Recyclerview In Kotlin Android

Video Demo:

Kotlin is very simple language you can easily learn it if you have a good knowledge of java and android studio. In this tutorial I am creating the list using kotlin classes. You can download the source code from below.

activity_main.xml:

<LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android" >

    <TextView
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:textColor="#ffffff"
        android:textSize="15dp"
        android:textStyle="bold"
        android:gravity="center"
        android:background="@color/colorPrimary"
        android:text="@string/app_name"/>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginEnd="8dp" />

</LinearLayout>

MainActivity.kt:

package com.deepshikha.recyclerviewkotlin
import android.app.Activity
import android.os.Bundle
import android.support.v7.widget.LinearLayoutManager
import android.view.Window
import android.view.WindowManager
import android.widget.LinearLayout
import kotlinx.android.synthetic.main.activity_main.*
import net.simplifiedcoding.recyclerviewexample.CustomAdapter

class MainActivity : Activity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        requestWindowFeature(Window.FEATURE_NO_TITLE)
        window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN)

        setContentView(R.layout.activity_main)

        val users = ArrayList()
        users.add(Model_Details("Kaju katli", "Kaju katli, also known as kaju Katari or kaju barfi, is an Indian dessert similar to a barfi.",R.drawable.kaju))
        users.add(Model_Details("Doughnut", "The doughnut is popular in many countries and prepared in various forms as a sweet snack that can be homemade or purchased in bakeries, supermarkets, food stalls, and franchised specialty outlets",R.drawable.donuts))
        users.add(Model_Details("Panna cotta", "Panna cotta is an Italian dessert of sweetened cream thickened with gelatin and molded. The cream may be aromatized with rum, coffee, vanilla, or other flavorings.",R.drawable.panna_cotta))
        users.add(Model_Details("Rose Cookies", "Rose cooky is a famous South Indian snack made during festivals",R.drawable.rosecookies))
        users.add(Model_Details("Belgian waffle", "In North America, Belgian waffles are a variety of waffle with a lighter batter, larger squares, and deeper pockets than ordinary American waffles",R.drawable.belgianwaffle))

        val obj_adapter = CustomAdapter(users)

        recyclerView.layoutManager = LinearLayoutManager(this, LinearLayout.VERTICAL, false)
        recyclerView.adapter = obj_adapter
    }

}

adapter_details.xml:

<?xml version="1.0" encoding="utf-8"?gt;
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="160dp"
    android:background="#EAEAEA"
    android:layout_centerHorizontal="true"
    android:orientation="horizontal"gt;

    <ImageView
        android:layout_width="155dp"
        android:scaleType="centerCrop"
        android:layout_height="155dp"
        android:id="@+id/iv_name"/gt;


<LinearLayout
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:background="#FFFFFF"
    android:padding="10dp"
    android:layout_marginBottom="5dp"
    android:layout_height="match_parent"gt;
    <TextView
        android:id="@+id/tv_name"
        android:textStyle="bold"
        android:text="adfaldfkjalk"
        android:textSize="15dp"
        android:textColor="#000000"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" /gt;

    <TextView
        android:id="@+id/tv_des"
        android:layout_marginTop="5dp"
        android:textColor="#000000"
        android:textSize="11dp"
        android:text="adfaldfkjalk "
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" /gt;
</LinearLayoutgt;
</LinearLayoutgt;

CustomAdapter.kt:

package net.simplifiedcoding.recyclerviewexample

import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import com.deepshikha.recyclerviewkotlin.Model_Details
import com.deepshikha.recyclerviewkotlin.R
import kotlinx.android.synthetic.main.adapter_details.view.*

class CustomAdapter(val userList: ArrayList) : RecyclerView.Adapter() {

    //this method is returning the view for each item in the list
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomAdapter.ViewHolder {
        val v = LayoutInflater.from(parent.context).inflate(R.layout.adapter_details, parent, false)
        return ViewHolder(v)
    }

