[dconf: 10/11] DConfClient: Add "writability-changed" signal

[Allison Ryan Lortie <desrt src gnome org>]

commit b9427b1b27f95fdb75a404d899de2383a62eb6d9
Author: Xavier Claessens <xavier claessens collabora com>
Date:   Fri Dec 4 11:19:01 2015 -0500

    DConfClient: Add "writability-changed" signal
    
    https://bugzilla.gnome.org/show_bug.cgi?id=759128

 client/dconf-client.c |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)
---
diff --git a/client/dconf-client.c b/client/dconf-client.c
index 11bdf3c..36b56aa 100644
--- a/client/dconf-client.c
+++ b/client/dconf-client.c
@@ -63,6 +63,7 @@ G_DEFINE_TYPE (DConfClient, dconf_client, G_TYPE_OBJECT)
 enum
 {
   SIGNAL_CHANGED,
+  SIGNAL_WRITABILITY_CHANGED,
   N_SIGNALS
 };
 static guint dconf_client_signals[N_SIGNALS];
@@ -135,6 +136,20 @@ dconf_client_class_init (DConfClientClass *class)
                                                        G_TYPE_STRING | G_SIGNAL_TYPE_STATIC_SCOPE,
                                                        G_TYPE_STRV | G_SIGNAL_TYPE_STATIC_SCOPE,
                                                        G_TYPE_STRING | G_SIGNAL_TYPE_STATIC_SCOPE);
+
+  /**
+   * DConfClient::writability-changed:
+   * @client: the #DConfClient reporting the change
+   * @path: the dir or key that changed
+   *
+   * Signal emitted when writability for a key (or all keys in a dir) changes.
+   * It will be immediately followed by #DConfClient::changed signal for
+   * the path.
+   */
+  dconf_client_signals[SIGNAL_WRITABILITY_CHANGED] = g_signal_new ("writability-changed", DCONF_TYPE_CLIENT,
+                                                                   G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
+                                                                   G_TYPE_NONE, 1,
+                                                                   G_TYPE_STRING | 
G_SIGNAL_TYPE_STATIC_SCOPE);
 }
 
 typedef struct
@@ -143,6 +158,7 @@ typedef struct
   gchar        *prefix;
   gchar       **changes;
   gchar        *tag;
+  gboolean      is_writability;
 } DConfClientChange;
 
 static gboolean
@@ -150,6 +166,16 @@ dconf_client_dispatch_change_signal (gpointer user_data)
 {
   DConfClientChange *change = user_data;
 
+  if (change->is_writability)
+    {
+      /* We know that the engine does it this way... */
+      g_assert (change->changes[0][0] == '\0' && change->changes[1] == NULL);
+
+      g_signal_emit (change->client,
+                     dconf_client_signals[SIGNAL_WRITABILITY_CHANGED], 0,
+                     change->prefix);
+    }
+
   g_signal_emit (change->client, dconf_client_signals[SIGNAL_CHANGED], 0,
                  change->prefix, change->changes, change->tag);
 
@@ -187,6 +213,7 @@ dconf_engine_change_notify (DConfEngine         *engine,
   change->prefix = g_strdup (prefix);
   change->changes = g_strdupv ((gchar **) changes);
   change->tag = g_strdup (tag);
+  change->is_writability = is_writability;
 
   g_main_context_invoke (client->context, dconf_client_dispatch_change_signal, change);
 }