Binary Viewer

A cross-platform Flutter application for viewing and analyzing binary files with multiple data interpretation modes and advanced scrolling capabilities.

Why This Exists

I couldn't find any good binary viewers for macOS that looked as nice as the ones I was used to on Windows (like this Binary Viewer). The macOS options all seemed lacking in terms of modern UI and good user experience.

Most existing options were either:

• Command-line only (xxd, hexdump) - functional but not great for interactive analysis
• Ancient GUI applications with outdated interfaces
• Heavy-weight development tools that were overkill for simple binary viewing
• Cross-platform Java applications that felt foreign on macOS

I wanted something that felt native, looked modern, and provided the dual-pane analysis capabilities I was used to on Windows. Rather than compromise or constantly switch platforms for binary analysis work, I decided to build exactly what I wanted - a clean, fast, feature-rich binary viewer that works beautifully on macOS and can be easily shared across platforms.

This project represents the binary viewer I wish existed when I started looking for one.

Features

Core Functionality

• File Selection: Browse and open any binary file using the native file picker
• Multi-View Interface: Dual-pane view allowing different data interpretations simultaneously
• Real-time File Reading: Efficient isolate-based file reading with caching and throttling
• Cross-Platform: Supports Windows, macOS, Linux, iOS, Android, and Web

Data View Modes

• Hexadecimal: Traditional hex view with byte-by-byte representation
• ASCII: Text representation of printable characters
• Binary: Raw binary representation (0s and 1s)
• Integer: 32-bit signed integer interpretation
• Float: 32-bit floating-point interpretation
• Double: 64-bit floating-point interpretation

Endianness Support

• Little Endian: Intel/AMD standard byte ordering
• Big Endian: Network/SPARC standard byte ordering
• Independent endianness selection for each view pane

Advanced UI Features

• Dual-Pane Layout: Left and right views can display different data interpretations simultaneously
• Interactive Address Navigation: Click on any byte to see its absolute address
• Custom Scrollbars: Enhanced scrollbar implementation with asymmetric margin support
• Synchronized Horizontal Scrolling: Both header and content scroll together
• Theming Support: 12 built-in color themes (Light/Dark variants of Default, Blue, Green, Orange, Violet, Rose)
• Responsive Design: Adapts to different window sizes and orientations

Performance Optimizations

• Virtual Scrolling: Only renders visible rows for optimal performance with large files
• Isolate-Based File I/O: Non-blocking file operations using Dart isolates
• Intelligent Caching: Row-based caching with automatic cleanup
• Throttled Reading: Configurable read throttling to prevent UI freezing (40 reads/second)
• Debounced Updates: Smooth scrolling with optimized update frequency

Technical Architecture

Core Components

• Main Application (lib/main.dart): Primary UI and business logic
• Custom Scrollbar (lib/widgets/scrollview.dart): Enhanced RawScrollbar with asymmetric margin support
• Theme System: Dynamic theme switching with persistent preferences
• File Reader Isolate: Background file processing for non-blocking I/O

Key Technical Features

• Asymmetric Scrollbar Margins: Custom EdgeInsets support instead of Flutter's symmetric constraints
• Force Interactive Scrollbars: Override default interactivity rules for better UX
• Dual ScrollController System: Independent vertical and horizontal scroll management
• Memory-Efficient Row Building: On-demand row construction with viewport-based optimization

Getting Started

Prerequisites

• Flutter SDK (>=3.9.0-100.2.beta)
• Dart SDK
• Platform-specific development tools (for building native apps)

Installation

1. Clone the repository

   git clone <repository-url>
   cd binary_viewer
   

2. Install dependencies

   flutter pub get
   

3. Run the application

   flutter run
   

Building for Production

Desktop (Recommended)

flutter build macos   # Tested platform
flutter build windows # Untested but should work
flutter build linux   # Untested but should work

Web

flutter build web

Mobile (Not Recommended)

While technically possible to build for mobile, the UI is not optimized for touch interfaces:

flutter build ios  # Poor UX - not recommended
flutter build apk  # Poor UX - not recommended  

Note: This application is designed for desktop use with keyboard and mouse interaction. Mobile builds will have usability issues due to small touch targets and complex multi-pane layouts.

