The project creates and patches Java to address the Linux caps-lock delay problems and attempt to fix them for Java UI applications. It does require you to also run the Github Linux CapsLock Delay Fixer fix if you haven't done so yet (I run it in a cron job).
There are many threads on the Internet on the subject. I personally an old typer that types very fast and uses Caps lock a lot to uppercase the first letter. The claim of please use shift to uppercase letters is not acceptible by me or by many others like myself who are used to this kind of typing ! :) This bug/feature in Linux causes typing of a word to appear like: HEllo instead of Hello. The workarounds in the market do solve the problem, however, for Java, UI apps such as IntelliJ still suffer from it.
Java uses XLib to open the keyboard via XGrabKeyboard and then pull events via XNextEvent and process it in the following classes:
XToolKit, XlibWrapper, XKeysym and generally in the sun.awt.X11 package.
In XKeysum.getKeysym Java looks on the key lock modifies and due to the Linux bug, it capitalizes the typed character
even when caps was released when it really shouldn't.
To address this, this project patches rt.jar in the Java JRE to fix the problem.
Ubuntu xorg caps lock delay bug 1376903
Github Linux CapsLock Delay Fixer
freedesktop.org bug report 27903
A patch done long time ago to Linux to enable the workarounds above
IntelliJ complaint regarding the issue
Compile using maven:
mvn compile install
Run your Java with additional VM options:
For example:
java -javaagent:/tmp/capsDelayPatcher.jar SomeClass
To make IntelliJ run with these VM options, you need to add the JavaAgent to the idea vm.options file, for example in my case:
/root/.IntelliJIdea2019.2/config/idea64.vmoptions
Custom IntelliJ IDEA VM options:
-javaagent:/mnt/nvme0n1p6/opt/Workspace/capsDelayPatch/target/capsDelayPatcher.jar -Xms128m -Xmx1946m -XX:ReservedCodeCacheSize=240m -XX:+UseConcMarkSweepGC -XX:SoftRefLRUPolicyMSPerMB=50 -ea -Dsun.io.useCanonCaches=false -Djava.net.preferIPv4Stack=true -XX:+HeapDumpOnOutOfMemoryError -XX:-OmitStackTraceInFastThrow -Dawt.useSystemAAFontSettings=lcd -Dsun.java2d.renderer=sun.java2d.marlin.MarlinRenderingEngine
Jordan Sheinfeld, [email protected]
Tested on Ubuntu 18.10
Tested on Java JDK 8, JDK 11
Tags: java, capslock, delay, swing, awt, ubuntu, linux, caps lock, kbd, keyboard