[gnome-software: 23/24] gs-category-page: Add a top carousel

[Milan Crha <mcrha src gnome org>]

commit 82ddfae57fc69e57bd0c14da9bd72a75aef332a5
Author: Philip Withnall <pwithnall endlessos org>
Date:   Wed Apr 28 13:39:08 2021 +0100

    gs-category-page: Add a top carousel
    
    As per the designs: 
https://gitlab.gnome.org/Teams/Design/software-mockups/-/blob/master/adaptive/category-page-mvp.png
    
    This lists a random 5 of the featured or recently updated apps in the
    category, with the list changing once a week.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>
    
    Helps: #1111

 src/gs-category-page.c  | 103 +++++++++++++++++++++++++++++++++++++++++++++++-
 src/gs-category-page.ui |  10 +++++
 2 files changed, 112 insertions(+), 1 deletion(-)
---
diff --git a/src/gs-category-page.c b/src/gs-category-page.c
index 8d467c774..979c25c74 100644
--- a/src/gs-category-page.c
+++ b/src/gs-category-page.c
@@ -15,6 +15,7 @@
 
 #include "gs-app-list-private.h"
 #include "gs-common.h"
+#include "gs-featured-carousel.h"
 #include "gs-summary-tile.h"
 #include "gs-category-page.h"
 #include "gs-utils.h"
@@ -28,6 +29,7 @@ struct _GsCategoryPage
        GsCategory      *category;
        GsCategory      *subcategory;
 
+       GtkWidget       *top_carousel;
        GtkWidget       *category_detail_box;
        GtkWidget       *scrolledwindow_category;
        GtkWidget       *featured_flow_box;
@@ -60,6 +62,16 @@ app_tile_clicked (GsAppTile *tile, gpointer data)
        g_signal_emit (self, obj_signals[SIGNAL_APP_CLICKED], 0, app);
 }
 
+static void
+top_carousel_app_clicked_cb (GsFeaturedCarousel *carousel,
+                             GsApp              *app,
+                             gpointer            user_data)
+{
+       GsCategoryPage *self = GS_CATEGORY_PAGE (user_data);
+
+       g_signal_emit (self, obj_signals[SIGNAL_APP_CLICKED], 0, app);
+}
+
 static gint
 _max_results_sort_cb (GsApp *app1, GsApp *app2, gpointer user_data)
 {
@@ -167,11 +179,85 @@ gs_category_page_get_apps_cb (GObject *source_object,
        load_category_finish (data);
 }
 
+static gboolean
+app_has_hi_res_icon (GsCategoryPage *self,
+                    GsApp *app)
+{
+       g_autoptr(GIcon) icon = NULL;
+
+       /* This is the minimum icon size needed by `GsFeatureTile`. */
+       icon = gs_app_get_icon_for_size (app,
+                                        128,
+                                        gtk_widget_get_scale_factor (GTK_WIDGET (self)),
+                                        NULL);
+
+       /* Returning TRUE means to keep the app in the list */
+       return (icon != NULL);
+}
+
+static GsAppList *
+choose_top_carousel_apps (LoadCategoryData *data,
+                          guint64           recently_updated_cutoff_secs)
+{
+       const guint n_top_carousel_apps = 5;
+       g_autoptr(GPtrArray) candidates = g_ptr_array_new_with_free_func (NULL);
+       g_autoptr(GsAppList) top_carousel_apps = gs_app_list_new ();
+       guint top_carousel_seed;
+       g_autoptr(GRand) top_carousel_rand = NULL;
+
+       /* The top carousel should contain @n_top_carousel_apps, taken from the
+        * set of featured or recently updated apps which have hi-res icons.
+        *
+        * The apps in the top carousel should be changed on a fixed schedule,
+        * once a week.
+        */
+       top_carousel_seed = (g_get_real_time () / G_USEC_PER_SEC) / (7 * 24 * 60 * 60);
+       top_carousel_rand = g_rand_new_with_seed (top_carousel_seed);
+       g_debug ("Top carousel seed: %u", top_carousel_seed);
+
+       for (guint i = 0; i < gs_app_list_length (data->apps); i++) {
+               GsApp *app = gs_app_list_index (data->apps, i);
+               gboolean is_featured, is_recently_updated, is_hi_res;
+
+               is_featured = (data->featured_app_ids != NULL &&
+                              g_hash_table_contains (data->featured_app_ids, gs_app_get_id (app)));
+               is_recently_updated = (gs_app_get_release_date (app) > recently_updated_cutoff_secs);
+               is_hi_res = app_has_hi_res_icon (data->page, app);
+
+               if ((is_featured || is_recently_updated) && is_hi_res)
+                       g_ptr_array_add (candidates, app);
+       }
+
+       /* If there aren’t enough candidate apps to populate the top carousel,
+        * return an empty app list. */
+       if (candidates->len < n_top_carousel_apps) {
+               g_debug ("Only %u candidate apps for top carousel; returning empty", candidates->len);
+               goto out;
+       }
+
+       /* Select @n_top_carousel_apps from @candidates uniformly randomly
+        * without replacement. */
+       for (guint i = 0; i < n_top_carousel_apps; i++) {
+               guint random_index = g_rand_int_range (top_carousel_rand, 0, candidates->len);
+               GsApp *app = g_ptr_array_index (candidates, random_index);
+
+               gs_app_list_add (top_carousel_apps, app);
+               g_ptr_array_remove_index_fast (candidates, random_index);
+       }
+
+ out:
+       g_assert (gs_app_list_length (top_carousel_apps) == 0 ||
+                 gs_app_list_length (top_carousel_apps) == n_top_carousel_apps);
+
+       return g_steal_pointer (&top_carousel_apps);
+}
+
 static void
 load_category_finish (LoadCategoryData *data)
 {
        GsCategoryPage *self = data->page;
        guint64 recently_updated_cutoff_secs;
+       g_autoptr(GsAppList) top_carousel_apps = NULL;
 
