aboutsummaryrefslogtreecommitdiffstats
path: root/shell/e-shell-backend.c
blob: d8af58c6b3bfa1944c956b6ba0019aeb86e675d2 (plain) (blame)
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
/*
 * e-shell-backend.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 * Authors:
 *   Jonathon Jongsma <jonathon.jongsma@collabora.co.uk>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 * Copyright (C) 2009 Intel Corporation
 */

/**
 * SECTION: e-shell-backend
 * @short_description: dynamically loaded capabilities
 * @include: shell/e-shell-backend.h
 **/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "e-shell-backend.h"

#include <errno.h>
#include <glib/gi18n.h>

#include "e-util/e-util.h"

#include "e-shell.h"
#include "e-shell-view.h"

struct _EShellBackendPrivate {

    /* We keep a reference to corresponding EShellView subclass
     * since it keeps a reference back to us.  This ensures the
     * subclass is not finalized before we are, otherwise it
     * would leak its EShellBackend reference. */
    EShellViewClass *shell_view_class;

    /* This tracks what the backend is busy doing. */
    GQueue *activities;

    gchar *config_dir;
    gchar *data_dir;

    guint started   : 1;
};

enum {
    PROP_0,
    PROP_BUSY
};

enum {
    ACTIVITY_ADDED,
    ACTIVITY_REMOVED,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

G_DEFINE_ABSTRACT_TYPE (EShellBackend, e_shell_backend, E_TYPE_EXTENSION)

static void
shell_backend_activity_finalized_cb (EShellBackend *shell_backend,
                                     EActivity *finalized_activity)
{
    g_queue_remove (shell_backend->priv->activities, finalized_activity);

    /* Only emit "notify::busy" when switching from busy to idle. */
    if (g_queue_is_empty (shell_backend->priv->activities))
        g_object_notify (G_OBJECT (shell_backend), "busy");

    g_object_unref (shell_backend);
}

static void
shell_backend_notify_busy_cb (EShellBackend *shell_backend,
                              GParamSpec *pspec,
                              EActivity *activity)
{
    /* Unreferencing the EActivity allows the shell to
     * proceed with shutdown. */
    if (!e_shell_backend_is_busy (shell_backend)) {
        g_signal_handlers_disconnect_by_func (
            shell_backend,
            shell_backend_notify_busy_cb,
            activity);
        g_object_unref (activity);
    }
}

static void
shell_backend_prepare_for_quit_cb (EShell *shell,
                                   EActivity *activity,
                                   EShellBackend *shell_backend)
{
    /* Referencing the EActivity delays shutdown; the
     * reference count acts like a counting semaphore. */
    if (e_shell_backend_is_busy (shell_backend))
        g_signal_connect (
            shell_backend, "notify::busy",
            G_CALLBACK (shell_backend_notify_busy_cb),
            g_object_ref (activity));
}

static GObject *
shell_backend_constructor (GType type,
                           guint n_construct_properties,
                           GObjectConstructParam *construct_properties)
{
    EShellBackend *shell_backend;
    EShellBackendClass *class;
    EShellViewClass *shell_view_class;
    EShell *shell;
    GObject *object;

    /* Chain up to parent's construct() method. */
    object = G_OBJECT_CLASS (e_shell_backend_parent_class)->constructor (
        type, n_construct_properties, construct_properties);

    shell_backend = E_SHELL_BACKEND (object);
    shell = e_shell_backend_get_shell (shell_backend);

    /* Install a reference to ourselves in the
     * corresponding EShellViewClass structure. */
    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);
    shell_view_class = g_type_class_ref (class->shell_view_type);
    shell_view_class->shell_backend = g_object_ref (shell_backend);
    shell_backend->priv->shell_view_class = shell_view_class;

    g_signal_connect (
        shell, "prepare-for-quit",
        G_CALLBACK (shell_backend_prepare_for_quit_cb),
        shell_backend);

    return object;
}

static void
shell_backend_get_property (GObject *object,
                            guint property_id,
                            GValue *value,
                            GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_BUSY:
            g_value_set_boolean (
                value, e_shell_backend_is_busy (
                E_SHELL_BACKEND (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
shell_backend_dispose (GObject *object)
{
    EShellBackendPrivate *priv;

    priv = E_SHELL_BACKEND (object)->priv;

    if (priv->shell_view_class != NULL) {
        g_type_class_unref (priv->shell_view_class);
        priv->shell_view_class = NULL;
    }

