shaon, Author at Coding Hunt

Android LiveData with Kotlin Coroutine + Flow

October 31, 2019October 31, 2019shaonLeave a comment

Here I have tried to show two procedures to implement Room using Kotlin Coroutine. Using Flow Reactive pattern

import androidx.room.Dao
import androidx.room.Insert
import androidx.room.OnConflictStrategy
import androidx.room.Query

import com.durbinlabs.roomdemo.model.Client
import kotlinx.coroutines.flow.Flow

/**
 * Created by Shaon on 31/10/2019.
 */

@Dao
interface ClientDao {
    @Query("SELECT * FROM client")
    fun all(): Flow<List<Client>>

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    suspend fun insert(vararg clients: Client)

    @Query("DELETE FROM client")
    suspend fun removeAllClients()
}

import androidx.room.Dao

import androidx.room.Insert

import androidx.room.OnConflictStrategy

import androidx.room.Query

import com.durbinlabs.roomdemo.model.Client

import kotlinx.coroutines.flow.Flow

/**

* Created by Shaon on 31/10/2019.

@Dao

interface ClientDao {

@Query("SELECT * FROM client")

fun all(): Flow<List<Client>>

@Insert(onConflict = OnConflictStrategy.IGNORE)

suspend fun insert(vararg clients: Client)

@Query("DELETE FROM client")

suspend fun removeAllClients()

}

import androidx.lifecycle.*
import com.durbinlabs.roomdemo.interfaces.ClientDao
import com.durbinlabs.roomdemo.model.Client
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.flow.flowOn
import kotlinx.coroutines.launch

/**
 * Created by Shaon on 10/30/2019.
 */

class ClientVM constructor(val clientDao: ClientDao) : ViewModel() {

    fun insert(client: Client) = viewModelScope.launch {
        clientDao.insert(client)
    }

    // The stream will run in io dispatcher
    val clients  = clientDao.all().flowOn(Dispatchers.IO).asLiveData()

}

import androidx.lifecycle.*

import com.durbinlabs.roomdemo.interfaces.ClientDao

import com.durbinlabs.roomdemo.model.Client

import kotlinx.coroutines.Dispatchers

import kotlinx.coroutines.flow.flowOn

import kotlinx.coroutines.launch

/**

* Created by Shaon on 10/30/2019.

class ClientVM constructor(val clientDao: ClientDao) : ViewModel() {

fun insert(client: Client) = viewModelScope.launch {

clientDao.insert(client)

}

// The stream will run in io dispatcher

val clients = clientDao.all().flowOn(Dispatchers.IO).asLiveData()

}

Using ViewModel Scope and liveData {} new Asynchronous pattern

import androidx.lifecycle.LiveData
import androidx.room.Dao
import androidx.room.Insert
import androidx.room.OnConflictStrategy
import androidx.room.Query

import com.durbinlabs.roomdemo.model.Client

/**
 * Created by Shaon on 31/10/2019.
 */

@Dao
interface ClientDao {


    Using suspend function
    @Query("SELECT * FROM client")
    suspend fun all(): LiveData<List<Client>>

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    suspend fun insert(vararg clients: Client)

    @Query("DELETE FROM client")
    suspend fun removeAllClients()
}

import androidx.lifecycle.LiveData

import androidx.room.Dao

import androidx.room.Insert

import androidx.room.OnConflictStrategy

import androidx.room.Query

import com.durbinlabs.roomdemo.model.Client

/**

* Created by Shaon on 31/10/2019.

