[android] dynamically add and remove view to viewpager

(I figured out a solution - please see my post in the Answer section below.)

In my app, the user will start with a single view of his data. I'd like to add a ViewPager and allow the user to add more views as desired. How do I do this? (I dont' want to use the FragmentPagerAdapter.)

I've read countless posts and overviews but am still missing something. Here's what I think I understand:

MainActivity creates a ViewPager and PagerAdapter:

ViewPager pager = null;
MainPagerAdapter adapter = null;
public void onCreate (Bundle savedInstanceState)
{
  super.onCreate (savedInstanceState);
  pager = new ViewPager (this);
  setContentView (pager);

  adapter = new MainPagerAdapter();
  pager.setAdapter (adapter); 

  View v0 = code_to_create_initial_view();
  adapter.add (v0, 0);      
}

Use a PagerAdapter to provide the sets of view. For this it seems I need methods to add and remove views, something like this; obviously more is needed to tell the ViewPager stuff has changed and how to show the change:

class MainPagerAdapter extends PagerAdapter
{
  // This holds all the currently displayable views, in order from left to right.
  private ArrayList<View> views = new ArrayList<View>();

  public void addView (View v, int position)
  {
    views.add (position, v);
  }

  public void removeView (int position)
  {
    views.remove (position);
  }
}

In addition, I need to implement the following vitual methods. I'm lost here - what calls them and what are they supposed to do (ok, getCount is obvious)?

  public object instantiateItem (ViewGroup pager, int position);
  public void destroyItem (ViewGroup, int, Object);
  public int getCount ();
  public boolean isViewFromObject (View, Object);
  • What are the ViewGroup params for - isn't the containing group the ViewPager itself?
  • What does isViewFromObject do - how does an object get associated with a view in the first place?
  • Should I be calling startUpdate and finishUdate when I add or remove views?

Thanks.

This question is related to android android-viewpager swipe

The answer is


There are quite a few discussions around this topic

Although we see it often, using POSITION_NONE does not seem to be the way to go as it is very inefficient memory-wise.

Here in this question, we should consider using Alvaro's approach:

... is to setTag() method in instantiateItem() when instantiating a new view. Then instead of using notifyDataSetChanged(), you can use findViewWithTag() to find the view you want to update.

Here is a SO answer with code based on this idea


I did a similar program. hope this would help you.In its first activity four grid data can be selected. On the next activity, there is a view pager which contains two mandatory pages.And 4 more pages will be there, which will be visible corresponding to the grid data selected.

Following is the mainactivty MainActivity

    package com.example.jeffy.viewpagerapp;
    import android.content.Context;
    import android.content.Intent;
    import android.content.SharedPreferences;
    import android.database.Cursor;
    import android.database.SQLException;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteOpenHelper;
    import android.os.Bundle;
    import android.os.Parcel;
    import android.support.design.widget.FloatingActionButton;
    import android.support.design.widget.Snackbar;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;
    import android.util.Log;
    import android.view.View;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.widget.AdapterView;
    import android.widget.Button;
    import android.widget.GridView;
    import java.lang.reflect.Array;
    import java.util.ArrayList;
    public class MainActivity extends AppCompatActivity {
    SharedPreferences pref;
    SharedPreferences.Editor editor;
    GridView gridView;
    Button button;
    private static final String DATABASE_NAME = "dbForTest.db";
    private static final int DATABASE_VERSION = 1;
    private static final String TABLE_NAME = "diary";
    private static final String TITLE = "id";
    private static final String BODY = "content";
    DBHelper  dbHelper = new DBHelper(this);
    ArrayList<String> frags = new ArrayList<String>();
    ArrayList<FragmentArray> fragmentArray = new ArrayList<FragmentArray>();
    String[] selectedData;
    Boolean port1=false,port2=false,port3=false,port4=false;
    int Iport1=1,Iport2=1,Iport3=1,Iport4=1,location;



