feat(preload): add file.list, file.pickFolder, file.pickFile convenience methods

src/main.js

@@ -3039,6 +3039,55 @@ ipcMain.on('select-folder', (event, type) => {
   }
 });
 
+// List directory contents as FileEntry[]
+ipcMain.handle('list-directory', async (event, dirPath) => {
+  try {
+    const entries = fs.readdirSync(dirPath, { withFileTypes: true });
+    return entries.map((dirent) => {
+      const fullPath = path.join(dirPath, dirent.name);
+      let size;
+      let modifiedAt;
+      if (!dirent.isDirectory()) {
+        try {
+          const stat = fs.statSync(fullPath);
+          size = stat.size;
+          modifiedAt = stat.mtime.toISOString();
+        } catch {
+          // ignore stat errors
+        }
+      }
+      return {
+        name: dirent.name,
+        path: fullPath,
+        isDirectory: dirent.isDirectory(),
+        size,
+        modifiedAt,
+      };
+    });
+  } catch (err) {
+    return { error: err.message };
+  }
+});
+
+// Show folder picker dialog and return selected path or null
+ipcMain.handle('pick-folder', async () => {
+  const result = await dialog.showOpenDialog(mainWindow, {
+    properties: ['openDirectory'],
+  });
+  if (result.canceled || result.filePaths.length === 0) return null;
+  return result.filePaths[0];
+});
+
+// Show file picker dialog for markdown files and return selected path or null
+ipcMain.handle('pick-file', async () => {
+  const result = await dialog.showOpenDialog(mainWindow, {
+    properties: ['openFile'],
+    filters: [{ name: 'Markdown', extensions: ['md', 'markdown', 'mdown', 'mkd'] }],
+  });
+  if (result.canceled || result.filePaths.length === 0) return null;
+  return result.filePaths[0];
+});
+
 ipcMain.on('export-spreadsheet', (event, { content, format }) => {
   const outputFile = dialog.showSaveDialogSync(mainWindow, {
     defaultPath: currentFile.replace(/\.[^/.]+$/, `.${format}`),

src/preload.js

@@ -237,7 +237,12 @@ const ALLOWED_RECEIVE_CHANNELS = [
   'load-template-menu',
   'toggle-command-palette',
   'toggle-sidebar-panel',
-  'toggle-bottom-panel'
+  'toggle-bottom-panel',
+
+  // File dialog / directory listing
+  'list-directory',
+  'pick-folder',
+  'pick-file'
 ];
 
 /**
@@ -344,7 +349,10 @@ contextBridge.exposeInMainWorld('electronAPI', {
     exists: (filePath) => ipcRenderer.invoke('path-exists', filePath),
     isDirectory: (filePath) => ipcRenderer.invoke('is-directory', filePath),
     copy: (source, destination) => ipcRenderer.invoke('copy-path', { source, destination }),
-    move: (source, destination) => ipcRenderer.invoke('move-path', { source, destination })
+    move: (source, destination) => ipcRenderer.invoke('move-path', { source, destination }),
+    list: (dirPath) => ipcRenderer.invoke('list-directory', dirPath),
+    pickFolder: () => ipcRenderer.invoke('pick-folder'),
+    pickFile: () => ipcRenderer.invoke('pick-file')
   },
 
   // Theme Operations

src/renderer/components/sidebar/Sidebar.tsx

@@ -1,4 +1,5 @@
-import { ChevronRight } from 'lucide-react';
+import { ChevronRight, FolderOpen } from 'lucide-react';
+import { Button } from '@/components/ui/button';
 import { Collapsible, CollapsibleTrigger, CollapsibleContent } from '@/components/ui/collapsible';
 import { ScrollArea } from '@/components/ui/scroll-area';
 import { useFileStore } from '@/stores/file-store';
@@ -6,7 +7,7 @@ import { FileTree } from './FileTree';
 import { Outline } from './Outline';
 
 export function Sidebar() {
-  const rootPath = useFileStore((s) => s.rootPath);
+  const tree = useFileStore((s) => s.tree);
 
   return (
     <div className="flex h-full flex-col gap-3">
@@ -20,9 +21,12 @@ export function Sidebar() {
         </CollapsibleTrigger>
         <CollapsibleContent>
           <ScrollArea className="h-[calc(100vh-240px)]">
-            {!rootPath ? (
-              <div className="flex flex-col items-center justify-center gap-2 py-8 text-xs text-muted-foreground">
+            {!tree ? (
+              <div className="flex flex-col items-center gap-2 p-4 text-xs text-muted-foreground">
                 <span>No folder opened</span>
+                <Button size="sm" variant="outline" onClick={() => useFileStore.getState().openFolderDialog()}>
+                  <FolderOpen className="mr-1" /> Open Folder
+                </Button>
               </div>
             ) : (
               <FileTree />

src/renderer/lib/ipc.ts

@@ -66,6 +66,10 @@ export const ipc = {
       safeCall('file', 'write', path, content),
     list: (dir: string): Promise<IpcResult<FileEntry[] | ChannelMissing>> =>
       safeCall('file', 'list', dir),
+    pickFolder: (): Promise<IpcResult<string | null | ChannelMissing>> =>
+      safeCall('file', 'pickFolder'),
+    pickFile: (): Promise<IpcResult<string | null | ChannelMissing>> =>
+      safeCall('file', 'pickFile'),
     onChange: (cb: (path: string) => void): (() => void) => {
       if (typeof window === 'undefined' || !window.electronAPI?.file?.onChange) {
         return () => {};

src/renderer/stores/file-store.ts

@@ -39,6 +39,9 @@ interface FileState {
   markTabClean: (id: string) => void;
   markTabDirty: (id: string) => void;
   reorderTabs: (fromIndex: number, toIndex: number) => void;
+  openFolderDialog: () => Promise<void>;
+  openFileDialog: () => Promise<void>;
+  saveActiveBuffer: () => Promise<boolean>;
 }
 
 function entryToNode(entry: FileEntry): FileNode {
@@ -191,5 +194,32 @@ export const useFileStore = create<FileState>()(
         tabs.splice(toIndex, 0, moved);
       });
     },
+
+    openFolderDialog: async () => {
+      const result = await ipc.file.pickFolder();
+      if (!result.ok || result.data === null) return;
+      await useFileStore.getState().openFolder(result.data);
+    },
+
+    openFileDialog: async () => {
+      const result = await ipc.file.pickFile();
+      if (!result.ok || result.data === null) return;
+      await useFileStore.getState().openFile(result.data);
+    },
+
+    saveActiveBuffer: async () => {
+      const { activeTabId } = useFileStore.getState();
+      if (!activeTabId) return false;
+
+      const buffer = useEditorStore.getState().buffers.get(activeTabId);
+      if (!buffer) return false;
+
+      const writeResult = await ipc.file.write(activeTabId, buffer.content);
+      if (!writeResult.ok) return false;
+
+      useEditorStore.getState().markSaved(activeTabId);
+      useFileStore.getState().markTabClean(activeTabId);
+      return true;
+    },
   }))
 );