Oakrey.Applications.Terminals 2.0.3

Oakrey.Applications.Terminals

A .NET 10 WPF library for building terminal-like interfaces in MVVM applications. It provides command history, message management, reactive updates, file export, and built-in integration with Oakrey.Log and Oakrey.Telemetry.

Main features

• Command history - navigable history of submitted commands with duplicate deduplication and a configurable capacity (default 20 entries).
• Generic message collection - IMessageCollection<TMessage> backed by a ReplaySubject for reactive change notifications.
• Built-in message types - StringMessage and StringAndDirectionMessage (with Direction) ship out of the box; custom types require only implementing IMessage.
• Sorting and display settings - IMessageViewSettings controls sort order (OldestOnTop / NewestOnTop), displayed message count, and timestamp visibility.
• File export - SaveToFile command writes messages to a .txt file via a standard save dialog with a configurable file name prefix.
• Context menu integration - ContextCommands collection is data-bindable and ships with "Clear" and "Save to file" entries.
• Logging and telemetry - all commands and file operations are traced through Oakrey.Log and Oakrey.Telemetry automatically.

Architecture

classDiagram
    class IMessage {
        +DateTime Timestamp
    }
    class StringMessage {
        +string Message
        +DateTime Timestamp
    }
    class StringAndDirectionMessage {
        +string Message
        +Direction Direction
        +DateTime Timestamp
    }
    class IMessageCollection~TMessage~ {
        +List~TMessage~ Messages
        +AddMessage(TMessage)
        +ClearMessages()
        +Subscribe(IObserver)
    }
    class MessageCollection~TMessage~
    class IMessageViewSettings {
        +SortOrder SortOrder
        +int DisplayedMessages
        +bool ShowTimestamp
    }
    class HistoryViewModel {
        +string Command
        +IStringHistoryProvider History
        +AddCommandToHistory()
        +HistoryUp()
        +HistoryDown()
        +Export() string
    }
    class TerminalViewModel~TMessage~ {
        +ObservableCollection~TMessage~ Messages
        +ObservableCollection~TMessage~ TerminalMessages
        +ObservableCollection~ContextMenuForViewModel~ ContextCommands
        +ICommand SendCommand
        +ICommand ClearMessages
        +ICommand SaveToFile
        #DefaultCommand()*
        #TraceLine(TMessage)*
        +string FilePrefix*
    }

    IMessage <|.. StringMessage
    IMessage <|.. StringAndDirectionMessage
    IMessageCollection <|.. MessageCollection
    HistoryViewModel <|-- TerminalViewModel
    TerminalViewModel o-- IMessageCollection
    TerminalViewModel o-- IMessageViewSettings

Key types

Requirements

• .NET 10 (Windows)
• WPF (Windows Presentation Foundation)

Installation

NuGet Package Manager

Search for Oakrey.Applications.Terminals in Visual Studio under Tools > NuGet Package Manager > Manage NuGet Packages for Solution.

.NET CLI

dotnet add package Oakrey.Applications.Terminals

Package Manager Console

Install-Package Oakrey.Applications.Terminals

Configuration

Inject or create an IMessageViewSettings instance and pass it to your TerminalViewModel subclass:

MessageViewSettings settings = new()
{
    SortOrder = SortOrder.NewestOnTop,
    DisplayedMessages = 200,
    ShowTimestamp = true
};

Example usage

Implement TerminalViewModel<TMessage> to create a concrete terminal:

public sealed class MyTerminalViewModel : TerminalViewModel<StringMessage>
{
    public override string FilePrefix => "my-terminal";

    protected override string TraceLine(StringMessage message)
        => $"[{message.Timestamp:HH:mm:ss}] {message.Message}";

    protected override void DefaultCommand()
    {
        if (string.IsNullOrWhiteSpace(Command))
        {
            return;
        }
        devices.AddMessage(new StringMessage(Command));
    }
}

Bind in XAML:

<ItemsControl ItemsSource="{Binding TerminalMessages}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Message}" />
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

<TextBox Text="{Binding Command, UpdateSourceTrigger=PropertyChanged}" />
<Button Content="Send" Command="{Binding SendCommand}" />
<ContextMenu ItemsSource="{Binding ContextCommands}">
    <ContextMenu.ItemContainerStyle>
        <Style TargetType="MenuItem">
            <Setter Property="Header" Value="{Binding DisplayName}" />
            <Setter Property="Command" Value="{Binding MessageContextMenuCommand}" />
        </Style>
    </ContextMenu.ItemContainerStyle>
</ContextMenu>

Development notes

• TerminalViewModel<TMessage> implements IDisposable. Always dispose instances that are no longer needed to unsubscribe from the reactive pipeline.
• CommandHistory capacity is fixed at 20 entries. Provide a custom IStringHistoryProvider to change this behaviour.
• MessageCollection<TMessage>.ClearMessages() calls messageSubject.OnNext(messages.Last()) after clearing; ensure the collection is non-empty before clearing or guard accordingly in derived code.
• Logging uses Oakrey.Log.LoggerFactory and tracing uses Oakrey.Telemetry.TracingFactory, both resolved by the concrete Type of the ViewModel subclass.

License

MIT - Copyright (c) Oakrey 2016-2025. See LICENSE for details.