1/*
2 * Copyright © 2018 Benjamin Otte
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at 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 Public
15 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
16 *
17 * Authors: Benjamin Otte <otte@gnome.org>
18 */
19
20
21/*
22 * GtkPropertyLookupListModel:
23 *
24 * `GtkPropertyLookupListModel` is a `GListModel` implementation that takes an
25 * object and a property and then recursively looks up the next element using
26 * the property on the previous object.
27 *
28 * For example, one could use this list model with the GtkWidget:parent property
29 * to get a list of a widgets and all its ancestors.
30 **/
31
32#include "config.h"
33
34#include "gtkpropertylookuplistmodelprivate.h"
35
36#include "gtkintl.h"
37#include "gtkprivate.h"
38
39enum {
40 PROP_0,
41 PROP_ITEM_TYPE,
42 PROP_OBJECT,
43 PROP_PROPERTY,
44 NUM_PROPERTIES
45};
46
47struct _GtkPropertyLookupListModel
48{
49 GObject parent_instance;
50
51 GType item_type;
52 char *property;
53 GPtrArray *items; /* list of items - lazily expanded if there's a NULL sentinel */
54};
55
56struct _GtkPropertyLookupListModelClass
57{
58 GObjectClass parent_class;
59};
60
61static GParamSpec *properties[NUM_PROPERTIES] = { NULL, };
62
63static GType
64gtk_property_lookup_list_model_get_item_type (GListModel *list)
65{
66 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (list);
67
68 return self->item_type;
69}
70
71static gboolean
72gtk_property_lookup_list_model_is_infinite (GtkPropertyLookupListModel *self)
73{
74 if (self->items->len == 0)
75 return FALSE;
76
77 return g_ptr_array_index (self->items, self->items->len - 1) == NULL;
78}
79
80static void
81gtk_property_lookup_list_model_notify_cb (GObject *object,
82 GParamSpec *pspec,
83 GtkPropertyLookupListModel *self);
84
85static guint
86gtk_property_lookup_list_model_clear (GtkPropertyLookupListModel *self,
87 guint remaining)
88{
89 guint i;
90
91 for (i = remaining; i < self->items->len; i++)
92 {
93 gpointer object = g_ptr_array_index (self->items, i);
94 if (object == NULL)
95 break;
96
97 g_signal_handlers_disconnect_by_func (object, gtk_property_lookup_list_model_notify_cb, self);
98 g_object_unref (object);
99 }
100
101 /* keeps the sentinel, yay! */
102 g_ptr_array_remove_range (array: self->items, index_: remaining, length: i - remaining);
103
104 return i - remaining;
105}
106
107static guint
108gtk_property_lookup_list_model_append (GtkPropertyLookupListModel *self,
109 guint n_items)
110{
111 gpointer last, next;
112 guint i, start;
113
114 g_assert (self->items->len > 0);
115 g_assert (!gtk_property_lookup_list_model_is_infinite (self));
116
117 last = g_ptr_array_index (self->items, self->items->len - 1);
118 start = self->items->len;
119 for (i = start; i < n_items; i++)
120 {
121 g_object_get (object: last, first_property_name: self->property, &next, NULL);
122 if (next == NULL)
123 return i - start;
124
125 g_signal_connect_closure_by_id (instance: next,
126 signal_id: g_signal_lookup (name: "notify", G_OBJECT_TYPE (next)),
127 detail: g_quark_from_static_string (string: self->property),
128 closure: g_cclosure_new (G_CALLBACK (gtk_property_lookup_list_model_notify_cb), G_OBJECT (self), NULL),
129 FALSE);
130
131 g_ptr_array_add (array: self->items, data: next);
132 last = next;
133 }
134
135 return i - start;
136}
137
138static void
139gtk_property_lookup_list_model_ensure (GtkPropertyLookupListModel *self,
140 guint n_items)
141{
142 if (!gtk_property_lookup_list_model_is_infinite (self))
143 return;
144
145 if (self->items->len - 1 >= n_items)
146 return;
147
148 /* remove NULL sentinel */
149 g_ptr_array_remove_index (array: self->items, index_: self->items->len - 1);
150
151 if (self->items->len == 0)
152 return;
153
154 if (gtk_property_lookup_list_model_append (self, n_items) == n_items)
155 {
156 /* re-add NULL sentinel */
157 g_ptr_array_add (array: self->items, NULL);
158 }
159}
160
161static void
162gtk_property_lookup_list_model_notify_cb (GObject *object,
163 GParamSpec *pspec,
164 GtkPropertyLookupListModel *self)
165{
166 guint position, removed, added;
167
168 if (!g_ptr_array_find (haystack: self->items, needle: object, index_: &position))
169 {
170 /* can only happen if we forgot to disconnect a signal handler */
171 g_assert_not_reached ();
172 }
173 /* we found the position of the item that notified, but the first change
174 * is its child.
