summaryrefslogtreecommitdiff
path: root/gedit/gedit-message-bus.c
blob: bb6017a32a15c2de6883274c7ada0e75fc81f4fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
#include "gedit-message-bus.h"

#include <string.h>
#include <stdarg.h>
#include <gobject/gvaluecollector.h>

/**
 * GeditMessageCallback:
 * @bus: the #GeditMessageBus on which the message was sent
 * @message: the #GeditMessage which was sent
 * @userdata: the supplied user data when connecting the callback
 *
 * Callback signature used for connecting callback functions to be called
 * when a message is received (see gedit_message_bus_connect()).
 *
 */

/**
 * SECTION:gedit-message-bus
 * @short_description: internal message communication bus
 * @include: gedit/gedit-message-bus.h
 *
 * gedit has a communication bus very similar to DBus. Its primary use is to
 * allow easy communication between plugins, but it can also be used to expose
 * gedit functionality to external applications by providing DBus bindings for
 * the internal gedit message bus.
 *
 * There are two different communication busses available. The default bus
 * (see gedit_message_bus_get_default()) is an application wide communication
 * bus. In addition, each #GeditWindow has a separate, private bus
 * (see gedit_window_get_message_bus()). This makes it easier for plugins to
 * communicate to other plugins in the same window.
 *
 * The concept of the message bus is very simple. You can register a message
 * type on the bus, specified as a Method at a specific Object Path with a
 * certain set of Method Arguments. You can then connect callback functions
 * for this message type on the bus. Whenever a message with the Object Path
 * and Method for which callbacks are connected is sent over the bus, the
 * callbacks are called. There is no distinction between Methods and Signals
 * (signals are simply messages where sender and receiver have switched places).
 *
 * <example>
 * <title>Registering a message type</title>
 * <programlisting>
 * GeditMessageBus *bus = gedit_message_bus_get_default ();
 *
 * // Register 'method' at '/plugins/example' with one required
 * // string argument 'arg1'
 * GeditMessageType *message_type = gedit_message_bus_register ("/plugins/example", "method", 
 *                                                              0, 
 *                                                              "arg1", G_TYPE_STRING,
 *                                                              NULL);
 * </programlisting>
 * </example>
 * <example>
 * <title>Connecting a callback</title>
 * <programlisting>
 * static void
 * example_method_cb (GeditMessageBus *bus,
 *                    GeditMessage    *message,
 *                    gpointer         userdata)
 * {
 * 	gchar *arg1 = NULL;
 *	
 * 	gedit_message_get (message, "arg1", &arg1, NULL);
 * 	g_message ("Evoked /plugins/example.method with: %s", arg1);
 * 	g_free (arg1);
 * }
 *
 * GeditMessageBus *bus = gedit_message_bus_get_default ();
 * 
 * guint id = gedit_message_bus_connect (bus, 
 *                                       "/plugins/example", "method",
 *                                       example_method_cb,
 *                                       NULL,
 *                                       NULL);
 *                                        
 * </programlisting>
 * </example>
 * <example>
 * <title>Sending a message</title>
 * <programlisting>
 * GeditMessageBus *bus = gedit_message_bus_get_default ();
 *
 * gedit_message_bus_send (bus, 
 *                         "/plugins/example", "method", 
 *                         "arg1", "Hello World", 
 *                         NULL);
 * </programlisting>
 * </example>
 *
 * Since: 2.25.3
 *
 */
 
#define GEDIT_MESSAGE_BUS_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE((object), GEDIT_TYPE_MESSAGE_BUS, GeditMessageBusPrivate))

typedef struct
{
	gchar *object_path;
	gchar *method;

	GList *listeners;
} Message;

typedef struct
{
	guint id;
	gboolean blocked;

	GDestroyNotify destroy_data;
	GeditMessageCallback callback;
	gpointer userdata;
} Listener;

typedef struct
{
	Message *message;
	GList *listener;
} IdMap;

struct _GeditMessageBusPrivate
{
	GHashTable *messages;
	GHashTable *idmap;

