x/y are screen coordinates; pass -1, -1 to position the menu at the
focused control (for a keyboard-triggered menu via the Apps key or
Shift+F10). The chosen command is delivered to parent as a WM_COMMAND,
so it routes through dispatchMenuCommand like any other menu command.
Show menu as a context menu owned by parent.
x/y are screen coordinates; pass -1, -1 to position the menu at the focused control (for a keyboard-triggered menu via the Apps key or Shift+F10). The chosen command is delivered to parent as a WM_COMMAND, so it routes through dispatchMenuCommand like any other menu command.