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 /**
  30  * SECTION:gsimpleaction
  31  * @title: GSimpleAction
  32  * @short_description: A simple GSimpleAction
  33  *
  34  * A #GSimpleAction is the obvious simple implementation of the #GAction
  35  * interface.  This is the easiest way to create an action for purposes of
  36  * adding it to a #GSimpleActionGroup.
  37  *
  38  * See also #GtkAction.
  39  **/
  40 struct _GSimpleAction
  41 {
  42   GObject       parent_instance;
  43
  44   gchar        *name;
  45   GVariantType *parameter_type;
  46   gboolean      enabled;
  47   GVariant     *state;
  48 };
  49
  50 typedef GObjectClass GSimpleActionClass;
  51
  52 static void g_simple_action_iface_init (GActionInterface *iface);
  53 G_DEFINE_TYPE_WITH_CODE (GSimpleAction, g_simple_action, G_TYPE_OBJECT,
  54   G_IMPLEMENT_INTERFACE (G_TYPE_ACTION, g_simple_action_iface_init))
  55
  56 enum
  57 {
  58   PROP_NONE,
  59   PROP_NAME,
  60   PROP_PARAMETER_TYPE,
  61   PROP_ENABLED,
  62   PROP_STATE_TYPE,
  63   PROP_STATE
  64 };
  65
  66 enum
  67 {
  68   SIGNAL_CHANGE_STATE,
  69   SIGNAL_ACTIVATE,
  70   NR_SIGNALS
  71 };
  72
  73 static guint g_simple_action_signals[NR_SIGNALS];
  74
  75 static const gchar *
  76 g_simple_action_get_name (GAction *action)
  77 {
  78   GSimpleAction *simple = G_SIMPLE_ACTION (action);
  79
  80   return simple->name;
  81 }
  82
  83 const GVariantType *
  84 g_simple_action_get_parameter_type (GAction *action)
  85 {
  86   GSimpleAction *simple = G_SIMPLE_ACTION (action);
  87
  88   return simple->parameter_type;
  89 }
  90
  91 static const GVariantType *
  92 g_simple_action_get_state_type (GAction *action)
  93 {
  94   GSimpleAction *simple = G_SIMPLE_ACTION (action);
  95
  96   if (simple->state != NULL)
  97     return g_variant_get_type (simple->state);
  98   else
  99     return NULL;
 100 }
 101
 102 static GVariant *
 103 g_simple_action_get_state_hint (GAction *action)
 104 {
 105   return NULL;
 106 }
 107
 108 static gboolean
 109 g_simple_action_get_enabled (GAction *action)
 110 {
 111   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 112
 113   return simple->enabled;
 114 }
 115
 116 static void
 117 g_simple_action_change_state (GAction  *action,
 118                               GVariant *value)
 119 {
 120   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 121
 122   /* If the user connected a signal handler then they are responsible
 123    * for handling state changes.
 124    */
 125   if (g_signal_has_handler_pending (action, g_simple_action_signals[SIGNAL_CHANGE_STATE], 0, TRUE))
 126     g_signal_emit (action, g_simple_action_signals[SIGNAL_CHANGE_STATE], 0, value);
 127
 128   /* If not, then the default behaviour is to just set the state. */
 129   else
 130     g_simple_action_set_state (simple, value);
 131 }
 132
 133 /**
 134  * g_simple_action_set_state:
 135  * @simple: a #GSimpleAction
 136  * @value: the new #GVariant for the state
 137  *
 138  * Sets the state of the action.
 139  *
 140  * This directly updates the 'state' property to the given value.
 141  *
 142  * This should only be called by the implementor of the action.  Users
 143  * of the action should not attempt to directly modify the 'state'
 144  * property.  Instead, they should call g_action_change_state() to
 145  * request the change.
 146  *
 147  * Since: 2.30
 148  **/
 149 void
 150 g_simple_action_set_state (GSimpleAction *simple,
 151                            GVariant      *value)
 152 {
 153   g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
 154   g_return_if_fail (value != NULL);
 155
 156   {
 157     const GVariantType *state_type;
 158
 159     state_type = simple->state ?
