[gnome-games] utils: Add CompositeCover

[Adrien Plazas <aplazas src gnome org>]

commit d128771ce2e19fde76dd25fdddf82d4c40736ee6
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Wed Aug 10 16:55:03 2016 +0200

    utils: Add CompositeCover
    
    This will be used in the next commit to get covers from multiple
    sources.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769676

 src/Makefile.am                |    1 +
 src/utils/composite-cover.vala |   25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 0 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 25412ad..2bf0703 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -106,6 +106,7 @@ gnome_games_SOURCES = \
        ui/search-bar.vala \
        ui/ui-state.vala \
        \
+       utils/composite-cover.vala \
        utils/cue-sheet/cue-sheet.vala \
        utils/cue-sheet/cue-sheet-error.vala \
        utils/cue-sheet/cue-sheet-file-format.vala \
diff --git a/src/utils/composite-cover.vala b/src/utils/composite-cover.vala
new file mode 100644
index 0000000..538d801
--- /dev/null
+++ b/src/utils/composite-cover.vala
@@ -0,0 +1,25 @@
+// This file is part of GNOME Games. License: GPLv3
+
+public class Games.CompositeCover : Object, Cover {
+       private Cover[] covers;
+
+       public CompositeCover (Cover[] covers) {
+               this.covers = covers;
+               foreach (var cover in covers)
+                       cover.changed.connect (on_cover_changed);
+       }
+
+       public GLib.Icon? get_cover () {
+               foreach (var cover in covers) {
+                       var result_cover = cover.get_cover ();
+                       if (result_cover != null)
+                               return result_cover;
+               }
+
+               return null;
+       }
+
+       private void on_cover_changed () {
+               changed ();
+       }
+}