fix(mdviewer): use separate rerender message to avoid resetting edit mode on file switch

Replaced inline markdown in MDVIEWR_SET_EDIT_MODE with a dedicated
MDVIEWR_RERENDER_CONTENT message sent only when user switches to reader.
Prevents edit mode from being reset during file switches.

Author: abose

src-mdviewer/src/bridge.js

@@ -147,6 +147,9 @@ export function initBridge() {
             case "MDVIEWR_HIGHLIGHT_SELECTION":
                 handleHighlightSelection(data);
                 break;
+            case "MDVIEWR_RERENDER_CONTENT":
+                handleRerenderContent(data);
+                break;
         }
     });
 
@@ -596,16 +599,20 @@ function handleSetTheme(data) {
 }
 
 function handleSetEditMode(data) {
-    const { editMode, markdown } = data;
+    const { editMode } = data;
     setState({ editMode });
+}
 
-    // When switching to reader, re-render from CM's current markdown
-    // so all elements get fresh data-source-line attributes for cursor sync.
-    if (!editMode && markdown) {
-        const parseResult = parseMarkdownToHTML(markdown);
-        setState({ currentContent: markdown, parseResult });
-        emit("file:rendered", parseResult);
-    }
+/**
+ * Re-render content from CM's authoritative markdown.
+ * Called when switching edit→reader so data-source-line attributes are accurate.
+ */
+function handleRerenderContent(data) {
+    const { markdown } = data;
+    if (!markdown) return;
+    const parseResult = parseMarkdownToHTML(markdown);
+    setState({ currentContent: markdown, parseResult });
+    emit("file:rendered", parseResult);
 }
 
 

src-mdviewer/to-create-tests.md

@@ -39,6 +39,10 @@
 - [ ] Content sync still works when cursor sync is disabled
 - [ ] Cursor sync toggle works in both reader and edit mode
 - [ ] Disabling cursor sync in reader mode prevents CM scroll on click
+- [ ] Cursor sync works on newly edited elements after edit→reader switch
+- [ ] Edit→reader switch re-renders from CM content (data-source-line attrs refreshed)
+- [ ] Switching MD files preserves current edit/reader mode
+- [ ] Edit mode not reset when switching between MD files
 
 ## Edit Mode & Entitlement Gating
 - [ ] Free user sees Edit button → clicking shows upsell dialog

src/extensionsIntegrated/Phoenix-live-preview/MarkdownSync.js

@@ -107,10 +107,16 @@ define(function (require, exports, module) {
                 _handleRedo();
                 break;
             case "mdviewrEditModeChanged":
-                // When switching to reader, send CM content back so the iframe
+                // When switching to reader, send CM content so the iframe
                 // can re-render with accurate data-source-line for cursor sync.
                 if (!data.editMode && _doc) {
-                    setEditMode(false);
+                    const iframeWindow = _getIframeWindow();
+                    if (iframeWindow) {
+                        iframeWindow.postMessage({
+                            type: "MDVIEWR_RERENDER_CONTENT",
+                            markdown: _doc.getText()
+                        }, "*");
+                    }
                 }
                 break;
             case "mdviewrRequestEditMode":
@@ -711,13 +717,7 @@ define(function (require, exports, module) {
         }
         const iframeWindow = _getIframeWindow();
         if (iframeWindow) {
-            const msg = { type: "MDVIEWR_SET_EDIT_MODE", editMode: editMode };
-            // When switching to reader, include current CM content so the iframe
-            // can re-render with accurate data-source-line attributes for cursor sync.
-            if (!editMode && _doc) {
-                msg.markdown = _doc.getText();
-            }
-            iframeWindow.postMessage(msg, "*");
+            iframeWindow.postMessage({ type: "MDVIEWR_SET_EDIT_MODE", editMode: editMode }, "*");
         }
     }