Develop Reference

android navigation drawer recreating fragments everytime

I am loading a simple navigation drawer with 3 fragments inside. When i go to 1st fragment and click a button in that fragment then the buttons background color is changed then i am navigating to second fragment and again i am coming back to the 1st fragment i want my fragment (With color changed button) in the backstack. But it is recreated everytime. I have tried multiple ways no luck. Since i am new to fragments i am stuck with this.
public class SampleActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener, Fragment1.OnFragmentInteractionListener,
Fragment2.OnFragmentInteractionListener, Fragment3.OnFragmentInteractionListener {
static Fragment fragment = null;
private static final String FRAGMENT1_TAG = "FRAGMENT1_TAG";
private static final String FRAGMENT2_TAG = "FRAGMENT2_TAG";
private static final String FRAGMENT3_TAG = "FRAGMENT3_TAG";
#Override
public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
super.onSaveInstanceState(outState, outPersistentState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sample);
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
// getMenuInflater().inflate(R.menu.dashboard, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
navigateToFragment(id);
return true;
}
#Override
public void onFragmentInteraction(Uri uri) {
}
public void navigateToFragment(int itemId) {
// Handle navigation view item clicks here.
String FRAGMENT_TAG="";
switch (itemId) {
case R.id.nav_fragment1:
FRAGMENT_TAG = FRAGMENT1_TAG;
fragment = Fragment1.newInstance();
break;
case R.id.nav_fragment2:
FRAGMENT_TAG = FRAGMENT2_TAG;
fragment = Fragment2.newInstance();
break;
case R.id.nav_fragment3:
FRAGMENT_TAG = FRAGMENT3_TAG;
fragment = Fragment3.newInstance();
break;
default:
FRAGMENT_TAG = FRAGMENT1_TAG;
fragment = Fragment1.newInstance();
break;
}
FragmentManager supportFragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
Fragment inputFragment = supportFragmentManager.findFragmentByTag(FRAGMENT_TAG);
if (inputFragment == null) {
fragmentTransaction.replace(R.id.content_frame, fragment, FRAGMENT_TAG).addToBackStack(null).commit();
} else {
fragmentTransaction.replace(R.id.content_frame, inputFragment, FRAGMENT_TAG).addToBackStack(null).commit();
}
DrawerLayout drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
drawerLayout.closeDrawer(GravityCompat.START);
}
}

You should add the code of Fragment2.newInstance(); to know better the behaviour.
This code probably solve your problem:
public class SampleActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener, Fragment1.OnFragmentInteractionListener,
Fragment2.OnFragmentInteractionListener, Fragment3.OnFragmentInteractionListener {
static Fragment fragment1 = null;
static Fragment fragment2 = null;
static Fragment fragment3 = null;
private static final String FRAGMENT1_TAG = "FRAGMENT1_TAG";
private static final String FRAGMENT2_TAG = "FRAGMENT2_TAG";
private static final String FRAGMENT3_TAG = "FRAGMENT3_TAG";
#Override
public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
super.onSaveInstanceState(outState, outPersistentState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sample);
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
// getMenuInflater().inflate(R.menu.dashboard, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
navigateToFragment(id);
return true;
}
#Override
public void onFragmentInteraction(Uri uri) {
}
public void navigateToFragment(int itemId) {
// Handle navigation view item clicks here.
String FRAGMENT_TAG="";
Fragment fragment = null;
switch (itemId) {
case R.id.nav_fragment2:
FRAGMENT_TAG = FRAGMENT2_TAG;
if(fragment2 == null) fragment2 = Fragment2.newInstance();
fragment = fragment2;
break;
case R.id.nav_fragment3:
FRAGMENT_TAG = FRAGMENT3_TAG;
if(fragment3 == null) fragment3 = Fragment3.newInstance();
fragment = fragment3;
break;
default:
FRAGMENT_TAG = FRAGMENT1_TAG;
if(fragment1 == null) fragment1 = Fragment1.newInstance();
fragment = fragment1;
break;
}
FragmentManager supportFragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
Fragment inputFragment = supportFragmentManager.findFragmentByTag(FRAGMENT_TAG);
if (inputFragment == null) {
fragmentTransaction.replace(R.id.content_frame, fragment, FRAGMENT_TAG).addToBackStack(null).commit();
} else {
fragmentTransaction.replace(R.id.content_frame, inputFragment, FRAGMENT_TAG).addToBackStack(null).commit();
}
DrawerLayout drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
drawerLayout.closeDrawer(GravityCompat.START);
}
}
I recommend you to refactor a little bit your code to get a more elegant solution.
Be sure that you're using fragmentTransaction.add() to add a fragment for the first time.

