Index: order.h
===================================================================
--- order.h	(revision 36885)
+++ order.h	(revision 36886)
@@ -35,13 +35,16 @@
 
 typedef struct pcb_order_field_s pcb_order_field_t;
 
-typedef struct{
+typedef struct  order_ctx_s  order_ctx_t;
+
+struct order_ctx_s {
 	RND_DAD_DECL_NOINIT(dlg)
 	int active; /* already open - allow only one instance */
 	vtp0_t names;
 	int wtab; /* widgets */
 	void *odata;                                   /* implementation-specific data of the current order */
-} order_ctx_t;
+	void (*field_change_cb)(order_ctx_t *octx, pcb_order_field_t *f) /* called after a field has been changed from the GUI */
+};
 
 /* order implementation - registered by an order plugin */
 typedef struct pcb_order_imp_s pcb_order_imp_t;
Index: order_dlg.c
===================================================================
--- order_dlg.c	(revision 36885)
+++ order_dlg.c	(revision 36886)
@@ -74,6 +74,12 @@
 	return imp->wid2field(imp, octx, wid);
 }
 
+static void cb_notify(order_ctx_t *octx, pcb_order_field_t *f)
+{
+	if (octx->field_change_cb != NULL)
+		octx->field_change_cb(octx, f);
+}
+
 static void pcb_order_enum_chg_cb(void *hid_ctx, void *caller_data, rnd_hid_attribute_t *attr_btn)
 {
 	order_ctx_t *octx = caller_data;
@@ -83,6 +89,7 @@
 		return;
 	}
 	f->val.lng = attr_btn->val.lng;
+	cb_notify(octx, f);
 }
 
 static void pcb_order_int_chg_cb(void *hid_ctx, void *caller_data, rnd_hid_attribute_t *attr_btn)
@@ -94,6 +101,7 @@
 		return;
 	}
 	f->val.lng = attr_btn->val.lng;
+	cb_notify(octx, f);
 }
 
 static void pcb_order_coord_chg_cb(void *hid_ctx, void *caller_data, rnd_hid_attribute_t *attr_btn)
@@ -105,6 +113,7 @@
 		return;
 	}
 	f->val.crd = attr_btn->val.crd;
+	cb_notify(octx, f);
 }
 
 static void pcb_order_str_chg_cb(void *hid_ctx, void *caller_data, rnd_hid_attribute_t *attr_btn)
@@ -117,6 +126,7 @@
 	}
 	free(f->val.str);
 	f->val.str = rnd_strdup(attr_btn->val.str);
+	cb_notify(octx, f);
 }