@Dao

interface ClientDao {

Using suspend function

@Query("SELECT * FROM client")

suspend fun all(): LiveData<List<Client>>

@Insert(onConflict = OnConflictStrategy.IGNORE)

suspend fun insert(vararg clients: Client)

@Query("DELETE FROM client")

suspend fun removeAllClients()

}

import androidx.lifecycle.*
import com.durbinlabs.roomdemo.interfaces.ClientDao
import com.durbinlabs.roomdemo.model.Client
import kotlinx.coroutines.launch

/**
 * Created by Shaon on 10/30/2019.
 */

class ClientVM constructor(val clientDao: ClientDao) : ViewModel() {

    fun insert(client: Client) = viewModelScope.launch {
        clientDao.insert(client)
    }

     val clients  = liveData {
         val data = clientDao.all()
         emitSource(data)
     }

}

import androidx.lifecycle.*

import com.durbinlabs.roomdemo.interfaces.ClientDao

import com.durbinlabs.roomdemo.model.Client

import kotlinx.coroutines.launch

/**

* Created by Shaon on 10/30/2019.

class ClientVM constructor(val clientDao: ClientDao) : ViewModel() {

fun insert(client: Client) = viewModelScope.launch {

clientDao.insert(client)

}

val clients = liveData {

val data = clientDao.all()

emitSource(data)

}

To get data in activity or fragment

clientVM.clients
    .observe(this, Observer {
    adapter.addAll(it)
})

clientVM.clients

.observe(this, Observer {

adapter.addAll(it)

})

Helping Gradle Dependency

 //Room
    implementation "androidx.room:room-runtime:$room_version"
    kapt "androidx.room:room-compiler:$room_version"
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    implementation "androidx.room:room-ktx:$room_version"

    //  LiveData
    implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
    implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.2.0-rc01"

    // ViewModel
    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
    implementation "android.arch.lifecycle:viewmodel:$lifecycle_version"

//Room

implementation "androidx.room:room-runtime:$room_version"

kapt "androidx.room:room-compiler:$room_version"

implementation 'androidx.legacy:legacy-support-v4:1.0.0'

implementation "androidx.room:room-ktx:$room_version"

// LiveData

implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"

implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.2.0-rc01"

// ViewModel

implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"

implementation "android.arch.lifecycle:viewmodel:$lifecycle_version"

Android Receiving location updates in Kotlin

May 29, 2018May 29, 2018shaonLeave a comment

Often we need our user location or need to update user location in our app. This is a simple util class that I build for my pet project. Use this below code as a util class

import android.Manifest
import android.annotation.SuppressLint
import android.app.Activity
import android.content.Context
import android.content.IntentSender
import android.content.pm.PackageManager
import android.os.Looper
import android.support.v4.app.ActivityCompat
import com.google.android.gms.common.api.ResolvableApiException
import com.google.android.gms.location.*
import com.google.android.gms.maps.model.LatLng
import com.google.android.gms.tasks.Task
import com.shaon2017.salahz.interfaces.SimpleCallback

/**
 * Created by Shaon on 4/18/2018.
 * Bismillahir Rohmanir Rohim :)
 */
class InitGeoLocationUpdate {
    companion object {
        private var locationCallBack: LocationCallback? = null
        private var fusedLocationClient: FusedLocationProviderClient? = null
        private val TAG = InitGeoLocationUpdate::class.simpleName
        private lateinit var locationLatLngCallback : SimpleCallback&lt;LatLng&gt;

        fun locationInit(context: Context, locationLatLngCallback: SimpleCallback&lt;LatLng&gt;) {
            this.locationLatLngCallback = locationLatLngCallback
            createLocationRequest(context, getLocationCallBack());
        }

        private fun getLocationCallBack(): LocationCallback {
            if (locationCallBack == null)
                return initLocationCallback()
            return locationCallBack!!
        }


        private fun initLocationCallback(): LocationCallback {
            locationCallBack = object : LocationCallback() {
                override fun onLocationResult(locationResult: LocationResult?) {
                    super.onLocationResult(locationResult)

                    val mCurrentLocation = locationResult!!.lastLocation
                    val mCurrentLatLng = LatLng(mCurrentLocation!!.latitude, mCurrentLocation.longitude)

                    locationLatLngCallback.callback(mCurrentLatLng)