        if (!data->get_featured_apps_finished ||
            !data->get_main_apps_finished)
@@ -185,15 +271,23 @@ load_category_finish (LoadCategoryData *data)
        /* Last 30 days */
        recently_updated_cutoff_secs = g_get_real_time () / G_USEC_PER_SEC - 30 * 24 * 60 * 60;
 
+       /* Apps to go in the top carousel */
+       top_carousel_apps = choose_top_carousel_apps (data, recently_updated_cutoff_secs);
+
        for (guint i = 0; i < gs_app_list_length (data->apps); i++) {
                GsApp *app = gs_app_list_index (data->apps, i);
-               gboolean is_featured, is_recently_updated;
+               gboolean is_featured, is_recently_updated, is_top_carousel;
                GtkWidget *tile;
 
+               is_top_carousel = gs_app_list_lookup (top_carousel_apps, gs_app_get_unique_id (app)) != NULL;
                is_featured = (data->featured_app_ids != NULL &&
                               g_hash_table_contains (data->featured_app_ids, gs_app_get_id (app)));
                is_recently_updated = (gs_app_get_release_date (app) > recently_updated_cutoff_secs);
 
+               /* To be listed in the top carousel? */
+               if (is_top_carousel)
+                       continue;
+
                tile = gs_summary_tile_new (app);
                g_signal_connect (tile, "clicked",
                                  G_CALLBACK (app_tile_clicked), self);
@@ -208,6 +302,9 @@ load_category_finish (LoadCategoryData *data)
                gtk_widget_set_can_focus (gtk_widget_get_parent (tile), FALSE);
        }
 
+       gtk_widget_set_visible (self->top_carousel, gs_app_list_length (top_carousel_apps) > 0);
+       gs_featured_carousel_set_apps (GS_FEATURED_CAROUSEL (self->top_carousel), top_carousel_apps);
+
        /* Show each of the flow boxes if they have any children. */
        gtk_widget_set_visible (self->featured_flow_box, gtk_flow_box_get_child_at_index (GTK_FLOW_BOX 
(self->featured_flow_box), 0) != NULL);
        gtk_widget_set_visible (self->recently_updated_flow_box, gtk_flow_box_get_child_at_index 
(GTK_FLOW_BOX (self->recently_updated_flow_box), 0) != NULL);
@@ -237,6 +334,7 @@ gs_category_page_load_category (GsCategoryPage *self)
                 gs_category_get_id (self->category),
                 gs_category_get_id (self->subcategory));
 
+       gtk_widget_hide (self->top_carousel);
        gs_category_page_add_placeholders (self, GTK_FLOW_BOX (self->category_detail_box),
                                           MIN (30, gs_category_get_size (self->subcategory)));
        gs_category_page_add_placeholders (self, GTK_FLOW_BOX (self->recently_updated_flow_box), 8);
@@ -483,10 +581,13 @@ gs_category_page_class_init (GsCategoryPageClass *klass)
 
        gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/Software/gs-category-page.ui");
 
+       gtk_widget_class_bind_template_child (widget_class, GsCategoryPage, top_carousel);
        gtk_widget_class_bind_template_child (widget_class, GsCategoryPage, category_detail_box);
        gtk_widget_class_bind_template_child (widget_class, GsCategoryPage, scrolledwindow_category);
        gtk_widget_class_bind_template_child (widget_class, GsCategoryPage, featured_flow_box);
        gtk_widget_class_bind_template_child (widget_class, GsCategoryPage, recently_updated_flow_box);
+
+       gtk_widget_class_bind_template_callback (widget_class, top_carousel_app_clicked_cb);
 }
 
 GsCategoryPage *
diff --git a/src/gs-category-page.ui b/src/gs-category-page.ui
index c9864c227..7bf14c104 100644
--- a/src/gs-category-page.ui
+++ b/src/gs-category-page.ui
@@ -27,6 +27,16 @@
                     <property name="margin-end">24</property>
                     <property name="margin-top">0</property><!-- top margin provided by headings -->
                     <property name="margin-bottom">24</property>
+
+                    <child>
+                      <object class="GsFeaturedCarousel" id="top_carousel">
+                        <property name="visible">False</property>
+                        <property name="height-request">150</property>
+                        <property name="margin_top">24</property>
+                        <signal name="app-clicked" handler="top_carousel_app_clicked_cb"/>
+                      </object>
+                    </child>
+
                     <child>
                       <object class="GtkLabel" id="featured_heading">
                         <property name="visible" bind-source="featured_flow_box" bind-property="visible" 
bind-flags="sync-create|bidirectional" />