On 9/25/2010 3:04 PM, Gwenio wrote:
I have been thinking about the design for event handlers, and have come up with the prototype:
class control_event_handler { public: enum events { // contains ids for events that can be stored with the "set" function }; template<class Func> control_event_handler(Func f) {f(*this);} // A function (object, pointer, or labanda) is passed to set the handlers. ~control_event_handler() {} template<class Func,events evt> void set(Func f); // Sets how to handle a specific type of event // Functions calling handlers go here private: // How the the function data is stored goes here }; A reference to an event handler object would be passed on the creation of each window or control. The intent is something like the vtable used for finding the function to call for virtual classes, only providing more flexablity in regard to reusing a function is for multiple handlers. Additional capabilities would be added for the release version such as copy function(s) (something like those for locales would be good) to make creating similar handlers.
I still have not determind how to store the data for event handlers, but it will likely be a series of function containers from one of the Boost libraries. I am not familiar enough with the function object libraries of Boost to really know which would be the best to use. Anyone care to provide an opinion about which would be best to use?
An event handler needs to be multi-cast, which means using boost::signals internally. Anything less is the same old limitation which inadequate GUI and component libraries always seem to settle upon for some hideous reason.