    //this method is binding the data on the list
    override fun onBindViewHolder(holder: CustomAdapter.ViewHolder, position: Int) {
        holder.bindItems(userList[position])
    }

    //this method is giving the size of the list
    override fun getItemCount(): Int {
        return userList.size
    }

    //the class is hodling the list view
    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

        fun bindItems(user: Model_Details) {
            itemView.tv_name.text=user.name
            itemView.tv_des.text=user.des
            itemView.iv_name.setImageResource(user.image)

        }
    }
}

Model_Details.kt:

package com.deepshikha.recyclerviewkotlin

/**
 * Created by deepshikha on 28/7/17.
 */
 data class Model_Details(val name:String,val des:String,val image:Int)

DOWNLOAD SOURCE CODE FROM HERE

Navigation drawer with expandablelistview in android

Video Demo:

In this tutorial I am using expandable listview with default navigation drawer. Download source code from here

activity_main.xml:

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >


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

        <LinearLayout
            android:id="@+id/container_toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

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

    <RelativeLayout
        android:layout_width="match_parent"
        android:background="#234E6F"
        android:layout_height="60dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20dp"
            android:textColor="#ffffff"
            android:layout_centerInParent="true"
            android:textStyle="bold"
            android:id="@+id/tv_name"/>


        <ImageView
            android:layout_width="25dp"
            android:layout_centerVertical="true"
            android:layout_height="30dp"
            android:layout_marginLeft="10dp"
            android:src="@drawable/menu_icon"/>
        <RelativeLayout
            android:layout_width="40dp"
            android:id="@+id/rl_menu"
            android:layout_height="match_parent"></RelativeLayout>

    </RelativeLayout>

        <FrameLayout
            android:id="@+id/content_frame"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
</LinearLayout>

    </LinearLayout>
    <LinearLayout
        android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:orientation="vertical"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="#FFFFFF">

        <include layout="@layout/menu_layout"></include>

    </LinearLayout>

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

menu_layout.xml:

<?xml version="1.0" encoding="utf-8"?>

<ScrollView android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android" >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFFFFF"
    android:orientation="vertical">


    <RelativeLayout
        android:id="@+id/rl_profile"
        android:layout_width="match_parent"
        android:layout_height="150dp">

        <ImageView

            android:id="@+id/iv_image"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:layout_centerVertical="true"
            android:src="@drawable/profile_image" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginLeft="20dp"
            android:layout_toRightOf="@+id/iv_image"
            android:text="David"
            android:textColor="#000000"
            android:textSize="15dp" />


    </RelativeLayout>

    <View
        android:layout_width="match_parent"
        android:layout_height="2dp"
        android:background="#EAEAEA"></View>


    <ExpandableListView
        android:id="@+id/ev_menu"
        android:nestedScrollingEnabled="false"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </ExpandableListView>
</LinearLayout>
</ScrollView>

MainActivity.java:

package com.deepshikha.navigationdrawer;

import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    ArrayList al_main = new ArrayList<>();
    ExpandableListView ev_list;
    CountryAdapter obj_adapter;
    String TAG = "MainActivity";
    private DrawerLayout mDrawerLayout;
    HomeFragment fragment;
    TextView tv_name;
    RelativeLayout rl_menu;

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

    }

    private void init() {

        getSupportActionBar().hide();
        ev_list = (ExpandableListView) findViewById(R.id.ev_menu);
        tv_name = (TextView) findViewById(R.id.tv_name);
        rl_menu = (RelativeLayout) findViewById(R.id.rl_menu);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        obj_adapter = new CountryAdapter(MainActivity.this, al_main);
        ev_list.setAdapter(obj_adapter);
        ev_list.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {

            @Override
            public boolean onGroupClick(ExpandableListView parent, View v,
                                        int groupPosition, long id) {
                setListViewHeight(parent, groupPosition);
                return false;
            }
        });

        setExpandableListViewHeightBasedOnChildren(ev_list);

        fragment = new HomeFragment();
        Bundle bundle = new Bundle();
        bundle.putString("name", al_main.get(0).getStr_country());
        bundle.putString("des", al_main.get(0).getAl_state().get(0).getStr_description());
        bundle.putString("dish", al_main.get(0).getAl_state().get(0).getStr_name());
        bundle.putString("image", al_main.get(0).getAl_state().get(0).getStr_image());
        tv_name.setText(al_main.get(0).getStr_country());

        fragment.setArguments(bundle);
        getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, fragment, "HomeFragment").addToBackStack("null").commit();


        rl_menu.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mDrawerLayout.openDrawer(Gravity.LEFT);
            }
        });
    }

    private void setListViewHeight(ExpandableListView listView, int group) {
        ExpandableListAdapter listAdapter = (ExpandableListAdapter) listView.getExpandableListAdapter();
        int totalHeight = 0;
        int desiredWidth = View.MeasureSpec.makeMeasureSpec(listView.getWidth(),
                View.MeasureSpec.EXACTLY);
        for (int i = 0; i < listAdapter.getGroupCount(); i++) {
            View groupItem = listAdapter.getGroupView(i, false, null, listView);
            groupItem.measure(desiredWidth, View.MeasureSpec.UNSPECIFIED);

            totalHeight += groupItem.getMeasuredHeight();

            if (((listView.isGroupExpanded(i)) && (i != group))
                    || ((!listView.isGroupExpanded(i)) && (i == group))) {
                for (int j = 0; j < listAdapter.getChildrenCount(i); j++) {
                    View listItem = listAdapter.getChildView(i, j, false, null,
                            listView);
                    listItem.measure(desiredWidth, View.MeasureSpec.UNSPECIFIED);

                    totalHeight += listItem.getMeasuredHeight();

                }
            }
        }

        ViewGroup.LayoutParams params = listView.getLayoutParams();
        int height = totalHeight
                + (listView.getDividerHeight() * (listAdapter.getGroupCount() - 1));
       /* if (height < 10)
            height = 200;*/
        params.height = height;
        listView.setLayoutParams(params);
        listView.requestLayout();

    }

    private void fn_data() {

        String str_data = loadJSONFromAsset();

        try {
            JSONObject jsonObject_country = new JSONObject(str_data);
            JSONArray jsonArray_country = jsonObject_country.getJSONArray("country");
            al_main = new ArrayList<>();
            for (int i = 0; i < jsonArray_country.length(); i++) {
                Model_country obj_country = new Model_country();
                JSONObject jsonObject = jsonArray_country.getJSONObject(i);
                JSONArray jsonArray_dishes = jsonObject.getJSONArray("dishes");
                ArrayList al_dishes = new ArrayList<>();
                for (int j = 0; j < jsonArray_dishes.length(); j++) {

                    JSONObject jsonObject_dishes = jsonArray_dishes.getJSONObject(j);
                    Model_Dish obj_dish = new Model_Dish();
                    obj_dish.setStr_name(jsonObject_dishes.getString("dishname"));
                    obj_dish.setStr_description(jsonObject_dishes.getString("description"));
                    obj_dish.setStr_image(jsonObject_dishes.getString("image"));
                    al_dishes.add(obj_dish);
                }

                obj_country.setAl_state(al_dishes);
                obj_country.setStr_country(jsonObject.getString("name"));

                al_main.add(obj_country);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }

    public static void setExpandableListViewHeightBasedOnChildren(ExpandableListView expandableListView) {
        CountryAdapter adapter = (CountryAdapter) expandableListView.getExpandableListAdapter();
        if (adapter == null) {
            return;
        }
        int totalHeight = expandableListView.getPaddingTop() + expandableListView.getPaddingBottom();
        for (int i = 0; i < adapter.getGroupCount(); i++) {
            View groupItem = adapter.getGroupView(i, false, null, expandableListView);
            groupItem.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
            totalHeight += groupItem.getMeasuredHeight();

            if (expandableListView.isGroupExpanded(i)) {
                for (int j = 0; j < adapter.getChildrenCount(i); j++) {
                    View listItem = adapter.getChildView(i, j, false, null, expandableListView);
                    listItem.setLayoutParams(new ViewGroup.LayoutParams(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED));
                    listItem.measure(View.MeasureSpec.makeMeasureSpec(0,
                            View.MeasureSpec.UNSPECIFIED), View.MeasureSpec
                            .makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
                    totalHeight += listItem.getMeasuredHeight();

