GtkListBox: Listen for adjustment changes

We automatically pick up an adjustment from our parent
scrollable, but we failed to update it when it changes.
This is happening in the places sidebar, and it was causing
the focus-tracking to fail there, letting the focus move
out of view. With this change, the focus remains visible.

diff --git a/gtk/gtklistbox.c b/gtk/gtklistbox.c
index ee70f58c80426115af588bd513145d561db41888..522e91f1eb4855e5911333c0790da11829d2a42e 100644 (file)
--- a/gtk/gtklistbox.c
+++ b/gtk/gtklistbox.c
@@ -949,8 +949,10 @@ gtk_list_box_set_adjustment (GtkListBox    *box,
   GtkListBoxPrivate *priv = BOX_PRIV (box);
 
   g_return_if_fail (GTK_IS_LIST_BOX (box));
+  g_return_if_fail (adjustment == NULL || GTK_IS_ADJUSTMENT (adjustment));
 
-  g_object_ref_sink (adjustment);
+  if (adjustment)
+    g_object_ref_sink (adjustment);
   if (priv->adjustment)
     g_object_unref (priv->adjustment);
   priv->adjustment = adjustment;
@@ -975,20 +977,37 @@ gtk_list_box_get_adjustment (GtkListBox *box)
   return BOX_PRIV (box)->adjustment;
 }
 
+static void
+adjustment_changed (GObject    *object,
+                    GParamSpec *pspec,
+                    gpointer    data)
+{
+  GtkAdjustment *adjustment;
+
+  adjustment = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (object));
+  gtk_list_box_set_adjustment (GTK_LIST_BOX (data), adjustment);
+}
+
 static void
 gtk_list_box_parent_set (GtkWidget *widget,
                          GtkWidget *prev_parent)
 {
   GtkWidget *parent;
-  GtkAdjustment *adjustment;
 
   parent = gtk_widget_get_parent (widget);
 
+  if (prev_parent && GTK_IS_SCROLLABLE (prev_parent))
+    g_signal_handlers_disconnect_by_func (prev_parent,
+                                          G_CALLBACK (adjustment_changed), widget);
+
   if (parent && GTK_IS_SCROLLABLE (parent))
     {
-      adjustment = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (parent));
-      gtk_list_box_set_adjustment (GTK_LIST_BOX (widget), adjustment);
+      adjustment_changed (G_OBJECT (parent), NULL, widget);
+      g_signal_connect (parent, "notify::vadjustment",
+                        G_CALLBACK (adjustment_changed), widget);
     }
+  else
+    gtk_list_box_set_adjustment (GTK_LIST_BOX (widget), NULL);
 }
 
 /**