175 */
176 position++;
177
178 removed = gtk_property_lookup_list_model_clear (self, remaining: position);
179
180 if (!gtk_property_lookup_list_model_is_infinite (self))
181 added = gtk_property_lookup_list_model_append (self, G_MAXUINT);
182 else
183 added = 0;
184
185 if (removed > 0 || added > 0)
186 g_list_model_items_changed (list: G_LIST_MODEL (ptr: self), position, removed, added);
187}
188
189static guint
190gtk_property_lookup_list_model_get_n_items (GListModel *list)
191{
192 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (list);
193
194 gtk_property_lookup_list_model_ensure (self, G_MAXUINT);
195
196 return self->items->len;
197}
198
199static gpointer
200gtk_property_lookup_list_model_get_item (GListModel *list,
201 guint position)
202{
203 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (list);
204
205 gtk_property_lookup_list_model_ensure (self, n_items: position + 1);
206
207 if (position >= self->items->len)
208 return NULL;
209
210 return g_object_ref (g_ptr_array_index (self->items, position));
211}
212
213static void
214gtk_property_lookup_list_model_list_model_init (GListModelInterface *iface)
215{
216 iface->get_item_type = gtk_property_lookup_list_model_get_item_type;
217 iface->get_n_items = gtk_property_lookup_list_model_get_n_items;
218 iface->get_item = gtk_property_lookup_list_model_get_item;
219}
220
221G_DEFINE_TYPE_WITH_CODE (GtkPropertyLookupListModel, gtk_property_lookup_list_model,
222 G_TYPE_OBJECT,
223 G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, gtk_property_lookup_list_model_list_model_init))
224
225static gboolean
226check_pspec (GType type,
227 GParamSpec *pspec)
228{
229 if (pspec == NULL)
230 return FALSE;
231
232 if (!G_IS_PARAM_SPEC_OBJECT (pspec))
233 return FALSE;
234
235 if (!g_type_is_a (G_PARAM_SPEC (pspec)->value_type, is_a_type: type))
236 return FALSE;
237
238 return TRUE;
239}
240
241static gboolean
242lookup_pspec (GType type,
243 const char *name)
244{
245 gboolean result;
246
247 if (g_type_is_a (type, G_TYPE_INTERFACE))
248 {
249 gpointer iface;
250 GParamSpec *pspec;
251
252 iface = g_type_default_interface_ref (g_type: type);
253 pspec = g_object_interface_find_property (g_iface: iface, property_name: name);
254 result = check_pspec (type, pspec);
255 g_type_default_interface_unref (g_iface: iface);
256 }
257 else
258 {
259 GObjectClass *klass;
260 GParamSpec *pspec;
261
262 klass = g_type_class_ref (type);
263 g_return_val_if_fail (klass != NULL, FALSE);
264 pspec = g_object_class_find_property (oclass: klass, property_name: name);
265 result = check_pspec (type, pspec);
266 g_type_class_unref (g_class: klass);
267 }
268
269 return result;
270}
271
272static void
273gtk_property_lookup_list_model_set_property (GObject *object,
274 guint prop_id,
275 const GValue *value,
276 GParamSpec *pspec)
277{
278 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
279
280 switch (prop_id)
281 {
282 case PROP_ITEM_TYPE:
283 self->item_type = g_value_get_gtype (value);
284 g_return_if_fail (self->item_type != 0);
285 break;
286
287 case PROP_OBJECT:
288 gtk_property_lookup_list_model_set_object (self, object: g_value_get_object (value));
289 break;
290
291 case PROP_PROPERTY:
292 self->property = g_value_dup_string (value);
293 break;
294
295 default:
296 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
297 break;
298 }
299
300 if (self->property && self->item_type &&
301 !lookup_pspec (type: self->item_type, name: self->property))
302 {
303 g_critical ("type %s has no property named \"%s\"", g_type_name (self->item_type), self->property);
304 }
305}
306
307static void
308gtk_property_lookup_list_model_get_property (GObject *object,
309 guint prop_id,
310 GValue *value,
311 GParamSpec *pspec)
312{
313 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
314
315 switch (prop_id)
316 {
317 case PROP_ITEM_TYPE:
318 g_value_set_gtype (value, v_gtype: self->item_type);
319 break;
320
321 case PROP_OBJECT:
322 g_value_set_object (value, v_object: gtk_property_lookup_list_model_get_object (self));
323 break;
324
325 case PROP_PROPERTY:
326 g_value_set_object (value, v_object: self->property);
327 break;
328
329 default:
330 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
331 break;
332 }
333}
334
335static void
336gtk_property_lookup_list_model_dispose (GObject *object)
337{
