4.2: slow responsiveness of GUI while using the NVDA screen reader

With FlashFXP 4.2.0.1730 under Windows 7 X64, I get very slow responsiveness while using the arrow keys or tab/shift+tab to navigate the interface using the NVDA screen reader.
This works correctly in 4.1.8.1701.

To reproduce this, you'll need the NVDA screen reader from http://nvda-project.org.
With NVDA running, launch FlashFXP. Accept the evaluation dialog if it appears, and you should land in the list of local files.
Press the down and up arrows to move through the files, and there is a large delay before NVDA reads the file information. Tab through the interface, and the delay is still there.

If the same steps are repeated with 4.1.8.1701, the delay is gone.

Hello,

Thank you for your bug report.

I am seeing the delay you reported, however I am not sure what is causing the delay.

Until today I have never used NVDA, so I am very unfamiliar with this software, Perhaps the NVDA developers might be able to assist and provide us with some possible reasons for the delay and how to address it.

Using my rather limited windows programming knowledge to debug this, my first observation is that your message loop seems considerably slower in 4.2.
Sending 100 messages to the list view control, we get:
4.1.8.1701: 0-16MS over repeated tries - some of this is most likely GetTickCount() overhead.
4.2.0.1730: around 1900MS for 100 messages.

I don't know how the internals of the windows accessibility APIs pass messages back to the screen reader, but this is the first thing I thought to try.

Please try this updated development build and let me know if it resolves the problem for you

download

Unzip the FlashFXP.exe into your FlashFXP program folder overwriting the existing FlashFXP.exe

So far, it's working great. I was able to download a file without any problems, and the interface is responsive again.
Thanks!

This issue is now resolved and is available for download as a beta update via live update from within FlashFXP.