Is there a non Lazarus means of accessing the mouse, and scroll wheel? I have an app that uses some old driver which doesn't address the wheel. I'm trying to make the wheel work. I have tried SDL and the demo code works but it seems to work only in an externally created window. I can't find any documentation for it nor can I post on the forum.

Thanks JY

2016-06-28 15:05 GMT+02:00 John Youngquist :

Accessing events like mouse and keyboard always requires to use some API. It may be high-level API like Lazarus LCL or SDL (or my TCastleWindow), it may be lower-level like GTK, or WinAPI, or even Xlib. For all these APIs, the exact answer "how to read mouse wheel events" is different:)

In most of them, you can only read mouse events that reach windows that you yourself created (windows for which you have a "handle" or some equivalent). If you want to get mouse wheel events that occur above *any* window --- you may be out of luck (or you may be able to use some hack in the lowest-level APIs, like WinAPI or Xlib, but I can't help you more here).

For SDL, the way to read mouse wheel is to

- either use https://wiki.libsdl.org/SDL_MouseWheelEvent (but it seems SDL_MOUSEWHEEL is not translated in FPC SDL headers, neither in original jedi-sdl headers),

- or you can watch for event types SDL_MOUSEBUTTONDOWN , SDL_MOUSEBUTTONUP with button set to SDL_BUTTON_WHEELUP or SDL_BUTTON_WHEELDOWN (this works without problems for me, trying on old jedi-sdl examples with FPC SDL units).

Regards,
Michalis

Michalis Kamburelis wrote

2016-06-28 15:05 GMT+02:00 John Youngquist :

Hello,

Apparently, the original poster forgot to mention that he wasn't subscribed to the list and thus he might not see responses to his question
- adding him in Cc: of the response below now...

Tomas