                    Lg.d(TAG!!, "Current Location Latitude: " + mCurrentLatLng.latitude + " Longitude: " +
                            mCurrentLatLng.longitude)
                }
            }
            return locationCallBack!!
        }

        @SuppressLint("RestrictedApi")
        private fun createLocationRequest(context: Context, locationCallback: LocationCallback) {
            val locationRequest = LocationRequest().apply {
                interval = 1000
                fastestInterval = 2000
                priority = LocationRequest.PRIORITY_HIGH_ACCURACY
            }
            buildLocationSettingsRequest(context, locationRequest, locationCallback);
        }

        private fun getFusedLocationClient(context: Context): FusedLocationProviderClient? {
            if (fusedLocationClient == null)
                return createFusedLocationClient(context)

            return fusedLocationClient
        }

        private fun createFusedLocationClient(context: Context): FusedLocationProviderClient? {
            fusedLocationClient = LocationServices.getFusedLocationProviderClient(context)
            return fusedLocationClient
        }

        private val REQUEST_CHECK_SETTINGS = 0x1
        private fun buildLocationSettingsRequest(context: Context, locationRequest: LocationRequest,
                                                 locationCallback: LocationCallback) {

            val builder = LocationSettingsRequest.Builder();
            builder.addLocationRequest(locationRequest).setAlwaysShow(true);
//        val mLocationSettingsRequest = builder.build();

            val client: SettingsClient = LocationServices.getSettingsClient(context)
            val task: Task&lt;LocationSettingsResponse&gt; = client.checkLocationSettings(builder.build())


            task.addOnSuccessListener(context as Activity, {
                if (ActivityCompat.checkSelfPermission(context,
                                Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED)
                    getFusedLocationClient(context)!!.requestLocationUpdates(locationRequest,
                            locationCallback, Looper.myLooper());
            }).addOnFailureListener {
                if (it is ResolvableApiException) {
                    // Location settings are not satisfied, but this can be fixed
                    // by showing the user a dialog.
                    try {
                        // Show the dialog by calling startResolutionForResult(),
                        // and check the result in onActivityResult().
                        it.startResolutionForResult(context as Activity,
                                REQUEST_CHECK_SETTINGS)
                    } catch (sendEx: IntentSender.SendIntentException) {
                        // Ignore the error.
                    }
                }
            }
        }

        fun stopLocationUpdate(context: Context) {
            getFusedLocationClient(context as Activity)!!.removeLocationUpdates(getLocationCallBack())
        }
    }
}

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import android.Manifest

import android.annotation.SuppressLint

import android.app.Activity

import android.content.Context

import android.content.IntentSender

import android.content.pm.PackageManager

import android.os.Looper

import android.support.v4.app.ActivityCompat

import com.google.android.gms.common.api.ResolvableApiException

import com.google.android.gms.location.*

import com.google.android.gms.maps.model.LatLng

import com.google.android.gms.tasks.Task

import com.shaon2017.salahz.interfaces.SimpleCallback

/**

* Created by Shaon on 4/18/2018.

* Bismillahir Rohmanir Rohim :)

class InitGeoLocationUpdate {

companion object {

private var locationCallBack: LocationCallback? = null

private var fusedLocationClient: FusedLocationProviderClient? = null

private val TAG = InitGeoLocationUpdate::class.simpleName

private lateinit var locationLatLngCallback : SimpleCallback<LatLng>

fun locationInit(context: Context, locationLatLngCallback: SimpleCallback<LatLng>) {

this.locationLatLngCallback = locationLatLngCallback

createLocationRequest(context, getLocationCallBack());

}

private fun getLocationCallBack(): LocationCallback {

if (locationCallBack == null)

return initLocationCallback()

return locationCallBack!!

