diff -r b25f54b51d76 -r d6baaa93f7be ui/gtk/button.c
--- a/ui/gtk/button.c	Sun Jul 13 11:02:45 2025 +0200
+++ b/ui/gtk/button.c	Sun Jul 13 11:38:27 2025 +0200
@@ -73,6 +73,7 @@
         event->callback = onclick;
         event->value = event_value;
         event->customdata = NULL;
+        event->customint = 0;
 
         g_signal_connect(
                 button,
@@ -113,6 +114,7 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.eventdata = NULL;
+    e.eventdatatype = 0;
     e.intval = event->value;
     e.set = ui_get_setop();
     event->callback(&e, event->userdata);
@@ -137,6 +139,7 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.eventdata = event->var->value;
+    e.eventdatatype = UI_EVENT_DATA_INTEGER_VALUE;
     e.intval = i->get(i);
     e.set = ui_get_setop();
     
@@ -149,6 +152,7 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.eventdata = NULL;
+    e.eventdatatype = 0;
     e.intval = gtk_toggle_button_get_active(widget);
     e.set = ui_get_setop();
     event->callback(&e, event->userdata);    
@@ -240,6 +244,7 @@
         event->callback = onchange;
         event->value = 0;
         event->customdata = NULL;
+        event->customint = 0;
         
         g_signal_connect(
                 widget,
@@ -260,6 +265,7 @@
         event->callback = NULL;
         event->value = enable_state;
         event->customdata = NULL;
+        event->customint = 0;
         
         g_signal_connect(
                 widget,
@@ -320,6 +326,7 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.eventdata = NULL;
+    e.eventdatatype = 0;
     e.intval = gtk_check_button_get_active(widget);
     e.set = ui_get_setop();
     event->callback(&e, event->userdata);    
@@ -391,6 +398,7 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.eventdata = NULL;
+    e.eventdatatype = 0;
     e.intval = RADIOBUTTON_GET_ACTIVE(widget);
     e.set = ui_get_setop();
     event->callback(&e, event->userdata);    
@@ -483,6 +491,7 @@
         event->callback = args->onchange;
         event->value = 0;
         event->customdata = NULL;
+        event->customint = 0;
         
         g_signal_connect(
                 rbutton,
@@ -510,6 +519,7 @@
     e.window = event->obj->window;
     e.document = event->obj->ctx->document;
     e.eventdata = NULL;
+    e.eventdatatype = 0;
     e.intval = i->get(i);
     
     ui_notify_evt(i->observers, &e);