Make Image Blur

Display Image into Blur effect

1) Edit MainActivity.Java in your project

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.TextView;


public class MainActivity extends ActionBarActivity {
    private ImageView android;
    private ImageView resultimg;
    private TextView text;
    private TextView statusText;
    Uri source;
    Bitmap bitmapMaster;
    Canvas canvasMaster;
    RenderScript _rs;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        android = (ImageView) findViewById(R.id.android1);
        resultimg = (ImageView) findViewById(R.id.resultimage);

        Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.android1);
        Bitmap resultbm = blurImage(bm, 10);
        resultimg.setImageBitmap(resultbm);


    }

private Bitmap blurImage(Bitmap sentBitmap, int radius) {
        if (Build.VERSION.SDK_INT > 16) {
            Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
           
            RenderScript rs = RenderScript.create(this);
            Allocation input = Allocation.createFromBitmap(rs, sentBitmap, Allocation.MipmapControl.MIPMAP_NONE,
                    Allocation.USAGE_SCRIPT);
            Allocation output = Allocation.createTyped(rs, input.getType());
            ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
            script.setRadius(radius /* e.g. 3.f */);
            script.setInput(input);
            script.forEach(output);
            output.copyTo(bitmap);
            return bitmap;
        } else {
            return sentBitmap;
        }

    }
}

2)Edit activity_main.xml file 

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

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

        <ImageView
            android:id="@+id/android1"
            android:layout_width="200dp"
            android:layout_height="200dp"
            android:layout_marginBottom="10dp"
            android:scaleType="centerCrop"
            android:src="@drawable/android1" />

        <ImageView
            android:id="@+id/resultimage"
            android:layout_width="200dp"
            android:layout_height="200dp"
            android:scaleType="centerCrop" />

    </LinearLayout>
</ScrollView>

Output

Post Data to google form

Here we have to learn how to post data from android app to google form

Reference Site : post-data-google-drive-sheet-through-mobile-app

Download libraries : okhttp

1) Edit MainActivity.Java in your project

import android.content.Context;

import android.os.AsyncTask;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.text.TextUtils;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

import com.squareup.okhttp.MediaType;

import com.squareup.okhttp.OkHttpClient;

import com.squareup.okhttp.Request;

import com.squareup.okhttp.RequestBody;

import com.squareup.okhttp.Response;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.net.URLEncoder;

public class MainActivity extends AppCompatActivity {

    //Post Data to Google Docs

    public static final MediaType FORM_DATA_TYPE

            = MediaType.parse("application/x-www-form-urlencoded; charset=utf-8");

    public static final String URL = "https://docs.google.com/forms/d/1_lR63RGcUzpu5qUAFJ0VTdMFMacasT8VHuCHXg8KzLg/formResponse";

    public static final String EMAIL_KEY = "entry_1382470853";

    public static final String SUBJECT_KEY = "entry_994168354";

    public static final String MESSAGE_KEY = "entry_1197258696";

    private Context mContext;

    private EditText emailEditText;

    private EditText subjectEditText;

    private EditText messageEditText;

    private Button sendButton;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mContext = this;

        emailEditText = (EditText) findViewById(R.id.edt_email);

        subjectEditText = (EditText) findViewById(R.id.edt_subject);

        messageEditText = (EditText) findViewById(R.id.edt_message);

        sendButton = (Button) findViewById(R.id.btn_send);

        sendButton.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                if (TextUtils.isEmpty(emailEditText.getText().toString()) ||

                        TextUtils.isEmpty(subjectEditText.getText().toString()) ||

                        TextUtils.isEmpty(messageEditText.getText().toString())) {

                    Toast.makeText(mContext, "All fields are mandatory.", Toast.LENGTH_LONG).show();

                    return;

                }

                if (!android.util.Patterns.EMAIL_ADDRESS.matcher(emailEditText.getText().toString()).matches()) {

                    Toast.makeText(mContext, "Please enter a valid email.", Toast.LENGTH_LONG).show();

                    return;

                }

                PostDataTask postDataTask = new PostDataTask();

                //execute asynctask

                postDataTask.execute(URL, emailEditText.getText().toString(),

                        subjectEditText.getText().toString(),

                        messageEditText.getText().toString());

            }

        });

    }

    private class PostDataTask extends AsyncTask<String, Void, Boolean> {

        @Override

        protected Boolean doInBackground(String... contactData) {

            Boolean result = true;

            String url = contactData[0];

            String email = contactData[1];

            String subject = contactData[2];

            String message = contactData[3];

            String postBody = "";

            try {

                //all values must be URL encoded to make sure that special characters like & | ",etc.

