---
title: Editor
description: A Notion-style block editor over the markdown document model — one entity, a scroll handle and an observe, and the markdown a save would write on every keystroke.
source: https://github.com/crabtalk/bezel/blob/main/apps/gallery/src/patterns/editor.rs
---

> One page of the bezel documentation. The index is https://bezel.pages.dev/llms.txt

# Editor

`markdown` holds the document and paints it; `editor::Editor` is the surface you type on — focus, keys, the mouse, undo and the menus.

```rust
use editor::Editor;

editor::init(cx);   // once, at startup

let scroll = ScrollHandle::new();
let editor = cx.new({
    let scroll = scroll.clone();
    |cx| Editor::new("# Notes", cx).with_scroll(scroll)
});
cx.observe(&editor, |_, _, cx| cx.notify()).detach();
```

Pass the scroll handle of the pane the document sits in, not one of the editor's own, or the caret cannot follow typing down the page.

Typing notifies the editor, so anything a host reads off it needs that `observe`. Without it the markdown pane on this page would freeze on the opening text and the toolbar would never appear at all.

`editor.source()` is the document written back to markdown, normalized, on every keystroke — what a save would write, and what fills the right pane here.

A toolbar is three calls: `selection_bounds()` for where to float it, `toggle_mark` for what a button does, and `covered_by` for whether it is lit. That is the same entry point cmd-B takes, so a button and a chord cannot disagree.

```rust
let lit = editor.doc().covered_by(editor.selection(), &mark);

editor.update(cx, |editor, cx| editor.toggle_mark(mark, cx));
```

`Mark::Code` over a selection spanning more than one line makes a fence instead of an inline span, and the same call takes it back out.

The slash menu, the gutter handle, drag-to-reorder, the language picker on a fence, the menu that turns a pasted URL into a chip, a bookmark or an embed, undo and the clipboard need no wiring — the source behind this page contains not one line for any of them. Undo keeps 100 steps, coalesced so a run of typing comes back as a word rather than a character; `with_undo_limit` for more.

`init` binds `ui::input::TextField`'s chords inside the editor's own key context, so `tab` indents a list here and means nothing outside one. Replace that call for a different keymap. Moving, duplicating and deleting a block ship as actions with no chord for an app to bind as it likes; the block menu on the gutter handle reaches them meanwhile.

`editor` is a peer crate you name yourself, alongside `markdown` and `syntax`.

The source is at `apps/gallery/src/patterns/editor.rs`. Copy the file.