NavDrawerFrag.java

package mx.ambmultimedia.brillamexico.fragments;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.Toolbar;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import mx.ambmultimedia.brillamexico.R;

public class NavDrawerFrag extends Fragment {
    public static final String PREF_FILE_NAME = "textprefbs";
    public static final String KEY_USER_LEARNED_DRAWER = "user_learned_drawer";

    private ActionBarDrawerToggle mDrawerToggle;
    private DrawerLayout mDrawerLayout;

    private boolean mUserLearnedDrawer;
    private boolean mFromSaveInstanceState;

    private View containView;

    public NavDrawerFrag() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mUserLearnedDrawer = Boolean.valueOf( readFromPreference(getActivity(), KEY_USER_LEARNED_DRAWER, "false") );
        if (savedInstanceState != null) {
            mFromSaveInstanceState = true;
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_nav_drawer, container, false);
    }

    public void setUp (int fragmentID, DrawerLayout drawer_layout, Toolbar toolbar) {
        containView = getActivity().findViewById(fragmentID);
        mDrawerLayout = drawer_layout;
        mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawer_layout, toolbar, R.string.dwOpen, R.string.dwClose) {
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                if (!mUserLearnedDrawer) {
                    mUserLearnedDrawer = true;
                    saveToPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer + "");
                }
                getActivity().invalidateOptionsMenu();
            }
            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                if (!mUserLearnedDrawer) {
                    mUserLearnedDrawer = false;
                    saveToPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer + "");
                }
                getActivity().invalidateOptionsMenu();

            }
        };
        if (!mUserLearnedDrawer && !mFromSaveInstanceState) {
            mDrawerLayout.openDrawer(containView);
        }
        containView.setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if (keyCode == KeyEvent.KEYCODE_BACK) {
                    mDrawerLayout.closeDrawer(containView);
                }
                return true;
            }
        });
        mDrawerLayout.setDrawerListener(mDrawerToggle);
        mDrawerLayout.post(new Runnable() {
            @Override
            public void run() {
                mDrawerToggle.syncState();
            }
        });
    }

    public static void saveToPreferences (Context context, String preferenceName, String preferenceValue) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(preferenceName, preferenceValue);
        editor.apply();
    }

    public static String readFromPreference (Context context, String prefenceName, String defaultValue) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
        return sharedPreferences.getString(prefenceName, defaultValue);
    }
}