    // This Data show in grid ( Used by adapter )
        CustomGridAdapter customGridAdapter = new           CustomGridAdapter(MainActivity.this,GRID_DATA);
    static final String[ ] GRID_DATA = new String[] {
            "1" ,
            "2",
            "3" ,
            "4"
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        frags.add("TabFragment3");
        frags.add("TabFragment4");
        frags.add("TabFragment5");
        frags.add("TabFragment6");
        dbHelper = new DBHelper(this);
        dbHelper.insertContact(1,0);
        dbHelper.insertContact(2,0);
        dbHelper.insertContact(3,0);
        dbHelper.insertContact(4,0);
        final Bundle selected = new Bundle();
        button = (Button) findViewById(R.id.button);
        pref = getApplicationContext().getSharedPreferences("MyPref", MODE_PRIVATE);
        editor = pref.edit();
        gridView = (GridView) findViewById(R.id.gridView1);

        gridView.setAdapter(customGridAdapter);

        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
              //view.findViewById(R.id.grid_item_image).setVisibility(View.VISIBLE);
                location = position + 1;
                if (position == 0) {
                    Iport1++;
                    Iport1 = Iport1 % 2;
                    if (Iport1 % 2 == 1) {
                        //dbHelper.updateContact(1,1);
                        view.findViewById(R.id.grid_item_image).setVisibility(View.VISIBLE);
                        dbHelper.updateContact(1,1);
                    } else {
                        //dbHelper.updateContact(1,0);
                        view.findViewById(R.id.grid_item_image).setVisibility(View.INVISIBLE);
                        dbHelper.updateContact(1, 0);
                    }
                }
                if (position == 1) {
                    Iport2++;
                    Iport1 = Iport1 % 2;
                    if (Iport2 % 2 == 1) {
                        //dbHelper.updateContact(2,1);
                        view.findViewById(R.id.grid_item_image).setVisibility(View.VISIBLE);
                        dbHelper.updateContact(2, 1);
                    } else {
                        //dbHelper.updateContact(2,0);
                        view.findViewById(R.id.grid_item_image).setVisibility(View.INVISIBLE);
                        dbHelper.updateContact(2,0);
                    }
                }
                if (position == 2) {
                    Iport3++;
                    Iport3 = Iport3 % 2;
                    if (Iport3 % 2 == 1) {
                        //dbHelper.updateContact(3,1);
                        view.findViewById(R.id.grid_item_image).setVisibility(View.VISIBLE);
                        dbHelper.updateContact(3, 1);
                    } else {
                        //dbHelper.updateContact(3,0);
                        view.findViewById(R.id.grid_item_image).setVisibility(View.INVISIBLE);
                        dbHelper.updateContact(3, 0);
                    }
                }
                if (position == 3) {
                    Iport4++;
                    Iport4 = Iport4 % 2;
                    if (Iport4 % 2 == 1) {
                        //dbHelper.updateContact(4,1);
                       view.findViewById(R.id.grid_item_image).setVisibility(View.VISIBLE);
                        dbHelper.updateContact(4, 1);
                    } else {
                        //dbHelper.updateContact(4,0);
                       view.findViewById(R.id.grid_item_image).setVisibility(View.INVISIBLE);
                        dbHelper.updateContact(4,0);
                    }
                }
            }
        });
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                editor.putInt("port1", Iport1);
                editor.putInt("port2", Iport2);
                editor.putInt("port3", Iport3);
                editor.putInt("port4", Iport4);
                Intent i = new Intent(MainActivity.this,Main2Activity.class);
                if(Iport1==1)
                    i.putExtra("3","TabFragment3");
                else
                    i.putExtra("3", "");
                if(Iport2==1)
                    i.putExtra("4","TabFragment4");
                else
                    i.putExtra("4","");
                if(Iport3==1)
                    i.putExtra("5", "TabFragment5");
                else
                    i.putExtra("5","");
                if(Iport4==1)
                    i.putExtra("6", "TabFragment6");
                else
                    i.putExtra("6","");
                dbHelper.updateContact(0, Iport1);
                dbHelper.updateContact(1, Iport2);
                dbHelper.updateContact(2, Iport3);
                dbHelper.updateContact(3, Iport4);
                startActivity(i);
            }
        });
    }
}

Here TabFragment1,TabFragment2 etc are fragment to be displayed on the viewpager.And I am not showing the layouts since they are out of scope of this project.

