window: Add API to check for subcompositor, use in subsurface example
This way we can fail with a nice error message.
diff --git a/clients/window.c b/clients/window.c
index 3410354..7223e37 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -5367,6 +5367,17 @@
return display->display;
}
+int
+display_has_subcompositor(struct display *display)
+{
+ if (display->subcompositor)
+ return 1;
+
+ wl_display_roundtrip(display->display);
+
+ return display->subcompositor != NULL;
+}
+
cairo_device_t *
display_get_cairo_device(struct display *display)
{