Desktop: Resolves #2242: Implements Sync-Scroll for Markdown Editor and Viewer (#5512)

packages/renderer/MdToHtml/rules/source_map.ts

@@ -0,0 +1,36 @@
+export default {
+	plugin: (markdownIt: any, params: any) => {
+
+		if (!params.mapsToLine) return;
+
+		const allowedLevels = {
+			paragraph_open: 0,
+			heading_open: 0,
+			// fence: 0, // fence uses custom rendering that doesn't propogate attr so it can't be used for now
+			blockquote_open: 0,
+			table_open: 0,
+			code_block: 0,
+			hr: 0,
+			html_block: 0,
+			list_item_open: 99, // this will stop matching if a list goes more than 99 indents deep
+			math_block: 0,
+		};
+
+		for (const [key, allowedLevel] of Object.entries(allowedLevels)) {
+			const precedentRule = markdownIt.renderer.rules[key];
+
+			markdownIt.renderer.rules[key] = (tokens: any[], idx: number, options: any, env: any, self: any) => {
+				if (!!tokens[idx].map && tokens[idx].level <= allowedLevel) {
+					const line = tokens[idx].map[0];
+					tokens[idx].attrJoin('class', 'maps-to-line');
+					tokens[idx].attrSet('source-line', `${line}`);
+				}
+				if (precedentRule) {
+					return precedentRule(tokens, idx, options, env, self);
+				} else {
+					return self.renderToken(tokens, idx, options);
+				}
+			};
+		}
+	},
+};