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 }
 295
 296 void
 297 g_simple_action_iface_init (GActionInterface *iface)
 298 {
 299   iface->get_name = g_simple_action_get_name;
 300   iface->get_parameter_type = g_simple_action_get_parameter_type;
 301   iface->get_state_type = g_simple_action_get_state_type;
 302   iface->get_state_hint = g_simple_action_get_state_hint;
 303   iface->get_enabled = g_simple_action_get_enabled;
 304   iface->get_state = g_simple_action_get_state;
 305   iface->change_state = g_simple_action_change_state;
 306   iface->activate = g_simple_action_activate;
 307 }
 308
 309 void
 310 g_simple_action_class_init (GSimpleActionClass *class)
 311 {
 312   GObjectClass *object_class = G_OBJECT_CLASS (class);
 313
 314   object_class->set_property = g_simple_action_set_property;
 315   object_class->get_property = g_simple_action_get_property;
 316   object_class->finalize = g_simple_action_finalize;
 317
 318   /**
 319    * GSimpleAction::activate:
 320    * @simple: the #GSimpleAction
 321    * @parameter: (allow-none): the parameter to the activation
 322    *
 323    * Indicates that the action was just activated.
 324    *
 325    * @parameter will always be of the expected type.  In the event that
 326    * an incorrect type was given, no signal will be emitted.
 327    *
 328    * Since: 2.28
 329    */
 330   g_simple_action_signals[SIGNAL_ACTIVATE] =
 331     g_signal_new (I_("activate"),
 332                   G_TYPE_SIMPLE_ACTION,
 333                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 334                   0, NULL, NULL,
 335                   g_cclosure_marshal_VOID__VARIANT,
 336                   G_TYPE_NONE, 1,
 337                   G_TYPE_VARIANT);
 338
 339   /**
 340    * GSimpleAction::change-state:
 341    * @simple: the #GSimpleAction
 342    * @value: (allow-none): the requested value for the state
 343    *
 344    * Indicates that the action just received a request to change its
 345    * state.
 346    *
 347    * @value will always be of the correct state type.  In the event that
 348    * an incorrect type was given, no signal will be emitted.
 349    *
 350    * If no handler is connected to this signal then the default
 351    * behaviour is to call g_simple_action_set_state() to set the state
 352    * to the requested value.  If you connect a signal handler then no
 353    * default action is taken.  If the state should change then you must
 354    * call g_simple_action_set_state() from the handler.
 355    *
 356    * <example>
 357    * <title>Example 'change-state' handler</title>
 358    * <programlisting>
 359    * static void
 360    * change_volume_state (GSimpleAction *action,
 361    *                      GVariant      *value,
 362    *                      gpointer       user_data)
 363    * {
 364    *   gint requested;
 365    *
 366    *   requested = g_variant_get_int32 (value);
 367    *
 368    *   // Volume only goes from 0 to 10
 369    *   if (0 <= requested && requested <= 10)
 370    *     g_simple_action_set_state (action, value);
 371    * }
 372    * </programlisting>
 373    * </example>
 374    *
 375    * The handler need not set the state to the requested value.  It
 376    * could set it to any value at all, or take some other action.
 377    *
 378    * Since: 2.30
 379    */
 380   g_simple_action_signals[SIGNAL_CHANGE_STATE] =
 381     g_signal_new (I_("change-state"),
 382                   G_TYPE_SIMPLE_ACTION,
 383                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 384                   0, NULL, NULL,
 385                   g_cclosure_marshal_VOID__VARIANT,
 386                   G_TYPE_NONE, 1,
 387                   G_TYPE_VARIANT);
 388
 389   /**
 390    * GSimpleAction:name:
 391    *
 392    * The name of the action.  This is mostly meaningful for identifying
 393    * the action once it has been added to a #GSimpleActionGroup.
 394    *
 395    * Since: 2.28
 396    **/
 397   g_object_class_install_property (object_class, PROP_NAME,
 398                                    g_param_spec_string ("name",
 399                                                         P_("Action Name"),
 400                                                         P_("The name used to invoke the action"),
 401                                                         NULL,
 402                                                         G_PARAM_READWRITE |
 403                                                         G_PARAM_CONSTRUCT_ONLY |
 404                                                         G_PARAM_STATIC_STRINGS));
 405
 406   /**
 407    * GSimpleAction:parameter-type:
 408    *
 409    * The type of the parameter that must be given when activating the
 410    * action.