MainActivity will intent to Main2Activity Main2Activity

    package com.example.jeffy.viewpagerapp;

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.TextUtils;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.FrameLayout;

import java.util.ArrayList;

public class Main2Activity extends AppCompatActivity {

    private ViewPager pager = null;
    private PagerAdapter pagerAdapter = null;
    DBHelper dbHelper;
    Cursor rs;
    int port1,port2,port3,port4;
    //-----------------------------------------------------------------------------
    @Override
    public void onCreate (Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        Toolbar toolbar = (Toolbar) findViewById(R.id.MyToolbar);
        setSupportActionBar(toolbar);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        CollapsingToolbarLayout collapsingToolbar =
                (CollapsingToolbarLayout) findViewById(R.id.collapse_toolbar);


        NestedScrollView scrollView = (NestedScrollView) findViewById (R.id.nested);
        scrollView.setFillViewport (true);

        ArrayList<String > selectedPort = new ArrayList<String>();

        Intent intent = getIntent();
        String Tab3 = intent.getStringExtra("3");
        String Tab4 = intent.getStringExtra("4");
        String Tab5 = intent.getStringExtra("5");
        String Tab6 = intent.getStringExtra("6");

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
        tabLayout.addTab(tabLayout.newTab().setText("View"));
        tabLayout.addTab(tabLayout.newTab().setText("All"));

        selectedPort.add("TabFragment1");
        selectedPort.add("TabFragment2");
        if(Tab3!=null && !TextUtils.isEmpty(Tab3))
        selectedPort.add(Tab3);
        if(Tab4!=null && !TextUtils.isEmpty(Tab4))
        selectedPort.add(Tab4);
        if(Tab5!=null && !TextUtils.isEmpty(Tab5))
        selectedPort.add(Tab5);
        if(Tab6!=null && !TextUtils.isEmpty(Tab6))
        selectedPort.add(Tab6);



        dbHelper = new DBHelper(this);
//        rs=dbHelper.getData(1);
//        port1 = rs.getInt(rs.getColumnIndex("id"));
//
//        rs=dbHelper.getData(2);
//        port2 = rs.getInt(rs.getColumnIndex("id"));
//
//        rs=dbHelper.getData(3);
//        port3 = rs.getInt(rs.getColumnIndex("id"));
//
//        rs=dbHelper.getData(4);
//        port4 = rs.getInt(rs.getColumnIndex("id"));


        Log.i(">>>>>>>>>>>>>>", "port 1" + port1 + "port 2" + port2 + "port 3" + port3 + "port 4" + port4);

        if(Tab3!=null && !TextUtils.isEmpty(Tab3))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 0"));
        if(Tab3!=null && !TextUtils.isEmpty(Tab4))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
        if(Tab3!=null && !TextUtils.isEmpty(Tab5))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
        if(Tab3!=null && !TextUtils.isEmpty(Tab6))
        tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
        final PagerAdapter adapter = new PagerAdapter
                (getSupportFragmentManager(), tabLayout.getTabCount(), selectedPort);
        viewPager.setAdapter(adapter);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        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) {

            }
        });
//        setContentView(R.layout.activity_main2);
//        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
//        setSupportActionBar(toolbar);

//        TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
//        tabLayout.addTab(tabLayout.newTab().setText("View"));
//        tabLayout.addTab(tabLayout.newTab().setText("All"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 0"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
//        tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
//        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);


