Editing behavior and keyboard shortcuts

Documentation index · Lists and tables

Source editing

Source mode in the WinForms sample: the Markdown delimiters, task markers, and pipe-table syntax remain editable text. The same note is shown in Visual mode in the lists and tables guide.

Source mode edits the literal string. Syntax decoration can use different colors, weight, style, and typography without inserting formatting into that string. The current colorizers are lexical; they do not compile SQL/JavaScript or provide semantic diagnostics, completion, refactoring, or a language server.

Wrapping, syntax decoration, line numbers, tab width, and indentation style are independent options. A multi-line selection followed by Tab indents the selected lines instead of replacing the selection. Shift+Tab outdents. If the selection ends at the start of a line, that otherwise-unselected final line is excluded. With a single caret, indentation respects the configured tab stops. Enter carries source indentation.

Markdown Source supports Ctrl/Cmd+B and Ctrl/Cmd+I by inserting/removing Markdown delimiters. This changes source text and participates in undo. Source-format commands support bold, italic, underline, strikethrough, inline code, superscript, subscript, text/background color, font, and font size. Typing a backtick with text selected applies inline code in both views. Underline uses embedded <u> tags and requires the embedded-HTML policy. Keyboard shortcuts toggle the mark; C# FormatSelectionAsync(mark, enabled) and JavaScript execute('format', { mark, value }) also accept explicit true/false for idempotent on/off behavior. Omitting that argument toggles. See the JavaScript API for collapsed-selection behavior.

Visual editing

Visual mode edits a supported block/run model: paragraphs, headings, lists/tasks, quotes, code, thematic breaks, tables, and block images. Inline marks include bold, italic, underline, strike, code, links, superscript, and subscript. Foreground/background color, font, and size choices depend on the selected storage policy. Both views offer these content formats. Markdown uses <sup>, <sub> and styled <span> tags for formats without native Markdown syntax, so these formats require embedded HTML to be enabled. Superscript and subscript replace each other; choosing Default clears a style override.

Toolbar commands act on the logical selection. With a collapsed selection, mark commands can affect subsequent typing. Raw preserved content is intentionally noneditable in Visual mode; use Source where allowed or explicitly convert the unsupported content.

To return a heading, list item, or quote to ordinary prose, choose Paragraph in the browser sample's paragraph-style selector. WinForms hosts call SetBlockStyleAsync(BlockStyle.Paragraph); JavaScript hosts call execute('heading', { type: 'p' }). Paragraph style preserves inline formatting. Click Bold/Italic again to toggle the mark off, or call FormatSelectionAsync(TextMark.Bold, false) / execute('format', { mark: 'bold', value: false }) explicitly. Clear (ClearFormatting) removes inline formatting from selected text; at a cursor it resets subsequent typing. It does not change the paragraph style. There is no separate None style.

Markdown-like input rules

With typing rules enabled, these are recognized in appropriate paragraph/list contexts:

These are input rules, not a separate full Markdown engine. Policy and context can suppress a transformation. They run during typing, not indiscriminately during load or paste. Undo can recover the literal typed marker from an automatic transformation.

Editing links

Select linked text or place the cursor inside it to show its contextual toolbar. The same controls are available for recognized Markdown links and HTML anchors in Source mode. Links inside code snippets remain literal code. The toolbar follows the active object and stays usable while its controls have focus.

1. Choose Link URL to change the destination. Unsafe URLs are rejected; canceling the prompt leaves the link unchanged.
2. Choose Content to replace the displayed text while retaining the destination. This replaces the link's content, rather than editing individual styled runs.
3. Choose Copy to copy the complete link with supported clipboard representations.
4. Choose Delete to remove the link and its text. To retain the text and remove only the hyperlink, use the host's unlink command (SetLinkAsync(null) in WinForms).

Visual links behave as atomic objects for selection/deletion. Typing beside a link creates ordinary prose. Edits participate in undo/redo. Updating a Source link can serialize it as an HTML anchor, so do not assume the original Markdown delimiters will remain byte-for-byte identical. Navigation is host-owned through openLinkRequested; editing a destination does not open it.

For linked pictures, use the separate image controls.

Keyboard map

On macOS browsers, Cmd is used where the adapter recognizes the platform modifier. WinForms uses Ctrl.

Ordinary selection, copy/cut/paste, and caret movement use browser/native behavior routed through the model adapter. Not all browser/platform shortcuts are intercepted. Avoid installing a host keyboard handler that consumes the same key before the editor receives it.

Find and replace

The WinForms control's internal search panel, with review highlighted in two places. The replacement field contains approved; no replacement has been applied in this screenshot. The All button performs Source-mode Replace All as one undoable operation.

The browser sample supplies its own find/replace bar above the editor. This capture uses the same search and replacement values, with two matches and no replacements applied. A custom JavaScript host supplies its own search UI using the component's search methods and shortcut events.

The search engine performs literal matching with optional case sensitivity and whole-word filtering. It returns flat UTF-16 ranges, and selectMatch selects/reveals a match. There is no regular-expression mode.

The WinForms popup supports find and individual replacement; Replace All requires Source mode. The browser demo also restricts its replacement UI in Visual mode. Rich single replacement is subject to editable-range constraints: spanning multiple table cells or raw content is not a generic replacement operation. Source Replace All is an undoable operation. Replacement text is literal, with no regular-expression capture substitution.

FindEnabled and ReplaceEnabled govern the WinForms popup. A custom JavaScript host decides what search controls to present; the editor emits shortcut events and exposes the search methods.

Read-only behavior and composition

Read-only blocks editing/history commands but still permits selection, copying, search, document loading, and preview. It is not access control against a host that owns the instance.

Composition is the multi-step text input used by IMEs and some mobile keyboards. The adapter avoids treating intermediate composition as committed document text. Operations that require committed content, such as snapshot retrieval or view switching, can reject while composition is active. Handle this as a temporary interaction state rather than deleting the user's partially composed text.

Focus and accessibility

Set a meaningful accessible label for every instance. Do not identify multiple editors only by a placeholder. The divider has a separator role and keyboard controls; line-number decoration is separate from the document. Native caret/selection behavior is used rather than a custom blinking caret. Screen-reader navigation, rich-list semantics, touch selection handles, and multilingual composition still require the platform checks listed in the test guide.