hex_viewer

Zero-dependency hexadecimal viewer widget for Flutter with advanced features:

• Zero dependencies - only Flutter SDK
• Virtualized scrolling - handles files of any size
• Byte selection - click to select, Shift+click to extend
• Copy support - hex, text, or binary format
• Configurable grouping - 4-4-4-4, 8-8, or no grouping
• Color coding - different colors for null bytes, ASCII, control chars
• Dark/light themes - automatic theme adaptation
• Keyboard support - Shift+click for range selection

Installation

Add this to your pubspec.yaml:

dependencies:
  hex_viewer: ^0.2.0

Then run:

flutter pub get

Quick Start

import 'package:hex_viewer/hex_viewer.dart';

// Simple usage
HexViewer(
  data: myBinaryData, // List<int>
)

// With configuration
HexViewer(
  data: myBinaryData,
  config: HexConfig(
    bytesPerLine: 16,
    groupSize: 8,
    colorScheme: ByteColorScheme.fromTheme(Theme.of(context)),
  ),
  onSelectionChanged: (selection) {
    print('Selected: ${selection?.length} bytes');
  },
)

Features

Byte Selection

• Click a byte to select it
• Shift+click to extend selection
• Selection info displayed in status bar

Copy to Clipboard

• Hex format: 48 65 6C 6C 6F
• Text format: Hello (with · for non-printable)
• Binary format: Raw bytes as string

Byte Grouping

• None: 48 65 6C 6C 6F 20 57 6F 72 6C 64
• 4-4-4-4: 48656C6C | 6F20576F | 726C64
• 8-8: 48 65 6C 6C 6F 20 57 6F | 72 6C 64

Color Coding

• Null bytes (0x00): Gray
• Printable ASCII (0x20-0x7E): Normal color
• Control chars (0x01-0x1F): Red
• Extended ASCII (0x80+): Blue

API

HexViewer

Parameter	Type	Description
data	List<int>	Binary data to display (required)
config	HexConfig	Display configuration
onSelectionChanged	ValueChanged<ByteSelection?>?	Selection callback
monospaceFontFamily	String?	Custom monospace font

HexConfig

Parameter	Type	Default	Description
bytesPerLine	int	16	Bytes per row (8, 16, or 32)
groupSize	int	8	Group separator (0, 4, or 8)
showOffset	bool	true	Show offset column
showAscii	bool	true	Show ASCII column
enableSelection	bool	true	Enable byte selection
enableCopy	bool	true	Enable copy to clipboard
colorScheme	ByteColorScheme	standard	Color scheme

Example Output

| OFFSET   | 00 01 02 03 04 05 06 07 | 08 09 0A 0B 0C 0D 0E 0F | ASCII            |
| -------- | ----------------------- | ----------------------- | ---------------- |
| 00000000 | 48 65 6C 6C 6F 20 57 6F | 72 6C 64 21 0A 00 00 00 | Hello World!···· |
| 00000010 | 54 68 69 73 20 69 73 20 | 62 69 6E 61 72 79 00 00 | This is binary·· |

License

See LICENSE file.