A sleek, dark-themed Java Swing code editor with robust Undo/Redo powered by the Memento Pattern.
You are building an online code editor that lets users write and edit code in real-time. It needs Undo and Redo functionality without exposing internal state or hogging memory.
- Dark Mode UI: Eye-friendly dark background with light-colored monospaced font.
- Memento-based History: Encapsulated state snapshots enable efficient undo/redo.
- Stack-based Navigation: Unlimited undo/redo operations via two history stacks.
- Fluent GUI Controls: Toolbar buttons for seamless user interaction.
Generate and paste UML diagram here.
The Memento Pattern provides the ability to restore an object to its previous state without exposing its internal structure. It involves three key participants:
-
Originator 🏭
- Holds the current state of the editor document (
String state). - Can create a Memento capturing its state and restore from it.
- Holds the current state of the editor document (
-
Memento 🎁
- A simple, immutable value object that stores the internal state snapshot.
- Does not expose its internals beyond what the Originator needs.
-
Caretaker 🤵
- Manages saving and retrieving Memento objects.
- Maintains two stacks: one for undo and one for redo history.
- Controls when to clear redo history to preserve correct behavior.
- On Every Edit: A new Memento is saved to the undo stack. The redo stack is cleared.
- Undo 🔙: Pop the top Memento from undo → push it to redo → restore the previous snapshot.
- Redo 🔜: Pop the top Memento from redo → restore it → push it back on undo.
- Encapsulation: The editor’s text content is never exposed; only the Originator knows its state.
# Clone the repo
git clone https://github.com/Tharindu714/Code-Editor-Memento.git
# Open in your favorite IDE
gradle run # or mvn compile exec:javaPull requests and issues are welcome! Feel free to improve docs, add features, or optimize performance.
This project is licensed under the MIT License. See LICENSE for details.