<Swing Dev> [9] Review Request: 8147994 [macosx] JScrollPane jitters up/down during trackpad scrolling on MacOS/Aqua

[Alexey Ivanov]

Hi Sergey,

The fix looks good.

Could you please make the frame disappear when the test completes?

Regards,
Alexey

On 15.02.2016 20:35, Sergey Bylokhov wrote:
> Hello.
>
> Please review the fix for jdk9. It will be backported to jdk8.
>
> This fix is a rework of the fix for JDK-8033000:
> http://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/c2acbd0292f3
> https://bugs.openjdk.java.net/browse/JDK-8033000
>
> After the fix for JDK-8033000 all our L&F have the next wheel logic:
>   1 If shift is not pressed and vertical scroll bar is visible it 
> should be scrolled.
>   2 If vertical scroll-bar is invisible then we should scroll 
> horizontal scroll bar if possible.
>   3 If shift is pressed and horizontal scroll-bar is visible it should 
> be scrolled, but if it is not visible then we should try vertical 
> scroll-bar.
>
> Note that the step 3 was added in the JDK-8033000. This caused an 
> issue which previously was reproduced in Aqua L&F only. When the user 
> uses diagonal scroll(top+right) and the application has only vertical 
> scroll-bar, then we try to scroll in opposite directions:
> - the top move generates the scroll down.
> - scroll to the right generate the wheel+shift, and since the 
> horizontal scroll-bar is not visible-> scroll up is executed.
>
> In the fix the logic of step 3 is changed:
>   3 If shift is pressed and horizontal scroll-bar is visible it should 
> be scrolled, otherwise do nothing.
>
> Testcase for JDK-8033000 is updated.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8147994
> Webrev can be found at: 
> http://cr.openjdk.java.net/~serb/8147994/webrev.01
>