Java Window Management library

Vision

JWM is a cross-platform Java window management and OS integration library.

JWM aims to expose an interface that abstracts over window creation, input handling and OS integration. It’s planned to support all the primary desktop platforms:

• Windows
• macOS
• X11
• Wayland

Primary goals:

• Native JVM API
• High-quality OS integration (indistinguishable from native apps)
• Plays well with (but does not require) Skija

Motto: “Electron for JVM, without Chrome and JS”

Comparison to other UI/window libraries

Traditionally, Java UIs struggled with high-quality OS integration. JWM plans to bring it to modern standards by implementing those integrations from scratch in modern low-level OS-native APIs. Prior art:

AWT:

• Bullet-proof, works everywhere
• Event loop is two-threaded (lags in UI)
• Dated font management, color management, dpi management
• No vsync

JavaFX:

• Fixed threading model
• Performance is sometimes great, sometimes terrible
• Even more limited fonts/color/graphics API
• VSync is weird in multi-monitor case
• No real extensibility

Winit:

• Tried at JetBrains
• Complicated event loop model (tries to unify desktop + web + mobile)
• https://github.com/rust-windowing/winit/blob/master/FEATURES.md

GLFW via LWJGL, SDL2:

• Game-oriented
• Bad window management
• No OS integration
• Create one window and go full-screen is the main use-case

Electron:

• Seems great, will use as inspiration
• https://www.electronjs.org/docs

Dependency

Repository URL:

https://packages.jetbrains.team/maven/p/jwm/maven

Artifacts:

Platform	groupId	artifactId	version
macOS Intel	org.jetbrains.jwm	jwm-macos-x64
macOS M1	org.jetbrains.jwm	jwm-macos-arm64
Linux	org.jetbrains.jwm	jwm-linux-x64
Windows	org.jetbrains.jwm	jwm-windows-x64

Getting started

See Getting Started

Status

Alpha. Expect API breakages.

App

	Windows	macOS	X11
init	✅	✅	✅
makeWindow	✅	#121	✅
start	✅	✅	✅
getScreens	✅	✅	✅
getPrimaryScreen	✅	✅	✅
runOnUIThread	✅	✅	#113
terminate	✅	✅	✅
Show notification	❌	❌	❌
System Theme	❌	❌	❌

Window

	Windows	macOS	X11
setEventListener	✅	✅	✅
setTextInputClient	✅	✅	✅
setTextInputEnabled	✅	❌	❌
unmarkText	✅	❌	❌
show	✅	✅	✅
getWindowRect	✅	✅	#109
getContentRect	✅	✅	✅
setWindowPosition	✅	✅	✅
setWindowSize	✅	✅	#109
setContentSize	✅	✅	✅
getScreen	✅	✅	✅
requestFrame	✅	✅	#113
close	✅	#107	✅
minimize	✅	✅	✅
maximize	✅	✅	✅
restore	✅	✅	✅
setTitle	✅	✅	✅
setIcon	✅	✅	#95
Set system cursor	✅	✅	#99
Remove decorations	#75	#75	#75
Set custom cursor	❌	❌	❌
openFile	❌	❌	❌
openFolder	❌	❌	❌
Transparency	✅	❌	❌
Toggle Fullscreen	❌	❌	❌
setMinimumSize	❌	❌	❌
setMaximumSize	❌	❌	❌
setResizable	❌	❌	❌

Events

	Windows	macOS	X11
EventFrame	✅	✅	✅
EventKey	#30	#30 #87	#30
EventMouseButton	✅	✅	✅
EventMouseMove	✅	✅	✅
EventMouseScroll	#115	✅	#115
EventTextInput	✅	#105	✅
EventTextInputMarked	✅	✅	✅
EventWindowCloseRequest	✅	✅	✅
EventWindowMove	✅	#116	✅
EventWindowResize	✅	✅	✅
EventWindowMinimize	✅	✅	#96
EventWindowMaximize	✅	✅	#96
EventWindowRestore	✅	✅	#96
EventWindowVisible	#140	#140	#140
EventWindowScreenChange	#117	#117	#117
Drag & Drop	❌	❌	❌
Touch events	❌	❌	❌
Theme Changed	❌	❌	❌

Screen

	Windows	macOS	X11
id	✅	✅	✅
isPrimary	✅	✅	✅
bounds	✅	✅	✅
scale	✅	✅	✅
workArea	✅	✅	#119
colorSpace	#122	#122	#122

Clipboard

	Windows	macOS	X11
set	✅	#51	✅
get	✅	#51	✅
getFormats	✅	#51	✅
clear	✅	#51	✅
registerFormat	✅	#51	✅

Layers

	Windows	macOS	X11
Raster	✅	#81	✅
OpenGL	✅	✅	✅
DirectX 11	❌	➖	➖
DirectX 12	✅	➖	➖
Metal	➖	✅	➖
Vulkan	❌	➖	❌

Packaging

	Windows	macOS	X11
Run on GraalVM	❌	❌	❌
App package	❌	❌	❌

Building from source

Prerequisites:

• Shared: Git, CMake, Ninja, C++ compiler, JDK 11+, $JAVA_HOME, Python 3
• Windows 10: Microsoft Visual C++ (MSVC), x64 Native Tools Command Prompt for VS
• Ubuntu 20.04: libxcomposite-dev libxrandr-dev libgl1-mesa-dev libxi-dev libxcursor-dev

Run:

./script/build.py

Run examples:

./script/run.py

Run examples without building (use version from the table above):

./script/run.py --jwm-version <version>

Contributing

PRs & issue reports are welcome!

Please read Conventions first.

If you are looking where to start, there’s a label: Good first issue.

Issues labeled “Design” and “Not sure” require prior discussion—leave a comment with your ideas!

Authors

• Nikita Prokopov
• Egor Orachyov
• Alexey Titov
• Pavel Sergeev

Initial development sponsored by:

• JetBrains