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android fragment does not show in view pager

I have an application. I use in Main activity tab layout with view pager. I tried to load a fragment in every 3 tab in my view pager.but my fragment does not show in view pager.I did it before several times but now it does not work!!
I dont know where is my mistake.
mainactivity.java:
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
ImageView hamgerMenu;
DrawerLayout drawer;
TabLayout tabLayout;
ViewPager viewPager;
ViewPagerAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
setupviews();
}
private void setupviews() {
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
viewPager = (ViewPager) findViewById(R.id.viewPager);
adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragments(new FragmentFriends(), "فعالیت ها");
adapter.addFragments(new FragmentFriends(), "فعالیت ها");
adapter.addFragments(new FragmentFriends(), "فعالیت ها");
adapter.addFragments(new FragmentFriends(), "فعالیت ها");
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(2);
tabLayout.setupWithViewPager(viewPager);
hamgerMenu = (ImageView) findViewById(R.id.img_mainactivity_hambermenu);
hamgerMenu.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
drawer.openDrawer(Gravity.RIGHT);
}
});
}
#Override
public void onBackPressed() {
if (drawer.isDrawerOpen(Gravity.RIGHT)) {
drawer.closeDrawer(Gravity.RIGHT);
} 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.nav_camera) {
// Handle the camera action
} else if (id == R.id.nav_gallery) {
} else if (id == R.id.nav_slideshow) {
} else if (id == R.id.nav_manage) {
} else if (id == R.id.nav_share) {
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(Gravity.RIGHT);
return true;
}
}
viewpagerAdapter:
public class ViewPagerAdapter extends FragmentPagerAdapter {
ArrayList<Fragment> fragments;
ArrayList<String> titles;
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
fragments=new ArrayList<>();
titles=new ArrayList<>();
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
public void addFragments(Fragment fragment,String title){
fragments.add(fragment);
titles.add(title);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return titles.get(position);
}
}
fragment:
public class FragmentFriends extends Fragment {
View view;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
inflater.inflate(R.layout.friends_fragment,container,false);
return view;
}
}
mainactivity.xml:
<android.support.v4.widget.DrawerLayout 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:id="#+id/drawer_layout"
android:layoutDirection="rtl"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">
<include
layout="#layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.design.widget.NavigationView
android:id="#+id/nav_view"
android:layoutDirection="rtl"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="right"
android:fitsSystemWindows="true"
app:headerLayout="#layout/nav_header_main"
app:menu="#menu/activity_main_drawer" />
</android.support.v4.widget.DrawerLayout>
appbarmain.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:layoutDirection="rtl"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layoutDirection="rtl"
android:elevation="0dp"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<RelativeLayout
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:layoutDirection="rtl">
<ImageView
android:id="#+id/img_mainactivity_hambermenu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="8dp"
android:src="#drawable/ic_hambermenu" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="#string/app_name"
android:textColor="#color/white"
android:textSize="18dp" />
</RelativeLayout>
<android.support.design.widget.TabLayout
android:id="#+id/tabLayout"
android:background="#color/colorPrimary"
app:tabIndicatorColor="#color/white"
app:tabSelectedTextColor="#color/colorAccent"
app:tabTextColor="#color/white"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</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"
app:srcCompat="#android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
contentmain.xml:
<LinearLayout 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:orientation="vertical"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
tools:showIn="#layout/app_bar_main">
<android.support.v4.view.ViewPager
android:layoutDirection="ltr"
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>

just make this change it will work
view = inflater.inflate(R.layout.friends_fragment,container,false);

