bezel

Patterns / Media

Editor

Markdown apps/gallery/src/patterns/editor.rs

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

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.

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.

Editor