Use stack to keep track on fragment.
Check below link for reference.
https://github.com/rathodchintan/Fragment-Back-Stack
1.do not use replace method if you don't want to reload your fragment.
Instead you it use add method with keeping fragment object in the stack.
if you want to use replace, than check whether fragment is their in the memory by using findFragmentByTag method, and if it's not null use it else create new fragment.

restore tab state on switching from navigation drawer

I have 4 tabs in Fragment A.The first tab has a listview. I have attached a Navigation drawer switching between other 3 tabs, Fragment B, C and D. Now when I switch from Fragment A to Fragment B and back, the first tab doesn't show the listview. But when I switch from 3rd tab and come back to 1st tab it gets the listview data and loads it. What am I doing wrong? I have attached my MainActivity which has implemented navigation drawer and my HomeFragment which has four tabs.
MainActivity.java
public class MainActivity extends AppCompatActivity implements {
// index to identify current nav menu item
public static int navItemIndex = 0;
// tags used to attach the fragments
// toolbar titles respected to selected nav menu item
private String[] activityTitles;
// flag to load home fragment when user presses back key
private boolean shouldLoadHomeFragOnBackPress = true;
private Handler mHandler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mDatabase1 = FirebaseDatabase.getInstance().getReference();
mHandler = new Handler();
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
navigationView = (NavigationView) findViewById(R.id.nav_view);
fab = (FloatingActionButton) findViewById(R.id.fab);
// Navigation view header
// load toolbar titles from string resources
activityTitles = getResources().getStringArray(R.array.nav_item_activity_titles);
// load nav menu header data
loadNavHeader();
// initializing navigation menu
setUpNavigationView();
if (savedInstanceState == null) {
navItemIndex = 0;
CURRENT_TAG = TAG_HOME;
loadHomeFragment();
}
}
/***
* Load navigation menu header information
* like background image, profile image
* name, website, notifications action view (dot)
*/
private void loadNavHeader() {
}
/***
* Returns respected fragment that user
* selected from navigation menu
*/
private void loadHomeFragment() {
// selecting appropriate nav menu item
selectNavMenu();
// set toolbar title
setToolbarTitle();
// if user select the current navigation menu again, don't do anything
// just close the navigation drawer
if (getSupportFragmentManager().findFragmentByTag(CURRENT_TAG) != null) {
drawer.closeDrawers();
// show or hide the fab button
toggleFab();
return;
}
// Sometimes, when fragment has huge data, screen seems hanging
// when switching between navigation menus
// So using runnable, the fragment is loaded with cross fade effect
// This effect can be seen in GMail app
Runnable mPendingRunnable = new Runnable() {
#Override
public void run() {
// update the main content by replacing fragments
Fragment fragment = getHomeFragment();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(android.R.anim.fade_in,
android.R.anim.fade_out);
fragmentTransaction.replace(R.id.frame, fragment, CURRENT_TAG);
fragmentTransaction.commitAllowingStateLoss();
}
};
// If mPendingRunnable is not null, then add to the message queue
if (mPendingRunnable != null) {
mHandler.post(mPendingRunnable);
}
// show or hide the fab button
toggleFab();
//Closing drawer on item click
drawer.closeDrawers();
// refresh toolbar menu
invalidateOptionsMenu();
}
private Fragment getHomeFragment() {
switch (navItemIndex) {
case 0:
// home
HomeFragment homeFragment = new HomeFragment();
return homeFragment;
case 1:
case 2:
case 3:
case 4:
default:
return new HomeFragment();
}
}
private void setToolbarTitle() {
getSupportActionBar().setTitle(activityTitles[navItemIndex]);
}
private void selectNavMenu() {
navigationView.getMenu().getItem(navItemIndex).setChecked(true);
}
private void setUpNavigationView() {
//Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
// This method will trigger on item Click of navigation menu
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
//Check to see which item was being clicked and perform appropriate action
switch (menuItem.getItemId()) {
//Replacing the main content with ContentFragment Which is our Inbox View;
case R.id.nav_home:
navItemIndex = 0;
break;
case R.id.nav_live:
navItemIndex = 1;
break;
case R.id.nav_edit:
navItemIndex = 2;
break;
case R.id.nav_competitions:
navItemIndex = 3;
break;
case R.id.nav_settings:
navItemIndex = 4;
break;
case R.id.nav_about_us:
// launch new intent instead of loading fragment
startActivity(new Intent(MainActivity.this, CompetitionActivity.class));
drawer.closeDrawers();
return true;
case R.id.nav_report_bug:
// launch new intent instead of loading fragment
startActivity(new Intent(MainActivity.this, ReportBugActivity.class));
drawer.closeDrawers();
return true;
default:
navItemIndex = 0;
}
//Checking if the item is in checked state or not, if not make it in checked state
if (menuItem.isChecked()) {
menuItem.setChecked(false);
} else {
menuItem.setChecked(true);
}
menuItem.setChecked(true);
loadHomeFragment();
return true;
}