Navigation Drawer too slow while opening and closing

Opening and closing of the drawer is very slow and laggy. No related errors are shown in monitor. If any one is familiar with this issue ? What might be possible errors ?
Thanks in advance
This is what i did
Recycler view adapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
String[] titles;
TypedArray icons;
Context context;
// The default constructor to receive titles,icons and context from MainActivity.
public RecyclerViewAdapter(String[] titles, TypedArray icons, Context context) {
this.titles = titles;
this.icons = icons;
this.context = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = (LayoutInflater) parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (viewType == 1) {
View itemLayout = layoutInflater.inflate(R.layout.drawer_item_layout, null);
return new ViewHolder(itemLayout, viewType, context);
} else if (viewType == 0) {
View itemHeader = layoutInflater.inflate(R.layout.header_layout, null);
return new ViewHolder(itemHeader, viewType, context);
}
return null;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
if (position != 0) {
holder.navTitle.setText(titles[position - 1]);
holder.navIcon.setImageResource(icons.getResourceId(position - 1, -1));
}
}
#Override
public int getItemCount() {
return titles.length + 1;
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView navTitle;
ImageView navIcon;
Context context;
public ViewHolder(View drawerItem, int itemType, Context context) {
super(drawerItem);
this.context = context;
drawerItem.setOnClickListener(this);
if (itemType == 1) {
navTitle = (TextView) itemView.findViewById(R.id.tv_NavTitle);
navIcon = (ImageView) itemView.findViewById(R.id.iv_NavIcon);
}
}
/**
* This defines onClick for every item with respect to its position.
*/
#Override
public void onClick(View v) {
switch (getAdapterPosition()){
case 1:
Intent home= new Intent(context,HomeActivity.class);
home.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
context.startActivity(home);
break;
case 2:
// Intent profile= new Intent(context,HomeActivity.class);
// profile.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
// context.startActivity(profile);
break;
case 3:
// Intent accnt= new Intent(context,HomeActivity.class);
// accnt.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
// context.startActivity(accnt);
break;
case 4:
Intent cart= new Intent(context,MyCartLoginActivity.class);
cart.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
context.startActivity(cart);
break;
case 5:
// Intent phis= new Intent(context,HomeActivity.class);
// phis.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
// context.startActivity(phis);
// break;
case 6:
Intent logout= new Intent(context,LoginActivity.class);
logout.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);
context.startActivity(logout);
break;
}
}
}
public int getItemViewType(int position) {
if (position == 0) return 0;
else return 1;
}
}
Main Activity
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
DrawerLayout drawerLayout;
RecyclerView recyclerView;
String navTitles[];
TypedArray navIcons;
RecyclerView.Adapter recyclerViewAdapter;
ActionBarDrawerToggle drawerToggle;
FrameLayout frameLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);frameLayout = (FrameLayout)findViewById(R.id.containerView);
setupToolbar();
//Initialize Views
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
drawerLayout = (DrawerLayout) findViewById(R.id.drawerMainActivity);
// Setup Titles and Icons of Navigation Drawer
navTitles = getResources().getStringArray(R.array.navDrawerItems);
navIcons = getResources().obtainTypedArray(R.array.navDrawerIcons);
