Fixing Gray Window screen, Java configuration error, window resize error

In this case, (Java) can be seen in this documentation article.

Gray window, applications not resizing with WM, menus immediately closing

The standard Java GUI toolkit has a hard-coded list of “non-reparenting” window managers. If using one that is not on that list, there can be some problems with running some Java applications. One of the most common problems is “gray blobs”, when the Java application renders as a plain gray box instead of rendering the GUI. Another one might be menus responding to your click, but closing immediately.

There are several things that may help:

• See #Impersonate another window manager.
• For jre8-openjdk, set the _JAVA_AWT_WM_NONREPARENTING=1 environment variable.
• For later versions, set the AWT_TOOLKIT=MToolkit environment variable.
• For xmonad, use SetWMName. However, its effect may be canceled when also using XMonad.Hooks.EwmhDesktops. In this case, appending >> setWMName "LG3D" to the LogHook may help.

See [1] for more information.

System freezes when debugging JavaFX Applications

If your system freezes while debugging a JavaFX Application, you can try to supply the JVM option -Dsun.awt.disablegrab=true.

See https://bugs.java.com/bugdatabase/view_bug?bug_id=6714678

JavaFX’s MediaPlayer constructor throws an exception

Creating instance of MediaPlayer class from JavaFX’s sound modules might throw following exception (both Oracle JDK and OpenJDK)

... (i.e. FXMLLoader construction exceptions) ...
Caused by: MediaException: UNKNOWN : com.sun.media.jfxmedia.MediaException: Could not create player! : com.sun.media.jfxmedia.MediaException: Could not create player!
 at javafx.scene.media.MediaException.exceptionToMediaException(MediaException.java:146)
 at javafx.scene.media.MediaPlayer.init(MediaPlayer.java:511)
 at javafx.scene.media.MediaPlayer.<init>(MediaPlayer.java:414)
 at <constructor call>
...

which is a result of some incompatibilities of JavaFX with modern ffmpeg build delivered within Arch Linux repository.

Working solution is to install **ffmpeg-compat-55**AUR.

See https://www.reddit.com/r/archlinux/comments/70o8o6/using_a_javafx_mediaplayer_in_arch/

Java applications cannot open external links

If a Java application is not able to open a link to, for example, your web browser, install gvfs. This is required by the Desktop.Action.BROWSE method. See [2]

Error initializing QuantumRenderer: no suitable pipeline found

Possible issues / solutions:

• GTK2 is missing. Install gtk2
• OpenJFX is missing. Install **java-openjfx**AUR