cs1302-code-visualizer

This project automates the creation of images that visualize a Java program's state. It also provides a Python interface for doing this.

Code	Output
public class Main { public static void main(String[] args) { Person alice = new Person("Alice", 42); } } record Person(String name, int age) { };

Usage

You should have the uv package manager installed. This program gets source code input from standard input and outputs image data to standard output. You should use shell input/output redirection.

$ uv run render_image < In.java > out.png

To view the execution trace fora program, use the generate_trace program (see generate_trace --help for available options):

$ uv run generate_trace < In.java > trace.json

To render a visualization using an existing execution trace for a Java program, use the generate_visualization program (see generate_visualization --help for available options):

$ uv run generate_visualization < trace.java > out.png

To see a list of available breakpoints (i.e., breakpoint line numbers) for Java program, use the list_breakpoints program (see list_breakpoints --help for available options):

$ uv run list_breakpoints < In.java

Usage information for the Python interface is provided as docstrings throughout the package.

Project overview

This project has three major components: the trace generator, the frontend, the browser driver.

The trace generator is essentially a Python wrapper around a Java tracer program. It:

• downloads and installs both the tracer (uses the URL given in pyproject.toml if one is given, otherwise falls back to the latest release) and the latest release of the JDK
• executes the tracer on the input code
• returns the output of the tracer

The frontend is a lightly modified version of OnlinePythonTutor. It is a web page that takes the trace generated by the Java tracer and turns it into a visualization.

The browser driver creates a headless Chrome browser process using Selenium, loads the frontend with the trace, and then takes a screenshot of the visualization created by the frontend.

When making a new release, make sure that the version of the tracer program that you want to use is specified in the tool.cs1302-code-visualizer object of pyproject.toml.