                //do not cause problems

                postBody = EMAIL_KEY + "=" + URLEncoder.encode(email, "UTF-8") +

                        "&" + SUBJECT_KEY + "=" + URLEncoder.encode(subject, "UTF-8") +

                        "&" + MESSAGE_KEY + "=" + URLEncoder.encode(message, "UTF-8");

            } catch (UnsupportedEncodingException ex) {

                result = false;

            }

            /*

            //If you want to use HttpRequest class from http://stackoverflow.com/a/2253280/1261816

            try {

HttpRequest httpRequest = new HttpRequest();

httpRequest.sendPost(url, postBody);

}catch (Exception exception){

result = false;

}

            */

            try {

                //Create OkHttpClient for sending request

                OkHttpClient client = new OkHttpClient();

                //Create the request body with the help of Media Type

                RequestBody body = RequestBody.create(FORM_DATA_TYPE, postBody);

                Request request = new Request.Builder()

                        .url(url)

                        .post(body)

                        .build();

                //Send the request

                Response response = client.newCall(request).execute();

            } catch (IOException exception) {

                result = false;

            }

            return result;

        }

        @Override

        protected void onPostExecute(Boolean result) {

            //Print Success or failure message accordingly

            Toast.makeText(mContext, result ? "Message successfully sent!" : "There was some error" +

                    " in sending message. Please try again after some time.", Toast.LENGTH_LONG).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;

        }

        return super.onOptionsItemSelected(item);

    }

}

2) Add Internet permission to Manifest.xml

  <uses-permission android:name="android.permission.INTERNET" />

Android Staggrred GridView Examples

Reference Links

• AndroidStaggeredGrid
• Android Staggeredgrid Layout Manager Example Tutorial
• AsymmetricGridView
• DynamicGrid

XML Parsing

Android XML Parsing

• Reference site : www.androidhive.info
• Now we have to how xml parsing done in android

1) Create XML Parser for parsing xml data

import android.util.Log;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import java.io.IOException;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

public class XMLParser {

    public XMLParser() {

    }

    public String getXmlFromUrl(String url) {
        String xml = null;
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
//            HttpClient httpClient = HttpClientBuilder.create().build();
            HttpPost httpPost = new HttpPost(url);
            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            xml = EntityUtils.toString(httpEntity);

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return xml;
    }

    public Document getDomElement(String xml) {
        Document doc = null;
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        try {

            DocumentBuilder db = dbf.newDocumentBuilder();

            InputSource is = new InputSource();
            is.setCharacterStream(new StringReader(xml));
            doc = db.parse(is);

        } catch (ParserConfigurationException e) {
            Log.e("Error: ", e.getMessage());
            return null;
        } catch (SAXException e) {
            Log.e("Error: ", e.getMessage());
            return null;
        } catch (IOException e) {
            Log.e("Error: ", e.getMessage());
            return null;
        }

        return doc;
    }

    public final String getElementValue(Node elem) {
        Node child;
        if (elem != null) {
            if (elem.hasChildNodes()) {
                for (child = elem.getFirstChild(); child != null; child = child.getNextSibling()) {
                    if (child.getNodeType() == Node.TEXT_NODE) {
                        return child.getNodeValue();
                    }
                }
            }
        }
        return "";
    }


    public String getValue(Element item, String str) {
        NodeList n = item.getElementsByTagName(str);
        return this.getElementValue(n.item(0));
    }

}

2) Edit MainActivity.Java in your project

import android.app.ListActivity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

import org.json.JSONArray;
import org.json.JSONObject;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import java.util.ArrayList;
import java.util.HashMap;


public class MainActivity extends ListActivity {

    // All static variables
    static final String XML_URL = "http://api.androidhive.info/pizza/?format=xml";
    // XML node keys
    static final String KEY_ITEM = "item"; // parent node
    static final String KEY_ID = "id";
    static final String KEY_NAME = "name";
    static final String KEY_COST = "cost";
    static final String KEY_DESC = "description";
    private Toolbar toolbar;