	GList *message_queue;
	guint idle_id;

	guint next_id;
	
	GHashTable *types; /* mapping from identifier to GeditMessageType */
};

/* signals */
enum
{
	DISPATCH,
	REGISTERED,
	UNREGISTERED,
	LAST_SIGNAL
};

static guint message_bus_signals[LAST_SIGNAL];

static void gedit_message_bus_dispatch_real (GeditMessageBus *bus,
				 	     GeditMessage    *message);

G_DEFINE_TYPE(GeditMessageBus, gedit_message_bus, G_TYPE_OBJECT)

static void
listener_free (Listener *listener)
{
	if (listener->destroy_data)
		listener->destroy_data (listener->userdata);

	g_free (listener);
}

static void
message_free (Message *message)
{
	g_free (message->method);
	g_free (message->object_path);
	
	g_list_foreach (message->listeners, (GFunc)listener_free, NULL);
	g_list_free (message->listeners);
	
	g_free (message);
}

static void
message_queue_free (GList *queue)
{
	g_list_foreach (queue, (GFunc)g_object_unref, NULL);
	g_list_free (queue);
}

static void
gedit_message_bus_finalize (GObject *object)
{
	GeditMessageBus *bus = GEDIT_MESSAGE_BUS (object);
	
	if (bus->priv->idle_id != 0)
		g_source_remove (bus->priv->idle_id);
	
	message_queue_free (bus->priv->message_queue);

	g_hash_table_destroy (bus->priv->messages);
	g_hash_table_destroy (bus->priv->idmap);
	g_hash_table_destroy (bus->priv->types);
	
	G_OBJECT_CLASS (gedit_message_bus_parent_class)->finalize (object);
}

static void
gedit_message_bus_class_init (GeditMessageBusClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);
	
	object_class->finalize = gedit_message_bus_finalize;
	
	klass->dispatch = gedit_message_bus_dispatch_real;

	/**
	 * GeditMessageBus::dispatch:
	 * @bus: a #GeditMessageBus
	 * @message: the #GeditMessage to dispatch
	 *
	 * The "dispatch" signal is emitted when a message is to be dispatched.
	 * The message is dispatched in the default handler of this signal. 
	 * Primary use of this signal is to customize the dispatch of a message
	 * (for instance to automatically dispatch all messages over DBus).
	 *2
	 */
	message_bus_signals[DISPATCH] =
   		g_signal_new ("dispatch",
			      G_OBJECT_CLASS_TYPE (object_class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (GeditMessageBusClass, dispatch),
			      NULL, NULL,
			      g_cclosure_marshal_VOID__OBJECT,
			      G_TYPE_NONE,
			      1,
			      GEDIT_TYPE_MESSAGE);

	/**
	 * GeditMessageBus::registered:
	 * @bus: a #GeditMessageBus
	 * @message_type: the registered #GeditMessageType
	 *
	 * The "registered" signal is emitted when a message has been registered
	 * on the bus.
	 *
	 */
	message_bus_signals[REGISTERED] =
   		g_signal_new ("registered",
			      G_OBJECT_CLASS_TYPE (object_class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (GeditMessageBusClass, registered),
			      NULL, NULL,
			      g_cclosure_marshal_VOID__BOXED,
			      G_TYPE_NONE,
			      1,
			      GEDIT_TYPE_MESSAGE_TYPE);