});
ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.openDrawer, R.string.closeDrawer) {
#Override
public void onDrawerClosed(View drawerView) {
// Code here will be triggered once the drawer closes as we dont want anything to happen so we leave this blank
super.onDrawerClosed(drawerView);
}
#Override
public void onDrawerOpened(View drawerView) {
// Code here will be triggered once the drawer open as we dont want anything to happen so we leave this blank
super.onDrawerOpened(drawerView);
}
};
//Setting the actionbarToggle to drawer layout
drawer.setDrawerListener(actionBarDrawerToggle);
//calling sync state is necessary or else your hamburger icon wont show up
actionBarDrawerToggle.syncState();
}
#Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawers();
return;
}
// This code loads home fragment when back key is pressed
// when user is in other fragment than home
if (shouldLoadHomeFragOnBackPress) {
// checking if user is on other navigation menu
// rather than home
if (navItemIndex != 0) {
navItemIndex = 0;
CURRENT_TAG = TAG_HOME;
loadHomeFragment();
return;
}
}
new AlertDialog.Builder(this).setIcon(android.R.drawable.ic_dialog_alert).setTitle("Exit")
.setMessage("Are you sure?")
.setPositiveButton("yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();
}
}).setNegativeButton("no", null).show();
//System.exit(0);
//super.onBackPressed();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
// show menu only when home fragment is selected
if (navItemIndex == 0) {
getMenuInflater().inflate(R.menu.main, menu);
}
// when fragment is notifications, load the menu created for notifications
if (navItemIndex == 3) {
getMenuInflater().inflate(R.menu.notifications, menu);
}
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_logout) {
auth = FirebaseAuth.getInstance();
auth.signOut();
startActivity(new Intent(MainActivity.this, LoginActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
// show or hide the fab
private void toggleFab() {
if (navItemIndex == 0)
fab.show();
else
fab.hide();
}
#Override
public void onFragmentInteraction(Uri uri) {
}
private int dpToPx(int dp)
{
float density = getApplication().getResources().getDisplayMetrics().density;
return Math.round((float)dp * density);
}
#Override
public void setActionBarTitle(String home) {
}`**
HomeFragment.java
public class HomeFragment extends android.support.v4.app.Fragment {
private AppCompatActivity aca=new AppCompatActivity();
//private class Act extends AppCompatActivity {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
//tabs
private String[] mPlanetTitles;
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
private int[] tabIcons = {
R.drawable.ic_question_answer_black_24dp,
R.drawable.ic_notifications_black_24dp,
R.drawable.ic_people_black_24dp,
R.drawable.ic_face_black_24dp,
};
private OnFragmentInteractionListener mListener;
private LayoutInflater inflator;
public ViewGroup container;
private Bundle savedInstancesState;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment HomeFragment.
*/
// TODO: Rename and change types and number of parameters
public HomeFragment newInstance(String param1, String param2) {
HomeFragment fragment = new HomeFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onActivityCreated(savedInstanceState);
}
public HomeFragment() {
// Required empty public constructor
}
LayoutInflater inflater;
#Override
public void onCreate(Bundle savedInstanceState) {
setRetainInstance(true);
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Context context=getContext();
inflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
View v=inflater.inflate(R.layout.fragment_home, container, false);
viewPager = (ViewPager) v.findViewById(R.id.viewpager);
//viewPager.setOffscreenPageLimit(3);
setupViewPager(viewPager);
tabLayout = (TabLayout) v.findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
setupTabIcons();
return v;
}
private void setupTabIcons() {
tabLayout.getTabAt(0).setIcon(tabIcons[0]);
tabLayout.getTabAt(1).setIcon(tabIcons[1]);
tabLayout.getTabAt(2).setIcon(tabIcons[2]);
tabLayout.getTabAt(3).setIcon(tabIcons[3]);
ColorStateList colors;
colors = getResources().getColorStateList(R.color.tab_icon);
for (int i = 0; i < tabLayout.getTabCount(); i++) {
TabLayout.Tab tab = tabLayout.getTabAt(i);
Drawable icon = tab.getIcon();
if (icon != null) {
icon = DrawableCompat.wrap(icon);
DrawableCompat.setTintList(icon, colors);
}
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
#Override
public void onDestroyView(){
super.onDestroyView();
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter((getActivity()).getSupportFragmentManager());
adapter.addFrag();
adapter.addFrag();
adapter.addFrag();
adapter.addFrag();
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<android.support.v4.app.Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public android.support.v4.app.Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFrag(android.support.v4.app.Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
//return mFragmentTitleList.get(position);
return null;
}
}
public void setActionBarTitle(String title) {
aca.getSupportActionBar().setTitle(title);
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
void setActionBarTitle(String home);
}
}

