EonaCat.Editor 0.0.2

EonaCat.Editor

A modern, lightweight, and highly extensible WPF text editor control for .NET applications.

EonaCat.Editor provides a fast editing experience with syntax highlighting, code completion, snippets, search, undo/redo, and a powerful document model, making it suitable for IDEs, scripting tools, configuration editors, and code editing applications.

Features

• 🚀 Fast WPF rendering engine
• 🎨 Syntax highlighting
• 💡 IntelliSense-style code completion
• 📝 Snippet support
• 🔍 Built-in search panel
• ↩️ Unlimited Undo / Redo
• 📑 Line numbers
• ✂️ Clipboard operations
• 🎯 Caret API
• 📐 Selection API
• 📄 TextDocument model
• 📜 Scroll position API
• 🔤 Word wrapping
• 🎛 Fully customizable through WPF styling
• ⚡ Optimized for large documents

Installation

Install from NuGet.

Package Manager

Install-Package EonaCat.Editor

.NET CLI

dotnet add package EonaCat.Editor

Quick Start

Add the namespace

xmlns:editor="clr-namespace:EonaCat.Editor.Core;assembly=EonaCat.Editor"

Add the editor

<Grid>

    <editor:TextEditor
        x:Name="Editor"
        FontFamily="Consolas"
        FontSize="14"
        ShowLineNumbers="True"
        VerticalScrollBarVisibility="Auto"
        HorizontalScrollBarVisibility="Auto"/>

</Grid>

Loading Text

Editor.Text = File.ReadAllText("Program.cs");

Saving Text

File.WriteAllText("Program.cs", Editor.Text);

Using a TextDocument

The editor stores all text inside a TextDocument.

Create a document:

var document = new TextDocument();

document.Text = "Hello World";

Editor.Document = document;

Read the current document:

string text = Editor.Document.Text;

Basic Properties

Text

Editor.Text = "Hello World";

string current = Editor.Text;

Read Only

Editor.IsReadOnly = true;

Word Wrap

Editor.WordWrap = true;

Show Line Numbers

Editor.ShowLineNumbers = true;

Font

<editor:TextEditor

    FontFamily="Consolas"
    FontSize="14"/>

Line Number Color

Editor.LineNumbersForeground = Brushes.Gray;

Undo / Redo

if (Editor.CanUndo)
{
    Editor.Undo();
}

if (Editor.CanRedo)
{
    Editor.Redo();
}

Caret

Move the caret.

Editor.CaretOffset = 0;

Read the current position.

int position = Editor.CaretOffset;

Selection

Read the selected text.

string text = Editor.SelectedText;

Select text.

Editor.SelectionStart = 50;
Editor.SelectionLength = 20;

Scrolling

double vertical = Editor.VerticalOffset;
double horizontal = Editor.HorizontalOffset;

Viewport size.

double width = Editor.ViewportWidth;
double height = Editor.ViewportHeight;

Syntax Highlighting

Assign a highlighting definition.

Editor.SyntaxHighlighting = myHighlightingDefinition;

You can create custom highlighting definitions for your own languages.

Search

The built-in search panel supports:

• Find
• Find Next
• Find Previous
• Match Case
• Whole Word
• Regular Expressions
• Highlight All

Example:

SearchPanel.Install(Editor.TextArea);

Code Completion

Show an IntelliSense completion window.

var completionWindow = new CompletionWindow(Editor.TextArea);

completionWindow.CompletionList.CompletionData.Add(
    new MyCompletionData("Console"));

completionWindow.Show();

The completion system supports:

• Keyboard navigation
• Icons
• Descriptions
• Automatic insertion
• Custom completion providers

Snippets

Insert reusable code templates.

Example features:

• Editable placeholders
• Caret positioning
• Bound fields
• Replaceable regions
• Selection support

Snippets can be created and inserted programmatically using the included snippet APIs.

Mouse Hover

Useful for tooltips and quick info.

Editor.MouseHover += Editor_MouseHover;
Editor.MouseHoverStopped += Editor_MouseHoverStopped;

Document Information

Determine whether the document has changed.

bool modified = Editor.IsModified;

Retrieve the number of lines.

int lines = Editor.LineCount;

Current encoding.

Encoding encoding = Editor.Encoding;

Styling

Since the editor is a normal WPF control, it fully supports:

• Styles
• Control Templates
• Resource Dictionaries
• Dynamic Resources
• Themes

Example:

<Style TargetType="editor:TextEditor">

    <Setter Property="Background"
            Value="#1E1E1E"/>

    <Setter Property="Foreground"
            Value="White"/>

</Style>

Complete Example

XAML

<Window
    x:Class="Sample.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:editor="clr-namespace:EonaCat.Editor.Core;assembly=EonaCat.Editor">

    <Grid>

        <editor:TextEditor
            x:Name="Editor"
            FontFamily="Consolas"
            FontSize="14"
            ShowLineNumbers="True"
            WordWrap="False"
            VerticalScrollBarVisibility="Auto"
            HorizontalScrollBarVisibility="Auto"/>

    </Grid>

</Window>

Code Behind

using System.Windows;

namespace Sample
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            Editor.Text =
@"using System;

Console.WriteLine(""Hello World!"");";
        }
    }
}

Included Components

The package includes:

• TextEditor
• TextDocument
• Search Panel
• Completion Window
• Completion List
• Insight Window
• Snippet Engine
• Syntax Highlighting Engine
• Rendering Engine
• Undo / Redo Manager

Typical Use Cases

EonaCat.Editor is ideal for:

• Source code editors
• IDEs
• Script editors
• JSON editors
• XML editors
• SQL editors
• Markdown editors
• Configuration editors
• Log viewers
• Custom programming languages

Supported Frameworks

• .NET Framework 4.8
• .NET 6 Windows