Core/EventArguments

Custom event argument classes for hex editor events.

📁 Contents

• ByteEventArgs.cs - Byte modification event data
  • Carries: Modified byte, position, action type
  • Used by: ByteModified event
  • Enables: Undo/redo tracking
  • Contains: Old value, new value, byte position
• ByteDifferenceEventArgs.cs - File comparison event data
  • Carries: List of byte differences between two files
  • Used by: File comparison features
  • Contains: Position list, difference count, color info
  • Enables: Highlighting of differences in UI
• CustomBackgroundBlockEventArgs.cs - Highlighting event data
  • Carries: Custom background block information
  • Used by: Syntax highlighting, search results
  • Contains: Start position, length, color
  • Enables: Visual markers and annotations

🎯 Purpose

These custom EventArgs classes provide strongly-typed event data for hex editor operations. They follow the standard .NET event pattern: EventHandler<TEventArgs>.

🔗 Event Flow

User Action
    ↓
HexEditor Operation
    ↓
Event Raised with EventArgs
    ↓
Subscribers Notified
    ↓
UI Update / Service Processing

🎓 Usage Example

ByteEventArgs:

// In HexEditor.xaml.cs
public event EventHandler<ByteEventArgs> ByteModified;

private void ModifyByte(long position, byte newValue, byte oldValue)
{
    // Perform modification
    _provider.AddByteModified(position, newValue, oldValue);

    // Raise event with custom args
    ByteModified?.Invoke(this, new ByteEventArgs
    {
        Position = position,
        NewValue = newValue,
        OldValue = oldValue,
        Action = ByteAction.Modified
    });
}

// Subscriber
hexEditor.ByteModified += (sender, e) =>
{
    Console.WriteLine($"Byte at {e.Position:X} changed: {e.OldValue:X2} → {e.NewValue:X2}");
};

ByteDifferenceEventArgs:

// After comparing two files
public event EventHandler<ByteDifferenceEventArgs> DifferencesFound;

private void CompareFiles(byte[] file1, byte[] file2)
{
    var differences = new List<long>();

    for (long i = 0; i < Math.Min(file1.Length, file2.Length); i++)
    {
        if (file1[i] != file2[i])
            differences.Add(i);
    }

    // Raise event with differences
    DifferencesFound?.Invoke(this, new ByteDifferenceEventArgs
    {
        Differences = differences,
        TotalCount = differences.Count
    });
}

CustomBackgroundBlockEventArgs:

// Highlight search results
public event EventHandler<CustomBackgroundBlockEventArgs> AddCustomBackgroundBlock;

private void HighlightSearchResults(long position, long length)
{
    AddCustomBackgroundBlock?.Invoke(this, new CustomBackgroundBlockEventArgs
    {
        StartPosition = position,
        Length = length,
        Color = Colors.Yellow
    });
}

📋 Event Patterns

All event args follow .NET conventions:

• Inherit from EventArgs
• Contain read-only properties
• Immutable after construction
• Used with EventHandler<T> delegate

🔔 Events Using These Args

ByteEventArgs:

• ByteModified - When a byte is changed
• ByteInserted - When bytes are inserted
• ByteDeleted - When bytes are deleted

ByteDifferenceEventArgs:

• DifferencesFound - After file comparison
• ComparisonComplete - Comparison finished

CustomBackgroundBlockEventArgs:

• AddCustomBackgroundBlock - Add visual marker
• RemoveCustomBackgroundBlock - Remove marker
• ClearAllCustomBackgroundBlocks - Clear all markers

✨ Features

• Type Safety: Strongly-typed event data
• Immutability: Properties set at construction
• Extensibility: Easy to add new properties
• Standard Pattern: Follows .NET conventions
• IntelliSense Friendly: Full code completion support

📚 Related Components

• HexEditor.xaml.cs - Raises these events
• ByteModified.cs - Data model for byte changes
• ByteDifference.cs - Data model for differences
• CustomBackgroundService - Uses CustomBackgroundBlockEventArgs

🎨 Design Pattern

// Standard event pattern
public class SomeEventArgs : EventArgs
{
    public SomeType SomeProperty { get; init; }
    public OtherType OtherProperty { get; init; }
}

// Usage
public event EventHandler<SomeEventArgs> SomeEvent;

protected virtual void OnSomeEvent(SomeEventArgs e) =>
    SomeEvent?.Invoke(this, e);

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✨ Strongly-typed event argument classes for hex editor events