Set Fragments with TabLayout and Navigation Drawer

My project has a NavigationDrawer and a TabLayout. I'm just looking for setting a specific fragment in a specific menu in a specific tab.
I mean, almost each menu item has 3 differents tabs (not specially the same) and I want to set a fragment who will be different in each tab for each menu item.
The 3 tabs are the same in each menu item.
What I have to do ? I though of about setContentView() but I cannot make it work properly.
Here is screenshots of my app:
Navigation Drawer with all menu items
Sliding Tabs of a menu item
Here is my MainActivity.java:
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Get the ViewPager and set it's PagerAdapter so that it can display items
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(new SampleFragmentPagerAdapter(getSupportFragmentManager(),
MainActivity.this));
// Give the TabLayout the ViewPager
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
findViewById(R.id.viewpager).setVisibility(View.GONE);
findViewById(R.id.sliding_tabs).setVisibility(View.GONE);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Pourquoi tu touches à ce bouton ?", Snackbar.LENGTH_SHORT)
.setAction("Action", null).show();
}
});
/*
Début Drawer Menu
*/
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
/*
Fin Drawer Menu
*/
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.content_main) {
findViewById(R.id.viewpager).setVisibility(View.GONE);
findViewById(R.id.sliding_tabs).setVisibility(View.GONE);
} else if (id == R.id.nav_equations) {
findViewById(R.id.viewpager).setVisibility(View.VISIBLE);
findViewById(R.id.sliding_tabs).setVisibility(View.VISIBLE);
} else if (id == R.id.nav_lois) {
findViewById(R.id.viewpager).setVisibility(View.VISIBLE);
findViewById(R.id.sliding_tabs).setVisibility(View.VISIBLE);
} else if (id == R.id.nav_stats) {
findViewById(R.id.viewpager).setVisibility(View.VISIBLE);
findViewById(R.id.sliding_tabs).setVisibility(View.VISIBLE);
} else if (id == R.id.nav_tests) {
findViewById(R.id.viewpager).setVisibility(View.VISIBLE);
findViewById(R.id.sliding_tabs).setVisibility(View.VISIBLE);
} else if (id == R.id.nav_partager) {
} else if (id == R.id.nav_parametres) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
#Override
public void onStart() {
super.onStart();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client.connect();
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"Main Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://com.example.slabre.mathix/http/host/path")
);
AppIndex.AppIndexApi.start(client, viewAction);
}
#Override
public void onStop() {
super.onStop();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"Main Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://com.example.slabre.mathix/http/host/path")
);
AppIndex.AppIndexApi.end(client, viewAction);
client.disconnect();
} }
This is the SampleFragmentPagerAdapter.java, used to manage the fragments but only on each tabs :
public class SampleFragmentPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[] = new String[] { "Calcul", "Résultat", "Infos" };
private Context context;
public SampleFragmentPagerAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return PageFragment.newInstance(position);
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
}
And so the PageFragment.java :
public class PageFragment extends Fragment{
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static PageFragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_page, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
Finally this is the app_bar_main.xml included by the activity_main.xml :
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.example.slabre.mathix.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay" />
<android.support.design.widget.TabLayout
android:id="#+id/sliding_tabs"
style="#style/MyCustomTabLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="scrollable" />
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1"
android:background="#android:color/white" />
</android.support.design.widget.AppBarLayout>
<include layout="#layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
android:src="#drawable/ic_add_black_24dp" />
</android.support.design.widget.CoordinatorLayout>
I really don't know if you need more files, just ask me if you want more.

