Place cover at vertical center

Signed-off-by: Vasiliy Doylov <nekocwd@mainlining.org>

src/player.vala

@@ -138,7 +138,9 @@ public class MediaPlayer.Player : Gtk.Box {
     // Start background generator
     run_color_thred (pixbuff.scale_simple (64, 64, Gdk.InterpType.BILINEAR));
 
-    return Utils.round_pixbuff (pixbuff, (110.0 - 10.0) /* pixel-size - padding :TODO: REMOVE WHEN PHOSH MOVES TO GTK4 */ / 10 / 100);
+    // TODO: REMOVE WHEN PHOSH MOVES TO GTK4
+    pixbuff = Utils.round_pixbuff (pixbuff, (110.0 - 10.0 /* pixel-size - padding */) / 10 / 100);
+    return Utils.rect_pixbuff (pixbuff);
   }
 
   public void bind_to_player (Gtk.Box player) {

src/utils.vala

@@ -65,6 +65,21 @@ namespace Utils {
     return Gdk.pixbuf_get_from_surface (surface, 0, 0, width, height);
   }
 
+  public Gdk.Pixbuf rect_pixbuff (Gdk.Pixbuf source) {
+    // That's a hack for GTK3. TODO: Remove when phosh will be moved to gtk4
+    var width = source.width;
+    var height = source.height;
+    if (width == height)
+      return source;
+    var max_dim = int.max (width, height);
+
+    var surface = new Cairo.ImageSurface (Cairo.Format.ARGB32, max_dim, max_dim);
+    var cr = new Cairo.Context (surface);
+    Gdk.cairo_set_source_pixbuf (cr, source, 0, (width - height) / 2);
+    cr.paint ();
+    return Gdk.pixbuf_get_from_surface (surface, 0, 0, max_dim, max_dim);
+  }
+
   public double deg (double deg) {
     return Math.PI / 180.0 * deg;
   }