android - How to detect expanding of status bar? -

my application allows launching of other application mine. none of activity shows status bar.but when launching other applications camera user can access status bar.so tried following code snippet collapsing status bar inside service(so collapse every time , code running always).

int currentapiversion = android.os.build.version.sdk_int; object service = getsystemservice("statusbar"); class<?> statusbarmanager = class.forname("android.app.statusbarmanager"); method collapse = null; if(currentapiversion <= 16){     collapse = statusbarmanager.getmethod("collapse"); }else{     collapse = statusbarmanager.getmethod("collapsepanels"); } collapse.setaccessible(true); collapse.invoke(service); 

now want collapse status bar if user try expand this.is there intent or intent filter exist detect expanding of status bar?

thanks in advance

there no callback of kind when notification bar dragged down on android.

this because android apps meant designed in way notification bar coming , going away not affect functioning in way.