    /* Chain up to parent's dispose() method. */
    G_OBJECT_CLASS (e_shell_backend_parent_class)->dispose (object);
}

static void
shell_backend_finalize (GObject *object)
{
    EShellBackendPrivate *priv;

    priv = E_SHELL_BACKEND (object)->priv;

    g_warn_if_fail (g_queue_is_empty (priv->activities));
    g_queue_free (priv->activities);

    g_free (priv->config_dir);
    g_free (priv->data_dir);

    /* Chain up to parent's finalize() method. */
    G_OBJECT_CLASS (e_shell_backend_parent_class)->finalize (object);
}

static const gchar *
shell_backend_get_config_dir (EShellBackend *shell_backend)
{
    EShellBackendClass *class;

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);

    /* Determine the user config directory for this backend. */
    if (G_UNLIKELY (shell_backend->priv->config_dir == NULL)) {
        const gchar *user_config_dir;

        user_config_dir = e_get_user_config_dir ();
        shell_backend->priv->config_dir =
            g_build_filename (user_config_dir, class->name, NULL);
        g_mkdir_with_parents (shell_backend->priv->config_dir, 0700);
    }

    return shell_backend->priv->config_dir;
}

static const gchar *
shell_backend_get_data_dir (EShellBackend *shell_backend)
{
    EShellBackendClass *class;

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);

    /* Determine the user data directory for this backend. */
    if (G_UNLIKELY (shell_backend->priv->data_dir == NULL)) {
        const gchar *user_data_dir;

        user_data_dir = e_get_user_data_dir ();
        shell_backend->priv->data_dir =
            g_build_filename (user_data_dir, class->name, NULL);
        g_mkdir_with_parents (shell_backend->priv->data_dir, 0700);
    }

    return shell_backend->priv->data_dir;
}

static void
e_shell_backend_class_init (EShellBackendClass *class)
{
    GObjectClass *object_class;
    EExtensionClass *extension_class;

    g_type_class_add_private (class, sizeof (EShellBackendPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->constructor = shell_backend_constructor;
    object_class->get_property = shell_backend_get_property;
    object_class->dispose = shell_backend_dispose;
    object_class->finalize = shell_backend_finalize;

    extension_class = E_EXTENSION_CLASS (class);
    extension_class->extensible_type = E_TYPE_SHELL;

    class->get_config_dir = shell_backend_get_config_dir;
    class->get_data_dir = shell_backend_get_data_dir;

    /**
     * EShellBackend:busy
     *
     * Whether any activities are still in progress.
     **/
    g_object_class_install_property (
        object_class,
        PROP_BUSY,
        g_param_spec_boolean (
            "busy",
            "Busy",
            "Whether any activities are still in progress",
            FALSE,
            G_PARAM_READABLE));

    /**
     * EShellBackend::activity-added
     * @shell_backend: the #EShellBackend that emitted the signal
     * @activity: an #EActivity
     *
     * Broadcasts a newly added activity.
     **/
    signals[ACTIVITY_ADDED] = g_signal_new (
        "activity-added",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        0, NULL, NULL,
        g_cclosure_marshal_VOID__OBJECT,
        G_TYPE_NONE, 1,
        E_TYPE_ACTIVITY);
}

static void
e_shell_backend_init (EShellBackend *shell_backend)
{
    shell_backend->priv = G_TYPE_INSTANCE_GET_PRIVATE (
        shell_backend, E_TYPE_SHELL_BACKEND, EShellBackendPrivate);
    shell_backend->priv->activities = g_queue_new ();
}