Usage

Basic Operations

1. Open a File: Use File → Open to select any binary file
2. Select View Mode: Choose interpretation mode from the dropdown (hex, ASCII, binary, etc.)
3. Choose Endianness: Select byte order interpretation (little/big endian)
4. Navigate: Scroll through the file or click on addresses for navigation
5. Switch Themes: Use Options → Theme to change the color scheme

View Modes Explained

• Hex View: Shows each byte as a two-digit hexadecimal number (00-FF)
• ASCII View: Displays printable characters (32-126) or dots for non-printable bytes
• Binary View: Shows each byte as 8 binary digits (00000000-11111111)
• Integer View: Interprets 4-byte chunks as signed 32-bit integers
• Float View: Interprets 4-byte chunks as IEEE 754 single-precision floats
• Double View: Interprets 8-byte chunks as IEEE 754 double-precision floats

Advanced Features

Address Navigation

• Click on any data element to see its absolute file address
• Addresses are displayed in hexadecimal format with 0x prefix
• Selected bytes are highlighted with a glowing border effect

Dual-Pane Analysis

• Left and right panes can show the same data in different formats
• Example: View hex on the left and ASCII interpretation on the right
• Independent endianness settings for each pane

Performance Tuning

The application automatically optimizes performance but you can adjust:

• maxReadsPerSecond: File read throttling (default: 40/sec)
• bufferRows: Viewport buffer size (default: 10 rows)
• Cache cleanup frequency based on scroll distance

Dependencies

Core Dependencies

• flutter: Framework
• file_picker: Native file selection dialogs
• shadcn_flutter: Modern UI components
• shared_preferences: Theme persistence
• provider: State management
• google_fonts: Typography

Development Dependencies

• flutter_test: Testing framework
• flutter_lints: Code quality linting

Architecture Details

Performance Considerations

The application is designed to handle large binary files efficiently:

• Lazy Loading: Only loads visible data chunks
• Memory Management: Automatic cache cleanup based on scroll distance
• Non-blocking I/O: File operations run in background isolates
• Viewport-based Rendering: Only renders visible rows plus buffer

Custom Scrollbar Implementation

The custom scrollbar widget extends Flutter's RawScrollbar with:

• EdgeInsets Support: Asymmetric margins (left≠right, top≠bottom)
• Force Interactive: Override default interactivity constraints
• Render Offset: Additional positioning control independent of margins
• Synchronized Scrolling: Coordinated horizontal and vertical scrollbars

Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feature-name
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin feature-name
5. Submit a pull request

Code Style

• Follow Flutter/Dart conventions
• Use meaningful variable names
• Comment complex algorithms
• Maintain performance considerations for large file handling

License

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

Platform Support

Platform	Status	Notes
macOS	✅ Tested	Fully tested, native file dialogs, optimal experience
Windows	⚠️ Untested	Should work, native file dialogs expected
Linux	⚠️ Untested	Should work, native file dialogs expected
Web	⚠️ Untested	Should work but with performance limitations
iOS	❌ Not Recommended	UI not optimized for mobile, poor UX expected
Android	❌ Not Recommended	UI not optimized for mobile, poor UX expected

Note: This application has only been tested on macOS, but there's no technical reason it shouldn't work on other desktop platforms. The UI is designed for desktop/laptop screens with mouse interaction and would provide a poor user experience on mobile devices due to small touch targets and complex multi-pane layout.

Performance Benchmarks

The application has been tested with files up to several GB in size:

• Small files (<1MB): Instant loading and scrolling
• Medium files (1MB-100MB): Smooth performance with minor loading delays
• Large files (100MB-1GB): Good performance with optimized memory usage
• Very large files (>1GB): Functional with slower initial loading

Memory usage scales with viewport size rather than file size due to the virtual scrolling implementation.