functions interfering

hello, I'm relatively new to c++ so please bare with me. I'm trying to write a program where the mouse will start moving when a key is pressed then stop when the key is released. I thought I had it but the mouse keeps going after the key is released. I think it's because my mmx function calls itself and the kbHookProc function can't listens for the release but I don't know how to get around this. Can somebody help? I know about mouse keys but I'm working with someone with a disability and have some odd parameters. Here is my code

Code:

#define _WIN32_WINNT 0x0500
#include<windows.h>
using namespace std;

int xg=0,nmy,nmx,x,y;
POINT p;

int mmx() {
    
GetCursorPos(&p);
x=p.x+1;
y=p.y;

                  SetCursorPos(x, y);  
Sleep(300);
if (xg==1) mmx();
return 0;
}

LRESULT CALLBACK kbHookProc(int nCode, WPARAM wParam, LPARAM lParam) {
        if(lParam>0) {

xg=1; mmx(); } 
else {
     xg=0;
 
}
}

int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nShowCmd) {

   // Set mouse hook
   HHOOK mouseHook = SetWindowsHookEx(
                  WH_KEYBOARD,      /* Type of hook */
                  kbHookProc,    /* Hook process */
                  hInstance,        /* Instance */
                  0);

   // Wait for user to exit
   MessageBox(NULL, "Press OK to close.", "", MB_OK);
   return 0;
}

Hmm, I see what you mean. I know almost zero about Windows programming, but it seems to me that you have a few ways of solving that: the first is to the main function do the looping. For example, it could use something like

Code:

for(;;) {
    if(xg) mmx();
    Sleep(300);
}

That means, of course, that you wouldn't be able to call MessageBox(), but perhaps there's a version of the function that allows your main thread to continue executing.

Alternatively, you could try to register a callback function. Perhaps Windows has a mechanism to allow you to have mmx() called automatically after 300 ms. This may or may not exist.

You could also create another thread to do the movement, but that would really be overkill!

after a couple of day of trying to get this to work, I figured out all I had to do is this
return 0;
if (xg==1) mmx();

Originally Posted by dwks

Hmm, I see what you mean. I know almost zero about Windows programming, but it seems to me that you have a few ways of solving that: the first is to the main function do the looping. For example, it could use something like

Code:

for(;;) {
    if(xg) mmx();
    Sleep(300);
}

That means, of course, that you wouldn't be able to call MessageBox(), but perhaps there's a version of the function that allows your main thread to continue executing.

Alternatively, you could try to register a callback function. Perhaps Windows has a mechanism to allow you to have mmx() called automatically after 300 ms. This may or may not exist.

You could also create another thread to do the movement, but that would really be overkill!

So in other words, just remove the recursion altogether? Because putting some code after a return statement means that that code will never be executed. I suppose it works because kbHookProc() is called for repeated keyboard presses. Makes sense.

Glad you got it working.