Index: trunk/src/data.c
===================================================================
--- trunk/src/data.c	(revision 29890)
+++ trunk/src/data.c	(revision 29891)
@@ -325,10 +325,8 @@
 void pcb_data_set_layer_parents(pcb_data_t *data)
 {
 	pcb_layer_id_t n;
-	for(n = 0; n < PCB_MAX_LAYER; n++) {
-		data->Layer[n].parent.data = data;
-		data->Layer[n].parent_type = PCB_PARENT_DATA;
-	}
+	for(n = 0; n < PCB_MAX_LAYER; n++)
+		pcb_layer_setup(&data->Layer[n], data);
 }
 
 void pcb_data_bind_board_layers(pcb_board_t *pcb, pcb_data_t *data, int share_rtrees)
Index: trunk/src/event.c
===================================================================
--- trunk/src/event.c	(revision 29890)
+++ trunk/src/event.c	(revision 29891)
@@ -47,7 +47,8 @@
 	"pcbev_rubber_constrain_main_line",
 	"pcbev_draw_crosshair_chatt",
 	"pcbev_drc_run",
-	"pcbev_net_indicate_short"
+	"pcbev_net_indicate_short",
+	"pcbev_layer_key_change"
 };
 
 void pcb_event_init_app(void)
Index: trunk/src/event.h
===================================================================
--- trunk/src/event.h	(revision 29890)
+++ trunk/src/event.h	(revision 29891)
@@ -57,6 +57,8 @@
 
 	PCB_EVENT_NET_INDICATE_SHORT,         /* called by core to get a shortcircuit indicated (e.g. by mincut). Args: (pcb_net_t *net, pcb_any_obj_t *offending_term, pcb_net_t *offending_net, int *handled, int *cancel) - if *handled is non-zero, the short is already indicated; if *cancel is non-zero the whole process is cancelled, no more advanced short checking should take place in this session */
 
+	PCB_EVENT_LAYER_KEY_CHANGE,           /* called by core if a pcb-rnd::key::* attribute on a layer changes */
+
 	PCB_EVENT_last                        /* not a real event */
 };
 
Index: trunk/src/layer.c
===================================================================
--- trunk/src/layer.c	(revision 29890)
+++ trunk/src/layer.c	(revision 29891)
@@ -127,6 +127,13 @@
 }
 
 
+static void layer_post_change(pcb_attribute_list_t *list, const char *name, const char *value)
+{
+	if (strncmp(name, "pcb-rnd::key::", 14) == 0)
+		pcb_event(&PCB->hidlib, PCB_EVENT_LAYER_KEY_CHANGE, NULL);
+}
+
+
 #define UFC(f) ((void (*)(void *))(f))
 void pcb_layer_free_fields(pcb_layer_t *layer, pcb_bool undoable)
 {
@@ -158,6 +165,7 @@
 	}
 	free((char *)layer->name);
 	memset(layer, 0, sizeof(pcb_layer_t));
+	layer->Attributes.post_change = layer_post_change;
 }
 
 pcb_bool pcb_layer_is_pure_empty(pcb_layer_t *layer)
@@ -489,6 +497,7 @@
 			free((char *)pcb->Data->Layer[n].name);
 		pcb->Data->Layer[n].name = pcb_strdup("<pcb_layers_reset>");
 		pcb->Data->Layer[n].meta.real.grp = -1;
+		pcb->Data->Layer[n].Attributes.post_change = layer_post_change;
 	}
 
 	/* reset layer groups */
@@ -506,6 +515,7 @@
 {
 	memset(dst, 0, sizeof(pcb_layer_t));
 	dst->meta.real.grp = -1;
+	dst->Attributes.post_change = layer_post_change;
 }
 
 static void pcb_layer_undoable_created(pcb_board_t *pcb, pcb_layer_t *l);
@@ -537,6 +547,7 @@
 	pcb->Data->Layer[id].parent_type = PCB_PARENT_DATA;
 	pcb->Data->Layer[id].parent.data = pcb->Data;
 	pcb->Data->Layer[id].type = PCB_OBJ_LAYER;
+	pcb->Data->Layer[id].Attributes.post_change = layer_post_change;
 
 	if (pcb == PCB)
 		pcb_board_set_changed_flag(1);
@@ -748,6 +759,14 @@
 	return &conf_core.appearance.color.layer[idx % clrs];
 }
 
+void pcb_layer_setup(pcb_layer_t *ly, pcb_data_t *parent_data)
+{
+	ly->Attributes.post_change = layer_post_change;
+	ly->parent.data = parent_data;
+	ly->parent_type = PCB_PARENT_DATA;
+	ly->type = PCB_OBJ_LAYER;
+}
+
 /* Initialize a new layer with safe initial values */
 static void layer_init(pcb_board_t *pcb, pcb_layer_t *lp, pcb_layer_id_t idx, pcb_layergrp_id_t gid, pcb_data_t *parent)
 {
@@ -764,9 +783,7 @@
 			default: break;
 		}
 	}
-	lp->parent.data = parent;
-	lp->parent_type = PCB_PARENT_DATA;
-	lp->type = PCB_OBJ_LAYER;
+	pcb_layer_setup(lp, parent);
 }
 
 static pcb_layer_t *pcb_layer_move_append_(pcb_board_t *pcb, pcb_layer_id_t new_index, pcb_layergrp_id_t new_in_grp)
Index: trunk/src/layer.h
===================================================================
--- trunk/src/layer.h	(revision 29890)
+++ trunk/src/layer.h	(revision 29891)
@@ -272,6 +272,9 @@
 
 /**** layer creation (for load/import code) ****/
 
+/* Set parent and attribute change callback */
+void pcb_layer_setup(pcb_layer_t *ly, pcb_data_t *parent_data);
+
 /* Reset layers and layer groups to empty */
 void pcb_layers_reset(pcb_board_t *pcb);