                }
            }
        }

        ViewGroup.LayoutParams params = expandableListView.getLayoutParams();
        int height = totalHeight + expandableListView.getDividerHeight() * (adapter.getGroupCount() - 1);

        if (height < 10)
            height = 100;
        params.height = height;
        expandableListView.setLayoutParams(params);
        expandableListView.requestLayout();
    }

    public String loadJSONFromAsset() {
        String json = null;
        try {

            InputStream is = getAssets().open("dishes.json");

            int size = is.available();

            byte[] buffer = new byte[size];

            is.read(buffer);

            is.close();

            json = new String(buffer, "UTF-8");


        } catch (IOException ex) {
            ex.printStackTrace();
            return null;
        }

        Log.e(TAG, "Json response " + json);
        return json;

    }

    public void fn_selectedPosition(int group, int child) {

        fragment = new HomeFragment();
        Bundle bundle = new Bundle();
        bundle.putString("name", al_main.get(group).getStr_country());
        bundle.putString("des", al_main.get(group).getAl_state().get(child).getStr_description());
        bundle.putString("dish", al_main.get(group).getAl_state().get(child).getStr_name());
        bundle.putString("image", al_main.get(group).getAl_state().get(child).getStr_image());
        fragment.setArguments(bundle);

        getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, fragment, "HomeFragment").addToBackStack("null").commit();
        mDrawerLayout.closeDrawer(Gravity.LEFT);

        tv_name.setText(al_main.get(group).getStr_country());
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
    }
}

Model_country.java:

package com.deepshikha.navigationdrawer;

import java.util.ArrayList;

/**
 * Created by deepshikha on 12/7/17.
 */

public class Model_country {
    String str_country;
    ArrayList al_state;
    public Model_country() {
    }

    public Model_country(String str_country, ArrayList al_state) {
        this.str_country = str_country;
        this.al_state = al_state;
    }


    public String getStr_country() {
        return str_country;
    }

    public void setStr_country(String str_country) {
        this.str_country = str_country;
    }

    public ArrayList getAl_state() {
        return al_state;
    }

    public void setAl_state(ArrayList al_state) {
        this.al_state = al_state;
    }
}

Model_Dish.java:

package com.deepshikha.navigationdrawer;

/**
 * Created by deepshikha on 12/7/17.
 */

public class Model_Dish {
    String str_name;
    String str_description;
    String str_image;

    public Model_Dish(String str_name, String str_description, String str_image) {
        this.str_name = str_name;
        this.str_description = str_description;
        this.str_image = str_image;
    }

    public String getStr_image() {
        return str_image;
    }

    public void setStr_image(String str_image) {
        this.str_image = str_image;
    }

    public Model_Dish() {

    }



    public String getStr_name() {
        return str_name;
    }

    public void setStr_name(String str_name) {
        this.str_name = str_name;
    }

    public String getStr_description() {
        return str_description;
    }

    public void setStr_description(String str_description) {
        this.str_description = str_description;
    }
}

fragment_home.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:background="#FFFFFF"
    android:orientation="vertical">

<RelativeLayout
    android:layout_width="match_parent"
    android:background="#FFFFFF"
    android:layout_height="240dp">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_marginTop="20dp"
        android:scaleType="centerCrop"
        android:id="@+id/iv_image"/>
</RelativeLayout>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Dish Name"
        android:textSize="25dp"
        android:id="@+id/tv_dishname"
        android:gravity="center"
        android:textStyle="bold"
        android:textColor="#000000"
        />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Dish Name"
        android:textSize="18dp"
        android:padding="10dp"
        android:layout_marginTop="5dp"
        android:id="@+id/tv_description"
        android:gravity="left"
        android:textColor="#000000"
        />

