Using the Mouse

#include "graphapp.h"

void mouse_click(drawing d, int buttons, point p)
{  
  if (buttons & LeftButton)
    setcolour(Red);
  else if (buttons & MiddleButton)
    setcolour(Green);
  else if (buttons & RightButton)
    setcolour(Blue);

  drawpoint(p);
}

void main(void)
{
  window w;
  drawing d;

  w = newwindow("Dots", rect(50,50,200,200),
                StandardWindow);
  d = newdrawing(rect(10,10,180,180), NULL);
  setbackground(w, LightGrey);

  setmousedown(d, mouse_click);
  setmousedrag(d, mouse_click);

  show(w);
  mainloop();
}

• Source code: dots.c