BITS Accessible Calculator

Overview

The BITS Accessible Calculator is a fully accessible, web-based calculator designed for everyone, including users with disabilities. It supports basic and advanced mathematical operations, persistent memory/variable storage, and a user-friendly interface that meets WCAG 2.2 AA guidelines. Built with only basic JavaScript, HTML, and CSS, it works on all major browsers and devices, including mobile and Safari.

Features

• Multiple Calculator Modes: Basic, Scientific, Programmer, Financial, Statistical, Unit Conversion, Date/Time, Hex/Binary, Matrix, Fraction, Scientific Constants
• Accessible UI: Keyboard navigation, screen reader support, focus indicators, ARIA attributes, skip links, and responsive design
• Memory & Variables: Store results in memory slots or named variables, recall, overwrite, clear, and rename
• History: Persistent, searchable, and exportable calculation history
• Copy & Paste: Dedicated buttons, clipboard history, and advanced session/memory copy/paste
• Formula Library: Save, manage, and insert reusable formulas/templates
• Smart Error Correction: Suggestions for common input mistakes
• Calculation Sharing: Share results via link, email, or social media
• Offline Support: Works offline using service workers
• Custom Mobile Keypad: Large, touch-friendly keypad for mobile users
• Scientific Constants: Quick access to constants (π, e, Avogadro, Planck, etc.)
• Expression Preview: Live preview of parsed expressions
• Multi-step Calculations: Display intermediate results
• Keyboard Shortcuts: Enter to calculate, Esc to clear, Ctrl+C to copy result, Ctrl+Z/Y for undo/redo
• Dark Mode: Toggle for improved accessibility and comfort
• Internationalization: Support for multiple languages
• Accessibility Testing: Integration and audit mode
• Speech Output: When enabled in the settings panel, calculation results are spoken aloud for accessibility
• Customizable Layouts & Themes: Personalize button layout and color themes
• Session Restore: Restore full calculator state after browser restart

Getting Started

1. Clone or Download

   • Download the repository or clone it using:

     git clone <repo-url>

2. Open in Browser
   • Open index.html in your preferred browser (Chrome, Firefox, Edge, Safari, etc.)
3. No Installation Required
   • All features work out of the box. No dependencies or build steps.

Usage

• Select Calculator Mode: Use the mode toggle buttons to switch between modes. Only one mode is visible at a time. The current mode is shown in the titlebar.
• Perform Calculations: Enter expressions using the input field or on-screen buttons. Use advanced functions and constants as needed.
• Memory & Variables: Store, recall, overwrite, clear, and rename memory slots or variables. All memory persists across sessions.
• History: View, search, and export your calculation history. Click history items to reuse results.
• Copy & Paste: Use dedicated buttons to copy results or paste clipboard contents. Copy/paste entire sessions or memory sets.
• Formula Library: Save frequently used formulas and insert them with one click.
• Error Correction: Receive suggestions for input mistakes in real time.
• Share Calculations: Share results via link, email, or social media.
• Offline & Mobile: Use the calculator offline and on mobile devices with a custom keypad.
• Accessibility: Navigate with keyboard, use screen readers, and benefit from high-contrast and focus indicators.
• Dark Mode & Themes: Toggle dark mode or customize the layout and colors.
• Speech Output: Enable speech output in the settings panel to have calculation results spoken aloud for accessibility.

Accessibility Highlights

• Fully keyboard navigable
• Screen reader support for all interactive elements
• ARIA attributes and landmarks
• Focus indicators for all controls
• Responsive design for desktop and mobile
• Accessible error messages and status updates
• Internationalization and language support
• Accessibility audit mode
• Input references preview and status via aria-describedby
• Searchable history with live filtering

Technical Details

• Tech Stack: HTML, CSS, JavaScript (no frameworks)
• Persistence: Uses browser localStorage for memory, history, last result, mode, templates, and clipboard history
• Clipboard: Uses native Clipboard API
• Offline: Service worker for offline support
• Compatibility: Works on all major browsers and devices
• No External Dependencies: All code is custom and self-contained

Contributing

Contributions are welcome! Please submit issues, feature requests, or pull requests to help improve the BITS Accessible Calculator.

License

This project is open source and available under the MIT License.

Contact

For questions, feedback, or accessibility support, please open an issue or contact the maintainers.