</LinearLayout>

HomeFragment.java:

package com.deepshikha.navigationdrawer;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;


public class HomeFragment extends Fragment {

    View view;
    TextView  tv_dishname, tv_description;
    ImageView iv_image;
    String str_name, str_disname, str_des, str_imagename;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_home, container, false);
        init();
        return view;
    }

    private void init() {

        str_name = getArguments().getString("name");
        str_disname = getArguments().getString("dish");
        str_des = getArguments().getString("des");
        str_imagename = getArguments().getString("image");
//        str_imagename = "chinese";
        tv_dishname = (TextView) view.findViewById(R.id.tv_dishname);
        tv_description = (TextView) view.findViewById(R.id.tv_description);
        iv_image = (ImageView) view.findViewById(R.id.iv_image);


        tv_dishname.setText(str_disname);
        tv_description.setText(str_des);

        int resourceImage = getActivity().getResources().getIdentifier(str_imagename, "drawable", getActivity().getPackageName());
        iv_image.setImageResource(resourceImage);


    }


}

adapter_childview.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:layout_marginLeft="20dp"
    android:paddingLeft="50dp"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:textSize="15dp"
        android:gravity="center_vertical"
        android:textColor="#000000"
        android:id="@+id/tv_name"/>



</LinearLayout>

adapter_header.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="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:textSize="15dp"
        android:paddingLeft="10dp"
        android:gravity="center_vertical"
        android:textColor="#ffffff"
        android:background="#234E6F"
        android:id="@+id/tv_name"/>

</LinearLayout>

CountryAdapter.java:

package com.deepshikha.navigationdrawer;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

import java.util.ArrayList;

/**
 * Created by deepshikha on 12/7/17.
 */

public class CountryAdapter extends BaseExpandableListAdapter {
    Context context;
    ArrayList al_country;

    public CountryAdapter(Context context, ArrayList al_country) {
        this.context = context;
        this.al_country = al_country;
    }

    @Override
    public int getGroupCount() {
        return al_country.size();
    }

    @Override
    public int getChildrenCount(int i) {
        return al_country.get(i).getAl_state().size();
    }

    @Override
    public Object getGroup(int i) {
        return al_country.get(i);
    }

    @Override
    public Object getChild(int i, int i1) {
        return al_country.get(i).getAl_state().get(i1);
    }

    @Override
    public long getGroupId(int i) {
        return i;
    }

    @Override
    public long getChildId(int i, int i1) {
        return i1;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
        if (view==null){

            LayoutInflater layoutInflater = (LayoutInflater) this.context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = layoutInflater.inflate(R.layout.adapter_header, null);
        }
        TextView tv_state = (TextView)view.findViewById(R.id.tv_name);
        tv_state.setText(al_country.get(i).getStr_country());
        return view;
    }

    @Override
    public View getChildView(final int i, final int i1, boolean b, View view, ViewGroup viewGroup) {
        if (view==null){

            LayoutInflater layoutInflater = (LayoutInflater) this.context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = layoutInflater.inflate(R.layout.adapter_childview, null);
        }

        TextView tv_state = (TextView)view.findViewById(R.id.tv_name);

        tv_state.setText(al_country.get(i).getAl_state().get(i1).getStr_name());
        tv_state.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ((MainActivity)context).fn_selectedPosition(i,i1);
            }
        });
        return view;
    }

    @Override
    public boolean isChildSelectable(int i, int i1) {
        return false;
    }


}

Open Pdf from url in Android Programmatically

Video Demo:

You can easily view your online pdf file from url in webview. To load the pdf file from url you need to use the google drive link. Download source code from here.

activity_main.xml

<RelativeLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <WebView
        android:layout_width="match_parent"
        android:id="@+id/webview"
        android:layout_height="match_parent">

    </WebView>

    <ProgressBar
        android:layout_width="wrap_content"
        android:id="@+id/progressbar"
        android:layout_centerInParent="true"
        android:layout_height="wrap_content" />


