Index: trunk/src/event.h
===================================================================
--- trunk/src/event.h	(revision 23662)
+++ trunk/src/event.h	(revision 23663)
@@ -28,6 +28,7 @@
 #define PCB_EVENT_H
 #include "config.h"
 #include "unit.h"
+#include "global_typedefs.h"
 
 typedef enum {
 	PCB_EVENT_GUI_INIT,               /* finished initializing the GUI called right before the main loop of the GUI; args: (void) */
@@ -92,9 +93,8 @@
 	PCB_EVARG_ANGLE											/* format char: a */
 } pcb_event_argtype_t;
 
-
 /* An argument is its type and value */
-typedef struct {
+struct pcb_event_arg_s {
 	pcb_event_argtype_t type;
 	union {
 		int i;
@@ -104,7 +104,7 @@
 		pcb_coord_t c;
 		pcb_angle_t a;
 	} d;
-} pcb_event_arg_t;
+};
 
 /* Initialize the event system */
 void pcb_events_init(void);
Index: trunk/src/global_typedefs.h
===================================================================
--- trunk/src/global_typedefs.h	(revision 23662)
+++ trunk/src/global_typedefs.h	(revision 23663)
@@ -76,6 +76,8 @@
 
 typedef struct pcb_hid_dad_subdialog_s pcb_hid_dad_subdialog_t;
 
+typedef struct pcb_event_arg_s pcb_event_arg_t;
+
 #include "pcb_bool.h"
 
 #include "unit.h"
Index: trunk/src/hid_dad.h
===================================================================
--- trunk/src/hid_dad.h	(revision 23662)
+++ trunk/src/hid_dad.h	(revision 23663)
@@ -32,6 +32,7 @@
 #include "compat_misc.h"
 #include "hid_attrib.h"
 #include "pcb-printf.h"
+#include "global_typedefs.h"
 
 
 /*** Helpers for building dynamic attribute dialogs (DAD) ***/
@@ -594,7 +595,18 @@
 
 /* sub-dialogs e.g. for the file selector dialog */
 struct pcb_hid_dad_subdialog_s {
+	/* filled in by the sub-dialog's creator */
 	PCB_DAD_DECL_NOINIT(dlg)
+
+	/* filled in by the parent dialog's code, the subdialog's code should
+	   call this to query/change properties of the parent dialog. cmd and
+	   argc/argv are all specific to the given dialog. Returns 0 on success,
+	   return payload may be placed in res (if it is not NULL). Parent poke:
+	     close()                   - cancel/close the dialog */
+	int (*parent_poke)(pcb_hid_dad_subdialog_t *sub, const char *cmd, pcb_event_arg_t *res, int argc, pcb_event_arg_t *argv[]);
+
+	void *parent_ctx; /* used by the parent dialog code */
+	void *sub_ctx;    /* used by the sub-dialog's creator */
 };
 
 #endif