Simple Drawing App in Java

This is a simple drawing application developed as part of a college assignment. The app demonstrates core Java concepts including ArrayLists, exception handling, mouse listeners, and key object-oriented principles such as Encapsulation, Association, Inheritance, and Polymorphism.

Features:

• Draw Shapes: The app allows users to draw two types of shapes: Squares and Circles. These shapes inherit from a common superclass, allowing easy management of their properties and behavior.

• Shape Customization: Users can configure the shape's color, size, and location before drawing. The app offers two modes for specifying the location:

  • Manual Input: The user specifies the position via fields.
  • Mouse Interaction: The user can click or drag on the canvas to place the shape.

• Dynamic Drawing: Once the user presses the Draw button, the shape is rendered on the canvas. Switching between Squares and Circles dynamically updates the drawing mode.

• Undo Functionality: Shapes can be removed from the canvas using the Undraw button. Each click of this button removes the most recently drawn shape, and the entire canvas is redrawn to reflect the changes.

• Error Handling: Robust error handling ensures that the application remains stable. Possible user errors, such as non-numeric input or out-of-range values for color, are caught and displayed in a user-friendly error label. The label provides:

  • The field that caused the error.
  • The type of error (e.g., out of range, non-numeric).

  When no errors are present, the label resets to a friendly "No Errors" message.

Key Concepts and Techniques:

• Inheritance & Polymorphism: Both the Square and Circle classes inherit from a common superclass (e.g., GeometricObject), allowing for shared functionality and dynamic shape behavior.
• ArrayLists: All drawn shapes are stored in an ArrayList, allowing users to undo their actions.
• Mouse Listeners: The app handles mouse clicks and drag events to place and draw shapes on the canvas.
• Exception Handling: Input validation ensures the app does not crash, with clear error messages for users.

Getting Started:

1. Clone the repository to your local machine.
2. Open the project in IntelliJ IDEA (Community Edition).
3. Make sure to use Java Version 15 (Liberica JDK 15) or higher.
4. Run the application and start drawing!

Screenshots:

Requirements:

• Java Version 15 (Liberica JDK 15) or higher
• IntelliJ IDEA (Community Edition)

License:

This project is licensed under the MIT License - see the LICENSE file for details.