javascript-app-wrapper

An executable JAR which can be run as a desktop app

• UI is JavaScript/HTML/CSS running in JavaFX WebView window (Webkit JS engine)
• Javascript worker threads for processor intensive work and system calls (Nashorn JS engine)
• Small Kotlin program linking UI and workers
• Dev mode to watch JavaScript/HTML/CSS and reload app on changes
• Firebug lite example for debugging UI

Quick start

• Make sure you have Java JRE installed so you can run executable JAR files (I used JDK 9 to test)
• Download release javascript-app-wrapper-0.0.1.jar
• Double-click the jar to run the demo app:

• Click "Log" to log a message to the Firebug console

• Click "Work" to do some work in a background thread. Click it a few times and watch your CPU go to 75% for a while.

• Exit the demo then extract the demo app files:

  C:\test>java -jar javascript-app-wrapper-0.0.1.jar unpackage
  Created: web\worker.js
  Created: web\ui.js
  Created: web\ui.html
  Created: web\ui.css
  

• Run the app from the command line in "dev" mode

  C:\test>java -jar javascript-app-wrapper-0.0.1.jar
  Nov. 23, 2017 8:08:07 PM tornadofx.Stylesheet$Companion detectAndInstallUrlHandler
  INFO: Installing CSS url handler, since it was not picked up automatically
  In dev mode. Watching C:\test\web
  

• Make some changes:

  • In the web folder edit ui.css and change the background to brown.
  • Edit ui.html and change the header to <h1>My Custom App!</h1>
  • Remove the debug lines from ui.html:

    <!-- Show debug tools -->
    <script type='text/javascript' src='http://getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js'></script>
    

  • Notice that the app reloads as each change is saved:

  

• Exit the modified app package the changes into a new executable jar:

  C:\test>java -jar javascript-app-wrapper-0.0.1.jar package MyCustomApp.jar
  Deleted: /web/worker.js
  Deleted: /web/ui.js
  Deleted: /web/ui.html
  Deleted: /web/ui.css
  Added: web/ui.css
  Added: web/ui.html
  Added: web/ui.js
  Added: web/worker.js
  Packaged: MyCustomApp.jar
  

• Double-click MyCustomApp.jar to run the customised code

Build and run from source

 ./gradlew clean shadowJar
 java -jar build/libs/javascript-app-wrapper-all.jar

To test dev mode unpack first...

java -jar build/libs/javascript-app-wrapper-all.jar unpackage

...then rebuild and run

./gradlew shadowJar && java -jar build/libs/javascript-app-wrapper-all.jar