Returns active keyboard layout index. [b]Note:[/b] This method is implemented on Linux, macOS and Windows. Returns the number of keyboard layouts. [b]Note:[/b] This method is implemented on Linux, macOS and Windows. Returns the ISO-639/BCP-47 language code of the keyboard layout at position [code]index[/code]. [b]Note:[/b] This method is implemented on Linux, macOS and Windows. Returns the localized name of the keyboard layout at position [code]index[/code]. [b]Note:[/b] This method is implemented on Linux, macOS and Windows. Sets active keyboard layout. [b]Note:[/b] This method is implemented on Linux, macOS and Windows. Return the greatest scale factor of all screens. [b]Note:[/b] On macOS returned value is [code]2.0[/code] if there is at least one hiDPI (Retina) screen in the system, and [code]1.0[/code] in all other cases. [b]Note:[/b] This method is implemented on macOS. Return the scale factor of the specified screen by index. [b]Note:[/b] On macOS returned value is [code]2.0[/code] for hiDPI (Retina) screen, and [code]1.0[/code] for all other cases. [b]Note:[/b] This method is implemented on macOS.