refactor[wip]: rich text editor state handling

Create dedicated RichTextEditState class, make editor configuration more
flexible, and modify schema to support multiple text blocks. Add keyboard
submission options.

src/lib/components/RichTextInput/RichTextEditState.svelte.ts

@@ -0,0 +1,25 @@
+import { DOMParser, Node, Schema } from 'prosemirror-model';
+import type { EditorState } from 'prosemirror-state';
+import { createEditorState, type EditorConfiguration } from './editorState';
+
+export class RichTextEditState {
+	state: EditorState;
+	doc: Node | undefined = $state();
+	plainText = $state('');
+
+	constructor(
+		config: EditorConfiguration,
+		schema?: Schema,
+		initialNodeOrPlainText?: Node | string
+	) {
+		if (initialNodeOrPlainText) {
+			if (typeof initialNodeOrPlainText === 'string') {
+				this.plainText = initialNodeOrPlainText;
+			} else {
+				this.doc = initialNodeOrPlainText;
+			}
+		}
+
+		this.state = createEditorState(config, schema);
+	}
+}

src/lib/components/RichTextInput/editorState.ts

@@ -1,13 +1,38 @@
-import { EditorState } from 'prosemirror-state';
+import { EditorState, type Command } from 'prosemirror-state';
 import { history, undo, redo } from 'prosemirror-history';
 import { keymap } from 'prosemirror-keymap';
 import { baseKeymap } from 'prosemirror-commands';
+import type { Schema } from 'prosemirror-model';
 
 import { messageSchema } from './schema';
 
-export function createMessageEditorState() {
+export type EditorConfiguration = {
+	keyboardSubmitMethod?: 'enter' | 'shiftEnter' | undefined;
+	onKeyboardSubmit?: () => void;
+};
+
+export function createEditorState(
+	{ keyboardSubmitMethod, onKeyboardSubmit }: EditorConfiguration,
+	schema: Schema = messageSchema
+) {
+	const submitCommand: Command = () => {
+		onKeyboardSubmit?.();
+		return true;
+	};
+	const newlineCommand: Command = baseKeymap.Enter;
+
+	const submitOrNewlineKeyMap: Record<string, Command> = {};
+
+	if (keyboardSubmitMethod === 'enter') {
+		submitOrNewlineKeyMap['Enter'] = submitCommand;
+		submitOrNewlineKeyMap['Shift-Enter'] = newlineCommand;
+	} else if (keyboardSubmitMethod === 'shiftEnter') {
+		submitOrNewlineKeyMap['Enter'] = newlineCommand;
+		submitOrNewlineKeyMap['Shift-Enter'] = submitCommand;
+	}
+
 	const state = EditorState.create({
-		schema: messageSchema,
+		schema,
 		plugins: [
 			history(),
 			keymap({
@@ -15,7 +40,7 @@ export function createMessageEditorState() {
 				'Mod-y': redo,
 				'Mod-Shift-z': redo
 			}),
-			keymap(baseKeymap)
+			keymap({ ...baseKeymap, ...submitOrNewlineKeyMap })
 		]
 	});
 

src/lib/components/RichTextInput/schema.ts

@@ -3,7 +3,7 @@ import { nodes as basicNodes, marks as basicMarks } from 'prosemirror-schema-bas
 
 export const messageSchema = new Schema({
 	nodes: {
-		doc: { content: 'block' }, // For now we only support a single block
+		doc: { content: 'block+' },
 		paragragh: {
 			content: 'inline*'
 		},