[fpc-pascal] Mouse, scroll wheel support?

Tomas Hajny XHajT03 at hajny.biz
Wed Jun 29 11:55:54 CEST 2016

On Wed, June 29, 2016 11:04, Michalis Kamburelis wrote:
> 2016-06-28 15:05 GMT+02:00 John Youngquist <johnyq999 at gmail.com>:


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...


>> 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.
> 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_BUTTON_WHEELDOWN (this works without problems for me, trying on
> old jedi-sdl examples with FPC SDL units).
> Regards,
> Michalis

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