Forem: Yogesh Choudhary Paliyal

How I became a Software Engineer without a Degree

Yogesh Choudhary Paliyal — Mon, 18 Dec 2023 09:03:25 +0000

I had never thought that I would come this far. Since childhood, this was my only goal to write code as a profession. Initially, no one was there to guide me and show me the right way to achieve my goals. But my friends and brothers supported and encouraged me that I can make my career in this field.

How it started

I started to learn about the basics of websites and how I can create my website.

My first website was on wapka.mobi(now shut down), this platform gave the option to create websites without writing the actual code.

Later on, I wanted to learn more about creating websites from scratch, so I started exploring the basics of FTP, shared servers, HTML, CSS, and PHP.

I learned the basics of these languages by trying and building a few basic websites.

2014 - April 2016 (Highschool)

In high school, I opted-in for Biology mainly because my father is a lab technician and he wanted to see me as a doctor; and also I was not interested in Maths.

I learnt HTML, CSS, VBS, and ASP in depth in school and got to know how things work internally. also built a few websites in PHP.

June 2016 (Medical Entrance preparation)

There are only a few options available after high school for biology students - graduation or preparing for medical entrance.

So I went ahead for Medical Entrance preparation, but deep down I knew that this was not my cup of tea. Meanwhile, I continued to learn and explore PHP and other technical things side by side.

June 2017 (Android Development coaching)

As expected, I didn't performed well in the medical entrance.

My brother encouraged me to follow my passion, So I decided to take a 3-month course for Android Development (without prior knowledge of Java or Kotlin) during my summer vacations.

I bought my first android mobile. Till here I learnt and implemented everything on Nokia keypad mobiles (X2-01 & 114).

Later I got admission into a distance learning college to pursue BCA. I have seen many developers with degrees doing the same work which I was doing, then what was the need for a degree? So I decided to drop out of college in 2021.

During those 3 months of Android training, I learnt the basics of Android and Kotlin. The coaching institute offered me an internship after the course completion. This was my happiest moment because I was getting closer to my dream job.

Then I went for a JAVA course to get a better understanding of Android. The colleagues were super helpful and they taught me how things work internally. Special Thanks, Sachin Rupani & Suraj Vaishnav for helping out.

2018 - Present (Real professional journey started)

I wanted to validate my knowledge so I went ahead and cleared the Associate Android Developer Certificate.

In these 4 years, I worked on many technologies like Android, Flutter, React Native, iOS and Angular and helped other developers too.

After working for 4 years as Android Developer in Jodhpur, I felt like I am stuck in a comfort zone and not growing and learning new things.

So I decided to switch job and began job hunting. I talked to a lot of my developer friends who are working in different companies to have a better understanding of big organisations work. These long discussions usually included what's new in Android and how to prepare for interviews.

I gave around 28 interviews, some of them went really well and some of them didn't.

A few companies rejected me because not having a degree, but many did not care about the degree. and then after 2 months of job hunting, I finally got a job offer from Flipkart, which gave me immense happiness and made me even more confident in this field.

I come from a small town with not have a lot of guidance to follow their passion and fulfill your dreams. I think I have broken this misconception about getting into a big organisation without having any degree, This is already encouraging many youngsters from my surrounding to go ahead and follow their passion.

I've come a long way but still have miles to go.

Special thanks to all the blogs and Open-Source projects for helping me in my journey.

Thank you, everyone. ♥️

Cracking the Code: A Journey through KeyPass App Crashes and Solutions

Yogesh Choudhary Paliyal — Sat, 26 Aug 2023 11:35:33 +0000

🔍 Debugging Chronicles: Unraveling KeyPass App Crashes 🔍

Hey fellow developers and tech enthusiasts! 👋 I recently embarked on a challenging debugging journey with my KeyPass app, and I thought it would be valuable to share my experience and findings. 🕵 So, buckle up as I walk you through the twists and turns of this adventure!

The Mystery Unveiled:

It all began with frequent crashes in my beloved KeyPass app. No matter how hard I tried, the root cause seemed elusive. After numerous failed attempts, I decided to go back to the basics and methodically reproduce the issue. Voila! 🎉 I was finally able to replicate the problem. The app consistently crashed right after setting up the password and reinstalling the app.

The Clues and Investigation:

Armed with this crucial clue, I delved deep into the codebase, leaving no stone unturned. Hours turned into days as I meticulously sifted through the code and exhaustively experimented with different scenarios. As I progressed, a pattern began to emerge. It became evident that the crashes were closely tied to uninstalling and reinstalling the app.

