Index: trunk/src_plugins/lib_hid_common/zoompan.h
===================================================================
--- trunk/src_plugins/lib_hid_common/zoompan.h	(nonexistent)
+++ trunk/src_plugins/lib_hid_common/zoompan.h	(revision 29928)
@@ -0,0 +1,51 @@
+/*
+ *                            COPYRIGHT
+ *
+ *  pcb-rnd, interactive printed circuit board design
+ *  Copyright (C) 2020 Tibor 'Igor2' Palinkas
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  Contact:
+ *    Project page: http://repo.hu/projects/pcb-rnd
+ *    lead developer: http://repo.hu/projects/pcb-rnd/contact.html
+ *    mailing list: pcb-rnd (at) list.repo.hu (send "subscribe")
+ */
+
+/* Return error from an action if there's no GUI, or set result to 0
+   if there's GUI */
+#define PCB_GUI_NOGUI() \
+do { \
+	if ((pcb_gui == NULL) || (!pcb_gui->gui)) { \
+		PCB_ACT_IRES(1); \
+		return 0; \
+	} \
+	PCB_ACT_IRES(0); \
+} while(0)
+
+
+/* Core of the generic Zoom() action; the actual action needs to be
+   implemented by the application so it can extend it with things like
+   Zoom(Selected). */
+
+#define pcb_gui_acts_zoom \
+	"Zoom()\n" \
+	"Zoom([+|-|=]factor)\n" \
+	"Zoom(x1, y1, x2, y2)\n" \
+	"Zoom(?)\n" \
+	"Zoom(get)\n" \
+
+fgw_error_t pcb_gui_act_zoom(fgw_arg_t *res, int argc, fgw_arg_t *argv);
+
Index: trunk/src_plugins/lib_hid_pcbui/act.c
===================================================================
--- trunk/src_plugins/lib_hid_pcbui/act.c	(revision 29927)
+++ trunk/src_plugins/lib_hid_pcbui/act.c	(revision 29928)
@@ -44,15 +44,6 @@
 #include "util.h"
 #include "act.h"
 
-#define NOGUI() \
-do { \
-	if ((pcb_gui == NULL) || (!pcb_gui->gui)) { \
-		PCB_ACT_IRES(1); \
-		return 0; \
-	} \
-	PCB_ACT_IRES(0); \
-} while(0)
-
 const char pcb_acts_Zoom[] =
 	pcb_gui_acts_zoom
 	"Zoom(found|selected)\n";
@@ -60,7 +51,7 @@
 /* DOC: zoom.html */
 fgw_error_t pcb_act_Zoom(fgw_arg_t *res, int argc, fgw_arg_t *argv)
 {
-	NOGUI();
+	PCB_GUI_NOGUI();
 
 	if (argc == 2) {
 		const char *vp;
@@ -97,7 +88,7 @@
 	int mode;
 	pcb_coord_t x, y;
 
-	NOGUI();
+	PCB_GUI_NOGUI();
 
 	pcb_hid_get_coords("Click on a place to pan", &x, &y, 0);
 
@@ -114,7 +105,7 @@
 fgw_error_t pcb_act_Center(fgw_arg_t *res, int argc, fgw_arg_t *argv)
 {
 	pcb_coord_t x, y;
-	NOGUI();
+	PCB_GUI_NOGUI();
 
 	pcb_hid_get_coords("Click to center", &x, &y, 0);
 
@@ -168,7 +159,7 @@
 	pcb_coord_t x, y;
 	double xcent, ycent, xoffs, yoffs;
 
-	NOGUI();
+	PCB_GUI_NOGUI();
 
 	pcb_hid_get_coords("Click to center of flip", &x, &y, 0);
 
@@ -264,7 +255,7 @@
 /* DOC: command */
 fgw_error_t pcb_act_Command(fgw_arg_t *res, int argc, fgw_arg_t *argv)
 {
-	NOGUI();
+	PCB_GUI_NOGUI();
 	pcb_gui->open_command(pcb_gui);
 	PCB_ACT_IRES(0);
 	return 0;
@@ -283,7 +274,7 @@
 		CTX_OBJ_TYPE
 	} ctx_sens = CTX_NONE;
 
-	NOGUI();
+	PCB_GUI_NOGUI();
 
 	if (argc != 2 && argc != 3)
 		PCB_ACT_FAIL(Popup);