[gtk/magnifier-shadow: 2/3] magnifier: Capture shadows

[Matthias Clasen <matthiasc src gnome org>]

commit a6a56f0bc87418c5f88a5947a4ce63e5cbe44ec4
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu May 5 15:21:03 2022 -0400

    magnifier: Capture shadows
    
    This is the expected behavior, we want to see shadows
    in the magnifier in the inspector.t

 gtk/gtkmagnifier.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gtk/gtkmagnifier.c b/gtk/gtkmagnifier.c
index 5b5b6ab7ac..9c3c659daf 100644
--- a/gtk/gtkmagnifier.c
+++ b/gtk/gtkmagnifier.c
@@ -112,6 +112,7 @@ gtk_magnifier_snapshot (GtkWidget   *widget,
 
   width = gtk_widget_get_width (widget);
   height = gtk_widget_get_height (widget);
+
   paintable_width = gdk_paintable_get_intrinsic_width (magnifier->paintable);
   paintable_height = gdk_paintable_get_intrinsic_height (magnifier->paintable);
   if (paintable_width <= 0.0 || paintable_height <= 0.0)
@@ -216,6 +217,8 @@ gtk_magnifier_init (GtkMagnifier *magnifier)
   magnifier->magnification = 1;
   magnifier->resize = FALSE;
   magnifier->paintable = gtk_widget_paintable_new (NULL);
+  gtk_widget_paintable_set_observed_area (GTK_WIDGET_PAINTABLE (magnifier->paintable),
+                                          GTK_WIDGET_PAINTABLE_AREA_RENDERED);
   g_signal_connect_swapped (magnifier->paintable, "invalidate-contents", G_CALLBACK (gtk_widget_queue_draw), 
magnifier);
   g_signal_connect_swapped (magnifier->paintable, "invalidate-size", G_CALLBACK (gtk_widget_queue_resize), 
magnifier);
 }