recyclerViewAdapter = new RecyclerViewAdapter(navTitles,navIcons,this);
recyclerView.setAdapter(recyclerViewAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
//recyclerView.setLayoutManager(new LinearLayoutManager(this));
// Finally setup ActionBarDrawerToggle
setupDrawerToggle();
}
void setupToolbar(){
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// toolbar.setNavigationIcon(R.drawable.ic_action_menu);
getSupportActionBar().setDisplayShowHomeEnabled(true);
}
void setupDrawerToggle(){
drawerToggle = new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.app_name,R.string.app_name);
//This is necessary to change the icon of the Drawer Toggle upon state change.
drawerToggle.setDrawerIndicatorEnabled(false);
drawerToggle.setHomeAsUpIndicator(R.drawable.ic_action_menu);
drawerToggle.syncState();
}
}
Header Layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorAccent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="25dp"
android:layout_marginTop="25dp">
<RelativeLayout
android:layout_width="90dp"
android:layout_height="90dp"
android:id="#+id/rlh"
android:layout_marginLeft="15dp"
android:background="#drawable/circ"
android:gravity="center">
<ImageView
android:id="#+id/icon"
android:layout_width="60dp"
android:layout_height="60dp"
android:layout_centerInParent="true"
android:scaleType="fitXY"
android:src="#drawable/logo5" />
</RelativeLayout>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="#+id/rlh"
android:layout_toEndOf="#+id/rlh"
android:layout_marginLeft="10dp"
android:layout_marginStart="10dp"
android:layout_marginTop="15dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Nithin Kumar"
android:textStyle="bold"
android:textColor="#FFF"
android:id="#+id/uname"
android:textSize="17dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/uname"
android:layout_marginTop="2dp"
android:textStyle="bold"
android:text="+919876543210"
android:textColor="#FFF"
android:textSize="13dp" />
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
Drawer Item Layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:gravity="center_horizontal"
android:layout_width="match_parent"
android:layout_marginTop="140dp"
android:layout_height="60dp">
<RelativeLayout
android:id="#+id/drawerItem"
android:layout_gravity="center_horizontal"
android:gravity="center_vertical"
android:layout_width="match_parent"
android:layout_height="40dp">
<ImageView
android:layout_marginLeft="45dp"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_gravity="center"
android:tint="#251e1e"
android:layout_centerVertical="true"
android:id="#+id/iv_NavIcon"/>
<de.morrox.fontinator.FontTextView
android:layout_toRightOf="#+id/iv_NavIcon"
app:font="Lato-Regular.ttf"
android:layout_gravity="center"
android:text="Claimed Offers"
android:layout_centerVertical="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:id="#+id/tv_NavTitle"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="#251e1e"
android:textSize="16sp"
android:gravity="center"/>
</RelativeLayout>
</RelativeLayout>
Main activity layout
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawerMainActivity"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<include
android:id="#+id/toolbar"
layout="#layout/toolbar" />
<FrameLayout
android:layout_below="#+id/toolbar"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/containerView">
</FrameLayout>
</RelativeLayout>
<android.support.v7.widget.RecyclerView
android:layout_width="240dp"
android:layout_height="fill_parent"
android:id="#+id/recyclerView"
android:scrollbars="vertical"
android:background="#FFF"
android:layout_gravity="left"
/>
</android.support.v4.widget.DrawerLayout>

