[gtk/wip/otte/for-master: 1/3] demo: Add a dnd special-case for textures

[Benjamin Otte <otte src gnome org>]

commit 7bc1c9a5626aa5d681b65507524aacd5da2d079f
Author: Benjamin Otte <otte redhat com>
Date:   Thu Aug 19 02:15:59 2021 +0200

    demo: Add a dnd special-case for textures
    
    If the DND/clipboard machinery knows a texture is a texture, it will try
    to serialize it. Paintables can't be serialized, so it wouldn't try.

 demos/gtk-demo/demoimage.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/demos/gtk-demo/demoimage.c b/demos/gtk-demo/demoimage.c
index a7ecb6e213..8fdc4257a5 100644
--- a/demos/gtk-demo/demoimage.c
+++ b/demos/gtk-demo/demoimage.c
@@ -100,7 +100,11 @@ prepare_drag (GtkDragSource *source,
   DemoImage *demo = DEMO_IMAGE (widget);
   GdkPaintable *paintable = get_image_paintable (GTK_IMAGE (demo->image));
 
-  return gdk_content_provider_new_typed (GDK_TYPE_PAINTABLE, paintable);
+  /* Textures can be serialized, paintables can't, so special case the textures */
+  if (GDK_IS_TEXTURE (paintable))
+    return gdk_content_provider_new_typed (GDK_TYPE_TEXTURE, paintable);
+  else
+    return gdk_content_provider_new_typed (GDK_TYPE_PAINTABLE, paintable);
 }
 
 static gboolean
@@ -129,7 +133,11 @@ copy_image (GtkWidget *widget,
   GdkPaintable *paintable = get_image_paintable (GTK_IMAGE (demo->image));
   GValue value = G_VALUE_INIT;
 
-  g_value_init (&value, GDK_TYPE_PAINTABLE);
+  /* Textures can be serialized, paintables can't, so special case the textures */
+  if (GDK_IS_TEXTURE (paintable))
+    g_value_init (&value, GDK_TYPE_TEXTURE);
+  else
+    g_value_init (&value, GDK_TYPE_PAINTABLE);
   g_value_set_object (&value, paintable);
   gdk_clipboard_set_value (clipboard, &value);
   g_value_unset (&value);