Return the current activity that was set by the Java method com.lispworks.Manager.setCurrentActivity.
android-get-current-activity returns the current activity that was set by the Java method com.lispworks.Manager.setCurrentActivity, if the current thread is the Android main thread.
android-get-current-activity first checks whether the current thread is the main thread, and if it is not returns
nil. Otherwise, it returns the activity that was last set by com.lispworks.Manager.setCurrentActivity (an object of class
android.app.Activity). This is the object that is needed to create dialogs.
LispWorks User Guide and Reference Manual - 13 Feb 2015