	/**
	 * GeditMessageBus::unregistered:
	 * @bus: a #GeditMessageBus
	 * @message_type: the unregistered #GeditMessageType
	 *
	 * The "unregistered" signal is emitted when a message has been 
	 * unregistered from the bus.
	 *
	 */
	message_bus_signals[UNREGISTERED] =
   		g_signal_new ("unregistered",
			      G_OBJECT_CLASS_TYPE (object_class),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (GeditMessageBusClass, unregistered),
			      NULL, NULL,
			      g_cclosure_marshal_VOID__BOXED,
			      G_TYPE_NONE,
			      1,
			      GEDIT_TYPE_MESSAGE_TYPE);

	g_type_class_add_private (object_class, sizeof(GeditMessageBusPrivate));
}

static Message *
message_new (GeditMessageBus *bus,
	     const gchar     *object_path,
	     const gchar     *method)
{
	Message *message = g_new (Message, 1);
	
	message->object_path = g_strdup (object_path);
	message->method = g_strdup (method);
	message->listeners = NULL;

	g_hash_table_insert (bus->priv->messages, 
			     gedit_message_type_identifier (object_path, method),
			     message);
	return message;
}

static Message *
lookup_message (GeditMessageBus *bus,
	       const gchar      *object_path,
	       const gchar      *method,
	       gboolean          create)
{
	gchar *identifier;
	Message *message;
	
	identifier = gedit_message_type_identifier (object_path, method);
	message = (Message *)g_hash_table_lookup (bus->priv->messages, identifier);
	g_free (identifier);

	if (!message && !create)
		return NULL;
	
	if (!message)
		message = message_new (bus, object_path, method);
	
	return message;
}

static guint
add_listener (GeditMessageBus      *bus,
	      Message		   *message,
	      GeditMessageCallback  callback,
	      gpointer		    userdata,
	      GDestroyNotify        destroy_data)
{
	Listener *listener;
	IdMap *idmap;
	
	listener = g_new (Listener, 1);
	listener->id = ++bus->priv->next_id;
	listener->callback = callback;
	listener->userdata = userdata;
	listener->blocked = FALSE;
	listener->destroy_data = destroy_data;

	message->listeners = g_list_append (message->listeners, listener);
	
	idmap = g_new (IdMap, 1);
	idmap->message = message;
	idmap->listener = g_list_last (message->listeners);

	g_hash_table_insert (bus->priv->idmap, GINT_TO_POINTER (listener->id), idmap);	
	return listener->id;
}

static void
remove_listener (GeditMessageBus *bus,
		 Message         *message,
		 GList		 *listener)
{
	Listener *lst;
	
	lst = (Listener *)listener->data;
	
	/* remove from idmap */
	g_hash_table_remove (bus->priv->idmap, GINT_TO_POINTER (lst->id));
	listener_free (lst);

	/* remove from list of listeners */
	message->listeners = g_list_delete_link (message->listeners, listener);
	
	if (!message->listeners)
	{
		/* remove message because it does not have any listeners */
		g_hash_table_remove (bus->priv->messages, message);
	}
}

static void
block_listener (GeditMessageBus *bus,
		Message		*message,
		GList		*listener)
{
	Listener *lst;
	
	lst = (Listener *)listener->data;
	lst->blocked = TRUE;
}

static void
unblock_listener (GeditMessageBus *bus,
		  Message	  *message,
		  GList		  *listener)
{
	Listener *lst;
	
	lst = (Listener *)listener->data;
	lst->blocked = FALSE;
}

static void
dispatch_message_real (GeditMessageBus *bus,
		       Message         *msg,
		       GeditMessage    *message)
{
	GList *item;
	
	for (item = msg->listeners; item; item = item->next)
	{
		Listener *listener = (Listener *)item->data;
		
		if (!listener->blocked)
			listener->callback (bus, message, listener->userdata);
	}
}

static void
gedit_message_bus_dispatch_real (GeditMessageBus *bus,
				 GeditMessage    *message)
{
	const gchar *object_path;
	const gchar *method;
	Message *msg;
	
	object_path = gedit_message_get_object_path (message);
	method = gedit_message_get_method (message);

	msg = lookup_message (bus, object_path, method, FALSE);
	
	if (msg)
		dispatch_message_real (bus, msg, message);
}

static void
dispatch_message (GeditMessageBus *bus,
		  GeditMessage    *message)
{
	g_signal_emit (bus, message_bus_signals[DISPATCH], 0, message);	
}

static gboolean
idle_dispatch (GeditMessageBus *bus)
{
	GList *list;
	GList *item;
	
