Click on JavaFX (Java 1.0.8-b123, VM 25.0-b70) on ARM

Question

I programmed the application in Oracles NetBeans for deployment on a raspberry Pi. The program itself works great with Runtime, as indicated in the title. To be precise, I have jdk-8-oracle-arm-vfp-hflt .

However, when I touch the screen, the following message is displayed in the console:

July 29, 2015 10:11:56 PM com.sun.glass.ui.lens.LensApplication nativeEventLoop
SEVERE: 4998 udevInput.c: 1596 lens_input_pointerEvents_handleSync: rejected multi touch event - ignore

Ive already read that there was a problem with the Lens base, and it’s better to use Monocle, but I can’t figure out how to enable Monocle and Drop Lens in NetBeans . (I am new to Java.)

Do you have an idea to solve this problem? I want to use multi-touch later if possible.

Answer 1

I have the same issue on my Hanns-G touchscreen RPI2, which works fine in X but not in a JavaFX application.

As you said, I tried using a monocle instead of a lens. This in itself is quite clogging. There are no ready-made and ready-made Monocle-Jars on the Internet. The only thing I find is the "headless" version, which works on my PI:

http://mvnrepository.com/artifact/org.jfxtras/openjfx-monocle/1.8.0_20

While starting my JavaFX application with this monocle:

java -Dglass.platform=Monocle -Dmonocle.platform=Headless -Dprism.order=sw -jar myJar.jar 

I am triggering and not creating these distorted multitouch events anymore. Disadvantage: the graphical interface is not displayed because it is "headless". Not so funny ...

Monocle also works with headless mode (with the launch of the GUI). But it seems that you need to build it yourself, as described here:

https://wiki.openjdk.java.net/display/OpenJFX/Monocle

Here my luck ceased. I have too few linux skills to build on my own. I started generosity, so hopefully an experienced person will help us ... Good luck! I also have a friend who has the same setup as me, and he claims to have touch access to JavaFX applications. He will show me soon. I'll keep you posted.

Answer 2

I finally got a job !!! Unfortunately, I can’t put together my Bounty :-) The solution to this problem in my environment was:

Just run the application using sudo:

 sudo java -jar myApp.jar 

The device driver for my touchscreen seems to need access to some files, etc., accessible only by root or with the sudo command. Give it a try!