in operators.py [0:0]
def add_event(self, event_type, message, long_message):
props = bpy.context.scene.meshgen_props
event = props.history.add()
event.type = event_type
if message:
event.content = message
if long_message:
lines = str(long_message).split("\n")
for line in lines:
self.log_text.write(line + "\n")