	/* make sure to set idle_id to 0 first so that any new async messages
	   will be queued properly */
	bus->priv->idle_id = 0;

	/* reverse queue to get correct delivery order */
	list = g_list_reverse (bus->priv->message_queue);
	bus->priv->message_queue = NULL;
	
	for (item = list; item; item = item->next)
	{
		GeditMessage *msg = GEDIT_MESSAGE (item->data);
		
		dispatch_message (bus, msg);
	}
	
	message_queue_free (list);
	return FALSE;
}

typedef void (*MatchCallback) (GeditMessageBus *, Message *, GList *);

static void
process_by_id (GeditMessageBus  *bus,
	       guint	         id,
	       MatchCallback     processor)
{
	IdMap *idmap;
	
	idmap = (IdMap *)g_hash_table_lookup (bus->priv->idmap, GINT_TO_POINTER (id));
	
	if (idmap == NULL)
	{
		g_warning ("No handler registered with id `%d'", id);
		return;
	}
		
	processor (bus, idmap->message, idmap->listener);
}

static void
process_by_match (GeditMessageBus      *bus,
	          const gchar          *object_path,
	          const gchar          *method,
	          GeditMessageCallback  callback,
	          gpointer              userdata,
	          MatchCallback         processor)
{
	Message *message;
	GList *item;
	
	message = lookup_message (bus, object_path, method, FALSE);
	
	if (!message)
	{
		g_warning ("No such handler registered for %s.%s", object_path, method);
		return;
	}
	
	for (item = message->listeners; item; item = item->next)
	{
		Listener *listener = (Listener *)item->data;
		
		if (listener->callback == callback && 
		    listener->userdata == userdata)
		{
			processor (bus, message, item);
			return;
		}
	}
	
	g_warning ("No such handler registered for %s.%s", object_path, method);
}

static void
gedit_message_bus_init (GeditMessageBus *self)
{
	self->priv = GEDIT_MESSAGE_BUS_GET_PRIVATE (self);
	
	self->priv->messages = g_hash_table_new_full (g_str_hash,
						      g_str_equal,
						      (GDestroyNotify)g_free,
						      (GDestroyNotify)message_free);

	self->priv->idmap = g_hash_table_new_full (g_direct_hash,
	 					   g_direct_equal,
	 					   NULL,
	 					   (GDestroyNotify)g_free);
	 					   
	self->priv->types = g_hash_table_new_full (g_str_hash,
						   g_str_equal,
						   (GDestroyNotify)g_free,
						   (GDestroyNotify)gedit_message_type_unref);
}

/**
 * gedit_message_bus_get_default:
 *
 * Get the default application #GeditMessageBus.
 *
 * Return value: the default #GeditMessageBus
 *
 */
GeditMessageBus *
gedit_message_bus_get_default (void)
{
	static GeditMessageBus *default_bus = NULL;
	
	if (G_UNLIKELY (default_bus == NULL))
	{
		default_bus = g_object_new (GEDIT_TYPE_MESSAGE_BUS, NULL);
		g_object_add_weak_pointer (G_OBJECT (default_bus),
				           (gpointer) &default_bus);
	}
	
	return default_bus;
}

/**
 * gedit_message_bus_new:
 * 
 * Create a new message bus. Use gedit_message_bus_get_default() to get the
 * default, application wide, message bus. Creating a new bus is useful for
 * associating a specific bus with for instance a #GeditWindow.
 *
 * Return value: a new #GeditMessageBus
 *
 */
GeditMessageBus *
gedit_message_bus_new (void)
{
	return GEDIT_MESSAGE_BUS (g_object_new (GEDIT_TYPE_MESSAGE_BUS, NULL));
}

