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 GAction implementation
  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 static 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_set_property (GObject    *object,
 212                               guint       prop_id,
 213                               const GValue     *value,
 214                               GParamSpec *pspec)
 215 {
 216   GSimpleAction *action = G_SIMPLE_ACTION (object);
 217
 218   switch (prop_id)
 219     {
 220     case PROP_NAME:
 221       action->name = g_strdup (g_value_get_string (value));
 222       break;
 223
 224     case PROP_PARAMETER_TYPE:
 225       action->parameter_type = g_value_dup_boxed (value);
 226       break;
 227
 228     case PROP_ENABLED:
 229       action->enabled = g_value_get_boolean (value);
 230       break;
 231
 232     case PROP_STATE:
 233       action->state = g_value_dup_variant (value);
 234       break;
 235
 236     default:
 237       g_assert_not_reached ();
 238     }
 239 }
 240
 241 static void
 242 g_simple_action_get_property (GObject    *object,
 243                               guint       prop_id,
 244                               GValue     *value,
 245                               GParamSpec *pspec)
 246 {
 247   GAction *action = G_ACTION (object);
 248
 249   switch (prop_id)
 250     {
 251     case PROP_NAME:
 252       g_value_set_string (value, g_simple_action_get_name (action));
 253       break;
 254
 255     case PROP_PARAMETER_TYPE:
 256       g_value_set_boxed (value, g_simple_action_get_parameter_type (action));
 257       break;
 258
 259     case PROP_ENABLED:
 260       g_value_set_boolean (value, g_simple_action_get_enabled (action));
 261       break;
 262
 263     case PROP_STATE_TYPE:
 264       g_value_set_boxed (value, g_simple_action_get_state_type (action));
 265       break;
 266
 267     case PROP_STATE:
 268       g_value_take_variant (value, g_simple_action_get_state (action));
 269       break;
 270
 271     default:
 272       g_assert_not_reached ();
 273     }
 274 }
 275
 276 static void
 277 g_simple_action_finalize (GObject *object)
 278 {
 279   GSimpleAction *simple = G_SIMPLE_ACTION (object);
 280
 281   g_free (simple->name);
 282   if (simple->parameter_type)
 283     g_variant_type_free (simple->parameter_type);
 284   if (simple->state)
 285     g_variant_unref (simple->state);
 286
 287   G_OBJECT_CLASS (g_simple_action_parent_class)
 288     ->finalize (object);
 289 }
 290
 291 void
 292 g_simple_action_init (GSimpleAction *simple)
 293 {
 294   simple->enabled = TRUE;
 295 }
 296
 297 void
 298 g_simple_action_iface_init (GActionInterface *iface)
 299 {
 300   iface->get_name = g_simple_action_get_name;
 301   iface->get_parameter_type = g_simple_action_get_parameter_type;
 302   iface->get_state_type = g_simple_action_get_state_type;
 303   iface->get_state_hint = g_simple_action_get_state_hint;
 304   iface->get_enabled = g_simple_action_get_enabled;
 305   iface->get_state = g_simple_action_get_state;
 306   iface->change_state = g_simple_action_change_state;
 307   iface->activate = g_simple_action_activate;
 308 }
 309
 310 void
 311 g_simple_action_class_init (GSimpleActionClass *class)
 312 {
 313   GObjectClass *object_class = G_OBJECT_CLASS (class);
 314
 315   object_class->set_property = g_simple_action_set_property;
 316   object_class->get_property = g_simple_action_get_property;
 317   object_class->finalize = g_simple_action_finalize;
 318
 319   /**
 320    * GSimpleAction::activate:
 321    * @simple: the #GSimpleAction
 322    * @parameter: (allow-none): the parameter to the activation
 323    *
 324    * Indicates that the action was just activated.
 325    *
 326    * @parameter will always be of the expected type.  In the event that
 327    * an incorrect type was given, no signal will be emitted.