}

private fun initLocationCallback(): LocationCallback {

locationCallBack = object : LocationCallback() {

override fun onLocationResult(locationResult: LocationResult?) {

super.onLocationResult(locationResult)

val mCurrentLocation = locationResult!!.lastLocation

val mCurrentLatLng = LatLng(mCurrentLocation!!.latitude, mCurrentLocation.longitude)

locationLatLngCallback.callback(mCurrentLatLng)

Lg.d(TAG!!, "Current Location Latitude: " + mCurrentLatLng.latitude + " Longitude: " +

mCurrentLatLng.longitude)

}

return locationCallBack!!

}

@SuppressLint("RestrictedApi")

private fun createLocationRequest(context: Context, locationCallback: LocationCallback) {

val locationRequest = LocationRequest().apply {

interval = 1000

fastestInterval = 2000

priority = LocationRequest.PRIORITY_HIGH_ACCURACY

}

buildLocationSettingsRequest(context, locationRequest, locationCallback);

}

private fun getFusedLocationClient(context: Context): FusedLocationProviderClient? {

if (fusedLocationClient == null)

return createFusedLocationClient(context)

return fusedLocationClient

}

private fun createFusedLocationClient(context: Context): FusedLocationProviderClient? {

fusedLocationClient = LocationServices.getFusedLocationProviderClient(context)

return fusedLocationClient

}

private val REQUEST_CHECK_SETTINGS = 0x1

private fun buildLocationSettingsRequest(context: Context, locationRequest: LocationRequest,

locationCallback: LocationCallback) {

val builder = LocationSettingsRequest.Builder();

builder.addLocationRequest(locationRequest).setAlwaysShow(true);

// val mLocationSettingsRequest = builder.build();

val client: SettingsClient = LocationServices.getSettingsClient(context)

val task: Task<LocationSettingsResponse> = client.checkLocationSettings(builder.build())

task.addOnSuccessListener(context as Activity, {

if (ActivityCompat.checkSelfPermission(context,

Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED)

getFusedLocationClient(context)!!.requestLocationUpdates(locationRequest,

locationCallback, Looper.myLooper());

}).addOnFailureListener {

if (it is ResolvableApiException) {

// Location settings are not satisfied, but this can be fixed

// by showing the user a dialog.

try {

// Show the dialog by calling startResolutionForResult(),

// and check the result in onActivityResult().

it.startResolutionForResult(context as Activity,

REQUEST_CHECK_SETTINGS)

} catch (sendEx: IntentSender.SendIntentException) {

// Ignore the error.

}

fun stopLocationUpdate(context: Context) {

getFusedLocationClient(context as Activity)!!.removeLocationUpdates(getLocationCallBack())

}

How to use? Follow the below code call this below code when you need location update. This…

Customization of RestApi call using Retrofit and RxJava in Kotlin

February 27, 2018shaonLeave a comment

Assuming you all are well aware of Retrofit and RxJava. Today I am going to write about how you can customize your RestApi call using Retrofit and RxJava. This will make your project neat and clean. We will build a class from where all our GET and POST request will be handled. Features: Check your internet is…

Android Line Chart Example

January 20, 2018shaonLeave a comment

repositories {
    maven { url "https://jitpack.io" }
}

repositories {

maven { url "https://jitpack.io" }

}

implementation 'com.github.PhilJay:MPAndroidChart:v3.0.3'

1	implementation 'com.github.PhilJay:MPAndroidChart:v3.0.3'

public class MainActivity extends AppCompatActivity {
    LineChart chart;

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

        chart = findViewById(R.id.chart);

        ArrayList<Entry> entries = new ArrayList<>();
        entries.add(new Entry(0, 4));
        entries.add(new Entry(1, 1));
        entries.add(new Entry(2, 2));
        entries.add(new Entry(3, 4));

        LineDataSet dataSet = new LineDataSet(entries, "Customized values");
        dataSet.setColor(ContextCompat.getColor(this, R.color.colorPrimary));
        dataSet.setValueTextColor(ContextCompat.getColor(this, R.color.colorPrimaryDark));

        //****
        // Controlling X axis
        XAxis xAxis = chart.getXAxis();
        // Set the xAxis position to bottom. Default is top
        xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);
        //Customizing x axis value
        final String[] months = new String[]{"Jan", "Feb", "Mar", "Apr"};