The problem was solved by clearing cache and increasing heap size of the application. Also decreased the size of the logo in the navigation drawer

Navigation Drawer: setNavigationItemSelectedListener is not working.

Here, This is my implementation in java:
import static com.example.krsnv.kooc.R.id.nav_gro;
public class Displayprofile extends AppCompatActivity {
private FirebaseRecyclerAdapter<User, userholder> mAdapter;
RecyclerView mRecyclerView;
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mToggle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.displayprofile);
mDrawerLayout = (DrawerLayout)findViewById(R.id.drawerlayout) ;
mToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
// getSupportActionBar().setDisplayHomeAsUpEnabled(true);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener(){
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
int id = menuItem.getItemId();
if (id == R.id.nav_account) {
Toast.makeText(Displayprofile.this, "my account",Toast.LENGTH_LONG).show();
}
else if (id == R.id.nav_settings)
{
Toast.makeText(Displayprofile.this,"settings",Toast.LENGTH_SHORT).show();
}
else if (id == R.id.nav_logout)
{
Toast.makeText(Displayprofile.this,"logout",Toast.LENGTH_SHORT).show();
}
else if (id == nav_gro)
{
Toast.makeText(Displayprofile.this,"groceries",Toast.LENGTH_SHORT).show();
}
return true;
}
} );
DatabaseReference mRef = FirebaseDatabase.getInstance().getReference().child("workers");
mRecyclerView = (RecyclerView) findViewById(R.id.userrecycler);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mAdapter = new FirebaseRecyclerAdapter<User, userholder>(User.class, android.R.layout.two_line_list_item, userholder.class, mRef) {
#Override
public void populateViewHolder(userholder userViewHolder, User users, int position) {
userViewHolder.setName(users.getName());
userViewHolder.setText(users.getPhone());
}
};
mRecyclerView.setAdapter(mAdapter);
mDrawerLayout.addDrawerListener(mToggle);
mToggle.syncState();
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mToggle.onOptionsItemSelected(item))
{
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onDestroy() {
super.onDestroy();
mAdapter.cleanup();
}
public static class userholder extends RecyclerView.ViewHolder {
private final TextView mNameField;
private final TextView mTextField;
public userholder(View itemView) {
super(itemView);
mNameField = (TextView) itemView.findViewById(android.R.id.text1);
mTextField = (TextView) itemView.findViewById(android.R.id.text2);
}
public void setName(String name) {
mNameField.setText(name);
}
public void setText(String text) {
mTextField.setText(text);
}
}
}
The xml code is given below:
>
<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#cecece"
>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="40dp"
android:orientation="vertical"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="3"
android:layout_gravity="center"
android:gravity="center"
android:textSize="18sp"
android:text="find chef's near you\n"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/userrecycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clipToPadding="false"
android:padding="16dp"
/>
</LinearLayout>
</ScrollView>
<android.support.design.widget.NavigationView
android:layout_width="wrap_content"
android:layout_height="match_parent"
app:menu="#menu/navigation_menu"
android:layout_gravity="start"
app:headerLayout="#layout/navigation_header"
android:id="#+id/nav_view">
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>
When I click an item in the navigation drawer it doesn't show the Toast message. Here, setNavigationItemSelectedListener is not working So, what can be done to solve this issue ?