</RelativeLayout>


MainActivity.java

package com.deepshikha.openpdf;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;

public class MainActivity extends AppCompatActivity {
    WebView webview;
    ProgressBar progressbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        webview = (WebView)findViewById(R.id.webview);
        progressbar = (ProgressBar) findViewById(R.id.progressbar);
        webview.getSettings().setJavaScriptEnabled(true);
        String filename ="http://www3.nd.edu/~cpoellab/teaching/cse40816/android_tutorial.pdf";
        webview.loadUrl("http://docs.google.com/gview?embedded=true&url=" + filename);

        webview.setWebViewClient(new WebViewClient() {

            public void onPageFinished(WebView view, String url) {
                // do your stuff here
                progressbar.setVisibility(View.GONE);
            }
        });

    }
}

ViewPager with previous and next page boundaries

Video Demo:

Show the viewpager with the boundaries of previous and next page in android programmatically. In this example I am using viewpager with fragments to show the left and right boundaries.Download source code from here

activity_main.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="#ffffff">

    <android.support.v4.view.ViewPager

        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="400dp"
        android:layout_centerInParent="true" />

</RelativeLayout>

MainActivity.java

package com.deepshikha.viewpager;

import android.content.Context;
import android.content.res.Configuration;
import android.os.Build;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.SparseArray;
import android.view.ViewGroup;

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

public class MainActivity extends FragmentActivity {

    ViewPager pager;
    MyPageAdapter obj_adapter;
    String str_device;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();


    }

    private void init() {
        pager = (ViewPager) findViewById(R.id.viewpager);
        differentDensityAndScreenSize(getApplicationContext());
        List<Fragment> fragments = getFragments();
        pager.setAdapter(obj_adapter);
        pager.setClipToPadding(false);


        if (str_device.equals("normal-hdpi")){
            pager.setPadding(160, 0, 160, 0);
        }else if (str_device.equals("normal-mdpi")){
            pager.setPadding(160, 0, 160, 0);
        }else if (str_device.equals("normal-xhdpi")){
            pager.setPadding(160, 0, 160, 0);
        }else if (str_device.equals("normal-xxhdpi")){
            pager.setPadding(180, 0, 180, 0);
        }else if (str_device.equals("normal-xxxhdpi")){
            pager.setPadding(180, 0, 180, 0);
        }else if (str_device.equals("normal-unknown")){
            pager.setPadding(160, 0, 160, 0);
        }else {

        }

        obj_adapter = new MyPageAdapter(getSupportFragmentManager(), fragments);
        pager.setPageTransformer(true, new ExpandingViewPagerTransformer());
        pager.setAdapter(obj_adapter);
    }

    class MyPageAdapter extends FragmentPagerAdapter {

        private List<Fragment> fragments;

        public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {

            super(fm);

            this.fragments = fragments;

        }

        @Override

        public Fragment getItem(int position) {

            return this.fragments.get(position);

        }

        @Override

        public int getCount() {

            return this.fragments.size();

        }

    }

    private List<Fragment> getFragments() {

        List<Fragment> fList = new ArrayList<Fragment>();

        fList.add(MyFragment.newInstance("Fragment 1",R.drawable.imags));
        fList.add(MyFragment.newInstance("Fragment 2",R.drawable.image1));
        fList.add(MyFragment.newInstance("Fragment 3",R.drawable.image2));
        fList.add(MyFragment.newInstance("Fragment 4",R.drawable.image3));
        fList.add(MyFragment.newInstance("Fragment 5",R.drawable.image4));

        return fList;

