<Swing Dev> Review request for JDK-8075084 JOptionPane.showMessageDialog causes JScrollBar to move

[Alexander Scherbatiy]

On 12/3/2015 11:08 AM, Rajeev Chamyal wrote:
>
> Hello Alexandr,
>
> Thanks for the review.
>
> When we open a JOption dialog from AdjustmentListener the scroll bar 
> arrow button is not receiving the mouse release event.
>
> As a result the JScrollBar: scrollTimer is not getting stopped and its 
> becoming a recursive call.
>

    I tried to run the BuggyDialog sample form the issue description 
with the suggested fix.
    I noticed a strange behavior when I press scroll down and click not 
on the JOptionPane OK button but on the close button.
    The scroll bar continues scrolling in this case.

    When a modal dialog is open it blocks others windows. Is it possible 
to check this event and stop the scroll timer in this case?

   Thanks,
   Alexandr.

> Regards,
>
> Rajeev Chamyal
>
> *From:*Alexandr Scherbatiy
> *Sent:* 02 December 2015 13:56
> *To:* Rajeev Chamyal; Sergey Bylokhov; Prasanta Sadhukhan; 
> swing-dev at openjdk.java.net
> *Subject:* Re: Review request for JDK-8075084 
> JOptionPane.showMessageDialog causes JScrollBar to move
>
> On 11/11/2015 7:47 AM, Rajeev Chamyal wrote:
>
>     Hello All,
>
>     Please review the following fix for Jdk9:
>
>       
>
>     Bug:https://bugs.openjdk.java.net/browse/JDK-8075084
>
>     Webrev:http://cr.openjdk.java.net/~rchamyal/8075084/webrev.00/
>     <http://cr.openjdk.java.net/%7Erchamyal/8075084/webrev.00/>
>
>     Issue: On running the sample program attached in bug JDK-8075084
>     user is expected to see a scrollbar and on clicking the scrollbar
>     tracker or scrollbar up/down arrow buttons a JOption dialog should
>     come once. The program works fine if scrollbar tracker is clicked
>     i.e. JOption dialog comes only once. But on clicking up/down arrow
>     buttons of scrollbar the JOption dialog keeps on coming repeatedly.
>
>     Cause: The mouse pressed event of scrollbar arrow buttons calls BasicScrollBarUI::scrollByUnit method which creates a property change event and calls scroll bar action listener which again calls BasicScrollBarUI::scrollByUnit. This is becoming a recursive call and causing the scrollbar slider to move repeatedly till it reaches the other end of scrollbar.
>
>    If I change the AdjustmentListener to not show the JOptionPane it 
> is called only one time.
>    What is the reason that showing JOptionPane causes that the 
> AdjustmentListener is called one more time?
>
>    Thanks,
>    Alexandr.
>
>
>       
>
>     Fix: Added checks in the BasicScrollBarUI action listener to stop the recursion.
>
>       
>
>     Regards,
>
>     Rajeev Chamyal
>