#17 Mouse droppings
The square mouse cursor can leave parts of itself
behind or refresh the screen to a dated image when
erasing itself.
To duplicate:
Pause lincity.
Call up a dialog box (e.g. the results dialog; press 'r')
Position the mouse at the very bottom of the OK button
and click the button.
Move the mouse very slightly to cause the square cursor
to be drawn.
Press the r button again.
Without moving the mouse, click the OK button again.
Now move the mouse out of that square.
Left behind is a remnant of the square cursor.
This happens because the square cursor is not drawn on
top of the dialog box and saves a drawback buffer
containing the green of that box. When the box is
removed the square cursor goes with it, but the system
still thinks its there. When the mouse is later moved
the square cursor is "erased", which draws the buffer
back where the cursor was. Only now, instead of the
outside edges of a module, it draws the green
background of the dialog box.
