App: Add "Open in Editor (F4) feature.

Author: vdavid

apps/desktop/src-tauri/src/commands/ui.rs

@@ -158,6 +158,24 @@ pub fn get_info(_path: String) -> Result<(), String> {
     Err("Get Info is only available on macOS".to_string())
 }
 
+/// Open file in the system's default text editor (macOS only)
+#[tauri::command]
+#[cfg(target_os = "macos")]
+pub fn open_in_editor(path: String) -> Result<(), String> {
+    Command::new("open")
+        .arg("-t")
+        .arg(&path)
+        .spawn()
+        .map_err(|e| e.to_string())?;
+    Ok(())
+}
+
+#[tauri::command]
+#[cfg(not(target_os = "macos"))]
+pub fn open_in_editor(_path: String) -> Result<(), String> {
+    Err("Open in editor is only available on macOS".to_string())
+}
+
 /// Executes a menu action for the current context.
 pub fn execute_menu_action<R: Runtime>(app: &AppHandle<R>, id: &str) {
     let state = app.state::<MenuState<R>>();
@@ -171,6 +189,12 @@ pub fn execute_menu_action<R: Runtime>(app: &AppHandle<R>, id: &str) {
         crate::menu::OPEN_ID => {
             let _ = app.opener().open_path(&context.path, None::<&str>);
         }
+        crate::menu::EDIT_ID => {
+            #[cfg(target_os = "macos")]
+            {
+                let _ = open_in_editor(context.path);
+            }
+        }
         crate::menu::SHOW_IN_FINDER_ID => {
             #[cfg(target_os = "macos")]
             {

apps/desktop/src-tauri/src/lib.rs

@@ -269,6 +269,7 @@ pub fn run() {
             commands::ui::copy_to_clipboard,
             commands::ui::quick_look,
             commands::ui::get_info,
+            commands::ui::open_in_editor,
             mcp::pane_state::update_left_pane_state,
             mcp::pane_state::update_right_pane_state,
             mcp::pane_state::update_focused_pane,

apps/desktop/src-tauri/src/mcp/executor.rs

@@ -9,7 +9,7 @@ use tauri::{AppHandle, Emitter, Manager, Runtime};
 use super::pane_state::PaneStateStore;
 use super::protocol::{INTERNAL_ERROR, INVALID_PARAMS};
 use crate::commands::ui::{
-    copy_to_clipboard, get_info, quick_look, set_view_mode, show_in_finder, toggle_hidden_files,
+    copy_to_clipboard, get_info, open_in_editor, quick_look, set_view_mode, show_in_finder, toggle_hidden_files,
 };
 
 /// Result of tool execution.
@@ -187,6 +187,10 @@ fn execute_file_command<R: Runtime>(app: &AppHandle<R>, name: &str) -> ToolResul
         .ok_or_else(|| ToolError::internal("No file under cursor"))?;
 
     match name {
+        "file_openInEditor" => {
+            open_in_editor(file_under_cursor.path.clone()).map_err(ToolError::internal)?;
+            Ok(json!({"success": true, "path": file_under_cursor.path}))
+        }
         "file_showInFinder" => {
             show_in_finder(file_under_cursor.path.clone()).map_err(ToolError::internal)?;
             Ok(json!({"success": true, "path": file_under_cursor.path}))

apps/desktop/src-tauri/src/mcp/tests.rs

@@ -105,12 +105,12 @@ fn test_tool_input_schemas_are_valid() {
 #[test]
 fn test_total_tool_count() {
     let tools = get_all_tools();
-    // 3 app + 3 view + 1 pane + 12 nav + 8 sort + 5 file + 2 volume + 5 selection = 39
+    // 3 app + 3 view + 1 pane + 12 nav + 8 sort + 6 file + 2 volume + 5 selection = 40
     // (context tools and volume_list moved to resources)
     assert_eq!(
         tools.len(),
-        39,
-        "Expected 39 tools, got {}. Did you add/remove tools?",
+        40,
+        "Expected 40 tools, got {}. Did you add/remove tools?",
         tools.len()
     );
 }

apps/desktop/src-tauri/src/mcp/tools.rs

@@ -115,6 +115,10 @@ fn get_sort_tools() -> Vec<Tool> {
 /// Get file action tools.
 fn get_file_tools() -> Vec<Tool> {
     vec![
+        Tool::no_params(
+            "file_openInEditor",
+            "Open file under the cursor in the default text editor",
+        ),
         Tool::no_params("file_showInFinder", "Show file under the cursor in Finder"),
         Tool::no_params("file_copyPath", "Copy path of the file under the cursor to clipboard"),
         Tool::no_params(
@@ -205,9 +209,9 @@ mod tests {
     #[test]
     fn test_all_tools_count() {
         let tools = get_all_tools();
-        // 3 app + 3 view + 1 pane + 12 nav + 8 sort + 5 file + 2 volume + 5 selection = 39
+        // 3 app + 3 view + 1 pane + 12 nav + 8 sort + 6 file + 2 volume + 5 selection = 40
         // (context tools and volume_list moved to resources)
-        assert_eq!(tools.len(), 39);
+        assert_eq!(tools.len(), 40);
     }
 
     #[test]

apps/desktop/src-tauri/src/menu.rs

@@ -11,6 +11,7 @@ pub const SHOW_HIDDEN_FILES_ID: &str = "show_hidden_files";
 pub const VIEW_MODE_FULL_ID: &str = "view_mode_full";
 pub const VIEW_MODE_BRIEF_ID: &str = "view_mode_brief";
 pub const OPEN_ID: &str = "open";
+pub const EDIT_ID: &str = "edit";
 pub const SHOW_IN_FINDER_ID: &str = "show_in_finder";
 pub const COPY_PATH_ID: &str = "copy_path";
 pub const COPY_FILENAME_ID: &str = "copy_filename";
@@ -119,6 +120,7 @@ pub fn build_menu<R: Runtime>(
 