 328    *
 329    * Since: 2.28
 330    */
 331   g_simple_action_signals[SIGNAL_ACTIVATE] =
 332     g_signal_new (I_("activate"),
 333                   G_TYPE_SIMPLE_ACTION,
 334                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 335                   0, NULL, NULL,
 336                   g_cclosure_marshal_VOID__VARIANT,
 337                   G_TYPE_NONE, 1,
 338                   G_TYPE_VARIANT);
 339
 340   /**
 341    * GSimpleAction::change-state:
 342    * @simple: the #GSimpleAction
 343    * @value: (allow-none): the requested value for the state
 344    *
 345    * Indicates that the action just received a request to change its
 346    * state.
 347    *
 348    * @value will always be of the correct state type.  In the event that
 349    * an incorrect type was given, no signal will be emitted.
 350    *
 351    * If no handler is connected to this signal then the default
 352    * behaviour is to call g_simple_action_set_state() to set the state
 353    * to the requested value.  If you connect a signal handler then no
 354    * default action is taken.  If the state should change then you must
 355    * call g_simple_action_set_state() from the handler.
 356    *
 357    * <example>
 358    * <title>Example 'change-state' handler</title>
 359    * <programlisting>
 360    * static void
 361    * change_volume_state (GSimpleAction *action,
 362    *                      GVariant      *value,
 363    *                      gpointer       user_data)
 364    * {
 365    *   gint requested;
 366    *
 367    *   requested = g_variant_get_int32 (value);
 368    *
 369    *   // Volume only goes from 0 to 10
 370    *   if (0 <= requested && requested <= 10)
 371    *     g_simple_action_set_state (action, value);
 372    * }
 373    * </programlisting>
 374    * </example>
 375    *
 376    * The handler need not set the state to the requested value.  It
 377    * could set it to any value at all, or take some other action.
 378    *
 379    * Since: 2.30
 380    */
 381   g_simple_action_signals[SIGNAL_CHANGE_STATE] =
 382     g_signal_new (I_("change-state"),
 383                   G_TYPE_SIMPLE_ACTION,
 384                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 385                   0, NULL, NULL,
 386                   g_cclosure_marshal_VOID__VARIANT,
 387                   G_TYPE_NONE, 1,
 388                   G_TYPE_VARIANT);
 389
 390   /**
 391    * GSimpleAction:name:
 392    *
 393    * The name of the action.  This is mostly meaningful for identifying
 394    * the action once it has been added to a #GSimpleActionGroup.
 395    *
 396    * Since: 2.28
 397    **/
 398   g_object_class_install_property (object_class, PROP_NAME,
 399                                    g_param_spec_string ("name",
 400                                                         P_("Action Name"),
 401                                                         P_("The name used to invoke the action"),
 402                                                         NULL,
 403                                                         G_PARAM_READWRITE |
 404                                                         G_PARAM_CONSTRUCT_ONLY |
 405                                                         G_PARAM_STATIC_STRINGS));
 406
 407   /**
 408    * GSimpleAction:parameter-type:
 409    *
 410    * The type of the parameter that must be given when activating the
 411    * action.
 412    *
 413    * Since: 2.28
 414    **/
 415   g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,
 416                                    g_param_spec_boxed ("parameter-type",
 417                                                        P_("Parameter Type"),
 418                                                        P_("The type of GVariant passed to activate()"),
 419                                                        G_TYPE_VARIANT_TYPE,
 420                                                        G_PARAM_READWRITE |
 421                                                        G_PARAM_CONSTRUCT_ONLY |
 422                                                        G_PARAM_STATIC_STRINGS));
 423
 424   /**
 425    * GSimpleAction:enabled:
 426    *
 427    * If @action is currently enabled.
 428    *
 429    * If the action is disabled then calls to g_action_activate() and
 430    * g_action_change_state() have no effect.
