getSystemService....

WINDOW_SERVICE	"window"	The top-level window manager in which you can place custom windows. The returned object is a WindowManager.
LAYOUT_INFLATER_SERVICE	"layout_inflater"	A LayoutInflater for inflating layout resources in this context.
ACTIVITY_SERVICE	"activity"	A ActivityManager for interacting with the global activity state of the system.
POWER_SERVICE	"power"	A PowerManager for controlling power management.
ALARM_SERVICE	"alarm"	A AlarmManager for receiving intents at the time of your choosing.
NOTIFICATION_SERVICE	"notification"	A NotificationManager for informing the user of background events.
KEYGUARD_SERVICE	"keyguard"	A KeyguardManager for controlling keyguard.
LOCATION_SERVICE	"location"	A LocationManager for controlling location e.g., GPS updates.
SEARCH_SERVICE	"search"	A SearchManager for handling search.
VIBRATOR_SERVICE	"vibrator"	A Vibrator for interacting with the vibrator hardware.
CONNECTIVITY_SERVICE	"connection"	A ConnectivityManager for handling management of network connections.
WIFI_SERVICE	"wifi"	A WifiManager for management of Wi-Fi connectivity.
INPUT_METHOD_SERVICE	"input_method"	An InputMethodManager for management of input methods.
UI_MODE_SERVICE	"uimode"	An UiModeManager for controlling UI modes.
DOWNLOAD_SERVICE	"download"	A DownloadManager for requesting HTTP downloads

I am looking for way to contorl whold system in app side.

getSystemService is very important keyword.

mWindowManager = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);

is needed to me.