}
    }

ViewPagerAdapter Viewpageradapter.class

package com.example.jeffy.viewpagerapp;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by Jeffy on 25-01-2016.
 */
public class PagerAdapter extends FragmentStatePagerAdapter {
    int mNumOfTabs;

    List<String> values;

    public PagerAdapter(FragmentManager fm, int NumOfTabs, List<String> Port) {
        super(fm);
        this.mNumOfTabs = NumOfTabs;
        this.values= Port;
    }


    @Override
    public Fragment getItem(int position) {


        String fragmentName = values.get(position);
        Class<?> clazz = null;
        Object fragment = null;
        try {
            clazz = Class.forName("com.example.jeffy.viewpagerapp."+fragmentName);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        try {
            fragment = clazz.newInstance();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        return (Fragment) fragment;
    }

    @Override
    public int getCount() {
        return values.size();
    }
}

Layout for main2activity acticity_main2.xml

    <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/main_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/MyAppbar"
            android:layout_width="match_parent"
            android:layout_height="256dp"
            android:fitsSystemWindows="true">

            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/collapse_toolbar"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_scrollFlags="scroll|exitUntilCollapsed"
                android:background="@color/material_deep_teal_500"
                android:fitsSystemWindows="true">

                <ImageView
                    android:id="@+id/bgheader"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:scaleType="centerCrop"
                    android:fitsSystemWindows="true"
                    android:background="@drawable/screen"
                    app:layout_collapseMode="pin" />

                <android.support.v7.widget.Toolbar
                    android:id="@+id/MyToolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:layout_collapseMode="parallax" />





            </android.support.design.widget.CollapsingToolbarLayout>

        </android.support.design.widget.AppBarLayout>

        <android.support.v4.widget.NestedScrollView
            android:layout_width="match_parent"
            android:id="@+id/nested"
            android:layout_height="match_parent"
            android:layout_gravity="fill_vertical"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/MyToolbar"
            android:background="?attr/colorPrimary"
            android:elevation="6dp"
            android:minHeight="?attr/actionBarSize"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>


        <android.support.v4.view.ViewPager
            xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/view_pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

        </android.support.v4.view.ViewPager>
    </LinearLayout>


        </android.support.v4.widget.NestedScrollView>

    </android.support.design.widget.CoordinatorLayout>

Mainactivity layout
activity_main.xml

        <?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.example.jeffy.viewpagerapp.MainActivity"
    tools:showIn="@layout/activity_main">


<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/gridView1"
        android:numColumns="2"
        android:gravity="center"
        android:columnWidth="100dp"
        android:stretchMode="columnWidth"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

    </GridView>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="SAVE"
        android:id="@+id/button" />

</LinearLayout>




</RelativeLayout>

Hope this would help someone... Click up button please if this helped you


I was looking for simple solution to remove views from viewpager (no fragments) dynamically. So, if you have some info, that your pages belongs to, you can set it to View as tag. Just like that (adapter code):

@Override
public Object instantiateItem(ViewGroup collection, int position)
{
    ImageView iv = new ImageView(mContext);
    MediaMessage msg = mMessages.get(position);
    ...

    iv.setTag(media);
    return iv;
}

@Override
public int getItemPosition (Object object)
{
    View o = (View) object;
    int index = mMessages.indexOf(o.getTag());
    if (index == -1)
        return POSITION_NONE;
    else
        return index;
}

You just need remove your info from mMessages, and then call notifyDataSetChanged() for your adapter. Bad news there is no animation in this case.