 411    *
 412    * Since: 2.28
 413    **/
 414   g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,
 415                                    g_param_spec_boxed ("parameter-type",
 416                                                        P_("Parameter Type"),
 417                                                        P_("The type of GVariant passed to activate()"),
 418                                                        G_TYPE_VARIANT_TYPE,
 419                                                        G_PARAM_READWRITE |
 420                                                        G_PARAM_CONSTRUCT_ONLY |
 421                                                        G_PARAM_STATIC_STRINGS));
 422
 423   /**
 424    * GSimpleAction:enabled:
 425    *
 426    * If @action is currently enabled.
 427    *
 428    * If the action is disabled then calls to g_action_activate() and
 429    * g_action_change_state() have no effect.
 430    *
 431    * Since: 2.28
 432    **/
 433   g_object_class_install_property (object_class, PROP_ENABLED,
 434                                    g_param_spec_boolean ("enabled",
 435                                                          P_("Enabled"),
 436                                                          P_("If the action can be activated"),
 437                                                          TRUE,
 438                                                          G_PARAM_READWRITE |
 439                                                          G_PARAM_CONSTRUCT_ONLY |
 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_CONSTRUCT_ONLY |
 473                                                          G_PARAM_STATIC_STRINGS));
 474 }
 475
 476 /**
 477  * g_simple_action_set_enabled:
 478  * @simple: a #GSimpleAction
 479  * @enabled: whether the action is enabled
 480  *
 481  * Sets the action as enabled or not.
 482  *
 483  * An action must be enabled in order to be activated or in order to
 484  * have its state changed from outside callers.
 485  *
 486  * This should only be called by the implementor of the action.  Users
 487  * of the action should not attempt to modify its enabled flag.
 488  *
 489  * Since: 2.28
 490  **/
 491 void
 492 g_simple_action_set_enabled (GSimpleAction *simple,
 493                              gboolean       enabled)
 494 {
 495   g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
 496
 497   enabled = !!enabled;
 498
 499   if (simple->enabled != enabled)
 500     {
 501       simple->enabled = enabled;
 502       g_object_notify (G_OBJECT (simple), "enabled");
 503     }
 504 }
 505 /**
 506  * g_simple_action_new:
 507  * @name: the name of the action
 508  * @parameter_type: (allow-none): the type of parameter to the activate function
 509  *
 510  * Creates a new action.
 511  *
 512  * The created action is stateless.  See g_simple_action_new_stateful().
 513  *
 514  * Returns: a new #GSimpleAction
 515  *
 516  * Since: 2.28
 517  **/
 518 GSimpleAction *
 519 g_simple_action_new (const gchar        *name,
 520                      const GVariantType *parameter_type)
 521 {
 522   return (GSimpleAction*) g_object_new (G_TYPE_SIMPLE_ACTION,
 523                                         "name", name,
 524                                         "parameter-type", parameter_type,
 525                                         NULL);
 526 }
 527
 528 /**
 529  * g_simple_action_new_stateful:
 530  * @name: the name of the action
 531  * @parameter_type: (allow-none): the type of the parameter to the activate function
 532  * @state: the initial state of the action
 533  *
 534  * Creates a new stateful action.
 535  *
 536  * @state is the initial state of the action.  All future state values
 537  * must have the same #GVariantType as the initial state.
 538  *
 539  * If the @state GVariant is floating, it is consumed.
 540  *
 541  * Returns: a new #GSimpleAction
 542  *
 543  * Since: 2.28
 544  **/
 545 GSimpleAction *
 546 g_simple_action_new_stateful (const gchar        *name,
 547                               const GVariantType *parameter_type,
 548                               GVariant           *state)
 549 {
 550   return (GSimpleAction*) g_object_new (G_TYPE_SIMPLE_ACTION,
 551                                         "name", name,
 552                                         "parameter-type", parameter_type,
 553                                         "state", state,
 554                                         NULL);
 555 }