[gtk/1476-nautilus-does-not-enable-to-connect-to-an-nfs-share: 3/4] placesview: Set .error style if unsupported protocol

[António Fernandes <antoniof src gnome org>]

commit 4bdf968702ffb275aa5c96bea17e6330265050f7
Author: António Fernandes <antoniof gnome org>
Date:   Sat Nov 24 00:31:07 2018 +0000

    placesview: Set .error style if unsupported protocol
    
    When the user types an address with a schema that is not supported,
    the Connect button doesn't become sensitive, but there is no visible
    feedback at all.
    
    This feels unresponsive and leaves the user clueless.
    
    While it doesn't help explain why the address doesn't work, this will
    provide a hint that the input was acknowledged but doesn't work.
    
    https://gitlab.gnome.org/GNOME/gtk/issues/1476

 gtk/gtkplacesview.c | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/gtk/gtkplacesview.c b/gtk/gtkplacesview.c
index 7401245da3..14b568dce4 100644
--- a/gtk/gtkplacesview.c
+++ b/gtk/gtkplacesview.c
@@ -1855,6 +1855,13 @@ on_address_entry_text_changed (GtkPlacesView *view)
 
 out:
   gtk_widget_set_sensitive (priv->connect_button, supported);
+  if (scheme && !supported)
+    gtk_style_context_add_class (gtk_widget_get_style_context (priv->address_entry),
+                                 GTK_STYLE_CLASS_ERROR);
+  else
+    gtk_style_context_remove_class (gtk_widget_get_style_context (priv->address_entry),
+                                    GTK_STYLE_CLASS_ERROR);
+
   g_free (address);
   g_free (scheme);
 }