/**
 * gedit_message_bus_lookup:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 *
 * Get the registered #GeditMessageType for @method at @object_path. The 
 * returned #GeditMessageType is owned by the bus and should not be unreffed.
 *
 * Return value: the registered #GeditMessageType or %NULL if no message type
 *               is registered for @method at @object_path
 *
 */
GeditMessageType *
gedit_message_bus_lookup (GeditMessageBus *bus,
			  const gchar	  *object_path,
			  const gchar	  *method)
{
	gchar *identifier;
	GeditMessageType *message_type;
	
	g_return_val_if_fail (GEDIT_IS_MESSAGE_BUS (bus), NULL);
	g_return_val_if_fail (object_path != NULL, NULL);
	g_return_val_if_fail (method != NULL, NULL);

	identifier = gedit_message_type_identifier (object_path, method);
	message_type = GEDIT_MESSAGE_TYPE (g_hash_table_lookup (bus->priv->types, identifier));
	
	g_free (identifier);
	return message_type;
}

/**
 * gedit_message_bus_register:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method to register
 * @num_optional: the number of optional arguments
 * @...: NULL terminated list of key/gtype method argument pairs
 *
 * Register a message on the bus. A message must be registered on the bus before
 * it can be send. This function registers the type arguments for @method at 
 * @object_path. The arguments are specified with the variable arguments which 
 * should contain pairs of const gchar *key and GType terminated by %NULL. The 
 * last @num_optional arguments are registered as optional (and are thus not
 * required when sending a message).
 *
 * This function emits a #GeditMessageBus::registered signal.
 *
 * Return value: the registered #GeditMessageType. The returned reference is
 *               owned by the bus. If you want to keep it alive after
 *               unregistering, use gedit_message_type_ref().
 *
 */
GeditMessageType *
gedit_message_bus_register (GeditMessageBus *bus,
			    const gchar     *object_path,
			    const gchar	    *method,
			    guint	     num_optional,
			    ...)
{
	gchar *identifier;
	gpointer data;
	va_list var_args;
	GeditMessageType *message_type;

	g_return_val_if_fail (GEDIT_IS_MESSAGE_BUS (bus), NULL);
	g_return_val_if_fail (gedit_message_type_is_valid_object_path (object_path), NULL);
	
	if (gedit_message_bus_is_registered (bus, object_path, method))
	{
		g_warning ("Message type for '%s.%s' is already registered", object_path, method);
		return NULL;
	}

	identifier = gedit_message_type_identifier (object_path, method);
	data = g_hash_table_lookup (bus->priv->types, identifier);
	
	va_start (var_args, num_optional);
	message_type = gedit_message_type_new_valist (object_path, 
						      method,
						      num_optional,
						      var_args);
	va_end (var_args);
	
	if (message_type)
	{
		g_hash_table_insert (bus->priv->types, identifier, message_type);
		g_signal_emit (bus, message_bus_signals[REGISTERED], 0, message_type);
	}
	else
	{
		g_free (identifier);
	}
	
	return message_type;	
}

static void
gedit_message_bus_unregister_real (GeditMessageBus  *bus,
				   GeditMessageType *message_type,
				   gboolean          remove_from_store)
{
	gchar *identifier;
	
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));

	identifier = gedit_message_type_identifier (gedit_message_type_get_object_path (message_type), 
						    gedit_message_type_get_method (message_type));
	
	/* Keep message type alive for signal emission */
	gedit_message_type_ref (message_type);

	if (!remove_from_store || g_hash_table_remove (bus->priv->types, identifier))
		g_signal_emit (bus, message_bus_signals[UNREGISTERED], 0, message_type);
	
	gedit_message_type_unref (message_type);
	g_free (identifier);
}

/**
 * gedit_message_bus_unregister:
 * @bus: a #GeditMessageBus
 * @message_type: the #GeditMessageType to unregister
 *
 * Unregisters a previously registered message type. This is especially useful 
 * for plugins which should unregister message types when they are deactivated.
 *
 * This function emits the #GeditMessageBus::unregistered signal.
 *
 */
void
gedit_message_bus_unregister (GeditMessageBus  *bus,
			      GeditMessageType *message_type)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	gedit_message_bus_unregister_real (bus, message_type, TRUE);
}

