Ely Office: six offline-first desktop apps in Rust and GPUI

ElyDoc, ElyTable, ElyShow (LibreOfficeKit), ElyPDF (MuPDF), ElyTree (Git),
ElyMark (Milkdown and CodeMirror in CEF). ElyMail and ElyAgent follow.

apps/ely-mark/web/src/code.js

@@ -0,0 +1,44 @@
+// Code blocks in CodeMirror; LaTeX and Mermaid preview.
+import { basicSetup, EditorView } from 'codemirror'
+import { EditorState } from '@codemirror/state'
+import { keymap } from '@codemirror/view'
+import { indentWithTab } from '@codemirror/commands'
+import { languages } from '@codemirror/language-data'
+import { codeBlockConfig } from '@milkdown/kit/component/code-block'
+import { theme } from './theme.js'
+import { icons } from './icons.js'
+import { render } from './math.js'
+
+/** Previews for one editor's code blocks. */
+function previews(owner) {
+  return (language, source, apply) => {
+    const kind = source.length === 0 ? '' : language.toLowerCase()
+    switch (kind) {
+      case 'latex':
+        return render(source, true, document.createElement('div'))
+      case 'mermaid':
+        return owner.show(source, apply)
+      default:
+        return null
+    }
+  }
+}
+
+/** Milkdown's code block config; read-only in preview. */
+export function code(texts, editable, owner) {
+  const locked = editable ? [] : [EditorState.readOnly.of(true), EditorView.editable.of(false)]
+  return (ctx) =>
+    ctx.update(codeBlockConfig.key, (prev) => ({
+      ...prev,
+      ...icons,
+      extensions: [basicSetup, keymap.of([indentWithTab]), theme, ...locked],
+      languages,
+      searchPlaceholder: texts.searchLanguage,
+      noResultText: texts.noResult,
+      copyText: texts.copy,
+      previewLabel: texts.preview,
+      previewLoading: texts.loading,
+      previewToggleButton: (only) => (only ? texts.edit : texts.hide),
+      renderPreview: previews(owner),
+    }))
+}