Given the uncertainty of the structure of high school this fall, I’ve been exploring various options my students in AP Computer Science A if they are learning outside of the classroom without access to our desktops. In the classroom, APCSA students use BlueJ and GitHub throughout the year and leverage Swing and third-party frameworks (i.e., media computation). All students have chromebooks and our district works with families if they don’t have wifi at home. During eLearning and Remote Learning during this past spring semester, we used repl.it as our programming environment. This sufficed given the programming activities and labs at that point in the semester, but it wasn’t ideal. It remains an option for the fall, and I’ll expand upon it later. The options that I explored may not be a good fit for your students, but I hope others find this information helpful.

VS Code

Most of my Software Engineering students use VS Code. I was able to get it running on our chromebooks (Acer Chromebook with x86_64 architecture).

Installation

• enable Linux via Chromebook Settings app
• download VS Code
• in the Chrome OS Files app, drag VS Code from the Downloads folder to the “Linux Files” folder.
• Install VS Code from the Linux VM by running:
  • sudo apt install ./code_1.45.1-1589445302_amd64.deb
• VS Code will now be available from the App Launcher
• install Java Extension Pack in VS Code
  • disable IntelliSense support
  • disable Maven support
• use JDK 11
  • add the following to /etc/apt/sources.list:
    • deb http://deb.debian.org/debian stretch-backports main
  • sudo apt update
  • sudo apt install openjdk-11-jdk
• configure GitHub
  • install GitHub Pull Request and Issues VS Code extension
  • set user name and email address from terminal
    • git config --global user.name “<name>"
    • git config --global user.email <email>
  • clone a repository
  • resolve issues authenticating
    • sudo apt install gnome-keyring
    • specify a password for the keychain

Configuration

• With BlueJ, jar files are automatically included in a project if they reside in a “+libs” folder. VS Code has a similar feature if the jar files are in a “lib” folder.
• With BlueJ, one can directly run any static method in any class. VS Code expects a standard main method to be defined.

Issues

• initial authorization of VS Code to use GitHub fails
  • second authorization of VS Code to use GitHub works if you copy and paste the authentication URL back into VS Code
• key chain didn’t work on a clean install, but did after a clean restart

Tradeoffs

Pros

• GitHub accessible
• debugger

Cons

• more sophisticated an IDE than desired for APCSA students
• requires enabling Linux on chromebook

BlueJ

APCSA students have always used BlueJ as their IDE. It was a good balance of features and simplicity as it is designed for educational settings.

Installation

• enable Linux via Chromebook Settings app
• install BlueJ
  • note that this is not the latest version of BlueJ as that requires Buster which is not running on our chromebooks
• install OpenJDK and JFX
  • sudo apt-get install openjdk-8-jdk
  • sudo apt-get install libopenjfx-java
• install BlueJ
  • sudo dpkg -i BlueJ-linux-414.deb
• BlueJ will now be available from the App Launcher

Issues (updated 16jul2020)

• windows are often opened in a default position such that its upper-left corner is positioned at the center of the screen which is annoying
• windows are often a single pixel which makes BlueJ unusable
  • workaround from BlueJ folks:
    • sudo apt-get install xdotool
    • xdotool search —class “BlueJ” windowsize %@ 800 600
    • incorporate the use of xdotool into a daemon that constantly monitors new BlueJ windows and resizes them

Tradeoffs (updated 16jul2020)

Pros

• IDE designed for education
• debugger
• GitHub support (integration via Team feature expects a one-to-one mapping between BlueJ projects and repositories, which is different than our model, but doable)

Cons

• requires enabling Linux on chromebook

repl.it

Students who have taken Computer Programming 1 and 2 before APCSA are familiar with repl.it as it is used extensively in those classes. As mentioned above, APCSA students used repl.it last spring during Remote Learning. However, I wanted a better experience if we use repl.it again this fall.

The GitHub and repl.it integration works best when the repository contains a single project. Historically, we have created a repository for each unit and that repository contains multiple practice programming projects and a summative lab. Forcing our repository model into repl.it requires some additional configuration.

Configuration

• GitHub Classroom now supports online IDEs (e.g., repl.it)
  • however, Classroom doesn’t support Java Swing at the moment
  • so, create the .replit file explicitly and add to the repo
  • still select repl.it as the online IDE when creating the Classroom assignment but don’t specify a language or a run command
• example .replit file
  • language = "java_swing"
  • run = "javac -classpath ./TurtleDemo:./TurtleDemo/+libs/* ./TurtleDemo/TurtleDemo.java; java -classpath ./TurtleDemo:./TurtleDemo/+libs/* TurtleDemo"
  • # specify additional run commands for each project but have them commented out
  • # run = "javac -classpath ./ClassNotes ./ClassNotes/SyntaxErrors.java; java -classpath ./ClassNotes SyntaxErrors"
  • [...]
  • # run = "javac -classpath ./TurtleLab:./TurtleLab/+libs/* ./TurtleLab/TurtleLab.java; java -classpath ./TurtleLab:./TurtleLab/+libs/* TurtleLab"

Tradeoffs

Pros

• GitHub support

Cons

• students have to edit .replit file when switching between activities
• no debugger

Which option will we pursue if we end up in a remote learning scenario? I’m not entirely sure. If I can convince our IT department to enable Linux on the chromebooks of those students enrolled in APCSA (quite likely as they are incredibly supportive), I think we will use BlueJ for APCSA and VS Code for Software Engineering. I need to further test the viability of a daemon that handles the BlueJ window size issue. (updated 16jul2020)

While exploring these options, I realized that there is an opportunity here even if students are in class with our desktops. While the programming activities and labs are designed so that everyone can complete them during class, some students, for a variety of reasons, need time outside of class. Enabling one or more of these options would provide all students the flexibility to program on their chromebook instead of relying on a Windows/macOS/Linux computer at home or working in the classroom before school.