Here's an alternative solution to this question. My adapter:

    private class PagerAdapter extends FragmentPagerAdapter implements 
                    ViewPager.OnPageChangeListener, TabListener {

    private List<Fragment> mFragments = new ArrayList<Fragment>();
    private ViewPager mPager;
    private ActionBar mActionBar;

    private Fragment mPrimaryItem;

    public PagerAdapter(FragmentManager fm, ViewPager vp, ActionBar ab) {
        super(fm);
        mPager = vp;
        mPager.setAdapter(this);
        mPager.setOnPageChangeListener(this);
        mActionBar = ab;
    }

    public void addTab(PartListFragment frag) {
        mFragments.add(frag);
        mActionBar.addTab(mActionBar.newTab().setTabListener(this).
                            setText(frag.getPartCategory()));
    }

    @Override
    public Fragment getItem(int position) {
        return mFragments.get(position);
    }

    @Override
    public int getCount() {
        return mFragments.size();
    }

    /** (non-Javadoc)
     * @see android.support.v4.app.FragmentStatePagerAdapter#setPrimaryItem(android.view.ViewGroup, int, java.lang.Object)
     */
    @Override
    public void setPrimaryItem(ViewGroup container, int position,
            Object object) {
        super.setPrimaryItem(container, position, object);
        mPrimaryItem = (Fragment) object;
    }

    /** (non-Javadoc)
     * @see android.support.v4.view.PagerAdapter#getItemPosition(java.lang.Object)
     */
    @Override
    public int getItemPosition(Object object) {
        if (object == mPrimaryItem) {
            return POSITION_UNCHANGED;
        }
        return POSITION_NONE;
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        mPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) { }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) { }

    @Override
    public void onPageScrollStateChanged(int arg0) { }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) { }

    @Override
    public void onPageSelected(int position) {
        mActionBar.setSelectedNavigationItem(position);
    }

    /**
     * This method removes the pages from ViewPager
     */
    public void removePages() {
        mActionBar.removeAllTabs();

                    //call to ViewPage to remove the pages
        vp.removeAllViews();
        mFragments.clear();

        //make this to update the pager
        vp.setAdapter(null);
        vp.setAdapter(pagerAdapter);
    }
}

Code to remove and add dynamically

//remove the pages. basically call to method removeAllViews from `ViewPager`
pagerAdapter.removePages();

pagerAdapter.addPage(pass your fragment);

After the advice of Peri Hartman, it started to work after I set null do ViewPager adapter and put the adapter again after the views removed. Before this the page 0 doesnt showed its list contents.

Thanks.


To remove you can use this directly:

getSupportFragmentManager().beginTransaction().remove(fragment).
                            commitAllowingStateLoss();

fragment is the fragment you want to remove.


I find a good solution for this issue, this solution can make it work and no need to recreate Fragments.
My key point is:

  1. setup ViewPager every time you delete or add Tab(Fragment).
  2. Override the getItemId method, return a specific id rather than position.

Source Code

package com.zq.testviewpager;

import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

import android.widget.TextView;

import java.util.ArrayList;
import java.util.Arrays;
/**
 * Created by [email protected] on 2017/5/31.
 * Implement dynamic delete or add tab(TAB_C in this test code).
 */
public class MainActivity extends AppCompatActivity {

    private static final int TAB_A = 1001;
    private static final int TAB_B = 1002;
    private static final int TAB_C = 1003;
    private static final int TAB_D = 1004;
    private static final int TAB_E = 1005;
    private Tab[] tabsArray = new Tab[]{new Tab(TAB_A, "A"),new Tab(TAB_B, "B"),new Tab(TAB_C, "C"),new Tab(TAB_D, "D"),new Tab(TAB_E, "E")};

    private ArrayList<Tab> mTabs = new ArrayList<>(Arrays.asList(tabsArray));

    private Tab[] tabsArray2 = new Tab[]{new Tab(TAB_A, "A"),new Tab(TAB_B, "B"),new Tab(TAB_D, "D"),new Tab(TAB_E, "E")};

    private ArrayList<Tab> mTabs2 = new ArrayList<>(Arrays.asList(tabsArray2));

