[gnome-software/1364-implement-other-apps-by-author-section-in-app-details-page: 155/156] gs-details-page: Remember selected app when changing through "Other apps for developer"

[Milan Crha <mcrha src gnome org>]

commit 9f8787e1c09827d308ed1d8bf2d83b0092968b1e
Author: Milan Crha <mcrha redhat com>
Date:   Fri May 6 10:48:39 2022 +0200

    gs-details-page: Remember selected app when changing through "Other apps for developer"
    
    Remember the selected app, to be able to go back to the previous app,
    not directly to the Overview page.

 src/gs-details-page.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/gs-details-page.h |  1 +
 2 files changed, 66 insertions(+)
---
diff --git a/src/gs-details-page.c b/src/gs-details-page.c
index 8c9395319..a4217af3c 100644
--- a/src/gs-details-page.c
+++ b/src/gs-details-page.c
@@ -70,6 +70,11 @@ static void gs_details_page_refresh_addons (GsDetailsPage *self);
 static void gs_details_page_refresh_all (GsDetailsPage *self);
 static void gs_details_page_app_refine_cb (GObject *source, GAsyncResult *res, gpointer user_data);
 
+typedef struct {
+       GsApp *app; /* owned */
+       gdouble vscroll_value;
+} BackEntry;
+
 typedef enum {
        GS_DETAILS_PAGE_STATE_LOADING,
        GS_DETAILS_PAGE_STATE_READY,
@@ -155,6 +160,7 @@ struct _GsDetailsPage
        GtkWidget               *other_apps_heading;
        GtkWidget               *box_other_apps;
        gchar                   *last_developer_name;
+       GQueue                  *back_entry_stack;
 };
 
 G_DEFINE_TYPE (GsDetailsPage, gs_details_page, GS_TYPE_PAGE)
@@ -174,6 +180,13 @@ typedef enum {
 static GParamSpec *obj_props[PROP_IS_NARROW + 1] = { NULL, };
 static guint signals[SIGNAL_LAST] = { 0 };
 
+static void
+free_back_entry (BackEntry *entry)
+{
+       g_clear_object (&entry->app);
+       g_free (entry);
+}
+
 static void
 gs_details_page_cancel_cb (GCancellable *cancellable,
                           GsDetailsPage *self)
@@ -968,10 +981,22 @@ gs_details_page_app_tile_clicked (GsAppTile *tile,
                                  gpointer user_data)
 {
        GsDetailsPage *self = GS_DETAILS_PAGE (user_data);
+       GtkAdjustment *adj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW 
(self->scrolledwindow_details));
+       BackEntry *entry;
        GsApp *app;
 
+       /* Remember the selected app */
+       entry = g_new0 (BackEntry, 1);
+       entry->app = g_object_ref (self->app);
+       entry->vscroll_value = gtk_adjustment_get_value (adj);
+       g_queue_push_head (self->back_entry_stack, entry);
+
+       /* Set the new app */
        app = gs_app_tile_get_app (tile);
        gs_details_page_set_app (self, app);
+
+       /* Scroll to the top */
+       gtk_adjustment_set_value (adj, gtk_adjustment_get_lower (adj));
 }
 
 /* Consider app IDs with and without the ".desktop" suffix being the same app */
@@ -2286,6 +2311,10 @@ gs_details_page_dispose (GObject *object)
                g_hash_table_unref (self->packaging_format_preference);
                self->packaging_format_preference = NULL;
        }
+       if (self->back_entry_stack) {
+               g_queue_free_full (self->back_entry_stack, (GDestroyNotify) free_back_entry);
+               self->back_entry_stack = NULL;
+       }
        g_clear_object (&self->app_local_file);
        g_clear_object (&self->app_reviews_dialog);
        g_clear_object (&self->plugin_loader);
@@ -2468,6 +2497,7 @@ gs_details_page_init (GsDetailsPage *self)
        gtk_widget_init_template (GTK_WIDGET (self));
 
        self->packaging_format_preference = g_hash_table_new_full (gs_details_page_strcase_hash, 
gs_details_page_strcase_equal, g_free, NULL);
+       self->back_entry_stack = g_queue_new ();
        self->settings = g_settings_new ("org.gnome.software");
        g_signal_connect_swapped (self->settings, "changed",
                                  G_CALLBACK (settings_changed_cb),
@@ -2750,3 +2780,38 @@ gs_details_page_set_metainfo (GsDetailsPage *self,
        g_task_set_task_data (task, g_object_ref (file), g_object_unref);
        g_task_run_in_thread (task, gs_details_page_metainfo_thread);
 }
+
+/**
+ * gs_details_page_go_back:
+ * @self: a #GsDetailsPage
+ *
+ * Changes the selected application to the previous, if any such exists.
+ *
+ * Returns: %TRUE, when moved to the previously selected app, %FALSE when not.
+ *
+ * Since: 43
+ **/
+gboolean
+gs_details_page_go_back (GsDetailsPage *self)
+{
+       GtkAdjustment *adj;
+       BackEntry *entry;
+
+       g_return_val_if_fail (GS_IS_DETAILS_PAGE (self), FALSE);
+
+       if (g_queue_is_empty (self->back_entry_stack))
+               return FALSE;
+
+       entry = g_queue_pop_head (self->back_entry_stack);
+
+       /* Set the previous app */
+       gs_details_page_set_app (self, entry->app);
+
+       /* Scroll to where the page was */
+       adj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (self->scrolledwindow_details));
+       gtk_adjustment_set_value (adj, entry->vscroll_value);
+
+       free_back_entry (entry);
+
+       return TRUE;
+}
diff --git a/src/gs-details-page.h b/src/gs-details-page.h
index 566e79b95..250b88c0e 100644
--- a/src/gs-details-page.h
+++ b/src/gs-details-page.h
@@ -35,5 +35,6 @@ void           gs_details_page_set_is_narrow  (GsDetailsPage  *self,
                                                 gboolean        is_narrow);
 void            gs_details_page_set_metainfo   (GsDetailsPage *self,
                                                 GFile *file);
+gboolean        gs_details_page_go_back        (GsDetailsPage *self);
 
 G_END_DECLS