<AWT Dev> [7u6] Review request for 7159266: [macosx] ApplicationDelegate should not be set in the headless mode

Anthony Petrov anthony.petrov at oracle.com
Thu Apr 5 08:23:00 PDT 2012

On 04/05/12 19:07, Mike Swingler wrote:
>> Please review a fix for http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7159266 at:
>> http://cr.openjdk.java.net/~anthony/7u6-4-fxHang-7159266.0/
>> With this fix we avoid setting an application delegate when AWT is started in the headless mode. This prevents a hang when another GUI toolkit (e.g. JavaFX) is already running in the same Java process.
> This would logically mean that you won't get eAWT events (file open, quit, etc) while started in this mode. Does this impact SWT as well?

In the headless mode an application doesn't have any UI, and as such 
there's no way to generate e.g. a Quit action. Hence the application 
delegate isn't necessary in this mode.

SWT uses a special "SWT mode" (== -XstartOnFirstThread) which is 
different from the headless mode. In the SWT mode the delegate will 
still be installed.

I think this may not work in case of running an SWT application together 
with the AWT in headless mode. However, I can't imagine who might want 
to run SWT/AWT in such configuration because the headless mode is 
supposed to be primarily used in server environments where a display is 
physically unavailable, in which case SWT wouldn't be able to run there 

best regards,

More information about the awt-dev mailing list