Notepad.Avalonia 0.2.2

Notepad.Avalonia

Two Avalonia UI controls for a single markdown note:

• NoteEditor — editable source view with inline image pasting.
• MarkdownViewer — read-only rendered view with full markdown support, free text selection and copy.

Features

NoteEditor

• Markdown text editing for a single note
• Inline image support (paste from clipboard or programmatic insert)
• Full undo/redo with intelligent coalescing
• Text selection (single and multi-line)
• Clipboard integration (text + images)
• Text wrapping
• Light/Dark theme support
• MVVM-ready via MarkdownText property binding
• Optimized for large documents (FormattedText caching, incremental layout, viewport culling)

MarkdownViewer

Renders markdown instead of showing its source. Read-only, but every rendered character can be selected and copied.

• Blocks: ATX and setext headings, paragraphs, thematic breaks, fenced and indented code blocks, nested blockquotes, nested ordered/unordered/task lists, GFM pipe tables (with column alignment)
• Inline: **bold**, *italic*, ***both***, ~~strikethrough~~, `code`, links (inline, reference and autolinks), images, hard line breaks, backslash escapes and HTML entities
• Selection: drag, Shift+click, double-click (word), triple-click (line), Ctrl+A, auto-scroll while dragging past the edge. The selection is dropped on lost focus (like Avalonia's TextBox); set ClearSelectionOnLostFocus="False" to keep it — it is then drawn with InactiveSelectionBrush
• Copy: Ctrl+C / context menu — copies the rendered text, not the markup
• Links: LinkClicked event, opens http/https/mailto in the browser by default
• Built-in scrollbar with viewport virtualization and light/dark themes

Quick Start

var editor = new NoteEditor
{
    DefaultFont = new FontFamily("Segoe UI"),
    DefaultFontSize = 15,
    MarkdownText = "Hello world\nSecond line with ![alt](imageKey)"
};

var viewer = new MarkdownViewer
{
    DefaultFontSize = 15,
    MarkdownText = "# Title\n\nSome **bold** text and a [link](https://example.com)."
};

viewer.SelectAll();
var text = viewer.SelectedText;   // rendered text, without the markup

Give the viewer a finite height (a DockPanel/Grid cell); like NoteEditor it scrolls its own content, so do not wrap it in a ScrollViewer.

If you do place viewers inside an outer scroll area (for example a list of notes), each one reports its full content height and renders every block — you lose the built-in scrollbar and virtualization, but selection still behaves correctly: clicking to select does not make the outer ScrollViewer jump, while Tab navigation still scrolls the control into view.

MVVM Usage

<notepad:NoteEditor MarkdownText="{Binding MarkdownText}"
                    Images="{Binding Images}" />

<notepad:MarkdownViewer MarkdownText="{Binding MarkdownText}"
                        Images="{Binding Images}" />

public class MyViewModel : INotifyPropertyChanged
{
    public string? MarkdownText { get; set; }
    public ObservableCollection<ImageEntry> Images { get; } = new();
}

Installation

dotnet add package Notepad.Avalonia

License

MIT