[gnome-software] Don't switch away from the loading page until the overview page is fully loaded

[Kalev Lember <klember src gnome org>]

commit 9cc3a4279a50483897395a05a8c9941054214ac9
Author: Kalev Lember <klember redhat com>
Date:   Wed Mar 20 12:23:01 2019 +0000

    Don't switch away from the loading page until the overview page is fully loaded
    
    Keep showing the loading page and only switch to the overview page when
    we know that the content has been fully loaded. This avoids visible
    jiggling while the UI is being loaded and laid out.
    
    Fixes: https://gitlab.gnome.org/GNOME/gnome-software/issues/612

 src/gs-shell.c | 35 +++++++++++++++++++++++++++++------
 1 file changed, 29 insertions(+), 6 deletions(-)
---
diff --git a/src/gs-shell.c b/src/gs-shell.c
index ae8c3f6d..215c31fa 100644
--- a/src/gs-shell.c
+++ b/src/gs-shell.c
@@ -522,24 +522,47 @@ gs_shell_reload_cb (GsPluginLoader *plugin_loader, GsShell *shell)
 }
 
 static void
-initial_refresh_done (GsLoadingPage *loading_page, gpointer data)
+overview_page_refresh_done (GsOverviewPage *overview_page, gpointer data)
 {
-       GsPage *page;
        GsShell *shell = data;
        GsShellPrivate *priv = gs_shell_get_instance_private (shell);
+       GsPage *page;
 
-       g_signal_handlers_disconnect_by_func (loading_page, initial_refresh_done, data);
+       g_signal_handlers_disconnect_by_func (overview_page, overview_page_refresh_done, data);
 
        page = GS_PAGE (gtk_builder_get_object (priv->builder, "updates_page"));
        gs_page_reload (page);
        page = GS_PAGE (gtk_builder_get_object (priv->builder, "installed_page"));
        gs_page_reload (page);
 
+       gs_shell_change_mode (shell, GS_SHELL_MODE_OVERVIEW, NULL, TRUE);
+
+       /* now that we're finished with the loading page, connect the reload signal handler */
+       g_signal_connect (priv->plugin_loader, "reload",
+                         G_CALLBACK (gs_shell_reload_cb), shell);
+}
+
+static void
+initial_refresh_done (GsLoadingPage *loading_page, gpointer data)
+{
+       GsShell *shell = data;
+       GsShellPrivate *priv = gs_shell_get_instance_private (shell);
+
+       g_signal_handlers_disconnect_by_func (loading_page, initial_refresh_done, data);
+
        g_signal_emit (shell, signals[SIGNAL_LOADED], 0);
 
-       /* go to OVERVIEW, unless the "loading" callbacks changed mode already */
-       if (priv->mode == GS_SHELL_MODE_LOADING)
-               gs_shell_change_mode (shell, GS_SHELL_MODE_OVERVIEW, NULL, TRUE);
+       /* if the "loaded" signal handler didn't change the mode, kick off async
+        * overview page refresh, and switch to the page once done */
+       if (priv->mode == GS_SHELL_MODE_LOADING) {
+               GsPage *page;
+
+               page = GS_PAGE (gtk_builder_get_object (priv->builder, "overview_page"));
+               g_signal_connect (page, "refreshed",
+                                 G_CALLBACK (overview_page_refresh_done), shell);
+               gs_page_reload (page);
+               return;
+       }
 
        /* now that we're finished with the loading page, connect the reload signal handler */
        g_signal_connect (priv->plugin_loader, "reload",