 160                    g_variant_get_type (simple->state) : NULL;
 161     g_return_if_fail (state_type != NULL);
 162     g_return_if_fail (g_variant_is_of_type (value, state_type));
 163   }
 164
 165   g_variant_ref_sink (value);
 166
 167   if (!simple->state || !g_variant_equal (simple->state, value))
 168     {
 169       if (simple->state)
 170         g_variant_unref (simple->state);
 171
 172       simple->state = g_variant_ref (value);
 173
 174       g_object_notify (G_OBJECT (simple), "state");
 175     }
 176
 177   g_variant_unref (value);
 178 }
 179
 180 static GVariant *
 181 g_simple_action_get_state (GAction *action)
 182 {
 183   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 184
 185   return simple->state ? g_variant_ref (simple->state) : NULL;
 186 }
 187
 188 static void
 189 g_simple_action_activate (GAction  *action,
 190                           GVariant *parameter)
 191 {
 192   GSimpleAction *simple = G_SIMPLE_ACTION (action);
 193
 194   g_return_if_fail (simple->parameter_type == NULL ?
 195                       parameter == NULL :
 196                     (parameter != NULL &&
 197                      g_variant_is_of_type (parameter,
 198                                            simple->parameter_type)));
 199
 200   if (parameter != NULL)
 201     g_variant_ref_sink (parameter);
 202
 203   if (simple->enabled)
 204     g_signal_emit (simple, g_simple_action_signals[SIGNAL_ACTIVATE], 0, parameter);
 205
 206   if (parameter != NULL)
 207     g_variant_unref (parameter);
 208 }
 209
 210 static void
 211 g_simple_action_get_property (GObject    *object,
 212                               guint       prop_id,
 213                               GValue     *value,
 214                               GParamSpec *pspec)
 215 {
 216   GAction *action = G_ACTION (object);
 217
 218   switch (prop_id)
 219     {
 220     case PROP_NAME:
 221       g_value_set_string (value, g_simple_action_get_name (action));
 222       break;
 223
 224     case PROP_PARAMETER_TYPE:
 225       g_value_set_boxed (value, g_simple_action_get_parameter_type (action));
 226       break;
 227
 228     case PROP_ENABLED:
 229       g_value_set_boolean (value, g_simple_action_get_enabled (action));
 230       break;
 231
 232     case PROP_STATE_TYPE:
 233       g_value_set_boxed (value, g_simple_action_get_state_type (action));
 234       break;
 235
 236     case PROP_STATE:
 237       g_value_take_variant (value, g_simple_action_get_state (action));
 238       break;
 239
 240     default:
 241       g_assert_not_reached ();
 242     }
 243 }
 244
 245 static void
 246 g_simple_action_finalize (GObject *object)
 247 {
 248   GSimpleAction *simple = G_SIMPLE_ACTION (object);
 249
 250   g_free (simple->name);
 251   if (simple->parameter_type)
 252     g_variant_type_free (simple->parameter_type);
 253   if (simple->state)
 254     g_variant_unref (simple->state);
 255
 256   G_OBJECT_CLASS (g_simple_action_parent_class)
 257     ->finalize (object);
 258 }
 259
 260 void
 261 g_simple_action_init (GSimpleAction *simple)
 262 {
 263 }
 264
 265 void
 266 g_simple_action_iface_init (GActionInterface *iface)
 267 {
 268   iface->get_name = g_simple_action_get_name;
 269   iface->get_parameter_type = g_simple_action_get_parameter_type;
 270   iface->get_state_type = g_simple_action_get_state_type;
 271   iface->get_state_hint = g_simple_action_get_state_hint;
 272   iface->get_enabled = g_simple_action_get_enabled;
 273   iface->get_state = g_simple_action_get_state;
 274   iface->change_state = g_simple_action_change_state;
 275   iface->activate = g_simple_action_activate;
 276 }
 277
 278 void
 279 g_simple_action_class_init (GSimpleActionClass *class)
 280 {
 281   GObjectClass *object_class = G_OBJECT_CLASS (class);
 282
 283   object_class->get_property = g_simple_action_get_property;
 284   object_class->finalize = g_simple_action_finalize;
 285
 286   /**
 287    * GSimpleAction::activate:
 288    * @simple: the #GSimpleAction
 289    * @parameter: (allow-none): the parameter to the activation
 290    *
 291    * Indicates that the action was just activated.
 292    *
 293    * @parameter will always be of the expected type.  In the event that
 294    * an incorrect type was given, no signal will be emitted.
