Project Lana EA build now available at - feedback requested.

Scott Palmer swpalmer at
Fri May 15 18:54:26 UTC 2020

Just tried this with NetBeans 12.0 Beta 4 using FlatLaf Dark.

MacBook Pro (Retina, 15-inch, Mid 2015)
Processor: 2.5 GHz Quad-Core Intel Core i7
Memory: 16 GB 1600 MHz DDR3
Graphics: AMD Radeon R9 M370X 2 GB
Intel Iris Pro 1536 MB

macOS Catalina Version 10.15.5 Beta (19F83c)

I added -J-Dsub.java2d.metal=true to the netbeans.conf file and the netbeans messages.log file confirms that option is present.

It seems to render most things correctly, I did not get black backgrounds on the toolbar and status bar as indicated on the download page, but what I noticed immediately is that it was very slow.  For example if I try to adjust the splitter between the project pane and the editors the rate of repainting was about 1fps.
Scrolling would start off unacceptably slow, then it seems to pick up the pace after scrolling around for a bit.

The scrolling performance has been reported already by Kevin as JDK-8238709 <>
The extremely slow performance adjust splitter positions I have reported as JDK-8245125 <>

Things were so slow the I wanted to confirm that it wasn’t something else.
I turned off the metal pipeline and tried again - everything was smooth.  
Then I switched metal back on and this second launch things were noticeably faster than the first launch.  However adjusting splitter positions was still noticeably slower that with the old pipeline. Scrolling would frequently freeze and then snap to the correct position to catch up.
Occasionally, while NetBeans was still running, the performance regressed to how it was on the first launch, 1 fps while adjusting splitter positions, even worse when resizing the window (the spinning beach-ball appeared several times).
I checked logs and, but didn’t notice any relevant messages.



> On May 14, 2020, at 6:20 PM, Philip Race <philip.race at> wrote:
> The first EA build of Project Lanai is available at
> This is a new Java2D graphics pipeline for macOS.
> It can run the usual client demos, such as SwingSet2 and J2Ddemo,
> and even a large app like an IDE, although not without glitches.
> The EA download page has a link to the list of known, open bugs you can consult.
> It is a first EA build and there is plenty of work still to be done
> and we have doubtless not tested every situation nor do we have
> every piece of mac hardware out there, so there will be unreported issues too.
> Please try it, and provide feedback to the lanai-dev at mailing list.
> Make sure you specify -Dsun.java2d.metal=true  !!
> -phil.

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