[nautilus/wip/exalm/spinner: 10/10] floating-bar: Don't start spinner if it's not visible

[António Fernandes <antoniof src gnome org>]

commit 1134d86886747f87806a2d90057dc2b398e66dd4
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Mon Feb 8 19:22:14 2021 +0500

    floating-bar: Don't start spinner if it's not visible
    
    Animating unmapped widgets can still change their size, so they have to
    be measured every time. https://gitlab.gnome.org/GNOME/gtk/-/issues/1025
    
    As a workaround, ensure the spinner doesn't animate while it's not shown,
    to reduce CPU usage.

 src/nautilus-floating-bar.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/src/nautilus-floating-bar.c b/src/nautilus-floating-bar.c
index 30fbf5779..fdb76fb95 100644
--- a/src/nautilus-floating-bar.c
+++ b/src/nautilus-floating-bar.c
@@ -399,7 +399,12 @@ nautilus_floating_bar_constructed (GObject *obj)
     w = gtk_spinner_new ();
     gtk_box_pack_start (GTK_BOX (box), w, FALSE, FALSE, 0);
     gtk_widget_set_visible (w, self->show_spinner);
-    gtk_spinner_start (GTK_SPINNER (w));
+    /* As a workaround for https://gitlab.gnome.org/GNOME/gtk/-/issues/1025,
+     * ensure the spinner animates if and only if it's visible, to reduce CPU
+     * usage. */
+    g_object_bind_property (obj, "show-spinner",
+                            w, "active",
+                            G_BINDING_SYNC_CREATE);
     self->spinner = w;
 
     gtk_widget_set_size_request (w, 16, 16);