MarkdownTextBlock

ProMarkdown.Controls.MarkdownTextBlock is the primary control for application views. It derives from SelectableTextBlock, renders a source-mapped Avalonia inline tree, and coordinates selection, links, editing, task lists, and render-resource lifetime.

Typical XAML

<markdown:MarkdownTextBlock Markdown="{Binding DocumentMarkdown}"
                            BaseUri="{Binding DocumentBaseUri}"
                            FontSize="14"
                            Padding="16"
                            TextWrapping="Wrap"
                            ThemePalette="{Binding MarkdownPalette}" />

Place wrapped documents in a vertically scrolling container and leave horizontal scrolling disabled. The control observes its own bounds and effective viewport so tables, code blocks, and embedded controls receive a useful available width.

Markdown properties

Property	Purpose
`Markdown`	Source text. Changing it reparses and rerenders the document.
`BaseUri`	Base for relative links and images.
`ThemePalette`	Semantic document brushes. If null, a built-in palette is selected from `Foreground`.
`ImageOptions`	Allowed image sources, byte and pixel limits, and remote timeout.
`ImageLoader`	Image-loading implementation. Defaults to `DefaultMarkdownImageLoader.Instance`.
`RenderController`	Parsing and rendering pipeline. Supply a custom instance to activate plugins.
`HitTestingService`	Maps pointer or rendered-text positions back to Markdown source.
`EditingService`	Resolves source elements to editor plugins and creates editor controls.
`EditorPreferences`	Selects a preferred editor ID for each editor feature.
`EditorPresentationMode`	Displays editors inline with content or in a card surface.
`IsEditingEnabled`	Allows `TryBeginEdit` to start an editor session.
`IsTaskListInteractive`	Allows rendered task checkboxes to accept input when a command is present.
`TaskListToggleCommand`	Receives a `MarkdownTaskListToggleRequest` containing updated source.

RenderController, HitTestingService, EditingService, EditorPreferences, and ImageLoader reject null assignments. Changing rendering, editing, text, theme, image configuration, or layout properties triggers the appropriate rerender or layout refresh. See Image Loading and Security before displaying untrusted Markdown.

Render state

The control exposes these render snapshots and activity properties:

LastRenderResult — rendered Avalonia inlines, parse result, source maps, and resource tracker
LastParseResult — the Markdig document, original source, transformed source, and parent map
LastRenderMap — mappings from rendered text and visual controls to Markdown AST nodes
ActiveEditorSession — the editor currently replacing a rendered element, or null
IsRendering — true while the current render generation has synchronous or registered asynchronous work

These values are null before the first non-empty attached render and after detaching from the visual tree. Treat them as snapshots: a Markdown, width, theme, or service change can replace them.

RenderCompleted fires when all work registered for the current generation has completed. A new render cancels the previous generation; stale asynchronous completions cannot change the current generation's state. Detaching the control also cancels active work and disposes render resources.

Methods, commands, and events

Member	Use
`HitTestMarkdown(Point)`	Resolve a control-relative point to source and AST metadata.
`TryBeginEdit(Point)`	Hit test a point and begin an editor session if a plugin supports it.
`TryBeginEdit(MarkdownHitTestResult)`	Begin editing from a previously resolved hit.
`CancelEdit()`	End the active session with the `UserRequested` reason.
`CopySelectionCommand`	Copy the active rendered-text selection. Its command state follows `CanCopyDocumentSelection`.
`SelectAllCommand`	Select every rendered document segment.
`SelectionChanged`	Observe document-wide selection changes across text and rich blocks.
`RenderCompleted`	Observe completion of the active render generation.
`MarkdownEdited`	Observe replacement, insertion, or removal and synchronize persisted source.
`MarkdownEditCanceled`	Observe cancellation caused by the user, a Markdown change, or disabled editing.

Editing is opt-in and gesture-neutral. Set IsEditingEnabled, then call TryBeginEdit from the pointer, keyboard, or command interaction that fits your application. See Source-Aware Editing.

Selection and clipboard

MarkdownTextBlock extends SelectableTextBlock with document-wide selection across rendered text and rich block controls. Pointer coordinates are translated through the visual tree, so selection remains aligned when the control is hosted in a scrolled view.

Use CanCopyDocumentSelection, CopySelectionCommand, and SelectAllCommand for menus, toolbars, and keyboard routing. The command state updates whenever the document selection changes.

MarkdownSelection also provides imperative helpers:

string selected = MarkdownSelection.GetSelectedText(markdownView);
string document = MarkdownSelection.GetDocumentText(markdownView);

await MarkdownSelection.CopyAsync(markdownView);
await MarkdownSelection.CopyDocumentTextAsync(markdownView);

GetDocumentText() and CopyDocumentTextAsync() operate on the complete rendered document without changing the active selection.

Inherited text behavior

The renderer reads FontFamily, FontSize, Foreground, and TextWrapping from the control. Standard text layout and inherited styling still come from SelectableTextBlock; ProMarkdown owns the cross-segment selection model and its clipboard commands.