_action_signals[SIGNAL_ACTIVATE] =
 324     g_signal_new (I_("activate"),
 325                   G_TYPE_SIMPLE_ACTION,
 326                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 327                   G_STRUCT_OFFSET (GSimpleActionClass, activate),
 328                   NULL, NULL,
 329                   g_cclosure_marshal_VOID__VARIANT,
 330                   G_TYPE_NONE, 1,
 331                   G_TYPE_VARIANT);
 332
 333   /**
 334    * GSimpleAction:name:
 335    *
 336    * The name of the action.  This is mostly meaningful for identifying
 337    * the action once it has been added to a #GSimpleActionGroup.
 338    *
 339    * Since: 2.28
 340    **/
 341   g_object_class_install_property (object_class, PROP_NAME,
 342                                    g_param_spec_string ("name",
 343                                                         P_("Action Name"),
 344                                                         P_("The name used to invoke the action"),
 345                                                         NULL,
 346                                                         G_PARAM_READWRITE |
 347                                                         G_PARAM_CONSTRUCT_ONLY |
 348                                                         G_PARAM_STATIC_STRINGS));
 349
 350   /**
 351    * GSimpleAction:parameter-type:
 352    *
 353    * The type of the parameter that must be given when activating the
 354    * action.
 355    *
 356    * Since: 2.28
 357    **/
 358   g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,
 359                                    g_param_spec_boxed ("parameter-type",
 360                                                        P_("Parameter Type"),
 361                                                        P_("The type of GVariant passed to activate()"),
 362                                                        G_TYPE_VARIANT_TYPE,
 363                                                        G_PARAM_READWRITE |
 364                                                        G_PARAM_CONSTRUCT_ONLY |
 365                                                        G_PARAM_STATIC_STRINGS));
 366
 367   /**
 368    * GSimpleAction:enabled:
 369    *
 370    * If @action is currently enabled.
 371    *
 372    * If the action is disabled then calls to g_simple_action_activate() and
 373    * g_simple_action_set_state() have no effect.
 374    *
 375    * Since: 2.28
 376    **/
 377   g_object_class_install_property (object_class, PROP_ENABLED,
 378                                    g_param_spec_boolean ("enabled",
 379                                                          P_("Enabled"),
 380                                                          P_("If the action can be activated"),
 381                                                          TRUE,
 382                                                          G_PARAM_CONSTRUCT |
 383                                                          G_PARAM_READWRITE |
 384                                                          G_PARAM_STATIC_STRINGS));
 385
 386   /**
 387    * GSimpleAction:state-type:
 388    *
 389    * The #GVariantType of the state that the action has, or %NULL if the
 390    * action is stateless.
 391    *
 392    * Since: 2.28
 393    **/
 394   g_object_class_install_property (object_class, PROP_STATE_TYPE,
 395                                    g_param_spec_boxed ("state-type",
 396                                                        P_("State Type"),
 397                                                        P_("The type of the state kept by the action"),
 398                                                        G_TYPE_VARIANT_TYPE,
 399                                                        G_PARAM_READABLE |
 400                                                        G_PARAM_STATIC_STRINGS));
 401
 402   /**
 403    * GSimpleAction:state:
 404    *
 405    * The state of the action, or %NULL if the action is stateless.
 406    *
 407    * Since: 2.28
 408    **/
 409   g_object_class_install_property (object_class, PROP_STATE,
 410                                    g_param_spec_variant ("state",
 411                                                          P_("State"),
 412                                                          P_("The state the action is in"),
 413                                                          G_VARIANT_TYPE_ANY,
 414                                                          NULL,
 415                                                          G_PARAM_CONSTRUCT |
 416                                                          G_PARAM_READWRITE |
 417                                                          G_PARAM_STATIC_STRINGS));
 418
 419   g_type_class_add_private (class, sizeof (GSimpleActionPrivate));
 420 }
 421
 422 /**
 423  * g_simple_action_set_enabled:
 424  * @simple: a #GSimpleAction
 425  * @enabled: whether the action is enabled
 426  *
 427  * Sets the action as enabled or not.
 428  *
 429  * An action must be enabled in order to be activated or in order to
 430  * have its state changed from outside callers.
 431  *
 432  * Since: 2.28
 433  **/
 434 void
 435 g_simple_action_set_enabled (GSimpleAction *simple,
 436                              gboolean       enabled)
 437 {
 438   g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
 439
 440   enabled = !!enabled;
 441
 442   if (simple->priv->enabled != enabled)
 443     {
 444       simple->priv->enabled = enabled;
 445       g_object_notify (G_OBJECT (simple), "enabled");
 446     }
 447 }
 448 /**
 449  * g_simple_action_new:
 450  * @name: the name of the action
 451  * @parameter_type: (allow-none): the type of parameter to the activate function
 452  *
 453  * Creates a new action.
 454  *
 455  * The created action is stateless.  See g_simple_action_new_stateful().
 456  *
 457  * Returns: a new #GSimpleAction
 458  *
 459  * Since: 2.28
 460  **/
 461 GSimpleAction *
 462 g_simple_action_new (const gchar        *name,
 463                      const GVariantType *parameter_type)
 464 {
 465   return g_object_new (G_TYPE_SIMPLE_ACTION,
 466                        "name", name,
 467                        "parameter-type", parameter_type,
 468                        NULL);
 469 }
 470
 471 /**
 472  * g_simple_action_new_stateful:
 473  * @name: the name of the action
 474  * @parameter_type: (allow-none): the type of the parameter to the activate function
 475  * @state: the initial state of the action
 476  *
 477  * Creates a new stateful action.
 478  *
 479  * @state is the initial state of the action.  All future state values
 480  * must have the same #GVariantType as the initial state.
 481  *
 482  * If the @state GVariant is floating, it is consumed.
 483  *
 484  * Returns: a new #GSimpleAction
 485  *
 486  * Since: 2.28
 487  **/
 488 GSimpleAction *
 489 g_simple_action_new_stateful (const gchar        *name,
 490                               const GVariantType *parameter_type,
 491                               GVariant           *state)
 492 {
 493   return g_object_new (G_TYPE_SIMPLE_ACTION,
 494                        "name", name,
 495                        "parameter-type", parameter_type,
 496                        "state", state,
 497                        NULL);
 498 }