    /**
     * The {@link android.support.v4.view.PagerAdapter} that will provide
     * fragments for each of the sections. We use a
     * {@link FragmentPagerAdapter} derivative, which will keep every
     * loaded fragment in memory. If this becomes too memory intensive, it
     * may be best to switch to a
     * {@link android.support.v4.app.FragmentStatePagerAdapter}.
     */
    private SectionsPagerAdapter mSectionsPagerAdapter;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    private ViewPager mViewPager;
    private TabLayout tabLayout;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(mTabs, getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(mViewPager);

        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();
            }
        });

    }


    @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;
        }else if (id == R.id.action_delete) {
            int currentItemPosition = mViewPager.getCurrentItem();
            Tab currentTab = mTabs.get(currentItemPosition);

            if(currentTab.id == TAB_C){
                currentTab = mTabs.get(currentItemPosition == 0 ? currentItemPosition +1 : currentItemPosition - 1);
            }

            mSectionsPagerAdapter = new SectionsPagerAdapter(mTabs2, getSupportFragmentManager());
            mViewPager.setAdapter(mSectionsPagerAdapter);
            tabLayout.setupWithViewPager(mViewPager);


            mViewPager.setCurrentItem(mTabs2.indexOf(currentTab), false);
            return true;
        }else if (id == R.id.action_add) {

            int currentItemPosition = mViewPager.getCurrentItem();
            Tab currentTab = mTabs2.get(currentItemPosition);

            mSectionsPagerAdapter = new SectionsPagerAdapter(mTabs, getSupportFragmentManager());
            mViewPager.setAdapter(mSectionsPagerAdapter);
            tabLayout.setupWithViewPager(mViewPager);

            mViewPager.setCurrentItem(mTabs.indexOf(currentTab), false);
            return true;
        }else

        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        public PlaceholderFragment() {
        }

        /**
         * Returns a new instance of this fragment for the given section
         * number.
         */
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        @Override
        public void onCreate(@Nullable Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            Log.e("TestViewPager", "onCreate"+getArguments().getInt(ARG_SECTION_NUMBER));
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            Log.e("TestViewPager", "onDestroy"+getArguments().getInt(ARG_SECTION_NUMBER));
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            TextView textView = (TextView) rootView.findViewById(R.id.section_label);
            textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
            return rootView;
        }
    }

    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {
        ArrayList<Tab> tabs;

        public SectionsPagerAdapter(ArrayList<Tab> tabs, FragmentManager fm) {
            super(fm);
            this.tabs = tabs;
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a PlaceholderFragment (defined as a static inner class below).
            return PlaceholderFragment.newInstance(tabs.get(position).id);
        }

        @Override
        public int getCount() {
            return tabs.size();
        }

        @Override
        public long getItemId(int position) {
            return tabs.get(position).id;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return tabs.get(position).title;
        }
    }

    private static class Tab {
        String title;
        public int id;

        Tab(int id, String title){
            this.id = id;
            this.title = title;
        }

        @Override
        public boolean equals(Object obj) {
            if(obj instanceof Tab){
                return ((Tab)obj).id == id;
            }else{
                return false;
            }
        }
    }
}

Code is at my Github Gist.


I've created a custom PagerAdapters library to change items in PagerAdapters dynamically.

You can change items dynamically like following by using this library.

@Override
protected void onCreate(Bundle savedInstanceState) {
        /** ... **/
    adapter = new MyStatePagerAdapter(getSupportFragmentManager()
                            , new String[]{"1", "2", "3"});
    ((ViewPager)findViewById(R.id.view_pager)).setAdapter(adapter);
     adapter.add("4");
     adapter.remove(0);
}

class MyPagerAdapter extends ArrayViewPagerAdapter<String> {

    public MyPagerAdapter(String[] data) {
        super(data);
    }

    @Override
    public View getView(LayoutInflater inflater, ViewGroup container, String item, int position) {
        View v = inflater.inflate(R.layout.item_page, container, false);
        ((TextView) v.findViewById(R.id.item_txt)).setText(item);
        return v;
    }
}

Thils library also support pages created by Fragments.


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