fix(menu): make View → Zoom In accept the unshifted Ctrl+= key (#55)

The app relied on Electron's default application menu, whose View → Zoom In
binds only `CommandOrControl+Plus`. On US / most keyboard layouts "+" is the
shifted form of `=`, so pressing Ctrl with the unshifted +/= key sends Ctrl+=
and nothing happened — while Zoom Out (`Ctrl+-`, no Shift) worked, making zoom
feel half-broken.

Install an explicit application menu that mirrors Electron's default via
role-based submenus and hand-builds only View, where Zoom In also accepts
`Ctrl+=` and numpad `+` (hidden sibling items keep `Ctrl+Shift+=` and numpad
working). Strictly additive — no other menu behaviour changes.


Claude-Session: https://claude.ai/code/session_01QbexxfTt8q2tAn436MqGWF

Co-authored-by: ChrisBeWithYou <chris@rifflarr.local>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

src/main/app-menu.ts

@@ -0,0 +1,51 @@
+import { Menu, MenuItemConstructorOptions } from 'electron';
+
+// Application menu.
+//
+// We previously relied on Electron's DEFAULT application menu. Its View
+// submenu binds Zoom In to `CommandOrControl+Plus` only. On US / most
+// keyboard layouts "+" is the SHIFTED form of the `=` key, so pressing
+// Ctrl with the (unshifted) +/= key sends `Ctrl+=`, which the default
+// accelerator does NOT match — Zoom In appears broken while Zoom Out
+// (`Ctrl+-`, no Shift needed) works. That asymmetry is the reported bug.
+//
+// This template reproduces Electron's default menu via role-based submenus
+// (so File/Edit/Window behaviour and their accelerators are unchanged) and
+// hand-builds only the View submenu, where Zoom In additionally accepts the
+// unshifted `=` key and the numpad `+`. Result: every way a user presses
+// "Ctrl and plus" — `Ctrl+=`, `Ctrl+Shift+=` (the literal `+`), and numpad
+// `Ctrl++` — now zooms in, restoring parity with Zoom Out.
+export function installAppMenu(): void {
+    const isMac = process.platform === 'darwin';
+
+    const viewSubmenu: MenuItemConstructorOptions[] = [
+        { role: 'reload' },
+        { role: 'forceReload' },
+        { role: 'toggleDevTools' },
+        { type: 'separator' },
+        { role: 'resetZoom' },
+        // Primary, shown in the menu: the unshifted +/= key. This is the
+        // keystroke the bug report says did nothing.
+        { role: 'zoomIn', accelerator: 'CommandOrControl+=' },
+        // Hidden siblings keep the other "plus" keystrokes working so this is
+        // strictly additive (no regression for users who pressed Shift, and
+        // numpad support for good measure). A MenuItem carries one accelerator,
+        // so extra bindings are extra (invisible) items.
+        { role: 'zoomIn', accelerator: 'CommandOrControl+Plus', visible: false },
+        { role: 'zoomIn', accelerator: 'CommandOrControl+numadd', visible: false },
+        { role: 'zoomOut' },
+        { role: 'zoomOut', accelerator: 'CommandOrControl+numsub', visible: false },
+        { type: 'separator' },
+        { role: 'togglefullscreen' },
+    ];
+
+    const template: MenuItemConstructorOptions[] = [
+        ...(isMac ? [{ role: 'appMenu' } as MenuItemConstructorOptions] : []),
+        { role: 'fileMenu' },
+        { role: 'editMenu' },
+        { label: 'View', submenu: viewSubmenu },
+        { role: 'windowMenu' },
+    ];
+
+    Menu.setApplicationMenu(Menu.buildFromTemplate(template));
+}

src/main/main.ts

@@ -124,6 +124,7 @@ import { initPluginManager } from './plugin-manager';
 import { initSoundfontManager, getDesktopConfig, setDesktopConfig } from './soundfont-manager';
 import * as updateManager from './update-manager';
 import type { UpdateChannel } from './update-manager';
+import { installAppMenu } from './app-menu';
 
 // Linux: enable Chromium's PipeWire capturer feature so getUserMedia can see
 // audio devices on PipeWire-only distros (Fedora 36+, recent Ubuntu, Arch).
@@ -1026,6 +1027,10 @@ async function startup(): Promise<void> {
     // Create the main window
     createWindow(port);
 
+    // Install our application menu (replaces Electron's default so View →
+    // Zoom In also accepts the unshifted Ctrl+= key — see app-menu.ts).
+    installAppMenu();
+
     // Register file picker IPC
     ipcMain.handle('dialog:pickFile', async (_event, filters?: { name: string; extensions: string[] }[]) => {
         if (!mainWindow) return null;