EnhancedPlatformMenuDelegate class

EnhancedPlatformMenuDelegate

A PlatformMenuDelegate that bridges Flutter’s platform menu API to a host-platform implementation over a MethodChannel ("enhanced_platform_menu"). It serializes Flutter PlatformMenuItem trees (including enhanced variants) into a channel-friendly payload, sends them to the host, and routes menu selection callbacks back into Flutter.

What it does

• setMenus / clearMenus: Publishes or clears the entire top-level menu structure via channel methods Menu.Set and Menu.Clear.
• Serialization: Converts PlatformMenu, PlatformMenuItem, and PlatformMenuItemGroup into a nested map:
  • Menus: { kind: 'menu', label, children, [identifier], [removeDefaults], [icon...] }
  • Leaf items: { kind: 'leaf', id, label, enabled, [shortcut], [checked], [icon...] }
  • Group separators are emitted between grouped items as { kind: 'separator' }.
  • Supports EnhancedPlatformMenu (identifier, removeDefaults, optional icon) and EnhancedPlatformMenuItem (checked, optional icon).
• Shortcuts: Serializes MenuSerializableShortcut using serializeForMenu().toChannelRepresentation().
• Selection handling: Registers a per-item callback keyed by a generated id. When the host sends Menu.Selected with that id, the delegate:
  1. Tries to invoke the item’s onSelectedIntent via Actions (using the current focus context or a debug-locked context), and if enabled, calls it; otherwise
  2. Falls back to calling onSelected.

Debug locking (assert-only)

• debugLockDelegate(context) and debugUnlockDelegate(context) enforce that only one BuildContext (the locker) may be used to resolve Actions when no focused context is available. In release builds these always return true.

Channel contract

• Outbound:
  • Menu.Set with { menus: [...] }
  • Menu.Clear
• Inbound:
  • Menu.Selected with { id: String } to trigger the registered callback.

Notes

• enabled for a leaf is true if onSelected or onSelectedIntent is present.
• Uses FocusManager.instance.primaryFocus?.context or the locked context to resolve Actions.find / Actions.invoke.
• Intended to run on the UI isolate; keep lifecycle of the delegate aligned with your app’s menu bar lifecycle.

Should be set in app's main function via WidgetsBinding.instance.platformMenuDelegate = EnhancedPlatformMenuDelegate();