If I understand the question correctly, you just need to implement getItem(int position) in the ViewPager adapter to return different Fragments for each of the possible positions in the adapter. Currently it only returns 1 type of Fragment, but passes in the position as an argument, so all menu items show "Fragment #X".
The first step you can do is create different Fragment classes with different layouts and return those in the getItem method.
For example, copy the entire class of PageFragment and create a PageTwoFragment class. Then in the PagerAdapter class, you can do something like
#Override
public int getCount() {
return PAGE_COUNT; // TODO: Change how many pages
}
#Override
public Fragment getItem(int position) {
if (position == 1) {
return new PageTwoFragment(); // TODO: Implement
} else {
return PageFragment.newInstance(position);
}
// TODO: Return other Fragments for other positions
}
The next step would be to create new ViewPager Adapter classes for each of the menu items in the NavigationView and reset the adapter of the ViewPager within the onNavigationItemSelected method like so
if (id == R.id.nav_equations) {
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
// TODO: Implement EquationsFragmentPagerAdapter
viewPager.setAdapter(new EquationsFragmentPagerAdapter(getSupportFragmentManager(), MainActivity.this));
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
}
Note: You would have less duplicate code if you made field variables for the ViewPager and TabLayout
That should get you different numbers of tabs and various Fragments to swipe through for each menu item.