 295    *
 296    * Since: 2.28
 297    */
 298   g_simple_action_signals[SIGNAL_ACTIVATE] =
 299     g_signal_new (I_("activate"),
 300                   G_TYPE_SIMPLE_ACTION,
 301                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 302                   0, NULL, NULL,
 303                   g_cclosure_marshal_VOID__VARIANT,
 304                   G_TYPE_NONE, 1,
 305                   G_TYPE_VARIANT);
 306
 307   /**
 308    * GSimpleAction::change-state:
 309    * @simple: the #GSimpleAction
 310    * @value: (allow-none): the requested value for the state
 311    *
 312    * Indicates that the action just received a request to change its
 313    * state.
 314    *
 315    * @value will always be of the correct state type.  In the event that
 316    * an incorrect type was given, no signal will be emitted.
 317    *
 318    * If no handler is connected to this signal then the default
 319    * behaviour is to call g_simple_action_set_state() to set the state
 320    * to the requested value.  If you connect a signal handler then no
 321    * default action is taken.  If the state should change then you must
 322    * call g_simple_action_set_state() from the handler.
 323    *
 324    * <example>
 325    * <title>Example 'change-state' handler</title>
 326    * <programlisting>
 327    * static void
 328    * change_volume_state (GSimpleAction *action,
 329    *                      GVariant      *value,
 330    *                      gpointer       user_data)
 331    * {
 332    *   gint requested;
 333    *
 334    *   requested = g_variant_get_int32 (value);
 335    *
 336    *   // Volume only goes from 0 to 10
 337    *   if (0 <= requested && requested <= 10)
 338    *     g_simple_action_set_state (action, value);
 339    * }
 340    * </programlisting>
 341    * </example>
 342    *
 343    * The handler need not set the state to the requested value.  It
 344    * could set it to any value at all, or take some other action.
 345    *
 346    * Since: 2.30
 347    */
 348   g_simple_action_signals[SIGNAL_CHANGE_STATE] =
 349     g_signal_new (I_("change-state"),
 350                   G_TYPE_SIMPLE_ACTION,
 351                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 352                   0, NULL, NULL,
 353                   g_cclosure_marshal_VOID__VARIANT,
 354                   G_TYPE_NONE, 1,
 355                   G_TYPE_VARIANT);
 356
 357   /**
 358    * GSimpleAction:name:
 359    *
 360    * The name of the action.  This is mostly meaningful for identifying
 361    * the action once it has been added to a #GSimpleActionGroup.
 362    *
 363    * Since: 2.28
 364    **/
 365   g_object_class_install_property (object_class, PROP_NAME,
 366                                    g_param_spec_string ("name",
 367                                                         P_("Action Name"),
 368                                                         P_("The name used to invoke the action"),
 369                                                         NULL,
 370                                                         G_PARAM_READABLE |
 371                                                         G_PARAM_STATIC_STRINGS));
 372
 373   /**
 374    * GSimpleAction:parameter-type:
 375    *
 376    * The type of the parameter that must be given when activating the
 377    * action.
 378    *
 379    * Since: 2.28
 380    **/
 381   g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,
 382                                    g_param_spec_boxed ("parameter-type",
 383                                                        P_("Parameter Type"),
 384                                                        P_("The type of GVariant passed to activate()"),
 385                                                        G_TYPE_VARIANT_TYPE,
 386                                                        G_PARAM_READABLE |
 387                                                        G_PARAM_STATIC_STRINGS));
 388
 389   /**
 390    * GSimpleAction:enabled:
 391    *
 392    * If @action is currently enabled.
 393    *
 394    * If the action is disabled then calls to g_simple_action_activate() and
 395    * g_simple_action_change_state() have no effect.
 396    *
 397    * Since: 2.28
 398    **/
 399   g_object_class_install_property (object_class, PROP_ENABLED,
 400                                    g_param_spec_boolean ("enabled",
 401                                                          P_("Enabled"),
 402                                                          P_("If the action can be activated"),
 403                                                          TRUE,
 404                                                          G_PARAM_READABLE |
 405                                                          G_PARAM_STATIC_STRINGS));
 406
 407   /**
 408    * GSimpleAction:state-type:
 409    *
 410    * The #GVariantType of the state that the action has, or %NULL if the
 411    * action is stateless.
