gre.add_event_listener(
event,
target,
callback
)
Add an event listener that will invoke a callback with the standard mapargs table as its first argument. The target option can be used to specify a model object to listen on, if it is not present the listener will be created at the application level.
Parameters: event The string name of the event to listen for target An optional parameter containing the fully qualified name of a model object to listen on callback A lua function that is invoked with mapargs as its first argument when the event fires Return: An integer that identifies the created listener or nil on failure. The identifier is required to remove the listener. Example:
-- Register a listener to log gre.press X coordinates on a layer to console
gre.add_event_listener("gre.press", "Layer", function(mapargs) gre.log(-1, "X: "..tostring(mapargs.context_event_data.x)) end)