From: Edward Diener (eddielee_at_[hidden])
Date: 2004-08-18 19:35:34
Reece Dunn wrote:
> John Torjo wrote:
>> Hi Reece,
>>> [3] The support for events via "listeners". This will most likely be
>>> geared towards key/mouse events and "action" events (e.g. when the
>>> user presses on a button).
>>
>> I'm not a big fan of listeners. You need to do a lot of coding
>> manually to set them, etc. I've implemented them totally different -
>> using event handler classes.
>
> My idea was something along the lines of:
>
> class MouseEvent
> {
> public:
> static const int LeftButton = 0;
> static const int MiddleButton = 1;
> static const int RightButton = 2;
> private:
> int button;
> unsigned int vkeys;
> win::api::point pt;
> public:
> inline MouseEvent( int, WPARAM, LPARAM );
> };
>
> MouseEvent::MouseEvent( int btn, WPARAM wp, LPARAM lp ):
> button( btn ),
> vkey( wp ),
> pt( lp )
> {
> }
>
> class MouseListener
> {
> public:
> virtual void mouseMove(
> const MouseEvent & );
> virtual void mouseButtonDown(
> const MouseEvent & );
> virtual void mouseButtonUp(
> const MouseEvent & );
> virtual void
> mouseButtonDoubleClick( const MouseEvent & );
> public:
> virtual ~MouseButtonListener();
> };
>
> With a common listener interface for GUI object actions, e.g.
> pressing a mouse button, selecting an item in a listbox, editing
> text, etc.
Why not use boost::signals for your event interface. It is much better than
hand-coded actions and listeners, since any type of function can handle an
event. The technology is already in Boost so why re-invent the wheel.