[gnome-games] collection: Add is_empty property

[Alexander Mikhaylenko <alexm src gnome org>]

commit 13b3abbda90985042709a7887237758e2d9f02ae
Author: Neville <nevilleantony98 gmail com>
Date:   Thu Jul 30 20:45:24 2020 +0530

    collection: Add is_empty property
    
    This property will be listened to invalidate CollectionMainPage's
    flowbox filter, so that empty collections can be hidden.

 src/collection/collection.vala                 |  2 ++
 src/collection/favorites-collection.vala       | 19 +++++++++++++++++++
 src/collection/recently-played-collection.vala | 19 +++++++++++++++++++
 3 files changed, 40 insertions(+)
---
diff --git a/src/collection/collection.vala b/src/collection/collection.vala
index 73b692b4c..9cbbaf01b 100644
--- a/src/collection/collection.vala
+++ b/src/collection/collection.vala
@@ -3,6 +3,8 @@
 private interface Games.Collection : Object {
        public signal void games_changed ();
 
+       public abstract bool is_empty { get; }
+
        public abstract void load ();
 
        public abstract string get_id ();
diff --git a/src/collection/favorites-collection.vala b/src/collection/favorites-collection.vala
index b611a64b6..ee3f5e2da 100644
--- a/src/collection/favorites-collection.vala
+++ b/src/collection/favorites-collection.vala
@@ -6,6 +6,11 @@ private class Games.FavoritesCollection : Object, Collection {
        private Database database;
        private GenericSet<Uid> favorite_game_uids;
 
+       private bool _is_empty = true;
+       public bool is_empty {
+               get { return _is_empty; }
+       }
+
        private ulong idle_id = 0;
 
        construct {
@@ -16,12 +21,26 @@ private class Games.FavoritesCollection : Object, Collection {
 
                game_model = new GameModel ();
                game_model.always_replace = true;
+               game_model.game_added.connect (() => {
+                       set_is_empty (false);
+               });
+               game_model.game_removed.connect (() => {
+                       set_is_empty (game_model.get_n_items () == 0);
+               });
        }
 
        public FavoritesCollection (Database database) {
                this.database = database;
        }
 
+       private void set_is_empty (bool value) {
+               if (is_empty == value)
+                       return;
+
+               _is_empty = value;
+               notify_property ("is-empty");
+       }
+
        public string get_id () {
                return "Favorites";
        }
diff --git a/src/collection/recently-played-collection.vala b/src/collection/recently-played-collection.vala
index 95a9891c7..c9240e490 100644
--- a/src/collection/recently-played-collection.vala
+++ b/src/collection/recently-played-collection.vala
@@ -6,6 +6,11 @@ private class Games.RecentlyPlayedCollection : Object, Collection {
        private Database database;
        private GenericSet<Uid> game_uids;
 
+       private bool _is_empty = true;
+       public bool is_empty {
+               get { return _is_empty; }
+       }
+
        public RecentlyPlayedCollection (Database database) {
                this.database = database;
 
@@ -17,6 +22,20 @@ private class Games.RecentlyPlayedCollection : Object, Collection {
                game_model = new GameModel ();
                game_model.always_replace = true;
                game_model.sort_type = GameModel.SortType.BY_LAST_PLAYED;
+               game_model.game_added.connect (() => {
+                       set_is_empty (false);
+               });
+               game_model.game_removed.connect (() => {
+                       set_is_empty (game_model.get_n_items () == 0);
+               });
+       }
+
+       private void set_is_empty (bool value) {
+               if (is_empty == value)
+                       return;
+
+               _is_empty = value;
+               notify_property ("is-empty");
        }
 
        public string get_id () {