How to get current content view of activity?

Question

I have a content view say primary set on main activity, when clicked on a button, it sets another content view say secondary with setContentView(R.layout.sec_content). What i want now that when Back Button Pressed, It should set the primary content if current view is secondary otherwise it should close the activity. how do i do that? here is my code

public class Ch_1 extends AppCompatActivity {

Button men1, men2, men3;
TextView tv1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_ch_1);

    men1 = (Button)findViewById(R.id.men1);
    men1.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            setContentView(R.layout.activity_read__view);
            TextView tv1 = (TextView)findViewById(R.id.read_view);
            tv1.setText("This is text in READ_VIEW activity");




        }
    });


}

}

Answer 1

public class MainActivity extends AppCompatActivity {

Boolean isClose = true;
Button btn;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btn = (Button) findViewById(R.id.button);
}

public void onpressed(View view){
    isClose = false;
    setContentView(R.layout.second);
}

@Override
public void onBackPressed() {
    if (isClose){
        finish();
    } else {
        setContentView(R.layout.activity_main);
        isClose = true;
    }
}

}