rem: case 4 : zoom(widget, (gpointer)ZOOM_IN);
add: case 4 : zoom(widget, (gpointer)ZOOM_IN_CMOUSE);
context: button_press_event (GtkWidget *widget, GdkEventButton *event){    switch (event->button) {    case 1 :	screen.state = MOVE;	screen.last_x = widget->allocation.height - event->x;	screen.last_y = widget->allocation.width  - event->y;	break;    case 2 :	/* And now, some Veribest-like mouse commands for	   all us who dislike scroll wheels ;) */	if((event->state & GDK_SHIFT_MASK) != 0) {	    /* Middle button + shift == zoom in */	    zoom(widget, (gpointer)ZOOM_IN);	} else {	    /* Only middle button == zoom out */	    zoom(widget, (gpointer)ZOOM_OUT);	}	break;    case 3 :	/* Add color selection code here? */	break;    case 4 : 	zoom(widget, (gpointer)ZOOM_IN);	break;    case 5 : 	zoom(widget, (gpointer)ZOOM_OUT);	break;    default:    }        return TRUE;} /* button_press_event */