    //Json Array Node Names
    private static final String TAG_COTACTS = "contacts";
    private static final String TAG_ID = "id";
    private static final String TAG_NAME = "name";
    private static final String TAG_EMAIL = "email";
    private static final String TAG_ADDRESS = "address";
    private static final String TAG_GENDER = "gender";
    private static final String TAG_PHONE = "phone";
    private static final String TAG_PHONE_MOBILE = "mobile";
    private static final String TAG_PHONE_OFFICE = "office";
    private static final String TAG_PHONE_HOME = "home";

    // Json Array
    JSONArray contacts = null;

    ArrayList<HashMap<String, String>> contactsList;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Json/Xml Parsing");
        
        // selecting single ListView item
        ListView lv = getListView();
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                // getting values from selected ListItem
                String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
                String cost = ((TextView) view.findViewById(R.id.cost)).getText().toString();
                String description = ((TextView) view.findViewById(R.id.description)).getText().toString();

                // Starting new intent
                Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
                in.putExtra(KEY_NAME, name);
                in.putExtra(KEY_COST, cost);
                in.putExtra(KEY_DESC, description);
                startActivity(in);

            }
        });
        new GetXmlData().execute();
    }

    private class GetJsonData extends AsyncTask<Void, Void, Void> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected Void doInBackground(Void... params) {
            ServiceHandler sh = new ServiceHandler();
            String jsonStr = sh.makeServiceCall(JSON_URL, ServiceHandler.GET);
            Log.d("Response = ", jsonStr);

            if (jsonStr != null) {
                try {
                    JSONObject jsonObject = new JSONObject(jsonStr);
                    contacts = jsonObject.getJSONArray(TAG_COTACTS);
                    for (int i = 0; i < contacts.length(); i++) {
                        JSONObject c = contacts.getJSONObject(i);
                        String id = c.getString(TAG_ID);
                        String name = c.getString(TAG_NAME);
                        String email = c.getString(TAG_EMAIL);
                        String address = c.getString(TAG_ADDRESS);
                        String gender = c.getString(TAG_GENDER);

                        JSONObject phoneNode = c.getJSONObject(TAG_PHONE);
                        String mobile = phoneNode.getString(TAG_PHONE_MOBILE);
                        String home = phoneNode.getString(TAG_PHONE_HOME);
                        String office = phoneNode.getString(TAG_PHONE_OFFICE);

                        HashMap<String, String> contact = new HashMap<String, String>();
                        contact.put(TAG_ID, id);
                        contact.put(TAG_NAME, name);
                        contact.put(TAG_EMAIL, email);
                        contact.put(TAG_PHONE_MOBILE, mobile);

                        contactsList.add(contact);
                    }

                } catch (Exception e) {
                    Log.e("Service Handler", "Coulden't get any data from Url");
                }
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void Void) {
            super.onPostExecute(Void);
            ListAdapter adapter = new SimpleAdapter(MainActivity.this, contactsList, R.layout.list_item,
                    new String[]{TAG_NAME, TAG_EMAIL, TAG_PHONE_MOBILE}, new int[]{
                    R.id.name, R.id.email, R.id.mobile});
            setListAdapter(adapter);
        }
    }

    private class GetXmlData extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected Void doInBackground(Void... params) {

            ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();

            XMLParser parser = new XMLParser();
            String xml = parser.getXmlFromUrl(XML_URL); // getting XML
            Document doc = parser.getDomElement(xml); // getting DOM element
            NodeList nl = doc.getElementsByTagName(KEY_ITEM);
            // looping through all item nodes <item>
            for (int i = 0; i < nl.getLength(); i++) {
                // creating new HashMap
                HashMap<String, String> map = new HashMap<String, String>();
                Element e = (Element) nl.item(i);
                // adding each child node to HashMap key => value
                map.put(KEY_ID, parser.getValue(e, KEY_ID));
                map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
                map.put(KEY_COST, "Rs." + parser.getValue(e, KEY_COST));
                map.put(KEY_DESC, parser.getValue(e, KEY_DESC));

