<AWT Dev> <Awt Dev> [9] Review Request for 8022057: JFileChooser blocks EDT in Win32ShellFolder2.getIcon

[Semyon Sadetsky]

Hello,

Please review fix for JDK9:

bug: https://bugs.openjdk.java.net/browse/JDK-8022057
webrev: http://cr.openjdk.java.net/~ssadetsky/8022057/webrev.00/

The full story can be found in the jira's comments and NetBeans tracker 
(https://netbeans.org/bugzilla/show_bug.cgi?id=188001).
It seems the bug proposes to change the design of the AWT shell support 
on Windows platform. But instead I tried to eliminate the user 
experience issue it can be a good step to improve the situation.
The user experience issue is the JFileChooser spontaneous delays caused 
by getIcon(): I could not reproduce this under Win7 and jdk8/9. But I 
found in MSDN that ExtractIcon Win32 API call can take significant 
amount of time in some cases. Mostly when the file is an executable or a 
link and its icon is not cached yet.
MS propose a way how to avoid that: use asynchronous flag GIL_ASYNC with 
GetIconLocation call which then may return E_PENDING which means 
consequent ExtractIcon call can take time. There are several ways to 
handle E_PENDING return I propose just to use the default icon for the 
file which can be obtained with GIL_DEFAULTICON flag and should be much 
faster. Since I cannot reproduce the issue I don't know how effective it 
will be.
Also in the fix I added possibility to get Windows-Libraries icons, 
which were not available before in the JFileChooser.

--Semyon