    }

    public int differentDensityAndScreenSize(Context context) {
        int value = 20;
        String str = "";
        if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_SMALL) {
            switch (context.getResources().getDisplayMetrics().densityDpi) {
                case DisplayMetrics.DENSITY_LOW:
                    str = "small-ldpi";
                    // Log.e("small 1","small-ldpi");
                    value = 20;
                    break;
                case DisplayMetrics.DENSITY_MEDIUM:
                    str = "small-mdpi";
                    // Log.e("small 1","small-mdpi");
                    value = 20;
                    break;
                case DisplayMetrics.DENSITY_HIGH:
                    str = "small-hdpi";
                    // Log.e("small 1","small-hdpi");
                    value = 20;
                    break;
                case DisplayMetrics.DENSITY_XHIGH:
                    str = "small-xhdpi";
                    // Log.e("small 1","small-xhdpi");
                    value = 20;
                    break;
                case DisplayMetrics.DENSITY_XXHIGH:
                    str = "small-xxhdpi";
                    // Log.e("small 1","small-xxhdpi");
                    value = 20;
                    break;
                case DisplayMetrics.DENSITY_XXXHIGH:
                    str = "small-xxxhdpi";
                    //Log.e("small 1","small-xxxhdpi");
                    value = 20;
                    break;
                case DisplayMetrics.DENSITY_TV:
                    str = "small-tvdpi";
                    // Log.e("small 1","small-tvdpi");
                    value = 20;
                    break;
                default:
                    str = "small-unknown";
                    value = 20;
                    break;
            }

        } else if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_NORMAL) {
            switch (context.getResources().getDisplayMetrics().densityDpi) {
                case DisplayMetrics.DENSITY_LOW:
                    str = "normal-ldpi";
                    // Log.e("normal-ldpi 1","normal-ldpi");
                    str_device = "normal-ldpi";
                    value = 82;
                    break;
                case DisplayMetrics.DENSITY_MEDIUM:
                    // Log.e("normal-mdpi 1","normal-mdpi");
                    str = "normal-mdpi";
                    value = 82;
                    str_device = "normal-mdpi";
                    break;
                case DisplayMetrics.DENSITY_HIGH:
                    // Log.e("normal-hdpi 1","normal-hdpi");
                    str = "normal-hdpi";
                    str_device = "normal-hdpi";
                    value = 82;
                    break;
                case DisplayMetrics.DENSITY_XHIGH:
                    //Log.e("normal-xhdpi 1","normal-xhdpi");
                    str = "normal-xhdpi";
                    str_device = "normal-xhdpi";
                    value = 90;
                    break;
                case DisplayMetrics.DENSITY_XXHIGH:
                    // Log.e("normal-xxhdpi 1","normal-xxhdpi");
                    str = "normal-xxhdpi";
                    str_device = "normal-xxhdpi";
                    value = 96;
                    break;
                case DisplayMetrics.DENSITY_XXXHIGH:
                    //Log.e("normal-xxxhdpi","normal-xxxhdpi");
                    str = "normal-xxxhdpi";
                    str_device = "normal-xxxhdpi";
                    value = 96;
                    break;
                case DisplayMetrics.DENSITY_TV:
                    //Log.e("DENSITY_TV 1","normal-mdpi");
                    str = "normal-tvdpi";
                    str_device = "normal-tvmdpi";
                    value = 96;
                    break;
                default:
                    // Log.e("normal-unknown","normal-unknown");
                    str = "normal-unknown";
                    str_device = "normal-unknown";
                    value = 82;
                    break;
            }
        } else if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_LARGE) {
            switch (context.getResources().getDisplayMetrics().densityDpi) {
                case DisplayMetrics.DENSITY_LOW:
                    str = "large-ldpi";
                    // Log.e("large-ldpi 1","normal-ldpi");
                    value = 78;
                    break;
                case DisplayMetrics.DENSITY_MEDIUM:
                    str = "large-mdpi";
                    //Log.e("large-ldpi 1","normal-mdpi");
                    value = 78;
                    break;
                case DisplayMetrics.DENSITY_HIGH:
                    //Log.e("large-ldpi 1","normal-hdpi");
                    str = "large-hdpi";
                    value = 78;
                    break;
                case DisplayMetrics.DENSITY_XHIGH:
                    // Log.e("large-ldpi 1","normal-xhdpi");
                    str = "large-xhdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_XXHIGH:
                    //Log.e("large-ldpi 1","normal-xxhdpi");
                    str = "large-xxhdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_XXXHIGH:
                    // Log.e("large-ldpi 1","normal-xxxhdpi");
                    str = "large-xxxhdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_TV:
                    //Log.e("large-ldpi 1","normal-tvdpi");
                    str = "large-tvdpi";
                    value = 125;
                    break;
                default:
                    str = "large-unknown";
                    value = 78;
                    break;
            }