 412    *
 413    * Since: 2.28
 414    **/
 415   g_object_class_install_property (object_class, PROP_STATE_TYPE,
 416                                    g_param_spec_boxed ("state-type",
 417                                                        P_("State Type"),
 418                                                        P_("The type of the state kept by the action"),
 419                                                        G_TYPE_VARIANT_TYPE,
 420                                                        G_PARAM_READABLE |
 421                                                        G_PARAM_STATIC_STRINGS));
 422
 423   /**
 424    * GSimpleAction:state:
 425    *
 426    * The state of the action, or %NULL if the action is stateless.
 427    *
 428    * Since: 2.28
 429    **/
 430   g_object_class_install_property (object_class, PROP_STATE,
 431                                    g_param_spec_variant ("state",
 432                                                          P_("State"),
 433                                                          P_("The state the action is in"),
 434                                                          G_VARIANT_TYPE_ANY,
 435                                                          NULL,
 436                                                          G_PARAM_READABLE |
 437                                                          G_PARAM_STATIC_STRINGS));
 438 }
 439
 440 /**
 441  * g_simple_action_set_enabled:
 442  * @simple: a #GSimpleAction
 443  * @enabled: whether the action is enabled
 444  *
 445  * Sets the action as enabled or not.
 446  *
 447  * An action must be enabled in order to be activated or in order to
 448  * have its state changed from outside callers.
 449  *
 450  * This should only be called by the implementor of the action.  Users
 451  * of the action should not attempt to modify its enabled flag.
 452  *
 453  * Since: 2.28
 454  **/
 455 void
 456 g_simple_action_set_enabled (GSimpleAction *simple,
 457                              gboolean       enabled)
 458 {
 459   g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
 460
 461   enabled = !!enabled;
 462
 463   if (simple->enabled != enabled)
 464     {
 465       simple->enabled = enabled;
 466       g_object_notify (G_OBJECT (simple), "enabled");
 467     }
 468 }
 469 /**
 470  * g_simple_action_new:
 471  * @name: the name of the action
 472  * @parameter_type: (allow-none): the type of parameter to the activate function
 473  *
 474  * Creates a new action.
 475  *
 476  * The created action is stateless.  See g_simple_action_new_stateful().
 477  *
 478  * Returns: a new #GSimpleAction
 479  *
 480  * Since: 2.28
 481  **/
 482 GSimpleAction *
 483 g_simple_action_new (const gchar        *name,
 484                      const GVariantType *parameter_type)
 485 {
 486   GSimpleAction *simple;
 487
 488   g_return_val_if_fail (name != NULL, NULL);
 489
 490   simple = g_object_new (G_TYPE_SIMPLE_ACTION, NULL);
 491   simple->name = g_strdup (name);
 492
 493   if (parameter_type)
 494     simple->parameter_type = g_variant_type_copy (parameter_type);
 495
 496   simple->enabled = TRUE;
 497
 498   return simple;
 499 }
 500
 501 /**
 502  * g_simple_action_new_stateful:
 503  * @name: the name of the action
 504  * @parameter_type: (allow-none): the type of the parameter to the activate function
 505  * @state: the initial state of the action
 506  *
 507  * Creates a new stateful action.
 508  *
 509  * @state is the initial state of the action.  All future state values
 510  * must have the same #GVariantType as the initial state.
 511  *
 512  * If the @state GVariant is floating, it is consumed.
 513  *
 514  * Returns: a new #GSimpleAction
 515  *
 516  * Since: 2.28
 517  **/
 518 GSimpleAction *
 519 g_simple_action_new_stateful (const gchar        *name,
 520                               const GVariantType *parameter_type,
 521                               GVariant           *state)
 522 {
 523   GSimpleAction *simple;
 524
 525   g_return_val_if_fail (name != NULL);
 526   g_return_val_if_fail (state != NULL);
 527
 528   simple = g_object_new (G_TYPE_SIMPLE_ACTION, NULL);
 529   simple->name = g_strdup (name);
 530
 531   if (parameter_type)
 532     simple->parameter_type = g_variant_type_copy (parameter_type);
 533
 534   simple->state = g_variant_ref_sink (state);
 535
 536   simple->enabled = TRUE;
 537
 538   return simple;
 539 }