In order to use this setNavigationItemSelectedListener you should have menu as give below in res->menu folder
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="#+id/menu_payment"
android:checked="false"
android:icon="#drawable/ic_action_payment"
android:title="#string/menu_payment" />
<item
android:id="#+id/menu_history"
android:checked="false"
android:icon="#drawable/ic_action_history"
android:title="#string/menu_history" />
</menu>

Add this
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.navigation_menu, menu);
return true;
}

Viewpager With tabLayout and PagerTabStrip

I Experimented a bit in viewPager.
One viewpager with different FragmentAdapter.
For now the code works perfectly but I don't know if its the right way to do that.
For my Activity is this.
public class Navigation extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener, TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener, View.OnClickListener {
private DrawerLayout drawer;
private ViewPager pager;
public static TabHost tabHost;
public static TabWidget tabWidget;
public static FloatingActionMenu fab;
private boolean doubleBackToExitPressedOnce = false;
private String currentTab;
private Button mButton;
private LinearLayout mLinearLayout;
private PagerSlidingTabStrip mTabLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().getAttributes().windowAnimations = 0;
setContentView(R.layout.activity_navigation);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
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();
fab = (FloatingActionMenu) findViewById(R.id.fabMenu);
fab.setVisibility(View.GONE);
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
tabHost = (TabHost) findViewById(R.id.tabHost);
tabHost.setup();
tabHost.setOnTabChangedListener(this);
tabWidget = (TabWidget) findViewById(android.R.id.tabs);
setNewTab(tabHost, "tab1", R.string.textTabTitle1, R.drawable.icon_search, R.id.tab1);
setNewTab(tabHost, "tab2", R.string.textTabTitle1, R.drawable.icon_comment, R.id.tab2);
setNewTab(tabHost, "tab3", R.string.textTabTitle1, R.drawable.icon_car, R.id.tab3);
mTabLayout = (PagerSlidingTabStrip) findViewById(R.id.tab);
pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(new FragmentAdapterSearch(getSupportFragmentManager()));
mTabLayout.setViewPager(pager);
pager.addOnPageChangeListener(this);
mButton = (Button) findViewById(R.id.btnSearch);
mLinearLayout = (LinearLayout) findViewById(R.id.btnSelectLocation);
mButton.setOnClickListener(this);
mLinearLayout.setOnClickListener(this);
TabIcon.setColor(0, mTabLayout, iconSearchOpac, iconSearch);
}
private void setNewTab(TabHost tabHost, String tag, int title, int icon, int contentID) {
TabHost.TabSpec tabSpec = tabHost.newTabSpec(tag);
tabSpec.setIndicator(getTabIndicator(tabHost.getContext(), title, icon));
tabSpec.setContent(contentID);
tabHost.addTab(tabSpec);
}
private View getTabIndicator(Context context, int title, int icon) {
View view = LayoutInflater.from(context).inflate(R.layout.tab_layout, null);
final ImageView iv = (ImageView) view.findViewById(R.id.imageView);
iv.setImageResource(icon);
TextView tv = (TextView) view.findViewById(R.id.textView);
tv.setText(title);
return view;
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else if (!drawer.isDrawerOpen(GravityCompat.START)) {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Tap Again to Exit Toweelo", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 2000);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.navigation, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
if (drawer.isDrawerOpen(Gravity.LEFT)) {
drawer.closeDrawer(Gravity.LEFT);
} else {
drawer.openDrawer(Gravity.LEFT);
}
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.nav_camera) {
} else if (id == R.id.nav_gallery) {
} else if (id == R.id.nav_slideshow) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
#Override
public void onTabChanged(String tabId) {
currentTab = tabId;
if (currentTab.equalsIgnoreCase("tab1")) {
if (pager != null) {
pager.setAdapter(new FragmentAdapterSearch(getSupportFragmentManager()));
mButton.setVisibility(View.VISIBLE);
TabIcon.setColor(0, mTabLayout, iconSearchOpac, iconSearch);
}
}
if (currentTab.equalsIgnoreCase("tab2")) {
if (pager != null) {
pager.setAdapter(new FragmentAdapterComments(getSupportFragmentManager()));
mButton.setVisibility(View.INVISIBLE);
TabIcon.setColor(0, mTabLayout, iconCommentOpac, iconComment);
}
}
if (currentTab.equalsIgnoreCase("tab3")) {
if (pager != null) {
pager.setAdapter(new FragmentAdapterCars(getSupportFragmentManager()));
mButton.setVisibility(View.VISIBLE);
TabIcon.setColor(0, mTabLayout, iconCarOpac, iconCar);
}
}
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
if (currentTab.equalsIgnoreCase("tab1")) {
TabIcon.setColor(position, mTabLayout, iconSearchOpac, iconSearch);
}
if (currentTab.equalsIgnoreCase("tab2")) {
TabIcon.setColor(position, mTabLayout, iconCommentOpac, iconComment);
}
if (currentTab.equalsIgnoreCase("tab3")) {
TabIcon.setColor(position, mTabLayout, iconCarOpac, iconCar);
}
}
#Override
public void onPageScrollStateChanged(int state) {
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btnSearch:
