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_set_property (GObject      *object,
 212                               guint         prop_id,
 213                               const GValue *value,
 214                               GParamSpec   *pspec)
 215 {
 216   GSimpleAction *simple = G_SIMPLE_ACTION (object);
 217
 218   switch (prop_id)
 219     {
 220     case PROP_NAME:
 221       g_assert (simple->name == NULL);
 222       simple->name = g_value_dup_string (value);
 223       break;
 224
 225     case PROP_PARAMETER_TYPE:
 226       g_assert (simple->parameter_type == NULL);
 227       simple->parameter_type = g_value_dup_boxed (value);
 228       break;
 229
 230     case PROP_ENABLED:
 231       g_simple_action_set_enabled (simple, g_value_get_boolean (value));
 232       break;
 233
 234     default:
 235       g_assert_not_reached ();
 236     }
 237 }
 238
 239 static void
 240 g_simple_action_get_property (GObject    *object,
 241                               guint       prop_id,
 242                               GValue     *value,
 243                               GParamSpec *pspec)
 244 {
 245   GAction *action = G_ACTION (object);
 246
 247   switch (prop_id)
 248     {
 249     case PROP_NAME:
 250       g_value_set_string (value, g_simple_action_get_name (action));
 251       break;
 252
 253     case PROP_PARAMETER_TYPE:
 254       g_value_set_boxed (value, g_simple_action_get_parameter_type (action));
 255       break;
 256
 257     case PROP_ENABLED:
 258       g_value_set_boolean (value, g_simple_action_get_enabled (action));
 259       break;
 260
 261     case PROP_STATE_TYPE:
 262       g_value_set_boxed (value, g_simple_action_get_state_type (action));
 263       break;
 264
 265     case PROP_STATE:
 266       g_value_take_variant (value, g_simple_action_get_state (action));
 267       break;
 268
 269     default:
 270       g_assert_not_reached ();
 271     }
 272 }
 273
 274 static void
 275 g_simple_action_finalize (GObject *object)
 276 {
 277   GSimpleAction *simple = G_SIMPLE_ACTION (object);
 278
 279   g_free (simple->name);
 280   if (simple->parameter_type)
 281     g_variant_type_free (simple->parameter_type);
 282   if (simple->state)
 283     g_variant_unref (simple->state);
 284
 285   G_OBJECT_CLASS (g_simple_action_parent_class)
 286     ->finalize (object);
 287 }
 288
 289 void
 290 g_simple_action_init (GSimpleAction *simple)
 291 {
 292 }
 293
 294 void
 295 g_simple_action_iface_init (GActionInterface *iface)
 296 {
 297   iface->get_name = g_simple_action_get_name;
 298   iface->get_parameter_type = g_simple_action_get_parameter_type;
 299   iface->get_state_type = g_simple_action_get_state_type;
 300   iface->get_state_hint = g_simple_action_get_state_hint;
 301   iface->get_enabled = g_simple_action_get_enabled;
 302   iface->get_state = g_simple_action_get_state;
 303   iface->change_state = g_simple_action_change_state;
 304   iface->activate = g_simple_action_activate;
 305 }
 306
 307 void
 308 g_simple_action_class_init (GSimpleActionClass *class)
 309 {
 310   GObjectClass *object_class = G_OBJECT_CLASS (class);
 311
 312   object_class->get_property = g_simple_action_get_property;
 313   object_class->set_property = g_simple_action_set_property;
 314   object_class->finalize = g_simple_action_finalize;
 315
 316   /**
 317    * GSimpleAction::activate:
 318    * @simple: the #GSimpleAction
 319    * @parameter: (allow-none): the parameter to the activation
 320    *
 321    * Indicates that the action was just activated.
 322    *
 323    * @parameter will always be of the expected type.  In the event that
 324    * an incorrect type was given, no signal will be emitted.