NavigationDrawer not show the view

I have a Navigation Drawer with Navigation View, there are four tabs, one of them is a fragment, which includes ViewPager, ie is a host for the other fragments. Everything works fine, but when switched from fragment with ViewPager any other fragment of NavigationDrawer shows nothing. Checked logs, onCreate, onCreateView these fragments are called, but why does not display... Who knows why?
NavigationDrawer
public class NavigationDrawerHost extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListener {
//буду использовать эту активность как хост под все фрагменты, чтобы верно работал мой drawer!
public static String WHERE_FROM = NavigationDrawerHost.class.getSimpleName();
public static Toolbar toolbar;
public static ProgressBar progressBar;
private DrawerLayout drawer;
private NavigationView navigationView;
private ActionBarDrawerToggle drawerToggle;
private int navItemId;
private static final String NAV_ITEM_ID = "NAV_ITEM_ID";
private TextView userFirstNameTextView, userLastNameTextView;
private ImageView userPhotoImageView;
private VKAccessToken access_token; //токен это информация о правах доступа
private VKApiUser user; //текущий пользователь
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.navigation_drawer_host);
progressBar = (ProgressBar) findViewById(R.id.progressBar);
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
// Find the toolbar view inside the activity layout
toolbar = (Toolbar) findViewById(R.id.toolbar);
// Set a Toolbar to replace the ActionBar.
setSupportActionBar(toolbar);
//setTitle(R.string.drawer_menu_posts);
// load saved navigation state if present
if (null == savedInstanceState) {
navItemId = R.id.posts_fragment;
} else {
navItemId = savedInstanceState.getInt(NAV_ITEM_ID);
}
// Find our drawer view
navigationView = (NavigationView) findViewById(R.id.nvView);
navigationView.setNavigationItemSelectedListener(this);
// select the correct nav menu item
navigationView.getMenu().findItem(navItemId).setChecked(true);
// если хотим добавить какие-то элементы в наш header,
// то нужно добавить их в layout, а затем инициализировать нижеприведенным способом
// Inflate the header view at runtime
View headerLayout = navigationView.inflateHeaderView(R.layout.nav_header);
// We can now look up items within the header if needed
userFirstNameTextView = (TextView) headerLayout.findViewById(R.id.user_first_name);
userLastNameTextView = (TextView) headerLayout.findViewById(R.id.user_last_name);
userPhotoImageView = (ImageView) headerLayout.findViewById(R.id.user_photo);
drawerToggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.drawer_open, R.string.drawer_close);
// Tie DrawerLayout events to the ActionBarToggle
drawer.setDrawerListener(drawerToggle);
drawerToggle.syncState();
selectItem(navItemId);
}
#Override
protected void onSaveInstanceState(final Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(NAV_ITEM_ID, navItemId);
}
// Menu icons are inflated just as they were with actionbar
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_exit:
//quitDialog();
VKSdk.logout();
finish();
return true;
default:
return drawerToggle.onOptionsItemSelected(item) || super.onOptionsItemSelected(item);
}
}
// Make sure this is the method with just `Bundle` as the signature
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
drawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggles
drawerToggle.onConfigurationChanged(newConfig);
}
private void selectItem(final int itemId) {
// perform the actual navigation logic, updating the main content fragment etc
// Create a new fragment and specify the planet to show based on position
Fragment fragment = null;
Class fragmentClass = null;
switch (itemId) {
case R.id.posts_fragment:
fragmentClass = PostsFragment.class;
fragment = new PostsFragment();
break;
case R.id.albums_fragment:
fragmentClass = FragmentTest.class;
fragment = new FragmentTest();
break;
case R.id.friends_fragment:
fragmentClass = FragmentTest.class;
fragment = new FragmentTest();
break;
case R.id.likes_fragment:
fragmentClass = LikesFragment.class;
fragment = new LikesFragment();
break;
/*default:
fragmentClass = PostsFragment.class;*/
}
/*try {
fragment = (Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}*/
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.fragment_container, fragment);
transaction.addToBackStack(null);
transaction.commit();
drawer.closeDrawers();
}
#Override
public boolean onNavigationItemSelected(final MenuItem item) {
// update highlighted item in the navigation menu
item.setChecked(true);
setTitle(item.getTitle());
navItemId = item.getItemId();
// allow some time after closing the drawer before performing real navigation
// so the user can see what is happening
drawer.closeDrawer(GravityCompat.START);
selectItem(item.getItemId());
return true;
}
#Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else if (getSupportFragmentManager().getBackStackEntryCount() == 0) {
quitDialog();
} else {
getSupportFragmentManager().popBackStack();
}
}
private void quitDialog() {
AlertDialog.Builder quitDialog = new AlertDialog.Builder(this);
quitDialog.setTitle("Вы хотите выйти?");
quitDialog.setPositiveButton("Да", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
//стираем БД
Delete.tables(PostTable.class, PictureTable.class, PostTableMyLikes.class, PictureTableMyLikes.class);
FlowManager.getDatabase(WallDatabase.DB_NAME).reset(NavigationDrawerHost.this);
FlowManager.getDatabase(WallDatabaseMyLikes.DB_NAME).reset(NavigationDrawerHost.this);
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
});
quitDialog.setNegativeButton("Нет",
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
});
quitDialog.show();
}
}
ViewPager host for fragments, which needs to display through ViewPager
//этот фрагмент является хостом для MyLikesFragment и FriendLikesFragment, так же тут содержатся табы
public class LikesFragment extends Fragment {
public static String WHERE_FROM_FRIENDS_LIKES = LikesFragment.class.getSimpleName() + "_FRIENDSLIKES";
private ViewPager viewPager;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.likes_fragment, container, false);
TabLayout tabLayout = (TabLayout) v.findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Мои лайки"));
tabLayout.addTab(tabLayout.newTab().setText("Лайки друзей"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
viewPager = (ViewPager) v.findViewById(R.id.view_pager);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
viewPager.setAdapter(new LikesPagerAdapter(getChildFragmentManager()));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
return v;
}
public static class LikesPagerAdapter extends FragmentPagerAdapter {
public LikesPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return 2;
}
//сделано так, чтобы передавать те аргументы, от которых будет зависеть функционал фрагмента
#Override
public Fragment getItem(int position) {
return (position == 0) ? new MyLikesPostsFragment() : new PostsFragment();
}
#Override
public CharSequence getPageTitle(int position) {
return (position == 0) ? "Мои лайки" : "Лайки друзей";
}
}
}
P.S. And after going to the same fragment ViewPager select several items in drawer, this should not be

The problem was that I called adapter.notifyDataSetChanged() in the main thread and onPostExecute() in AsyncTask. My carelessness...