startActivity(new Intent(Navigation.this, SelectCategory.class));
break;
case R.id.btnSelectLocation:
startActivity(new Intent(Navigation.this, SelectLocation.class));
}
}
}
And for my XML is this.
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:fab="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:background="#color/colorWhite"
android:fitsSystemWindows="true"
tools:context="com.toweelo.Navigation">
<android.support.design.widget.AppBarLayout
android:id="#+id/appBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:theme="#style/AppTheme.AppBarOverlay"
app:elevation="0dp">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
>
<LinearLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:weightSum="10">
<LinearLayout android:id="#+id/btnSelectLocation"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="5.5"
android:background="#drawable/ripple_effect"
android:clickable="true"
android:gravity="center_horizontal"
android:orientation="horizontal"
android:paddingLeft="8dp">
<com.toweelo.custom.CustomTextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="Quezon City"
android:textColor="#color/colorWhite"
android:textSize="#dimen/title"/>
<ImageView
android:layout_width="24dp"
android:layout_height="match_parent"
android:src="#drawable/ic_down_arrow"/>
</LinearLayout>
<RelativeLayout android:layout_width="0dp"
android:layout_height="36dp"
android:layout_marginLeft="10dp"
android:layout_weight="4.5">
<Button android:id="#+id/btnSearch"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/custom_search_button"
android:drawableRight="#drawable/ic_search"
android:text="Search"
android:textColor="#color/colorWhite"
android:textSize="14dp"/>
</RelativeLayout>
</LinearLayout>
</android.support.v7.widget.Toolbar>
<com.astuetz.PagerSlidingTabStrip
android:id="#+id/tab"
android:layout_width="match_parent"
android:layout_height="48dp"
android:background="#color/colorPrimary"
app:pstsDividerColor="#color/colorPrimary"
app:pstsIndicatorColor="#color/colorWhite"
app:pstsIndicatorHeight="3dp"
app:pstsShouldExpand="true"
app:pstsTextAllCaps="false"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
/>
<com.github.clans.fab.FloatingActionMenu
android:id="#+id/fabMenu"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
fab:menu_animationDelayPerItem="50"
fab:menu_backgroundColor="#B3FFFFFF"
fab:menu_buttonSpacing="0dp"
fab:menu_colorNormal="#DA4336"
fab:menu_colorPressed="#E75043"
fab:menu_colorRipple="#99FFFFFF"
fab:menu_fab_size="normal"
fab:menu_icon="#drawable/fab_add"
fab:menu_labels_colorNormal="#color/colorWhite"
fab:menu_labels_cornerRadius="3dp"
fab:menu_labels_ellipsize="none"
fab:menu_labels_margin="0dp"
fab:menu_labels_maxLines="-1"
fab:menu_labels_padding="8dp"
fab:menu_labels_paddingBottom="4dp"
fab:menu_labels_paddingLeft="8dp"
fab:menu_labels_paddingRight="8dp"
fab:menu_labels_paddingTop="4dp"
fab:menu_labels_position="left"
fab:menu_labels_showShadow="true"
fab:menu_labels_singleLine="false"
fab:menu_labels_textColor="#color/colorBlack"
fab:menu_labels_textSize="14sp"
fab:menu_openDirection="up"
fab:menu_shadowColor="#66000000"
fab:menu_shadowRadius="4dp"
fab:menu_shadowXOffset="1dp"
fab:menu_shadowYOffset="3dp"
fab:menu_showShadow="true"
>
<com.github.clans.fab.FloatingActionButton
android:id="#+id/menuIn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_premium"
fab:fab_colorNormal="#color/colorPremium"
fab:fab_colorPressed="#color/colorPremiumDark"
fab:fab_colorRipple="#color/colorPremiumAccent"
fab:fab_label="Premium"
fab:fab_size="mini"
/>
<com.github.clans.fab.FloatingActionButton
android:id="#+id/menuOut"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_saves"
fab:fab_colorNormal="#color/colorSaves"
fab:fab_colorPressed="#color/colorSavesDark"
fab:fab_colorRipple="#color/colorSavesAccent"
fab:fab_label="Saves"
fab:fab_size="mini"/>
<com.github.clans.fab.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_edit"
fab:fab_colorNormal="#color/colorPrimary"
fab:fab_colorPressed="#color/colorPrimaryDark"
fab:fab_colorRipple="#color/colorAccent"
fab:fab_label="Write"
fab:fab_size="mini"/>
</com.github.clans.fab.FloatingActionMenu>
<TabHost android:id="#+id/tabHost"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1">
<LinearLayout
android:id="#+id/tab1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorWhite"
android:orientation="vertical">
</LinearLayout>
<LinearLayout
android:id="#+id/tab2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorWhite"
android:orientation="vertical">
</LinearLayout>
<LinearLayout
android:id="#+id/tab3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorWhite"
android:orientation="vertical">
</LinearLayout>
</FrameLayout>
<TabWidget
android:id="#android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="52dp"
android:layout_weight="0"
android:showDividers="none"/>
</LinearLayout>
</TabHost>
</android.support.design.widget.CoordinatorLayout>
So I'am wondering if my code will do some errors in the future use?
I mean, will it have out of memory problem since i am using only one viewpager for different adapters.
And for the tab with pagerTabStrip Am i doing it right implemeting it both?
Thanks.