338 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
339
340 gtk_property_lookup_list_model_clear (self, remaining: 0);
341
342 G_OBJECT_CLASS (gtk_property_lookup_list_model_parent_class)->dispose (object);
343}
344
345static void
346gtk_property_lookup_list_model_finalize (GObject *object)
347{
348 GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
349
350 g_ptr_array_unref (array: self->items);
351 g_free (mem: self->property);
352
353 G_OBJECT_CLASS (gtk_property_lookup_list_model_parent_class)->finalize (object);
354}
355
356static void
357gtk_property_lookup_list_model_class_init (GtkPropertyLookupListModelClass *klass)
358{
359 GObjectClass *object_class = G_OBJECT_CLASS (klass);
360
361 object_class->get_property = gtk_property_lookup_list_model_get_property;
362 object_class->set_property = gtk_property_lookup_list_model_set_property;
363 object_class->dispose = gtk_property_lookup_list_model_dispose;
364 object_class->finalize = gtk_property_lookup_list_model_finalize;
365
366 /**
367 * GtkPropertyLookupListModel:item-type:
368 *
369 * The `GType` for elements of this object
370 */
371 properties[PROP_ITEM_TYPE] =
372 g_param_spec_gtype (name: "item-type",
373 P_("Item type"),
374 P_("The type of elements of this object"),
375 G_TYPE_OBJECT,
376 GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY);
377
378 /**
379 * GtkPropertyLookupListModel:property:
380 *
381 * Name of the property used for lookups
382 */
383 properties[PROP_PROPERTY] =
384 g_param_spec_string (name: "property",
385 P_("type"),
386 P_("Name of the property used for lookups"),
387 NULL,
388 GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY);
389
390 /**
391 * GtkPropertyLookupListModel:object:
392 *
393 * The root object
394 */
395 properties[PROP_OBJECT] =
396 g_param_spec_object (name: "object",
397 P_("Object"),
398 P_("The root object"),
399 G_TYPE_LIST_MODEL,
400 GTK_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
401
402 g_object_class_install_properties (oclass: object_class, n_pspecs: NUM_PROPERTIES, pspecs: properties);
403}
404
405static void
406gtk_property_lookup_list_model_init (GtkPropertyLookupListModel *self)
407{
408 self->items = g_ptr_array_new ();
409 /* add sentinel */
410 g_ptr_array_add (array: self->items, NULL);
411}
412
413GtkPropertyLookupListModel *
414gtk_property_lookup_list_model_new (GType item_type,
415 const char *property_name)
416{
417 g_return_val_if_fail (g_type_is_a (item_type, G_TYPE_OBJECT), NULL);
418 g_return_val_if_fail (property_name != NULL, NULL);
419
420 return g_object_new (GTK_TYPE_PROPERTY_LOOKUP_LIST_MODEL,
421 first_property_name: "item-type", item_type,
422 "property", property_name,
423 NULL);
424}
425
426void
427gtk_property_lookup_list_model_set_object (GtkPropertyLookupListModel *self,
428 gpointer object)
429{
430 guint removed, added;
431
432 g_return_if_fail (GTK_IS_PROPERTY_LOOKUP_LIST_MODEL (self));
433
434 if (object)
435 {
436 if (self->items->len != 0 &&
437 g_ptr_array_index (self->items, 0) == object)
438 return;
439
440 removed = gtk_property_lookup_list_model_clear (self, remaining: 0);
441
442 g_ptr_array_insert (array: self->items, index_: 0, g_object_ref (object));
443 g_signal_connect_closure_by_id (instance: object,
444 signal_id: g_signal_lookup (name: "notify", G_OBJECT_TYPE (object)),
445 detail: g_quark_from_static_string (string: self->property),
446 closure: g_cclosure_new (G_CALLBACK (gtk_property_lookup_list_model_notify_cb), G_OBJECT (self), NULL),
447 FALSE);
448 added = 1;
449 if (!gtk_property_lookup_list_model_is_infinite (self))
450 added += gtk_property_lookup_list_model_append (self, G_MAXUINT);
451 }
452 else
453 {
454 if (self->items->len == 0 ||
455 g_ptr_array_index (self->items, 0) == NULL)
456 return;
457
458 removed = gtk_property_lookup_list_model_clear (self, remaining: 0);
459 added = 0;
460 }
461
462 g_assert (removed != 0 || added != 0);
463
464 g_list_model_items_changed (list: G_LIST_MODEL (ptr: self), position: 0, removed, added);
465}
466
467gpointer
468gtk_property_lookup_list_model_get_object (GtkPropertyLookupListModel *self)
469{
470 g_return_val_if_fail (GTK_IS_PROPERTY_LOOKUP_LIST_MODEL (self), NULL);
471
472 if (self->items->len == 0)
473 return NULL;
474
475 return g_ptr_array_index (self->items, 0);
476}
477
478

source code of gtk/gtk/gtkpropertylookuplistmodel.c