/**
 * e_shell_backend_compare:
 * @shell_backend_a: an #EShellBackend
 * @shell_backend_b: an #EShellBackend
 *
 * Using the <structfield>sort_order</structfield> field from both backends'
 * #EShellBackendClass, compares @shell_backend_a with @shell_mobule_b and
 * returns -1, 0 or +1 if @shell_backend_a is found to be less than, equal
 * to or greater than @shell_backend_b, respectively.
 *
 * Returns: -1, 0 or +1, for a less than, equal to or greater than result
 **/
gint
e_shell_backend_compare (EShellBackend *shell_backend_a,
                         EShellBackend *shell_backend_b)
{
    gint a = E_SHELL_BACKEND_GET_CLASS (shell_backend_a)->sort_order;
    gint b = E_SHELL_BACKEND_GET_CLASS (shell_backend_b)->sort_order;

    return (a < b) ? -1 : (a > b);
}

/**
 * e_shell_backend_get_config_dir:
 * @shell_backend: an #EShellBackend
 *
 * Returns the absolute path to the configuration directory for
 * @shell_backend.  The string is owned by @shell_backend and should
 * not be modified or freed.
 *
 * Returns: the backend's configuration directory
 **/
const gchar *
e_shell_backend_get_config_dir (EShellBackend *shell_backend)
{
    EShellBackendClass *class;

    g_return_val_if_fail (E_IS_SHELL_BACKEND (shell_backend), NULL);

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);
    g_return_val_if_fail (class->get_config_dir != NULL, NULL);

    return class->get_config_dir (shell_backend);
}

/**
 * e_shell_backend_get_data_dir:
 * @shell_backend: an #EShellBackend
 *
 * Returns the absolute path to the data directory for @shell_backend.
 * The string is owned by @shell_backend and should not be modified or
 * freed.
 *
 * Returns: the backend's data directory
 **/
const gchar *
e_shell_backend_get_data_dir (EShellBackend *shell_backend)
{
    EShellBackendClass *class;

    g_return_val_if_fail (E_IS_SHELL_BACKEND (shell_backend), NULL);

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);
    g_return_val_if_fail (class->get_data_dir != NULL, NULL);

    return class->get_data_dir (shell_backend);
}

/**
 * e_shell_backend_get_shell:
 * @shell_backend: an #EShellBackend
 *
 * Returns the #EShell singleton.
 *
 * Returns: the #EShell
 **/
EShell *
e_shell_backend_get_shell (EShellBackend *shell_backend)
{
    EExtensible *extensible;

    g_return_val_if_fail (E_IS_SHELL_BACKEND (shell_backend), NULL);

    extensible = e_extension_get_extensible (E_EXTENSION (shell_backend));

    return E_SHELL (extensible);
}

/**
 * e_shell_backend_add_activity:
 * @shell_backend: an #EShellBackend
 * @activity: an #EActivity
 *
 * Emits an #EShellBackend::activity-added signal and tracks the @activity
 * until it is finalized.
 **/
void
e_shell_backend_add_activity (EShellBackend *shell_backend,
                              EActivity *activity)
{
    EActivityState state;

    g_return_if_fail (E_IS_SHELL_BACKEND (shell_backend));
    g_return_if_fail (E_IS_ACTIVITY (activity));

    state = e_activity_get_state (activity);

    /* Disregard cancelled or completed activities. */

    if (state == E_ACTIVITY_CANCELLED)
        return;

    if (state == E_ACTIVITY_COMPLETED)
        return;

    g_queue_push_tail (shell_backend->priv->activities, activity);

    /* Emit the "activity-added" signal before adding a weak reference
     * to the EActivity because EShellTaskbar's signal handler also adds
     * a weak reference to the EActivity, and we want its GWeakNotify
     * to run before ours, since ours may destroy the EShellTaskbar
     * during application shutdown. */
    g_signal_emit (shell_backend, signals[ACTIVITY_ADDED], 0, activity);

    /* We reference the backend on every activity to
     * guarantee the backend outlives the activity. */
    g_object_weak_ref (
        G_OBJECT (activity), (GWeakNotify)
        shell_backend_activity_finalized_cb,
        g_object_ref (shell_backend));

