[A5] Mouse cursor changig when holding down mouse button problem

no-reply@allegro.cc (mickwa) — Mon, 20 Feb 2012 00:47:48 +0000

Hi,

I want to change mouse cursor on press and release mouse button events. When I press and hold mouse button, ALLEGRO_EVENT_MOUSE_BUTTON_DOWN event occurres, I get "grab cursor set" message in console, but cursor remains unchanged until I release the button. I don't know why it works like that, I expected that the cursor will change when I press and hold button. Am I missing something? Thank for help.

#SelectExpand
  1#include 
  2#include 
  3#include 
  4#include 
  5using std::cout;
  6using std::endl;
  7
  8int main(int argc, char **argv)
  9{
if(!al_init()) {
  return -1;
}
al_init_image_addon();
al_init_primitives_addon();
   
ALLEGRO_DISPLAY *display = NULL;
 17
display = al_create_display(555,567);
al_install_mouse();
 
ALLEGRO_MOUSE_CURSOR *freeCursor = NULL;
ALLEGRO_MOUSE_CURSOR *grabCursor = NULL;
 
ALLEGRO_BITMAP *freeBmp = al_load_bitmap("handCursor.bmp");
ALLEGRO_BITMAP *grabBmp = al_load_bitmap("handCursorGrab.bmp");

freeCursor = al_create_mouse_cursor(freeBmp,5,5);
grabCursor = al_create_mouse_cursor(grabBmp,5,5);

ALLEGRO_EVENT_QUEUE *mouseEvents = NULL;
mouseEvents = al_create_event_queue();
al_register_event_source(mouseEvents, al_get_mouse_event_source());
ALLEGRO_EVENT button;
bool cursorChange1= false,cursorChange2=false;
al_show_mouse_cursor(display);
cout<<"start"<<endl;

while(1)
{   
  al_wait_for_event(mouseEvents,&button);
 
  switch (button.type)
  {
    case ALLEGRO_EVENT_MOUSE_BUTTON_DOWN  :
    {
      cursorChange2 = al_set_mouse_cursor(display,grabCursor);
      if (cursorChange2)
        cout<<"grabCursor set"<<endl;
      else
        cout<<"failed to set grabCursor"<<endl;
    
      al_rest(3); // for testing
      break;
    }
 55
    case ALLEGRO_EVENT_MOUSE_BUTTON_UP  :
    {
      cursorChange1 = al_set_mouse_cursor(display,freeCursor);
      if (cursorChange1)
        cout<<"freeCursor set"<<endl;
      else
        cout<<"failed to set freeCursor"<<endl;
      break;
    }   
  }
}
return 0;
 68}

no-reply@allegro.cc (Peter Wang) — Mon, 20 Feb 2012 03:43:39 +0000

What operating system? I believe in Windows the cursor wouldn't change until you moved the mouse following the al_set_mouse_cursor call.

no-reply@allegro.cc (mickwa) — Mon, 20 Feb 2012 04:18:24 +0000

It is Windows 7 32bit. Moving mouse does not solve the problem. When I add hiding and showing cursor like this it works fine.

#SelectExpand
 1cursorChange2 = al_set_mouse_cursor(display,grabCursor);
 2al_hide_mouse_cursor(display);
 3al_show_mouse_cursor(display);

But I still don't understand why this code in my first post does not change cursor.

no-reply@allegro.cc (Peter Wang) — Mon, 20 Feb 2012 17:31:35 +0000

Could well be a bug in Allegro.

no-reply@allegro.cc (mickwa) — Tue, 21 Feb 2012 23:04:45 +0000

Maybe it is a bug. Can this post be moved to Allegro Development? I would be very thankful if someone could reply.

no-reply@allegro.cc (Thomas Fjellstrom) — Tue, 21 Feb 2012 23:25:32 +0000

mickwa said:

Maybe it is a bug. Can this post be moved to Allegro Development? I would be very thankful if someone could reply.

Someone did Peter is our defacto "Dear" leader.

no-reply@allegro.cc (mickwa) — Wed, 22 Feb 2012 15:20:59 +0000

Hi Peter, hi Thomas
Thanks for Your support.
I have tested this code on Ubuntu and it works different. On Ubuntu I don't have to release mouse button to change cursor.