Google Navigation Drawer, handling backpress to set correct checked ite

Currently Used Google Navigation Drawer, having some problem when user backpress.
When user backpress, they didn't update menu Item
Example When I click the App. The sequence are A>B>C>B>C ,if I backpress I wanted to be C>B>A. How should I code this way out ?
My code
public class MainActivity extends AppCompatActivity {
private String appTitle;
private Toolbar toolbar;
private NavigationView navigationView;
private DrawerLayout drawerLayout;
private TextView toolbarTitle;
private Fragment fragment;
private FragmentManager fragmentManager;
private Title title;
private MenuItem menuItem2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Actionbar
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbarTitle = (TextView) toolbar.findViewById(R.id.toolbar_title);
toolbarTitle.setTextColor(Color.parseColor("#FFFFFF"));
setTitle("");
fragmentManager = getSupportFragmentManager();
fragment= new HomeFragment();
title = new Title(getApplicationContext());
fragmentManager.beginTransaction().replace(R.id.content_frame,fragment , title.getStrHome()).commit();
navigationView = (NavigationView) findViewById(R.id.navigation_view);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
menuItem2 = menuItem;
menuItem.setChecked(true);
drawerLayout.closeDrawers();
if (menuItem.getItemId() == R.id.nav_home) {
fragment = new HomeFragment();
appTitle = title.getStrHome();
} else if ((menuItem.getItemId() == R.id.nav_direction)) {
fragment = new DirectionFragment();
appTitle = title.getStrDirection();
} else if ((menuItem.getItemId() == R.id.nav_more)) {
fragment = new MoreFragment();
appTitle = title.getStrMore();
} else if((menuItem.getItemId()==R.id.nav_directory)){
fragment = new DirectoryFragment();
appTitle = title.getStrDirectory();
}
else {
Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_SHORT).show();
}
replaceFragment(fragment,appTitle);
return true;
}
});
drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
ActionBarDrawerToggle actionBarDrawerToggle =
new ActionBarDrawerToggle
(this,drawerLayout,toolbar,R.string.drawer_open,R.string.drawer_close){
#Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
}
#Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
}
};
drawerLayout.setDrawerListener(actionBarDrawerToggle);
actionBarDrawerToggle.syncState();
}
public void onBackPressed() {
if(drawerLayout.isDrawerOpen(GravityCompat.START)){
drawerLayout.closeDrawer(GravityCompat.START);
}
else {
if (fragmentManager.getBackStackEntryCount() > 0 ){
fragmentManager.popBackStack();
toolbarTitle.setText(appTitle);
menuItem2.setChecked(true);
} else {
finish();
}
}
}
public void replaceFragment(Fragment fragment, String tag){
toolbarTitle.setText(tag);
FragmentTransaction ft = fragmentManager.beginTransaction().replace(R.id.content_frame, fragment, tag);
ft.addToBackStack(tag);
ft.commit();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}

As stated on the official page on Android tasks and back stack you can see how you can accomplish your desired behaviour using the FLAG_ACTIVITY_CLEAR_TOP in your Intent flags. This picture demonstrates it very well.
Your regular back button proceeds as:
When you specify this flag, you get a behavior like you need
Edit:
The official documentation states:
FLAG_ACTIVITY_CLEAR_TOP
If the activity being started is already running in the current task, then instead of launching a new instance of that activity, all of the
other activities on top of it are destroyed
This means, there will be no duplicates of your different Activities, and you will have a clean Back Stack.
In your example A>B>C>B>C would not be possible. Instead it would be A>B>C, since B and C already exist in the stack, they will not be added, but replaced instead.

Study the Android Activity Launch Mode.
here is the clear Explanation available.
Just take a look.