[evolution] EMailConfigAssistant: Hack the "Go Back" button after autoconfig.

[Matthew Barnes <mbarnes src gnome org>]

commit 528ef6db79c8d389e6a005dcbe5028fe6219b0a3
Author: Matthew Barnes <mbarnes redhat com>
Date:   Tue Feb 11 10:36:17 2014 -0500

    EMailConfigAssistant: Hack the "Go Back" button after autoconfig.
    
    After account autoconfiguration, you can click the "Go Back" button to
    revise the account details.  That's been in place for some time now, but
    it's not obvious from the button label.  "Go Back" implies going back to
    the Identity page.
    
    Temporarily rename the "Go Back" button on the Summary page to something
    more accurate after a successful autoconfiguration, then reset it to its
    original "Go Back" label.
    
    Unfortunately the GtkAssistant API does not make this easy.  I had to
    resort to crawling the assistant's internal child widgets and comparing
    button labels to locate the right button.  So this hack may not be very
    future-proof.

 mail/e-mail-config-assistant.c |   77 +++++++++++++++++++++++++++++++++++++--
 1 files changed, 73 insertions(+), 4 deletions(-)
---
diff --git a/mail/e-mail-config-assistant.c b/mail/e-mail-config-assistant.c
index aceeacc..6294494 100644
--- a/mail/e-mail-config-assistant.c
+++ b/mail/e-mail-config-assistant.c
@@ -35,6 +35,9 @@
        (G_TYPE_INSTANCE_GET_PRIVATE \
        ((obj), E_TYPE_MAIL_CONFIG_ASSISTANT, EMailConfigAssistantPrivate))
 
+/* GtkAssistant's back button label. */
+#define BACK_BUTTON_LABEL N_("Go _Back")
+
 typedef struct _AutoconfigContext AutoconfigContext;
 
 struct _EMailConfigAssistantPrivate {
@@ -47,7 +50,10 @@ struct _EMailConfigAssistantPrivate {
        EMailConfigSummaryPage *summary_page;
        EMailConfigPage *lookup_page;
        GHashTable *visited_pages;
-       gboolean auto_configure_done;
+       gboolean auto_configured;
+
+       /* GtkAssistant owns this. */
+       GtkButton *back_button;  /* not referenced */
 };
 
 struct _AutoconfigContext {
@@ -273,9 +279,6 @@ mail_config_assistant_autoconfigure_cb (GObject *source_object,
        context = (AutoconfigContext *) user_data;
        priv = E_MAIL_CONFIG_ASSISTANT_GET_PRIVATE (context->assistant);
 
-       /* Whether it works or not, we only do this once. */
-       priv->auto_configure_done = TRUE;
-
        autoconfig = e_mail_autoconfig_finish (result, &error);
 
        /* We don't really care about errors, we only capture the GError
@@ -292,6 +295,9 @@ mail_config_assistant_autoconfigure_cb (GObject *source_object,
        /* Autoconfiguration worked!  Feed the results to the
         * service pages and then skip to the Summary page. */
 
+       /* For the summary page... */
+       priv->auto_configured = TRUE;
+
        e_mail_config_service_page_auto_configure (
                priv->receiving_page, autoconfig);
 
@@ -395,6 +401,40 @@ mail_config_assistant_close_cb (GObject *object,
 }
 
 static void
+mail_config_assistant_find_back_button_cb (GtkWidget *widget,
+                                           gpointer user_data)
+{
+       EMailConfigAssistant *assistant;
+
+       assistant = E_MAIL_CONFIG_ASSISTANT (user_data);
+
+       if (GTK_IS_BUTTON (widget)) {
+               GtkButton *button;
+               const gchar *gtk_label;
+               const gchar *our_label;
+
+               button = GTK_BUTTON (widget);
+
+               /* XXX The gtkassistant.ui file assigns the back button
+                *     an ID of "back", but I don't think we have access
+                *     to it from here.  I guess just compare by label,
+                *     and hope our translation matches GTK's.  Yuck. */
+
+               gtk_label = gtk_button_get_label (button);
+               our_label = gettext (BACK_BUTTON_LABEL);
+
+               if (g_strcmp0 (gtk_label, our_label) == 0)
+                       assistant->priv->back_button = button;
+
+       } else if (GTK_IS_CONTAINER (widget)) {
+               gtk_container_forall (
+                       GTK_CONTAINER (widget),
+                       mail_config_assistant_find_back_button_cb,
+                       assistant);
+       }
+}
+
+static void
 mail_config_assistant_set_session (EMailConfigAssistant *assistant,
                                    EMailSession *session)
 {
@@ -565,6 +605,16 @@ mail_config_assistant_constructed (GObject *object)
        session = e_mail_config_assistant_get_session (assistant);
        registry = e_mail_session_get_registry (session);
 
+       /* XXX Locate the GtkAssistant's internal "Go Back" button so
+        *     we can temporarily rename it for autoconfigure results.
+        *     Walking the container like this is an extremely naughty
+        *     and brittle hack, but GtkAssistant does not provide API
+        *     to access it directly. */
+       gtk_container_forall (
+               GTK_CONTAINER (assistant),
+               mail_config_assistant_find_back_button_cb,
+               assistant);
+
        /* Configure a new identity source. */
 
        identity_source = e_source_new (NULL, NULL, NULL);
@@ -817,6 +867,25 @@ mail_config_assistant_prepare (GtkAssistant *assistant,
                first_visit = TRUE;
        }
 
+       /* Are we viewing autoconfiguration results?  If so, temporarily
+        * rename the back button to clarify that account details can be
+        * revised.  Otherwise reset the button to its original label. */
+       if (priv->back_button != NULL) {
+               gboolean auto_configure_results;
+               const gchar *label;
+
+               auto_configure_results =
+                       E_IS_MAIL_CONFIG_SUMMARY_PAGE (page) &&
+                       priv->auto_configured && first_visit;
+
+               if (auto_configure_results)
+                       label = _("_Revise Details");
+               else
+                       label = gettext (BACK_BUTTON_LABEL);
+
+               gtk_button_set_label (priv->back_button, label);
+       }
+
        if (E_IS_MAIL_CONFIG_LOOKUP_PAGE (page)) {
                AutoconfigContext *context;
                ESource *source;