 325    *
 326    * Since: 2.28
 327    */
 328   g_simple_action_signals[SIGNAL_ACTIVATE] =
 329     g_signal_new (I_("activate"),
 330                   G_TYPE_SIMPLE_ACTION,
 331                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 332                   0, NULL, NULL,
 333                   g_cclosure_marshal_VOID__VARIANT,
 334                   G_TYPE_NONE, 1,
 335                   G_TYPE_VARIANT);
 336
 337   /**
 338    * GSimpleAction::change-state:
 339    * @simple: the #GSimpleAction
 340    * @value: (allow-none): the requested value for the state
 341    *
 342    * Indicates that the action just received a request to change its
 343    * state.
 344    *
 345    * @value will always be of the correct state type.  In the event that
 346    * an incorrect type was given, no signal will be emitted.
 347    *
 348    * If no handler is connected to this signal then the default
 349    * behaviour is to call g_simple_action_set_state() to set the state
 350    * to the requested value.  If you connect a signal handler then no
 351    * default action is taken.  If the state should change then you must
 352    * call g_simple_action_set_state() from the handler.
 353    *
 354    * <example>
 355    * <title>Example 'change-state' handler</title>
 356    * <programlisting>
 357    * static void
 358    * change_volume_state (GSimpleAction *action,
 359    *                      GVariant      *value,
 360    *                      gpointer       user_data)
 361    * {
 362    *   gint requested;
 363    *
 364    *   requested = g_variant_get_int32 (value);
 365    *
 366    *   // Volume only goes from 0 to 10
 367    *   if (0 <= requested && requested <= 10)
 368    *     g_simple_action_set_state (action, value);
 369    * }
 370    * </programlisting>
 371    * </example>
 372    *
 373    * The handler need not set the state to the requested value.  It
 374    * could set it to any value at all, or take some other action.
 375    *
 376    * Since: 2.30
 377    */
 378   g_simple_action_signals[SIGNAL_CHANGE_STATE] =
 379     g_signal_new (I_("change-state"),
 380                   G_TYPE_SIMPLE_ACTION,
 381                   G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
 382                   0, NULL, NULL,
 383                   g_cclosure_marshal_VOID__VARIANT,
 384                   G_TYPE_NONE, 1,
 385                   G_TYPE_VARIANT);
 386
 387   /**
 388    * GSimpleAction:name:
 389    *
 390    * The name of the action.  This is mostly meaningful for identifying
 391    * the action once it has been added to a #GSimpleActionGroup.
 392    *
 393    * Since: 2.28
 394    **/
 395   g_object_class_install_property (object_class, PROP_NAME,
 396                                    g_param_spec_string ("name",
 397                                                         P_("Action Name"),
 398                                                         P_("The name used to invoke the action"),
 399                                                         NULL,
 400                                                         G_PARAM_READWRITE |
 401                                                         G_PARAM_CONSTRUCT_ONLY |
 402                                                         G_PARAM_STATIC_STRINGS));
 403
 404   /**
 405    * GSimpleAction:parameter-type:
 406    *
 407    * The type of the parameter that must be given when activating the
 408    * action.
 409    *
 410    * Since: 2.28
 411    **/
 412   g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,
 413                                    g_param_spec_boxed ("parameter-type",
 414                                                        P_("Parameter Type"),
 415                                                        P_("The type of GVariant passed to activate()"),
 416                                                        G_TYPE_VARIANT_TYPE,
 417                                                        G_PARAM_READWRITE |
 418                                                        G_PARAM_CONSTRUCT_ONLY |
 419                                                        G_PARAM_STATIC_STRINGS));
 420
 421   /**
 422    * GSimpleAction:enabled:
 423    *
 424    * If @action is currently enabled.
 425    *
 426    * If the action is disabled then calls to g_simple_action_activate() and
 427    * g_simple_action_change_state() have no effect.
 428    *
 429    * Since: 2.28
 430    **/
 431   g_object_class_install_property (object_class, PROP_ENABLED,
 432                                    g_param_spec_boolean ("enabled",
 433                                                          P_("Enabled"),
 434                                                          P_("If the action can be activated"),
 435                                                          TRUE,
 436                                                          G_PARAM_CONSTRUCT |
 437                                                          G_PARAM_READWRITE |
 438                                                          G_PARAM_STATIC_STRINGS));
 439
 440   /**
 441    * GSimpleAction:state-type:
 442    *
 443    * The #GVariantType of the state that the action has, or %NULL if the
 444    * action is stateless.
