TimeRail

A visual code history plugin for IntelliJ IDEA — browse your full branching edit history as a tree and restore any past state with one click.

What it does

TimeRail runs quietly in the background while you code. Every time your caret moves to a new line and you make an edit, it automatically captures a full screenshot of your editor and saves a complete snapshot of the file at that moment.

When you want to review your history, click Open to bring up a translucent overlay panel showing an interactive tree diagram of all your snapshots. Each card shows a live visual preview of the editor at that point in time. Click any card to instantly restore your file to that exact state — and if you keep coding after restoring, TimeRail automatically opens a new branch from that point rather than overwriting the original timeline.

Features

• Automatic snapshot capture — triggered by line changes, not every keystroke (200ms debounce)
• Branching history tree — restoring a past snapshot spawns a new branch, so no history is ever lost
• Visual tree UI — translucent overlay panel with a horizontal tree diagram rendered inside IntelliJ
• Editor screenshots — each node displays a rendered preview of the editor at capture time
• Zoom — + / - / 1x buttons in the title bar to zoom the tree in and out
• One-click restore — click any snapshot to rewrite the file back to that state; panel closes automatically
• Lightweight controls — Start / Stop / Clear / Open from a sidebar tool window

Demo

Tech Stack

• Kotlin
• IntelliJ Platform SDK
• Gradle (Kotlin DSL)
• Swing / JBPopup — custom-painted tree canvas with Scrollable interface for reliable zoomed scrolling

Getting Started

1. Clone the repo
2. Open in IntelliJ IDEA
3. Run the Gradle runIde task to launch a sandboxed IDE with the plugin loaded
4. Open any file, click Start Recording in the TimeRail tool window, and start coding
5. Click Open to view your branching history tree

./gradlew runIde

Requires Java 21. If you have multiple JDKs installed:

export JAVA_HOME=$(/usr/libexec/java_home -v 21)
./gradlew runIde

Project Structure

src/
└── main/
    ├── kotlin/com/timerail/timerail/
    │   └── TimeRailToolWindowFactory.kt   # Core plugin logic
    └── resources/META-INF/
        ├── plugin.xml                     # Plugin registration
        └── pluginIcon.svg                 # Plugin icon

Author

Dexter (Yulin) Peng Computer Science, University of Minnesota Twin Cities GitHub