XWayland server provides limited capabilities for X11 desktop applications (see X11 Application Support and JDK-8269245). In order to get full support of the desktop features, we need to implement a pure Wayland client toolkit for java. Wayland architecture in many ways differs from X11, so we cannot reuse XAWT even for basic capabilities. The new toolkit should be implemented from scratch. Here are some major chunks of work:
Event handling
Dispatch native events on EDT, to avoid potential race conditions when the state is updated both from EDT and toolkit thread. See the full proposal here
Graphics devices support
Onscreen/offscreen Wayland surface management
Adopt OGL pipeline for rendering on Wayland surfaces
Implement a new rendering pipeline based on Vulkan (for better performance)
java.awt.Robot
Sending input events
Reading screen data (at least current java application windows)
Client-side decorations for windows
Swing internal frames rendering code can be reused
The prototype implementation of the pure Wayland toolkit (JDK-8281970) based on OpneJDK 21 source base can be found in the Wakefield repository (jdk21.0.1-wayland branch). It has two rendering pipelines:
java -Dawt.toolkit.name=WLToolkit -Dsun.java2d.vulkan=True J2Ddemo.jar
Here is an updated build instruction for building jdk21.0.1-wayland branch (on ubunu 24.04):
$ sudo wget -qO- https://packages.lunarg.com/lunarg-signing-key-pub.asc | tee /etc/apt/trusted.gpg.d/lunarg.asc
$ sudo wget -qO /etc/apt/sources.list.d/lunarg-vulkan-noble.list https://packages.lunarg.com/vulkan/lunarg-vulkan-noble.list
$ sudo apt update
$ sudo apt-get -y install openjdk-21-jdk file zip unzip autoconf make build-essential libx11-dev libxext-dev libxrender-dev \
libxtst-dev libxt-dev libxrandr-dev libcups2-dev libfontconfig1-dev libasound2-dev libwayland-dev \
libxkbcommon-x11-0 vulkan-sdk vulkan-utility-libraries-dev
$ sh configure --with-vulkan
$ make images