So you are setting a new FragmentPagerAdapter on each TabHost, thus creating 3 new fragments at runtime when the user clicks another tab. This might cause confusion to the user and if the framgments load heavy resources, greater memory consumption and further user annoyance.

Recycler view not displaying items-Android studio

I am making an app which consists of a navigation drawer and a recycler view inside it. However, the items inside the recycler view are not being displayed. I am not sure what I have been doing wrong. I will provide what I have. If you require anything please ask. Thanks
Adapter
public class Adapter extends RecyclerView.Adapter<Adapter.MyViewHolder> {
private LayoutInflater inflater;
List<Information> data = Collections.emptyList();
public Adapter(Context context, List<Information> data){
inflater=LayoutInflater.from(context);
this.data=data;
}
public MyViewHolder onCreateViewHolder(ViewGroup parent, int i) {
View view = inflater.inflate(R.layout.custom_row, parent, false);
MyViewHolder holder= new MyViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(MyViewHolder viewHolder, int i) {
Information current = data.get(i);
viewHolder.title.setText(current.title);
viewHolder.icon.setImageResource(current.iconId);
}
#Override
public int getItemCount() {
return 0;
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView title;
ImageView icon;
public MyViewHolder(View itemView) {
super(itemView);
title = (TextView) itemView.findViewById(R.id.listText);
icon = (ImageView) itemView.findViewById(R.id.listIcon);
}
}
}
Information
public class Information {
int iconId;
String title;
}
NavigationDrawerFragment
public class NavigationDrawerFragment extends Fragment {
private RecyclerView recyclerView;
public static final String PREF_FILE_NAME = "testpref";
public static final String KEY_USER_LEARNED_DRAWER = "user_learned_drawer";
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private boolean mUserLearnedDrawer;
private View containerView;
private Adapter adapter;
private boolean mFromSavedInstanceState;
public NavigationDrawerFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mUserLearnedDrawer= Boolean.valueOf(readFrompreferences(getActivity(),KEY_USER_LEARNED_DRAWER,"false"));
if(savedInstanceState!=null)
{
mFromSavedInstanceState=true;
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
recyclerView=(RecyclerView) layout.findViewById(R.id.drawerList);
adapter = new Adapter(getActivity(),getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
return layout;
}
public static List<Information> getData(){
List<Information> data = new ArrayList<>();
int[] icons={R.drawable.thechefhat,R.drawable.thegrocerybasket,R.drawable.favouritesstar,R.drawable.supported};
String[] titles = {"Recipes","Ingredients","Favourites","Help"};
for(int i=0;i<titles.length&&i<icons.length;i++){
Information current = new Information();
current.iconId=icons[i];
current.title = titles[i];
data.add(current);
}
return data;
}
public void setUp(int fragmentID, DrawerLayout drawerLayout, final Toolbar toolbar) {
containerView =getActivity().findViewById(fragmentID);
mDrawerLayout=drawerLayout;
mDrawerToggle = new ActionBarDrawerToggle(getActivity(),drawerLayout,toolbar,R.string.drawer_open,R.string.drawer_close){
#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);
getActivity().invalidateOptionsMenu();
}
#Override
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, slideOffset);
if(slideOffset<0.6)
toolbar.setAlpha(1-slideOffset);
}
};
if(!mUserLearnedDrawer&&!mFromSavedInstanceState){
mDrawerLayout.openDrawer(containerView);
}
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 readFrompreferences(Context context, String preferenceName, String defaultValue){
SharedPreferences sharedPreferences=context.getSharedPreferences(PREF_FILE_NAME,Context.MODE_PRIVATE);
return sharedPreferences.getString(preferenceName,defaultValue);
}
}
Main Activity
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar)findViewById(R.id.app_bar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowHomeEnabled(true);
NavigationDrawerFragment drawerFragment = (NavigationDrawerFragment)
getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
drawerFragment.setUp(R.id.fragment_navigation_drawer,(DrawerLayout)findViewById(R.id.drawer_Layout), toolbar);
}
#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) {
// 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);
}
}
custom_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<ImageView
android:padding="8dp"
android:id="#+id/listIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:src="#drawable/supported"
/>
<TextView
android:id="#+id/listText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Dummy Text"
android:padding="8dp"
android:layout_gravity="center_vertical" />
</LinearLayout>
fragment_navigation_drawer.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/lightPrimaryColor"
tools:context="com.example.ivan.tutorialapp.NavigationDrawerFragment">
<LinearLayout
android:id="#+id/containerDrawerImage"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:layout_width="280dp"
android:layout_height="140dp"
android:layout_marginBottom="16dp"
android:src="#drawable/banner" />
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/drawerList"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>
custom_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<ImageView
android:padding="8dp"
android:id="#+id/listIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:src="#drawable/supported"
/>
<TextView
android:id="#+id/listText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Dummy Text"
android:padding="8dp"
android:layout_gravity="center_vertical" />
</LinearLayout>
activity_main.xml
<android.support.v4.widget.DrawerLayout
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:id="#+id/drawer_Layout"
android:layout_width="match_parent"
android:fitsSystemWindows="true"
android:layout_height="match_parent">
<RelativeLayout
android:fitsSystemWindows="true"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.ivan.tutorialapp.MainActivity">
<include
android:id="#+id/app_bar"
layout="#layout/app_bar">
</include>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/app_bar"
android:text="#string/hello_world"
/>
</RelativeLayout>
<fragment
android:id="#+id/fragment_navigation_drawer"
android:name="com.example.ivan.tutorialapp.NavigationDrawerFragment"
android:layout_width="280dp"
android:layout_height="match_parent"
android:layout_gravity="start"
app:layout="#layout/fragment_navigation_drawer"
tools:layout="#layout/fragment_navigation_drawer">
</fragment>
</android.support.v4.widget.DrawerLayout>

You should change this method to return actual item count
#Override
public int getItemCount() {
return 0;
}