    /* Only emit "notify::busy" when switching from idle to busy. */
    if (g_queue_get_length (shell_backend->priv->activities) == 1)
        g_object_notify (G_OBJECT (shell_backend), "busy");
}

/**
 * e_shell_backend_is_busy:
 * @shell_backend: an #EShellBackend
 *
 * Returns %TRUE if any activities passed to e_shell_backend_add_activity()
 * are still in progress, %FALSE if the @shell_backend is currently idle.
 *
 * Returns: %TRUE if activities are still in progress
 **/
gboolean
e_shell_backend_is_busy (EShellBackend *shell_backend)
{
    g_return_val_if_fail (E_IS_SHELL_BACKEND (shell_backend), FALSE);

    return !g_queue_is_empty (shell_backend->priv->activities);
}

/**
 * e_shell_backend_cancel_all:
 * @shell_backend: an #EShellBackend
 *
 * Cancels all activities passed to e_shell_backend_add_activity() that
 * have not already been finalized.  Note that an #EActivity can only be
 * cancelled if it was given a #GCancellable object.
 *
 * Also, assuming all activities are cancellable, there may still be a
 * delay before e_shell_backend_is_busy() returns %FALSE, because some
 * activities may not be able to respond to the cancellation request
 * immediately.  Connect to the "notify::busy" signal if you need
 * notification of @shell_backend becoming idle.
 **/
void
e_shell_backend_cancel_all (EShellBackend *shell_backend)
{
    GList *list, *iter;

    g_return_if_fail (E_IS_SHELL_BACKEND (shell_backend));

    list = g_queue_peek_head_link (shell_backend->priv->activities);

    for (iter = list; iter != NULL; iter = g_list_next (iter)) {
        EActivity *activity;
        GCancellable *cancellable;

        activity = E_ACTIVITY (iter->data);
        cancellable = e_activity_get_cancellable (activity);
        g_cancellable_cancel (cancellable);
    }
}

/**
 * e_shell_backend_start:
 * @shell_backend: an #EShellBackend
 *
 * Tells the @shell_backend to begin loading data or running background
 * tasks which may consume significant resources.  This gets called in
 * reponse to the user switching to the corresponding #EShellView for
 * the first time.  The function is idempotent for each @shell_backend.
 **/
void
e_shell_backend_start (EShellBackend *shell_backend)
{
    EShellBackendClass *class;

    g_return_if_fail (E_IS_SHELL_BACKEND (shell_backend));

    if (shell_backend->priv->started)
        return;

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);

    if (class->start != NULL)
        class->start (shell_backend);

    shell_backend->priv->started = TRUE;
}

/**
 * e_shell_backend_is_started:
 * @shell_backend: an #EShellBackend
 *
 * Returns whether was shelll_backend already started, by
 * calling e_shell_backend_start().
 **/
gboolean
e_shell_backend_is_started (EShellBackend *shell_backend)
{
    g_return_val_if_fail (E_IS_SHELL_BACKEND (shell_backend), FALSE);

    return shell_backend->priv->started;
}

/**
 * e_shell_backend_migrate:
 * @shell_backend: an #EShellBackend
 * @major: major part of version to migrate from
 * @minor: minor part of version to migrate from
 * @micro: micro part of version to migrate from
 * @error: return location for a #GError, or %NULL
 *
 * Attempts to migrate data and settings from version %major.%minor.%micro.
 * Returns %TRUE if the migration was successful or if no action was
 * necessary.  Returns %FALSE and sets %error if the migration failed.
 *
 * Returns: %TRUE if successful, %FALSE otherwise
 **/
gboolean
e_shell_backend_migrate (EShellBackend *shell_backend,
                        gint major,
                        gint minor,
                        gint micro,
                        GError **error)
{
    EShellBackendClass *class;

    g_return_val_if_fail (E_IS_SHELL_BACKEND (shell_backend), TRUE);

    class = E_SHELL_BACKEND_GET_CLASS (shell_backend);

    if (class->migrate == NULL)
        return TRUE;

    return class->migrate (shell_backend, major, minor, micro, error);
}