 431    *
 432    * Since: 2.28
 433    **/
 434   g_object_class_install_property (object_class, PROP_ENABLED,
 435                                    g_param_spec_boolean ("enabled",
 436                                                          P_("Enabled"),
 437                                                          P_("If the action can be activated"),
 438                                                          TRUE,
 439                                                          G_PARAM_READWRITE |
 440                                                          G_PARAM_STATIC_STRINGS));
 441
 442   /**
 443    * GSimpleAction:state-type:
 444    *
 445    * The #GVariantType of the state that the action has, or %NULL if the
 446    * action is stateless.
 447    *
 448    * Since: 2.28
 449    **/
 450   g_object_class_install_property (object_class, PROP_STATE_TYPE,
 451                                    g_param_spec_boxed ("state-type",
 452                                                        P_("State Type"),
 453                                                        P_("The type of the state kept by the action"),
 454                                                        G_TYPE_VARIANT_TYPE,
 455                                                        G_PARAM_READABLE |
 456                                                        G_PARAM_STATIC_STRINGS));
 457
 458   /**
 459    * GSimpleAction:state:
 460    *
 461    * The state of the action, or %NULL if the action is stateless.
 462    *
 463    * Since: 2.28
 464    **/
 465   g_object_class_install_property (object_class, PROP_STATE,
 466                                    g_param_spec_variant ("state",
 467                                                          P_("State"),
 468                                                          P_("The state the action is in"),
 469                                                          G_VARIANT_TYPE_ANY,
 470                                                          NULL,
 471                                                          G_PARAM_READWRITE |
 472                                                          G_PARAM_STATIC_STRINGS));
 473 }
 474
 475 /**
 476  * g_simple_action_set_enabled:
 477  * @simple: a #GSimpleAction
 478  * @enabled: whether the action is enabled
 479  *
 480  * Sets the action as enabled or not.
 481  *
 482  * An action must be enabled in order to be activated or in order to
 483  * have its state changed from outside callers.
 484  *
 485  * This should only be called by the implementor of the action.  Users
 486  * of the action should not attempt to modify its enabled flag.
 487  *
 488  * Since: 2.28
 489  **/
 490 void
 491 g_simple_action_set_enabled (GSimpleAction *simple,
 492                              gboolean       enabled)
 493 {
 494   g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
 495
 496   enabled = !!enabled;
 497
 498   if (simple->enabled != enabled)
 499     {
 500       simple->enabled = enabled;
 501       g_object_notify (G_OBJECT (simple), "enabled");
 502     }
 503 }
 504 /**
 505  * g_simple_action_new:
 506  * @name: the name of the action
 507  * @parameter_type: (allow-none): the type of parameter to the activate function
 508  *
 509  * Creates a new action.
 510  *
 511  * The created action is stateless.  See g_simple_action_new_stateful().
 512  *
 513  * Returns: a new #GSimpleAction
 514  *
 515  * Since: 2.28
 516  **/
 517 GSimpleAction *
 518 g_simple_action_new (const gchar        *name,
 519                      const GVariantType *parameter_type)
 520 {
 521   return g_object_new (G_TYPE_SIMPLE_ACTION,
 522                        "name", name,
 523                        "parameter-type", parameter_type,
 524                        NULL);
 525 }
 526
 527 /**
 528  * g_simple_action_new_stateful:
 529  * @name: the name of the action
 530  * @parameter_type: (allow-none): the type of the parameter to the activate function
 531  * @state: the initial state of the action
 532  *
 533  * Creates a new stateful action.
 534  *
 535  * @state is the initial state of the action.  All future state values
 536  * must have the same #GVariantType as the initial state.
 537  *
 538  * If the @state GVariant is floating, it is consumed.
 539  *
 540  * Returns: a new #GSimpleAction
 541  *
 542  * Since: 2.28
 543  **/
 544 GSimpleAction *
 545 g_simple_action_new_stateful (const gchar        *name,
 546                               const GVariantType *parameter_type,
 547                               GVariant           *state)
 548 {
 549   return g_object_new (G_TYPE_SIMPLE_ACTION,
 550                        "name", name,
 551                        "parameter-type", parameter_type,
 552                        "state", state,
 553                        NULL);
 554 }