The fix for 6730447 (Support for high resolution mouse wheel is still incomplete. AWT panel needs to be supported) is to have the counter per HW component to accumulate the mouse wheel messages. The fix works OK for the testcase attached to the bug report 6730447. Nevertheless, having the counter per HW component isn't enough to be 100% compatible with native applications on Windows. The results of experiments with native applications (Notepad) - we need to reset the counter based on focus transfer. That is, given buttons A and B:

- button A is focus owner, mousewheel moves incrementally in A
- move focus out of A into B
- button B is focus owner, mousewheel moves incrementally in B
- move focus out of B into A
- button A is focus owner, mousewheel moves incrementally in A

We don't want to record the total movement in B as the movement in A+B. So we would have to keep separate counts. We don't want to add the wheel movements in both the first and second times in A; these should be considered separate motions. So we need to reset the counter to 0 when the focus left A or re-entered A. If A and B are HW components - it works OK. But if A and B are LW components from the same HW component - the counter will be shared between the LW components.