Intercepting mouse events in windows

Question

Well the title seems pretty clear about what I want to do. More precisely: I want to create a program (c++ or java is preferred) that manipulates the mouse in two ways, like: changing its position and doing clicks. I was thinking about using allegro (it has mouse routines to manipulate the things cited above) or sdl(which I don't know if has that kind of routine). I tried with allegro nsuccessfully. My problem here was that I couldn`t virtually "do" clicks. I also couldn't redirect the stuff changed by my program to some other window.

Any tips?

Answer 1

There are a couple of ways to try automating other applications on Windows...

At the simplest level, one can use PostMessage to post keyboard and mouse messages to another application's windows. This has the advantage that it could work even if the other application is minimized. Unfortunately, this approach skips the majority of the input processing logic so applications that directly access key state using GetAsyncKeyState will not see (for example) the control key being 'down' no matter how many WM_KEYDOWN, vk=VK_CONTROL messages you send.

As Hans Passant commented, SendImput places input events in a lower level input event queue, and so can fully simulate modifier keys. These input events are not posted to windows however, so to get the input events delivered successfully the normal windows rules of activation and focus need to be followed. That said, this is the approach used by most testing-automation software (and is why most testing automation software requires the application being tested be the active application).

The last of the automation methods Ill mention - and sadly the least likley to work - is the Microsoft UI Automation framework. This framework is intended to allow applications to be used by disabled and/or special needs users. Sadly - very few software providers bother to implement this API in their products.