                // adding HashList to ArrayList
                menuItems.add(map);
            }
            ListAdapter adapter = new SimpleAdapter(getApplicationContext(), menuItems,
                    R.layout.list_item,
                    new String[]{KEY_NAME, KEY_DESC, KEY_COST}, new int[]{
                    R.id.name, R.id.email, R.id.mobile});

            setListAdapter(adapter);
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
        }
    }

}

3)Add Internet permission to AndroidManifest.xml

 <uses-permission android:name="android.permission.INTERNET" />

Json Parsing

Android Json Parsing Example

• Reference site : www.androidhive.info
• JSON is very light weight, structured, easy to parse and much human readable. JSON is best alternative to XML when your android app needs to interchange data with your server

1) create ServiceHandler.Java Class for creating request to get json data from URL

import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.NameValuePair;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.client.utils.URLEncodedUtils;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.util.EntityUtils;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.util.List;

public class ServiceHandler {

    public static final int GET = 1;

    public static final int POST = 2;

    static String response = null;

    public ServiceHandler() {

    }

    public String makeServiceCall(String Url, int method) {

        return this.makeServiceCall(Url, method, null);

    }

    public String makeServiceCall(String Url, int method, List<NameValuePair> params) {

        try {

            DefaultHttpClient httpClient = new DefaultHttpClient();

            HttpEntity httpEntity = null;

            HttpResponse httpResponse = null;

            if (method == POST) {

                HttpPost httpPost = new HttpPost(Url);

                if (params != null) {

                    httpPost.setEntity(new UrlEncodedFormEntity(params));

                }

                httpResponse = httpClient.execute(httpPost);

            } else if (method == GET) {

                if (params != null) {

                    String paramString = URLEncodedUtils.format(params, "utf-8");

                    Url += "?" + paramString;

                }

                HttpGet httpGet = new HttpGet(Url);

                httpResponse = httpClient.execute(httpGet);

            }

            httpEntity = httpResponse.getEntity();

            response = EntityUtils.toString(httpEntity);

        } catch (ClientProtocolException e) {

            e.printStackTrace();

        } catch (UnsupportedEncodingException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

        return response;

    }

}

2) Edit MainActivity.java file in your project

import android.app.ListActivity;

import android.os.AsyncTask;

import android.os.Bundle;

import android.util.Log;

import android.view.Menu;

import android.view.MenuItem;

import android.widget.ListAdapter;

import android.widget.ListView;

import android.widget.SimpleAdapter;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import java.util.ArrayList;

import java.util.HashMap;

public class MainActivity extends ListActivity {

    public static final String Url = "http://api.androidhive.info/contacts/";

    static final String TAG_CONTACTS = "contacts";

    static final String TAG_ID = "id";

    static final String TAG_NAME = "name";

    static final String TAG_EMAIL = "email";

    static final String TAG_ADDRESS = "address";

    static final String TAG_PHONE = "phone";

    static final String TAG_PHONE_HOME = "home";

    static final String TAG_PHONE_MOBILE = "mobile";

    static final String TAG_PHONE_OFFICE = "office";

    static final String TAG_GENDER = "gender";

    ArrayList<HashMap<String, String>> contactsList;

    JSONArray contacts = null;

    ListView lv;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        contactsList = new ArrayList<HashMap<String, String>>();

        lv = getListView();

        new getJsonData().execute();

    }

    @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;

    }

    private class getJsonData extends AsyncTask<Void, Void, Void> {

        @Override

        protected void onPreExecute() {

            super.onPreExecute();

        }

        @Override

        protected Void doInBackground(Void... params) {

            ServiceHandler sh = new ServiceHandler();

            String jsonStr = sh.makeServiceCall(Url, ServiceHandler.GET);

            if (jsonStr != null)

                try {

                    JSONObject jsonObject = new JSONObject(jsonStr);

                    contacts = jsonObject.getJSONArray(TAG_CONTACTS);

                    for (int i = 0; i < contacts.length(); i++) {

                        JSONObject c = contacts.getJSONObject(i);