 445    *
 446    * Since: 2.28
 447    **/
 448   g_object_class_install_property (object_class, PROP_STATE_TYPE,
 449                                    g_param_spec_boxed ("state-type",
 450                                                        P_("State Type"),
 451                                                        P_("The type of the state kept by the action"),
 452                                                        G_TYPE_VARIANT_TYPE,
 453                                                        G_PARAM_READABLE |
 454                                                        G_PARAM_STATIC_STRINGS));
 455
 456   /**
 457    * GSimpleAction:state:
 458    *
 459    * The state of the action, or %NULL if the action is stateless.
 460    *
 461    * Since: 2.28
 462    **/
 463   g_object_class_install_property (object_class, PROP_STATE,
 464                                    g_param_spec_variant ("state",
 465                                                          P_("State"),
 466                                                          P_("The state the action is in"),
 467                                                          G_VARIANT_TYPE_ANY,
 468                                                          NULL,
 469                                                          G_PARAM_READABLE |
 470                                                          G_PARAM_STATIC_STRINGS));
 471 }
 472
 473 /**
 474  * g_simple_action_set_enabled:
 475  * @simple: a #GSimpleAction
 476  * @enabled: whether the action is enabled
 477  *
 478  * Sets the action as enabled or not.
 479  *
 480  * An action must be enabled in order to be activated or in order to
 481  * have its state changed from outside callers.
 482  *
 483  * This should only be called by the implementor of the action.  Users
 484  * of the action should not attempt to modify its enabled flag.
 485  *
 486  * Since: 2.28
 487  **/
 488 void
 489 g_simple_action_set_enabled (GSimpleAction *simple,
 490                              gboolean       enabled)
 491 {
 492   g_return_if_fail (G_IS_SIMPLE_ACTION (simple));
 493
 494   enabled = !!enabled;
 495
 496   if (simple->enabled != enabled)
 497     {
 498       simple->enabled = enabled;
 499       g_object_notify (G_OBJECT (simple), "enabled");
 500     }
 501 }
 502 /**
 503  * g_simple_action_new:
 504  * @name: the name of the action
 505  * @parameter_type: (allow-none): the type of parameter to the activate function
 506  *
 507  * Creates a new action.
 508  *
 509  * The created action is stateless.  See g_simple_action_new_stateful().
 510  *
 511  * Returns: a new #GSimpleAction
 512  *
 513  * Since: 2.28
 514  **/
 515 GSimpleAction *
 516 g_simple_action_new (const gchar        *name,
 517                      const GVariantType *parameter_type)
 518 {
 519   return g_object_new (G_TYPE_SIMPLE_ACTION,
 520                        "name", name,
 521                        "parameter-type", parameter_type,
 522                        NULL);
 523 }
 524
 525 /**
 526  * g_simple_action_new_stateful:
 527  * @name: the name of the action
 528  * @parameter_type: (allow-none): the type of the parameter to the activate function
 529  * @state: the initial state of the action
 530  *
 531  * Creates a new stateful action.
 532  *
 533  * @state is the initial state of the action.  All future state values
 534  * must have the same #GVariantType as the initial state.
 535  *
 536  * If the @state GVariant is floating, it is consumed.
 537  *
 538  * Returns: a new #GSimpleAction
 539  *
 540  * Since: 2.28
 541  **/
 542 GSimpleAction *
 543 g_simple_action_new_stateful (const gchar        *name,
 544                               const GVariantType *parameter_type,
 545                               GVariant           *state)
 546 {
 547   GSimpleAction *simple;
 548
 549   simple = g_object_new (G_TYPE_SIMPLE_ACTION,
 550                          "name", name,
 551                          "parameter-type", parameter_type,
 552                          NULL);
 553
 554   if (state)
 555     simple->state = g_variant_ref_sink (state);
 556
 557   return simple;
 558 }