        } else if ((context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
            switch (context.getResources().getDisplayMetrics().densityDpi) {
                case DisplayMetrics.DENSITY_LOW:
                    // Log.e("large-ldpi 1","normal-ldpi");
                    str = "xlarge-ldpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_MEDIUM:
                    // Log.e("large-ldpi 1","normal-mdpi");
                    str = "xlarge-mdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_HIGH:
                    //Log.e("large-ldpi 1","normal-hdpi");
                    str = "xlarge-hdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_XHIGH:
                    // Log.e("large-ldpi 1","normal-hdpi");
                    str = "xlarge-xhdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_XXHIGH:
                    // Log.e("large-ldpi 1","normal-xxhdpi");
                    str = "xlarge-xxhdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_XXXHIGH:
                    // Log.e("large-ldpi 1","normal-xxxhdpi");
                    str = "xlarge-xxxhdpi";
                    value = 125;
                    break;
                case DisplayMetrics.DENSITY_TV:
                    //Log.e("large-ldpi 1","normal-tvdpi");
                    str = "xlarge-tvdpi";
                    value = 125;
                    break;
                default:
                    str = "xlarge-unknown";
                    value = 125;
                    break;
            }
        }

        return value;
    }
}

myfragment_layout.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="250dp"
    android:layout_height="250dp"
    android:background="#EAEAEA"
    android:orientation="vertical">

    <TextView

        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"

        />

    <ImageView
        android:id="@+id/iv_image"
        android:scaleType="fitXY"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

MyFragment.java

package com.deepshikha.viewpager;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

/**
 * Created by deepshikha on 6/7/17.
 */
public class MyFragment extends Fragment {

    View view;
    ImageView iv_image;

    public static final String EXTRA_MESSAGE = "EXTRA_MESSAGE";
    public static final String IMAGE = "EXTRA_IMAGE";

    public static final MyFragment newInstance(String message, int int_image)

    {

        MyFragment f = new MyFragment();

        Bundle bdl = new Bundle(1);
        bdl.putString(EXTRA_MESSAGE, message);
        bdl.putInt(IMAGE, int_image);

        f.setArguments(bdl);

        return f;

    }

    @Override

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        String message = getArguments().getString(EXTRA_MESSAGE);
        int int_image = getArguments().getInt(IMAGE);

        view = inflater.inflate(R.layout.myfragment_layout, container, false);

        TextView messageTextView = (TextView) view.findViewById(R.id.textView);

        ImageView iv_image = (ImageView) view.findViewById(R.id.iv_image);

        iv_image.setImageResource(int_image);
        messageTextView.setText(message);

        return view;

    }

}

ExpandingViewPagerTransformer.java:

package com.deepshikha.viewpager;

import android.os.Build;
import android.support.v4.view.ViewPager;
import android.view.View;

import android.os.Build;
import android.support.v4.view.ViewPager;
import android.view.View;

/**
 * Created by Qs on 16/5/30.
 */
public class ExpandingViewPagerTransformer implements ViewPager.PageTransformer {

    public static final float MAX_SCALE = 1.0f;
    public static final float MIN_SCALE = 0.8f;

    @Override
    public void transformPage(View page, float position) {

        position = position < -1 ? -1 : position;
        position = position > 1 ? 1 : position;

        float tempScale = position < 0 ? 1 + position : 1 - position;

        float slope = (MAX_SCALE - MIN_SCALE) / 1;
        float scaleValue = MIN_SCALE + tempScale * slope;
        page.setScaleX(scaleValue);
        page.setScaleY(scaleValue);
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            page.getParent().requestLayout();
        }
    }
}