        IAxisValueFormatter formatter = new IAxisValueFormatter() {
            @Override
            public String getFormattedValue(float value, AxisBase axis) {
                return months[(int) value];
            }
        };
        xAxis.setGranularity(1f); // minimum axis-step (interval) is 1
        xAxis.setValueFormatter(formatter);

        //***
        // Controlling right side of y axis
        YAxis yAxisRight = chart.getAxisRight();
        yAxisRight.setEnabled(false);

        //***
        // Controlling left side of y axis
        YAxis yAxisLeft = chart.getAxisLeft();
        yAxisLeft.setGranularity(1f);

        // Setting Data
        LineData data = new LineData(dataSet);
        chart.setData(data);
        chart.animateX(2500);
        //refresh
        chart.invalidate();
    }
}

public class MainActivity extends AppCompatActivity {

LineChart chart;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

chart = findViewById(R.id.chart);

ArrayList<Entry> entries = new ArrayList<>();

entries.add(new Entry(0, 4));

entries.add(new Entry(1, 1));

entries.add(new Entry(2, 2));

entries.add(new Entry(3, 4));

LineDataSet dataSet = new LineDataSet(entries, "Customized values");

dataSet.setColor(ContextCompat.getColor(this, R.color.colorPrimary));

dataSet.setValueTextColor(ContextCompat.getColor(this, R.color.colorPrimaryDark));

//****

// Controlling X axis

XAxis xAxis = chart.getXAxis();

// Set the xAxis position to bottom. Default is top

xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);

//Customizing x axis value

final String[] months = new String[]{"Jan", "Feb", "Mar", "Apr"};

IAxisValueFormatter formatter = new IAxisValueFormatter() {

@Override

public String getFormattedValue(float value, AxisBase axis) {

return months[(int) value];

}

};

xAxis.setGranularity(1f); // minimum axis-step (interval) is 1

xAxis.setValueFormatter(formatter);

//***

// Controlling right side of y axis

YAxis yAxisRight = chart.getAxisRight();

yAxisRight.setEnabled(false);

//***

// Controlling left side of y axis

YAxis yAxisLeft = chart.getAxisLeft();

yAxisLeft.setGranularity(1f);

// Setting Data

LineData data = new LineData(dataSet);

chart.setData(data);

chart.animateX(2500);

//refresh

chart.invalidate();

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.shaon.mpandroidchartdemo.MainActivity">

    <com.github.mikephil.charting.charts.LineChart
        android:id="@+id/chart"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></com.github.mikephil.charting.charts.LineChart>

</LinearLayout>

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

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

xmlns:app="http://schemas.android.com/apk/res-auto"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context="com.example.shaon.mpandroidchartdemo.MainActivity">

<com.github.mikephil.charting.charts.LineChart

android:id="@+id/chart"

android:layout_width="match_parent"

android:layout_height="match_parent"></com.github.mikephil.charting.charts.LineChart>

</LinearLayout>

Android RxJava Tutorial | Make your code reactive

January 13, 2018January 13, 2018shaonLeave a comment

Android RxJava Tutorial In this tutorial, we will learn how to implement RxJava, Room and Retrofit 2.0 in Android Application Development. RxJava: It is one of the popular library that you should use in your android app. RxJava is the ability to compose asynchronous events in a more straightforward way. To run multiple events in asynchronous…

Room Persistence Library – Learn Deeply

January 1, 2018January 1, 2018shaonLeave a comment

বিসমিল্লাহির রহমানির রহিম 🙂 Room Persistence Library কেন আমরা ROOM ব্যবহার করব? GOOGLE highly recommend to use Room instead of SQLite রুম হচ্ছে SQLite DB এর একটি এবস্ট্রাকশন লেয়ার, যেটি দিয়ে DB থেকে খুব সহজেই ডাটা পাওয়া যায়। রুম ব্যবহার করে আমরা বয়লারপ্লেট কোড কমাতে পারি। ইন্সার্টন এবং ডিলেশন ব্যাপারগুলো খুব সহজ করা হয়েছে এখানে।…