typedef struct 
{
	GeditMessageBus *bus;
	const gchar *object_path;
} UnregisterInfo;

static gboolean
unregister_each (const gchar      *identifier,
		 GeditMessageType *message_type,
		 UnregisterInfo   *info)
{
	if (strcmp (gedit_message_type_get_object_path (message_type),
		    info->object_path) == 0)
	{	
		gedit_message_bus_unregister_real (info->bus, message_type, FALSE);
		return TRUE;
	}
	
	return FALSE;
}

/**
 * gedit_message_bus_unregister_all:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 *
 * Unregisters all message types for @object_path. This is especially useful for
 * plugins which should unregister message types when they are deactivated.
 *
 * This function emits the #GeditMessageBus::unregistered signal for all
 * unregistered message types.
 *
 */
void
gedit_message_bus_unregister_all (GeditMessageBus *bus,
			          const gchar     *object_path)
{
	UnregisterInfo info = {bus, object_path};

	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	g_return_if_fail (object_path != NULL);

	g_hash_table_foreach_remove (bus->priv->types, 
				     (GHRFunc)unregister_each,
				     &info);
}

/**
 * gedit_message_bus_is_registered:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 *
 * Check whether a message type @method at @object_path is registered on the 
 * bus.
 *
 * Return value: %TRUE if the @method at @object_path is a registered message 
 *               type on the bus
 *
 */
gboolean
gedit_message_bus_is_registered (GeditMessageBus	*bus,
				 const gchar	*object_path,
				 const gchar	*method)
{
	gchar *identifier;
	gboolean ret;
	
	g_return_val_if_fail (GEDIT_IS_MESSAGE_BUS (bus), FALSE);
	g_return_val_if_fail (object_path != NULL, FALSE);
	g_return_val_if_fail (method != NULL, FALSE);

	identifier = gedit_message_type_identifier (object_path, method);
	ret = g_hash_table_lookup (bus->priv->types, identifier) != NULL;
	
	g_free(identifier);
	return ret;
}

typedef struct
{
	GeditMessageBusForeach func;
	gpointer userdata;
} ForeachInfo;

static void
foreach_type (const gchar      *key,
	      GeditMessageType *message_type,
	      ForeachInfo      *info)
{
	gedit_message_type_ref (message_type);
	info->func (message_type, info->userdata);
	gedit_message_type_unref (message_type);
}

/**
 * gedit_message_bus_foreach:
 * @bus: the #GeditMessagebus
 * @func: the callback function
 * @userdata: the user data to supply to the callback function
 *
 * Calls @func for each message type registered on the bus
 *
 */
void 
gedit_message_bus_foreach (GeditMessageBus        *bus,
			   GeditMessageBusForeach  func,
			   gpointer		   userdata)
{
	ForeachInfo info = {func, userdata};
	
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	g_return_if_fail (func != NULL);

	g_hash_table_foreach (bus->priv->types, (GHFunc)foreach_type, &info);
}

/**
 * gedit_message_bus_connect:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 * @callback: function to be called when message @method at @object_path is sent
 * @userdata: userdata to use for the callback
 * @destroy_data: function to evoke with @userdata as argument when @userdata
 *                needs to be freed
 *
 * Connect a callback handler to be evoked when message @method at @object_path
 * is sent over the bus.
 *
 * Return value: the callback identifier
 *
 */
guint
gedit_message_bus_connect (GeditMessageBus	*bus, 
		           const gchar		*object_path,
		           const gchar		*method,
		           GeditMessageCallback  callback,
		           gpointer		 userdata,
		           GDestroyNotify	 destroy_data)
{
	Message *message;

	g_return_val_if_fail (GEDIT_IS_MESSAGE_BUS (bus), 0);
	g_return_val_if_fail (object_path != NULL, 0);
	g_return_val_if_fail (method != NULL, 0);
	g_return_val_if_fail (callback != NULL, 0);
	
