ToolbarToggleUtils.java

// This method allow to handle Drawer and back functionality with state.

public class ToolbarToggleUtils {
  public static void enableViews(boolean enable) {

        // To keep states of ActionBar and ActionBarDrawerToggle synchronized,
        // when you enable on one, you disable on the other.
        // And as you may notice, the order for this operation is disable first, then enable - VERY VERY IMPORTANT.
        if(enable) {
            //You may not want to open the drawer on swipe from the left in this case  
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED);
            // Remove hamburger
            mDrawerToggle.setDrawerIndicatorEnabled(false);
            // Show back button
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            // when DrawerToggle is disabled i.e. setDrawerIndicatorEnabled(false), navigation icon
            // clicks are disabled i.e. the UP button will not work.
            // We need to add a listener, as in below, so DrawerToggle will forward
            // click events to this listener.
            if(!mToolBarNavigationListenerIsRegistered) {
                mDrawerToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        // Doesn't have to be onBackPressed
                        onBackPressed();
                    }
                });

                mToolBarNavigationListenerIsRegistered = true;
            }

        } else {
            //You must regain the power of swipe for the drawer. 
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED);

            // Remove back button
            getSupportActionBar().setDisplayHomeAsUpEnabled(false);
            // Show hamburger 
            mDrawerToggle.setDrawerIndicatorEnabled(true);
            // Remove the/any drawer toggle listener
            mDrawerToggle.setToolbarNavigationClickListener(null);
            mToolBarNavigationListenerIsRegistered = false;
        }

        // So, one may think "Hmm why not simplify to:
        // .....
        // getSupportActionBar().setDisplayHomeAsUpEnabled(enable);
        // mDrawer.setDrawerIndicatorEnabled(!enable);
        // ......
        // To re-iterate, the order in which you enable and disable views IS important #dontSimplify.
    }
}