[gnome-software] Fix back button visibility when changing modes

[Joaquim Manuel Pereira Rocha <jrocha src gnome org>]

commit b913ad5660b6e062341bd20a37a9d10cd39b28cd
Author: Joaquim Rocha <jrocha endlessm com>
Date:   Wed Jul 13 00:13:08 2016 +0100

    Fix back button visibility when changing modes
    
    When the back button is visible from the search bar and the user changes
    to the overview, installed or updates mode, the button should always be
    hidden.
    
    These changes ensure no matter how many views have been pushed to the
    view stack, changing to those modes always hides the back button by
    clearing the used stack.

 src/gs-shell.c |   53 +++++++++++++++++++++++++++++++----------------------
 1 files changed, 31 insertions(+), 22 deletions(-)
---
diff --git a/src/gs-shell.c b/src/gs-shell.c
index 0f526a9..1e29e0d 100644
--- a/src/gs-shell.c
+++ b/src/gs-shell.c
@@ -202,6 +202,29 @@ gs_shell_set_header_end_widget (GsShell *shell, GtkWidget *widget)
        }
 }
 
+static void
+free_back_entry (BackEntry *entry)
+{
+       if (entry->focus != NULL)
+               g_object_remove_weak_pointer (G_OBJECT (entry->focus),
+                                             (gpointer *) &entry->focus);
+       g_clear_object (&entry->category);
+       g_clear_object (&entry->app);
+       g_free (entry->search);
+       g_free (entry);
+}
+
+static void
+gs_shell_clean_back_entry_stack (GsShell *shell)
+{
+       GsShellPrivate *priv = gs_shell_get_instance_private (shell);
+       BackEntry *entry;
+
+       while ((entry = g_queue_pop_head (priv->back_entry_stack)) != NULL) {
+               free_back_entry (entry);
+       }
+}
+
 void
 gs_shell_change_mode (GsShell *shell,
                      GsShellMode mode,
@@ -241,10 +264,6 @@ gs_shell_change_mode (GsShell *shell,
        /* TRANSLATORS: this is the main window title */
        gtk_window_set_title (priv->main_window, _("Software"));
 
-       /* show the back button if needed */
-       widget = GTK_WIDGET (gtk_builder_get_object (priv->builder, "button_back"));
-       gtk_widget_set_visible (widget, !g_queue_is_empty (priv->back_entry_stack));
-
        /* update main buttons according to mode */
        priv->ignore_primary_buttons = TRUE;
        widget = GTK_WIDGET (gtk_builder_get_object (priv->builder, "button_all"));
@@ -267,9 +286,11 @@ gs_shell_change_mode (GsShell *shell,
        priv->mode = mode;
        switch (mode) {
        case GS_SHELL_MODE_OVERVIEW:
+               gs_shell_clean_back_entry_stack (shell);
                new_page = GS_PAGE (priv->shell_overview);
                break;
        case GS_SHELL_MODE_INSTALLED:
+               gs_shell_clean_back_entry_stack (shell);
                new_page = GS_PAGE (priv->shell_installed);
                break;
        case GS_SHELL_MODE_MODERATE:
@@ -283,6 +304,7 @@ gs_shell_change_mode (GsShell *shell,
                new_page = GS_PAGE (priv->shell_search);
                break;
        case GS_SHELL_MODE_UPDATES:
+               gs_shell_clean_back_entry_stack (shell);
                new_page = GS_PAGE (priv->shell_updates);
                break;
        case GS_SHELL_MODE_DETAILS:
@@ -305,6 +327,10 @@ gs_shell_change_mode (GsShell *shell,
                g_assert_not_reached ();
        }
 
+       /* show the back button if needed */
+       widget = GTK_WIDGET (gtk_builder_get_object (priv->builder, "button_back"));
+       gtk_widget_set_visible (widget, !g_queue_is_empty (priv->back_entry_stack));
+
        gs_page_switch_to (new_page, scroll_up);
 
        /* update header bar widgets */
@@ -371,18 +397,6 @@ save_back_entry (GsShell *shell)
 }
 
 static void
-free_back_entry (BackEntry *entry)
-{
-       if (entry->focus != NULL)
-               g_object_remove_weak_pointer (G_OBJECT (entry->focus),
-                                             (gpointer *) &entry->focus);
-       g_clear_object (&entry->category);
-       g_clear_object (&entry->app);
-       g_free (entry->search);
-       g_free (entry);
-}
-
-static void
 gs_shell_back_button_cb (GtkWidget *widget, GsShell *shell)
 {
        GsShellPrivate *priv = gs_shell_get_instance_private (shell);
@@ -521,16 +535,11 @@ main_window_closed_cb (GtkWidget *dialog, GdkEvent *event, gpointer user_data)
 {
        GsShell *shell = user_data;
        GsShellPrivate *priv = gs_shell_get_instance_private (shell);
-       BackEntry *entry;
 
        /* When the window is closed, reset the initial mode to overview */
        priv->mode = GS_SHELL_MODE_OVERVIEW;
 
-       /* ... and clear any remaining entries in the back button stack */
-       while ((entry = g_queue_pop_head (priv->back_entry_stack)) != NULL) {
-               free_back_entry (entry);
-       }
-
+       gs_shell_clean_back_entry_stack (shell);
        gtk_widget_hide (dialog);
        return TRUE;
 }