                        String id = c.getString(TAG_ID);

                        String name = c.getString(TAG_NAME);

                        String email = c.getString(TAG_EMAIL);

                        String gender = c.getString(TAG_GENDER);

                        String address = c.getString(TAG_ADDRESS);

                        JSONObject phone = c.getJSONObject(TAG_PHONE);

                        String mobile = phone.getString(TAG_PHONE_MOBILE);

                        String office = phone.getString(TAG_PHONE_OFFICE);

                        String home = phone.getString(TAG_PHONE_HOME);

                        HashMap<String, String> contact = new HashMap<String, String>();

                        contact.put(TAG_ID, id);

                        contact.put(TAG_NAME, name);

                        contact.put(TAG_EMAIL, email);

                        contact.put(TAG_PHONE_MOBILE, mobile);

                        contactsList.add(contact);

                    }

                } catch (JSONException e) {

                    e.printStackTrace();

                    Log.e("Service Handler", "Coulden't get any data from Url");

                }

            return null;

        }

        @Override

        protected void onPostExecute(Void aVoid) {

            super.onPostExecute(aVoid);

            ListAdapter adapter = new SimpleAdapter(MainActivity.this, contactsList, R.layout.list_item,

                    new String[]{TAG_NAME, TAG_EMAIL, TAG_PHONE_MOBILE},

                    new int[]{R.id.name, R.id.email, R.id.phone});

            setListAdapter(adapter);

        }

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

}

3)Add Internet permission to AndroidManifest.xml

  <uses-permission android:name="android.permission.INTERNET" />

Android ViewHolder Basic example

What is View Holder and why we use it?

      The View Holder design pattern enables you to access each list item view without the need for the look up, saving valuable processor cycles. Specifically, it avoids frequent call of findViewById() during List View scrolling, and that will make it smooth.

1) Take List View in you activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
    <ListView android:id="@+id/list"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:transcriptMode="alwaysScroll"
              android:listSelector="@android:color/transparent"/>
</LinearLayout>

2) Create list_item.xml for list item

 <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="horizontal"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/list_item"
        android:gravity="center_vertical">
    <TextView android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:id="@+id/list_item_text_view"
              android:textSize="20sp"
              android:padding="10dp"
              android:layout_marginLeft="5dp"/>
</LinearLayout>

3) Create Custom Adapter for ViewHoder to set text in TextView "CustomAdapter.java"

package com.example;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.ArrayList;
public class CustomAdapter extends BaseAdapter {
    private ArrayList<String> mListItems;
    private LayoutInflater mLayoutInflater;
    public CustomAdapter(Context context, ArrayList<String> arrayList){
        mListItems = arrayList;
        //get the layout inflater
        mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }
    @Override
    public int getCount() {
        //getCount() represents how many items are in the list
        return mListItems.size();
    }
    @Override
    //get the data of an item from a specific position
    //i represents the position of the item in the list
    public Object getItem(int i) {
        return null;
    }
    @Override
    //get the position id of the item from the list
    public long getItemId(int i) {
        return 0;
    }
    @Override
    public View getView(int position, View view, ViewGroup viewGroup) {
        ViewHolder holder;
        if (view == null) {
            holder = new ViewHolder();
            view = mLayoutInflater.inflate(R.layout.list_item, null);
            holder.itemName = (TextView) view.findViewById(R.id.list_item_text_view);
        } else {
            holder = (ViewHolder)view.getTag();
        }
        String stringItem = mListItems.get(position);
        if (stringItem != null) {
            if (holder.itemName != null) {
                //set the item name on the TextView
                holder.itemName.setText(stringItem);
            }
        }
        return view;
    }
    private static class ViewHolder {
        protected TextView itemName;
    }
}

4) MainActivity .java

package com.example;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import java.util.ArrayList;
public class MyActivity extends Activity
{
    private ListView myList;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ArrayList<String> list = new ArrayList();
        for (int i = 0; i < 20; i++){
            list.add("Odoo" + i);
        }
        myList = (ListView)findViewById(R.id.list);
ning the data backing this list and for producing
   
        myList.setAdapter(new CustomAdapter(MyActivity.this,list));
    }
}

Output