     // Add File menu items
     let open_item = tauri::menu::MenuItem::with_id(app, OPEN_ID, "Open", true, None::<&str>)?;
+    let edit_item = tauri::menu::MenuItem::with_id(app, EDIT_ID, "Edit", true, Some("F4"))?;
     let show_in_finder_item =
         tauri::menu::MenuItem::with_id(app, SHOW_IN_FINDER_ID, "Show in Finder", true, Some("Opt+Cmd+O"))?;
     let copy_path_item =
@@ -139,6 +141,7 @@ pub fn build_menu<R: Runtime>(
             submenu.prepend(&copy_filename_item)?;
             submenu.prepend(&copy_path_item)?;
             submenu.prepend(&show_in_finder_item)?;
+            submenu.prepend(&edit_item)?;
             submenu.prepend(&open_item)?;
             break;
         }
@@ -302,6 +305,7 @@ pub fn build_context_menu<R: Runtime>(
     let menu = Menu::new(app)?;
 
     let open_item = tauri::menu::MenuItem::with_id(app, OPEN_ID, "Open", true, None::<&str>)?;
+    let edit_item = tauri::menu::MenuItem::with_id(app, EDIT_ID, "Edit", true, Some("F4"))?;
     let show_in_finder_item =
         tauri::menu::MenuItem::with_id(app, SHOW_IN_FINDER_ID, "Show in Finder", true, Some("Opt+Cmd+O"))?;
     let copy_path_item =
@@ -319,6 +323,7 @@ pub fn build_context_menu<R: Runtime>(
     // Add items to menu
     if !is_directory {
         menu.append(&open_item)?;
+        menu.append(&edit_item)?;
     }
     menu.append(&show_in_finder_item)?;
     menu.append(&tauri::menu::PredefinedMenuItem::separator(app)?)?;

apps/desktop/src/lib/commands/command-registry.ts

@@ -184,6 +184,13 @@ export const commands: Command[] = [
     // ============================================================================
     // File list - File action commands
     // ============================================================================
+    {
+        id: 'file.edit',
+        name: 'Edit in default editor',
+        scope: 'Main window/File list',
+        showInPalette: true,
+        shortcuts: ['F4'],
+    },
     {
         id: 'file.showInFinder',
         name: 'Show in Finder',

apps/desktop/src/lib/file-explorer/FilePane.svelte

@@ -33,6 +33,7 @@
         listVolumes,
         mountNetworkShare,
         openFile,
+        openInEditor,
         showFileContextMenu,
         type UnlistenFn,
         updateMenuContext,
@@ -964,6 +965,13 @@
         }
     }
 
+    /** Gets the file entry under the cursor from the current list view */
+    function getEntryUnderCursor(): FileEntry | undefined {
+        const listRef = viewMode === 'brief' ? briefListRef : fullListRef
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-return
+        return listRef?.getEntryAt(cursorIndex)
+    }
+
     // Exported so DualPaneExplorer can forward keyboard events
     export function handleKeyDown(e: KeyboardEvent) {
         if (isNetworkView) {
@@ -973,16 +981,24 @@
 
         // Handle Enter key - navigate into the entry under the cursor
         if (e.key === 'Enter') {
-            const listRef = viewMode === 'brief' ? briefListRef : fullListRef
-            // eslint-disable-next-line @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-assignment
-            const entry: FileEntry | undefined = listRef?.getEntryAt(cursorIndex)
+            const entry = getEntryUnderCursor()
             if (entry) {
                 e.preventDefault()
                 void handleNavigate(entry)
                 return
             }
         }
 
+        // Handle F4 key - open file in default text editor
+        if (e.key === 'F4') {
+            const entry = getEntryUnderCursor()
+            if (entry && !entry.isDirectory) {
+                e.preventDefault()
+                void openInEditor(entry.path)
+                return
+            }
+        }
+
         // Handle Backspace or ⌘↑ - go to parent directory
         if ((e.key === 'Backspace' || (e.key === 'ArrowUp' && e.metaKey)) && hasParent) {
             e.preventDefault()

apps/desktop/src/lib/tauri-commands.ts

@@ -403,6 +403,15 @@ export async function getInfo(path: string): Promise<void> {
     await invoke('get_info', { path })
 }
 
+/**
+ * Open file in the system's default text editor (macOS only).
+ * Uses `open -t` which opens the file in the default text editor.
+ * @param path - Absolute path to the file.
+ */
+export async function openInEditor(path: string): Promise<void> {
+    await invoke('open_in_editor', { path })
+}
+
 /**
  * Shows the main window.
  * Should be called when the frontend is ready to avoid white flash.

apps/desktop/src/routes/+page.svelte

@@ -16,6 +16,7 @@
         copyToClipboard,
         quickLook,
         getInfo,
+        openInEditor,
         toggleHiddenFiles,
         setViewMode,
         getWindowTitle,
@@ -452,6 +453,15 @@
                 return
 
             // === File action commands ===
+            case 'file.edit': {
+                const entryUnderCursor = explorerRef?.getFileAndPathUnderCursor()
+                if (entryUnderCursor) {
+                    await openInEditor(entryUnderCursor.path)
+                }
+                explorerRef?.refocus()
+                return
+            }
+
             case 'file.showInFinder': {
                 const entryUnderCursor = explorerRef?.getFileAndPathUnderCursor()
                 if (entryUnderCursor) {