	/* lookup the message and create if it does not exist yet */
	message = lookup_message (bus, object_path, method, TRUE);
	
	return add_listener (bus, message, callback, userdata, destroy_data);
}

/**
 * gedit_message_bus_disconnect:
 * @bus: a #GeditMessageBus
 * @id: the callback id as returned by gedit_message_bus_connect()
 *
 * Disconnects a previously connected message callback.
 *
 */
void
gedit_message_bus_disconnect (GeditMessageBus *bus,
			      guint            id)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	
	process_by_id (bus, id, remove_listener);
}

/**
 * gedit_message_bus_disconnect_by_func:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 * @callback: the connected callback
 * @userdata: the userdata with which the callback was connected
 *
 * Disconnects a previously connected message callback by matching the 
 * provided callback function and userdata. See also 
 * gedit_message_bus_disconnect().
 *
 */
void
gedit_message_bus_disconnect_by_func (GeditMessageBus      *bus,
				      const gchar	   *object_path,
				      const gchar	   *method,
				      GeditMessageCallback  callback,
				      gpointer		    userdata)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	
	process_by_match (bus, object_path, method, callback, userdata, remove_listener);
}

/**
 * gedit_message_bus_block:
 * @bus: a #GeditMessageBus
 * @id: the callback id
 *
 * Blocks evoking the callback specified by @id. Unblock the callback by
 * using gedit_message_bus_unblock().
 *
 */
void
gedit_message_bus_block (GeditMessageBus *bus,
			 guint		  id)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	
	process_by_id (bus, id, block_listener);
}

/**
 * gedit_message_bus_block_by_func:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 * @callback: the callback to block
 * @userdata: the userdata with which the callback was connected
 *
 * Blocks evoking the callback that matches provided @callback and @userdata.
 * Unblock the callback using gedit_message_unblock_by_func().
 *
 */
void
gedit_message_bus_block_by_func (GeditMessageBus      *bus,
				 const gchar	      *object_path,
				 const gchar	      *method,
				 GeditMessageCallback  callback,
				 gpointer	       userdata)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	
	process_by_match (bus, object_path, method, callback, userdata, block_listener);
}

/**
 * gedit_message_bus_unblock:
 * @bus: a #GeditMessageBus
 * @id: the callback id
 *
 * Unblocks the callback specified by @id.
 *
 */
void
gedit_message_bus_unblock (GeditMessageBus *bus,
			   guint	    id)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	
	process_by_id (bus, id, unblock_listener);
}

/**
 * gedit_message_bus_unblock_by_func:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 * @callback: the callback to block
 * @userdata: the userdata with which the callback was connected
 *
 * Unblocks the callback that matches provided @callback and @userdata.
 *
 */
void
gedit_message_bus_unblock_by_func (GeditMessageBus      *bus,
				   const gchar	        *object_path,
				   const gchar	        *method,
				   GeditMessageCallback  callback,
				   gpointer	         userdata)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	
	process_by_match (bus, object_path, method, callback, userdata, unblock_listener);
}

static gboolean
validate_message (GeditMessage *message)
{
	if (!gedit_message_validate (message))
	{
		g_warning ("Message '%s.%s' is invalid", gedit_message_get_object_path (message),
							 gedit_message_get_method (message));
		return FALSE;
	}
	
	return TRUE;
}

static void
send_message_real (GeditMessageBus *bus,
		   GeditMessage    *message)
{
	if (!validate_message (message))
	{
		return;
	}
	
	bus->priv->message_queue = g_list_prepend (bus->priv->message_queue, 
						   g_object_ref (message));

	if (bus->priv->idle_id == 0)
		bus->priv->idle_id = g_idle_add_full (G_PRIORITY_HIGH,
						      (GSourceFunc)idle_dispatch,
						      bus,
						      NULL);
}