এন্ড্রয়েডে ডাটাবাইন্ডিং লাইব্রেরী ব্যবহার – পর্ব – ২

October 25, 2017October 27, 2017shaonLeave a comment

ডাটাবাইন্ডিং প্রথম পর্ব এন্ড্রয়েডে ডাটাবাইন্ডিং লাইব্রেরী ব্যবহার – পর্ব-১ এই পর্বে আমরা জানবো কিভাবে রিসাইকেলার ভিউ তে ডাটা বাইন্ড করতে হয়। এই পর্বে আমরা টু ওয়ে বাইন্ডিং, ইমেজ সেট করা, বাটন ইমপ্লিমেন্টেশন, অব্জারভেবল ফিল্ড নিয়ে কাজ শিখব। এই প্রজেক্টে দুটি মডেল ক্লাস ব্যবহার করা হয়েছে। নিচের ডিপেন্ডেন্সি গুলো build.gradle এপে এড করি।…

এন্ড্রয়েডে ডাটাবাইন্ডিং লাইব্রেরী ব্যবহার – পর্ব-১

October 23, 2017October 23, 2017shaonLeave a comment

ইউজার ইন্টারফেসের সাথে ক্লাস এবং ডাটা সরাসরি বাইন্ড করার জন্যে এন্ড্রয়েডের রয়েছে সাপোর্ট লাইব্রেরী (ডাটা বাইন্ডিং)। এই লাইব্রেরী ব্যবহার করে ইউজার ইন্টারফেসে সরাসরি মডেল ক্লাস থেকে ডাটা লোড করা যায়। এটি রিসাইকেলার ভিউ এর অধিকাংশ কোড কমিয়ে দিয়েছে। রিসাইকেলারের প্রত্যেক আইটেমকে একসাথেই বাইন্ড করে ফেলে। আমরা ধীরে ধীরে দেখব কিভাবে আমরা সরাসরি ভিউ বাইন্ড করতে…

এন্ড্রয়েডের ব্যাকগ্রাউন্ডে কাজ পরিচিতি

August 21, 2017August 21, 2017shaonLeave a comment

এন্ড্রয়েডের ব্যাকগ্রাউন্ডে কাজ মেইন থ্রেড/ইউআই থ্রেড/লুপারঃ যখন একটি এপ্লিকেশন শুরু হয় তখন এর সকল কাজ একটি থ্রেডের নিয়ন্ত্রণে থাকে। এটি এপের এক্টিভিটি, সার্ভিস এবং এদের যাবতীয় সকল কোড নিয়ন্ত্রণ করে। এটি এপ স্ট্রাকচারে গুরুত্বপূর্ণ অর্থ বহন করে। এটি এপের সকল ঘটনা, ইউজার ইন্টারফেস ধারণ করে। এটিকে আবার UI Thread ও বলা হয়ে থাকে। এই…

Android Timer and TimerTask Example And Explanation

August 17, 2017August 17, 2017shaonLeave a comment

টাইমার/ টাইমার টাস্কঃ ব্যকগ্রাউন্ড থ্রেডে ভবিষ্যত কর্মনির্ধাণের জন্যে এটি ব্যবহৃত হয়। থ্রেডে কাজ গুলো একবারের জন্যেও হতে পারে বা কিছু কর্মবিরতির পর পর ও কাজ গুলো হতে পারে। আমাদের কাজ শেষ হলে timer.cancel() ফাংশন কল করব। হ্যান্ডেলারঃ এটি একটি থ্রেডের সাথে তৈরি করা হয়। ব্যাকগ্রাউন্ড থ্রেড থেকে মেইন থ্রেডে রানেবল কোড বা মেসেজ পাঠাতে এটি…