A Boolean value that indicates whether the window can become the application’s main window.
- macOS 10.0+
The value of this property is
true when the window can become the main window; otherwise,
Attempts to make the window the main window are abandoned if the value of this property is
false. The value of the property is
true if the window is visible, is not an
NSPanel object, and has a title bar or a resize mechanism. Otherwise, the value is