/**
 * gedit_message_bus_send_message:
 * @bus: a #GeditMessageBus
 * @message: the message to send
 *
 * This sends the provided @message asynchronously over the bus. To send
 * a message synchronously, use gedit_message_bus_send_message_sync(). The 
 * convenience function gedit_message_bus_send() can be used to easily send
 * a message without constructing the message object explicitly first.
 *
 */
void
gedit_message_bus_send_message (GeditMessageBus *bus,
			        GeditMessage    *message)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	g_return_if_fail (GEDIT_IS_MESSAGE (message));
	
	send_message_real (bus, message);
}

static void
send_message_sync_real (GeditMessageBus *bus,
                        GeditMessage    *message)
{
	if (!validate_message (message))
	{
		return;
	}
	
	dispatch_message (bus, message);
}

/**
 * gedit_message_bus_send_message_sync:
 * @bus: a #GeditMessageBus
 * @message: the message to send
 *
 * This sends the provided @message synchronously over the bus. To send
 * a message asynchronously, use gedit_message_bus_send_message(). The 
 * convenience function gedit_message_bus_send_sync() can be used to easily send
 * a message without constructing the message object explicitly first.
 *
 */
void
gedit_message_bus_send_message_sync (GeditMessageBus *bus,
			             GeditMessage    *message)
{
	g_return_if_fail (GEDIT_IS_MESSAGE_BUS (bus));
	g_return_if_fail (GEDIT_IS_MESSAGE (message));

	send_message_sync_real (bus, message);	
}

static GeditMessage *
create_message (GeditMessageBus *bus,
		const gchar     *object_path,
		const gchar     *method,
		va_list          var_args)
{
	GeditMessageType *message_type;
	
	message_type = gedit_message_bus_lookup (bus, object_path, method);
	
	if (!message_type)
	{
		g_warning ("Could not find message type for '%s.%s'", object_path, method);
		return NULL;
	}

	return gedit_message_type_instantiate_valist (message_type, 
						      var_args);
}

/**
 * gedit_message_bus_send:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 * @...: NULL terminated list of key/value pairs
 *
 * This provides a convenient way to quickly send a message @method at 
 * @object_path asynchronously over the bus. The variable argument list 
 * specifies key (string) value pairs used to construct the message arguments. 
 * To send a message synchronously use gedit_message_bus_send_sync().
 *
 */
void
gedit_message_bus_send (GeditMessageBus *bus,
			const gchar     *object_path,
			const gchar     *method,
			...)
{
	va_list var_args;
	GeditMessage *message;
	
	va_start (var_args, method);

	message = create_message (bus, object_path, method, var_args);
	
	if (message)
	{
		send_message_real (bus, message);
		g_object_unref (message);
	}
	else
	{
		g_warning ("Could not instantiate message");
	}

	va_end (var_args);
}

/**
 * gedit_message_bus_send_sync:
 * @bus: a #GeditMessageBus
 * @object_path: the object path
 * @method: the method
 * @...: NULL terminated list of key/value pairs
 *
 * This provides a convenient way to quickly send a message @method at 
 * @object_path synchronously over the bus. The variable argument list 
 * specifies key (string) value pairs used to construct the message 
 * arguments. To send a message asynchronously use gedit_message_bus_send().
 *
 * Return value: the constructed #GeditMessage. The caller owns a reference
 *               to the #GeditMessage and should call g_object_unref() when
 *               it is no longer needed
 */
GeditMessage *
gedit_message_bus_send_sync (GeditMessageBus *bus,
			     const gchar     *object_path,
			     const gchar     *method,
			     ...)
{
	va_list var_args;
	GeditMessage *message;
	
	va_start (var_args, method);
	message = create_message (bus, object_path, method, var_args);
	
	if (message)
		send_message_sync_real (bus, message);

	va_end (var_args);
	
	return message;
}

// ex:ts=8:noet: