[gimp] plug-ins: tile-small should respect the user-set transparency rendering.

[Jehan <jehanp src gnome org>]

commit 1787492710fbee7bd68be61b9d471c9c33ad0f10
Author: Jehan <jehan girinstud io>
Date:   Sat May 14 00:17:06 2022 +0200

    plug-ins: tile-small should respect the user-set transparency rendering.
    
    Right now, the various Gimp*Preview classes have code initializing their
    transparency colors correctly. Some plug-ins, such as tile-small are
    directly using a GimpPreviewArea and need to be initialized directly by
    the plug-in.
    
    I also realized that several plug-ins (such as gradient-flare) are
    rendering their own alpha checkboard, despite using a GimpPreviewArea
    (maybe was it code from a time before this class had support for alpha
    checkboard rendering?). So this would have to be improved later.

 plug-ins/common/tile-small.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/plug-ins/common/tile-small.c b/plug-ins/common/tile-small.c
index d09cf24b25..91ae180a95 100644
--- a/plug-ins/common/tile-small.c
+++ b/plug-ins/common/tile-small.c
@@ -474,6 +474,12 @@ tileit_dialog (GimpDrawable *drawable)
   gtk_widget_show (frame);
 
   tint.preview = gimp_preview_area_new ();
+  g_object_set (tint.preview,
+                "check-size",          gimp_check_size (),
+                "check-type",          gimp_check_type (),
+                "check-custom-color1", gimp_check_custom_color1 (),
+                "check-custom-color2", gimp_check_custom_color2 (),
+                NULL);
   gtk_widget_set_size_request (tint.preview, preview_width, preview_height);
   gtk_widget_set_events (GTK_WIDGET (tint.preview), PREVIEW_MASK);
   gtk_container_add (GTK_CONTAINER (frame), tint.preview);