The Eureka Moment:

After what felt like an eternity of debugging, I stumbled upon a game-changing revelation. It turns out that the datastore file was persisting even after uninstalling the app. 📦 This hidden remnant was wreaking havoc, leading to crashes upon reinstall. The encryption key would reset as intended, but the old datastore file was sticking around like a stubborn guest at a party.

The Decrypting Dilemma:

The cause of this lingering crash became clear. The new encryption key couldn't decrypt the older datastore file, resulting in a catastrophic failure. I couldn't help but marvel at the intricate web of interconnected elements that software development involves. 🕸

The Culprit: allowBackup="true":

But what was causing the datastore file to be so stubborn? As it turned out, the AndroidManifest held the answer. The innocent-looking allowBackup="true" attribute was granting permission for the backup and restore process, inadvertently keeping the datastore file intact even after uninstallation.

The Lessons Learned:

This debugging ordeal has reaffirmed some crucial lessons for me as a developer:

Persistence Pays Off: Debugging requires a mix of patience, determination, and the willingness to explore uncharted territories.

The Devil's in the Details: Small configuration settings like allowBackup can have far-reaching consequences. Always scrutinize the impact of such settings on your app's behaviour.

Community Support: Shoutout to the developer community for sharing insights and solutions. Collaborative learning accelerates growth.

The Resolution: After identifying the root cause, rectifying the issue was a relatively straightforward task. Adjusting the allowBackup attribute to false in the AndroidManifest ensured that the datastore file didn't linger beyond its welcome.

In Closing: This debugging saga was a rollercoaster ride of frustration, excitement, and enlightenment. I hope my experience sheds light on the intricacies of app development and serves as a reminder that every challenge brings a valuable lesson.

Here's to unravel coding conundrums and crafting more resilient apps! 🚀💻 Have you encountered similar debugging adventures?

Share your stories and insights below! Let's learn and grow together. 💬👇

Scope Storage in Android: A Guide to Securing Your App and Supporting All API Versions

Yogesh Choudhary Paliyal — Fri, 13 Jan 2023 05:07:59 +0000

Introduction

Android app development can be tricky, especially when it comes to ensuring compatibility with different API versions. In this post, we'll explore the concept of "scope storage" in Android, and how it can be used to provide support for all API versions. We'll also include some code snippets in Kotlin to illustrate key concepts.

What is Scope Storage in Android?

In Android, "scope storage" refers to the portion of an app's storage that is accessible to the app's code. By default, an app's storage is available to all of the app's code, but it is possible to use scope storage to limit the portion of storage that is accessible to specific parts of an app's code.

How to Use Scope Storage

To use scope storage in your Android app, you'll need to add the following line of code to your app's AndroidManifest.xml file:

<manifest ... >
    <application ... >
        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="com.example.myapp.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_paths" />
        </provider>
    </application>
</manifest>

This code sets up a FileProvider that can be used to limit the portion of storage that is accessible to your app's code. The authorities attribute specifies the unique name of the provider, and the exported attribute is set to false to prevent other apps from accessing the provider.

You can also create a resource file in the xml directory named file_paths.xml to specify the paths that are accessible through the provider:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="my_images" path="Android/data/com.example.myapp/files/Pictures" />
</paths>

With the provider set up and the file_paths defined, you can now use the FileProvider to access specific portions of storage in your app's code. For example, the following code snippet demonstrates how to use the FileProvider to open an image file in Kotlin:

val photoUri = FileProvider.getUriForFile(context, "com.example.myapp.fileprovider", photoFile)
val intent = Intent(Intent.ACTION_VIEW).apply {
    setDataAndType(photoUri, "image/*")
    addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
}
startActivity(intent)

This code uses the FileProvider to get the Uri for the photo file and then opens it in the default image viewer app on the device. The addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION) is used to grant temporary read access to the file to the activity.

By using scope storage, you can ensure that your app's code only accesses the specific portions of storage that are necessary for the app to function correctly. This can help to improve the security of your app and prevent errors that might occur when the app attempts to access storage that is not available. Additionally, by limiting the scope of storage that your app's code can access, you can also make it easier to maintain your app and provide support for different API versions.

Conclusion

In this post, we've explored the concept of scope storage in Android and how it can be used to provide support for all API versions. By setting up a FileProvider and limiting the portion of storage that is accessible to your app's code, you can improve the security and stability of your app. Additionally, by providing code snippets in Kotlin, you can see how easy it is to implement scope storage in your own app. Remember that by using scope storage, you'll be making your app more secure and more robust, which will make it easier to maintain and support over time.

Generated using ChatGPT.

Type of Recursion

Yogesh Choudhary Paliyal — Sun, 24 Oct 2021 17:58:56 +0000

Recursion

Calling same function inside function is known as Recursion.

Every recurring function must have a breaking condition which break recursion.

Time taken by Recursion

O(n) if there is no loop inside the recursion

Types of Recursion

1. Tail Recursion

Recurring function is called at end of all the statements.
There should not be handling of return type.

Tail Recursion can be converted to loop easily

Example:

fun main(){
    fun1(5)
}
/* Example with recursion
* Time -> O(n)
* Space -> O(n)
*/
fun fun1(n){
    if(n > 0){
        print(n)
        fun1(n-1) // tail recursion
    }
}
/*
* Converted to while loop
* Time -> O(n)
* Space -> O(1)
*/
fun fun1(n){
    while(n > 0){
        print(n)
        n--
    }
}

2. Head Recursion

Recurring function is called at start before any statements, just after the break condition.

Example:

  fun main() {
      fun1(5)
  }

  fun fun1(n) {
      if (n > 0) { 
          fun1(n - 1) // head recursion 
          print(n)
      }
  }

3. Tree Recursion

More than once the self function is called from inside the function

Example:

fun main() {
      fun1(5)
  }

  fun fun1(n) {
      if (n > 0) { 
          fun1(n - 1) // tree recursion 
          fun1(n - 1) // tree recursion
          print(n)
      }
  }

4. Indirect Recursion

Recurring via multiple loops, like function A calls B and B calls A

Example:

fun main(){
    funA(5)
}

fun funA(n: Int){
    if (n > 0){
        funB(n-1)
    }
}

fun funB(n: Int){ 
    funA(n)
}

5. Nested Recursion

Function is calling itself with returning value and that will be used to call self function.

Example:

fun main(){
    fun1(90)
}

fun fun1(n){
  return if(n > 100){
         n - 10
    }else{
        fun1(fun1(n + 11)) // Nested recursion
    }
}

Universal Recycler Adapter for 90% of your needs

Yogesh Choudhary Paliyal — Thu, 02 Sep 2021 18:23:00 +0000

Android Universal Recycler Adapter

Tired of creating 100s of Adapters and View Models.
This Library will make it easy, No need to create an Adapter, ViewHolder for every list

🤔 How?

Using Resource Pattern to find the status of the list and show view types according to that.

Step #1. Add the JitPack repository to your build file:

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

Step #2. Add the dependency (See latest release).

dependencies {
    implementation 'com.github.yogeshpaliyal:Android-Universal-Recycler-View-Adapter:+'
}

🛠️ Used in this Project

🤩 Features

Content Listing (Supports Multiple View Types)
Loading + Listing (Showing shimmer items for Loading then showing the actual Listing)
Loading + LoadMore (Showing loading items and add an item at bottom to create infinite Listing)
No Data Found
Error Page
Async DiffUtils for better performance

When to show which item?

Status	List Size	Result Behaviour
LOADING	0	Show Loading Cells (default 5 items)
SUCCESS	0	No Record Found Layout will be displayed
ERROR	0	Error Layout Shown
LOADING	more than 0	Data Cells + load more at end
SUCCESS	more than 0	Data Cells
ERROR	more than 0	Data Cells + error cell at the end

XML Variables

To bind your view item with Adapter using dataBinding you have to create use these Variables
name must be as follows

`binding`

Type should be the same as your resource binding file.
This can be used to update your views in the callback, after changing the variable value in the model, for example, check UserListingActivity.

All Adapters layout using this variable

<variable
            name="binding"
            type="androidx.databinding.ViewDataBinding" />

`model`

Type should be same as model you are passing to Adapter.

Content layout using this variable

<variable
            name="model"
            type="com.techpaliyal.androidkotlinmvvm.model.BasicModel" />

`listener`

Type Any/Object, should be same as you passing while create Adapter.

Content & Error layout using this variable

<variable
            name="listener"
            type="com.techpaliyal.androidkotlinmvvm.model.BasicListener" />

`message`

Type will be String.

Error layout using this variable

<variable
            name="message"
            type="String" />

Show me the code

 private val mAdapter by lazy {
        UniversalRecyclerAdapter.Builder<UserModel>(
            lifecycleOwner = this,
            content = UniversalAdapterViewType.Content(resource = R.layout.item_user,
                object : BasicListener<UserModel> {
                    override fun onClick(model: UserModel) {
                        Toast.makeText(this@LoadingListingActivity, model.name, Toast.LENGTH_SHORT)
                            .show()
                    }
                }),
            loading = UniversalAdapterViewType.Loading(
                resourceLoading = R.layout.layout_loading_full_page,
                defaultLoadingItems = 1
            ),
            error = UniversalAdapterViewType.Error(errorLayout = R.layout.item_error),
            loadingFooter = UniversalAdapterViewType.LoadingFooter(loaderFooter = R.layout.item_loading_more)
        ).build()
    }

Note: All the parameters in **UniversalRecyclerAdapter.Builder* are optional, use only those you want to use*

lifecycleOwner = This will be used to notify your view to update on data change.

content = Your primary list element.

- resource = Element layout id.

- listener = Pass the interface you want to send to your item layout

loading = Your loading list element. (like shimmer or just a loader).

- resourceLoading = loading layout id.

- defaultLoadingItems = Items you want to show while loading.

error = Layout to be shown when Status == Status.ERROR

- errorLayout = error layout id.

- listener = Pass the interface you want to send to your error layout.

Examples

Simple List

List item (File)

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:app="http://schemas.android.com/apk/res-auto">
    <data>
        <variable
            name="model"
            type="com.techpaliyal.androidkotlinmvvm.model.BasicModel" />
        <variable
            name="listener"
            type="com.techpaliyal.androidkotlinmvvm.listeners.BasicListener" />
    </data>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:padding="5dp"
        android:textSize="16sp"
        android:text="@{model.name}"
        android:onClick="@{()->listener.onClick(model)}"/>

</androidx.constraintlayout.widget.ConstraintLayout>
</layout>

Initialize Adapter (File)

 private val mAdapter by lazy {
        UniversalRecyclerAdapter.Builder<BasicModel>(
            lifecycleOwner = this,
            content = UniversalAdapterViewType.Content(
                R.layout.item_simple,
                listener = object : BasicListener<BasicModel> {
                    override fun onClick(model: BasicModel) {
                        Toast.makeText(this@BasicListingActivity, model.name, Toast.LENGTH_SHORT)
                            .show()
                    }
                })
        ).build()
    }

Attach to adapter

binding.recyclerView.adapter = mAdapter.getAdapter()

Update Data

mAdapter.updateData(Resource.success(list))

Loading + Content + Error

example: Hitting an API for loading showing a shimmer and then when API response came to show the data or getting an error

Initialize Adapter

private val mAdapter by lazy {
        UniversalRecyclerAdapter.Builder<UserModel>(
            lifecycleOwner = this,
            content = UniversalAdapterViewType.Content(R.layout.item_user,
                object : BasicListener<UserModel> {
                override fun onClick(model: UserModel) {
                    Toast.makeText(this@LoadingListingActivity, model.name, Toast.LENGTH_SHORT)
                        .show()
                }
            }),
            loading = UniversalAdapterViewType.Loading(R.layout.layout_loading_full_page, defaultLoadingItems = 1),
            error = UniversalAdapterViewType.Error(R.layout.item_error)).build()
    }

Attach to adapter

binding.recyclerView.adapter = mAdapter.getAdapter()

Update Data

 mViewModel.data.observe(this, Observer { data -> 
     // The data type is like Resource<List<T>>
     // if data.status == Status.LOADING thenn it will show the loading view
     // if data.status == Status.SUCCESS then it will show the content list
     // if data.status == Status.ERROR then it will show the error View and data.message will be passed to view as message variable
            mAdapter.updateContent(it)
})

Multiple View Types

Show multiple view types in your listing, for eg: heading and list

implement UniversalViewType in your model and override getLayoutId()

screenshot : view fullscreen

example :

Heading Model

data class HeadingModel(val title: String) : UniversalViewType,SchoolListing {
    override fun getLayoutId(): Int {
        return R.layout.item_heading
    }
}

List Model

data class ListItemModel(val name: String) : UniversalViewType,SchoolListing {
    override fun getLayoutId(): Int {
        return R.layout.item_list
    }
}

SchoolListing.kt

This interface is used to identify models to use in a recycler view, to prevent adding of other types of models in the array except for models that implements SchoolListing

interface SchoolListing

Adding data to array

val tempArray = ArrayList<SchoolListing>()
        tempArray.add(HeadingModel("Principal"))
        tempArray.add(ListItemModel("Yogesh Paliyal"))

        tempArray.add(HeadingModel("Staff"))
        tempArray.add(ListItemModel("Sachin Rupani"))
        tempArray.add(ListItemModel("Suraj Vaishnav"))
        tempArray.add(ListItemModel("Himanshu Choudhan"))
        tempArray.add(ListItemModel("Pramod Patel"))
        tempArray.add(ListItemModel("Bharath"))
        tempArray.add(ListItemModel("Sanjay"))
        tempArray.add(ListItemModel("Surendra Singh"))


        tempArray.add(HeadingModel("Students"))
        tempArray.add(ListItemModel("Bhoma Ram"))
        tempArray.add(ListItemModel("Deepak"))
        tempArray.add(ListItemModel("Sohan"))
        tempArray.add(ListItemModel("Umesh"))
        tempArray.add(ListItemModel("Amanda Howard"))
        tempArray.add(ListItemModel("Jeremy Glover"))
        tempArray.add(ListItemModel("Ginger Larson"))
        tempArray.add(ListItemModel("Lincoln Pierpoint"))
        tempArray.add(ListItemModel("Brian Brooks"))
        tempArray.add(ListItemModel("Erasmus Hall"))
        tempArray.add(ListItemModel("Amber Lane"))
        tempArray.add(ListItemModel("Elsie Cole"))

View full example

Feedback

Having an issue to get you are looking for, feel free to put your question in Discussion Section and help us Improving this library and Documentation.

Happy Coding 😁

Guide to Android Data Binding

Yogesh Choudhary Paliyal — Thu, 02 Sep 2021 17:36:01 +0000

What is Data Binding?

It is a technique to connect Data with your views.

How it works?

It generates a java file that connects your views with the data.

Setting up project for Data Binding

build.gradle(:app)

plugins {
    ...
    id 'kotlin-kapt'
}

android {

    ...

    buildFeatures{
        dataBinding = true
    }
}
...

Getting Started with the code

To add data binding wrap your parent view/view group with the <layout> tag

<layout> tag contains 2 sections <data> and your parent view group.

<data> tag can contain 2 more tags, <import> & <variable>, as the name shows import is used to import the dependencies like class, interface, etc. And variable used to declare variables that we can use in our layout file (later in this post).

Our hierarchy looks like this.

activity_main.xml

<layout>
     <data>

         <import name="com.sample.MyViewModel" />

         <variable 
                name="mViewModel"
                type="MyViewModel" />

     </data>

     <FrameLayout>
         ..............
     </FrameLayout>
</layout>

Setup binding in Activity

class MainActivity: AppCompatActivity() {

       private lateinit var binding : ActivityMainBinding

        override fun onCreate(savedInstanceState: Bundle?) {
              super.onCreate(savedInstanceState)
              binding = ActivityMainBinding.inflate(layoutInflater)
              setContentView(binding.root)
              // start using the binding
        }

}

Note: **ActivityMainBinding* is an auto-generated file, the file name will be based on your XML file, (not the activity or fragment file) *

Setup binding in Fragment

class SampleFragment : Fragment() {

    private  lateinit var binding: FragmentSampleBinding

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        binding = FragmentSampleBinding.inflate(inflater, container, false)
        return binding.root
    }

}

Assign value to XML variables

binding.mViewModel = mViewModel

// adding lifecycler owner to binding to use live data inside your XML
// this refer to lifecycler owner in Activity
binding.lifecycleOwner = this

// use viewLifecycleOwner to get lifecyclerOwner for Fragment, Bottomsheet, Dialog, etc.
binding.lifecycleOwner = viewLifecycleOwner 

// this will do the pending binding things
binding.executePendingBindings()

Handle Variable inside the Data Binding

To use variables in XML you have to wrap your value inside @{YOUR-VALUE}

<TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="@{mViewModel.username}" />

Handle interface inside the Data Binding

<TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="@{()->mViewModel.yourFunction()}" />

Note: you can also get the reference of current view by

(view) -> mViewModel.yourFunction(view)

Default values and Null safety

Default value is used to show in the preview

 android:text="@{mViewModel.name, default =`Default Value` }"

Handle null variables ??

android:text="@{mViewModel.name ?? `Nullable Value`}"

If mViewModel or name is null or not assigned then TextView will show 'Nullable Value'

Resource Reference

Dimen

android:padding="@{large? @dimen/largePadding : @dimen/smallPadding}"

String & plurals

android:text="@{@string/nameFormat(firstName, etFirstName.text)}"
android:text="@{@plurals/banana(bananaCount)}"

etFirstName is an edit text in the same layout file

Passing variables to included layout

sample_layout.xml

<layout>
               <data>
                   <variable 
                       name="customTitle"
                       type="String" />
               </data>
            ....
</layout>

main_layout.xml

<include
       app:customTitle="@{`Test Title`}"
       ...
      />

Note: You must provide value in @{} if you want to send the value as a variable

Thank you, guys.

Keep learning, Keep Sharing ❤️

Original post on yogeshpaliyal.com

Android Fast Networking with Kotlin Coroutines

Yogesh Choudhary Paliyal — Mon, 28 Jun 2021 14:47:38 +0000

Android Fast Networking is a great library for networking I am using since 2016, It has many features that are not available in similar networking libraries.

AFN provides direct support for RxJava but not for Coroutines, so we create by ourself

Adding AFN and Kotlin Coroutines to the project

// GSON
implementation 'com.google.code.gson:gson:2.8.6'

// Android Fast Networking
implementation 'com.amitshekhar.android:android-networking:1.0.2'

// Coroutines
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.9'

In this project, we are using the State Management approach class Resource

The resource is a wrapper class that contains status (Loading, Success, Error), message, Data

Creating a BaseCaller, every API call will be going through this class, this is the class where the magic happens.

BaseApiModel is an API structure that is used for all APIs like, change as per requirements

{
  "status" : 200,
  "message" : "Api hit success",
  "data" : {
      "name" : "Yogesh Paliyal"
  }
}

ExoPlayer : Getting Started

Yogesh Choudhary Paliyal — Mon, 26 Apr 2021 14:46:57 +0000

Exoplayer is a Powerfull MediaPlayer Library that is developed by Google and better than the MediaPlayer API.

It has many advantages over MediaPlayer API.

It is used by many video platform applications like Youtube, Netflix, etc.

First thing first: Add Dependency

implementation 'com.google.android.exoplayer:exoplayer:2.13.3'

Add Player to UI

<com.google.android.exoplayer2.ui.PlayerView
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    android:id="@+id/videoPlayer"/>

for now we are using default controller and player, we can customize as per requirement, we will create our custom controller in future posts.

Initialize Player

Declare a video player global variable

private var mPlayer: SimpleExoPlayer? = null

Initialize ExoPlayer object

mPlayer = SimpleExoPlayer.Builder(this).build()

Create A MediaItem : mediaItem is used to give source of video to play, here videoUrl is the Uri of the video.

val mediaItem = MediaItem.Builder()
    .setUri(videoUrl)
    .build()

set mediaItem to player

mPlayer?.setMediaItem(mediaItem)
mPlayer?.playWhenReady = true
binding.videoPlayer.player = mPlayer
mPlayer?.prepare()

playWhenReady : It starts video playback when video is ready to play

binding.videoPlayer.player = mPlayer : Attack player to UI

mPlayer?.prepare() : It will start preparing player to stating playing the video

Free up resources

override fun onDestroy() {
    mPlayer?.release()
    mPlayer = null
    super.onDestroy()
}

mPlayer?.release() : This will release the memory taken by the player

Check out the source code on GitHub

Source Code

The post ExoPlayer : Getting Started appeared first on TechPaliyal.

Android Spannable TextView

Yogesh Choudhary Paliyal — Tue, 30 Jun 2020 17:09:31 +0000

A spannable TextView can be used in Android to highlight a particular portion of text with a different color, style,

size, and/or click event in a single TextView widget.

Consider that you have defined a TextView as follows:

TextView textview=findViewById(R.id.textview);

Then you can apply different highlighting to it as shown below:

Spannable color: In order to set a different color to some portion of text, a ForegroundColorSpan can be

used, as shown in the following example:

Spannable spannable = new SpannableString(firstWord + lastWord);
spannable.setSpan(new ForegroundColorSpan(firstWordColor), 0, firstWord.length(),
    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(lastWordColor), firstWord.length(),
    firstWord.length() + lastWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textview.setText(spannable);

Output created by the code above:

Spannable font: In order to set a different font size to some portion of text, a RelativeSizeSpan can be

used, as shown in the following example:

Spannable spannable = new SpannableString(firstWord + lastWord);
spannable.setSpan(new RelativeSizeSpan(1.1 f), 0, firstWord.length(),
    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // set size
spannable.setSpan(new RelativeSizeSpan(0.8 f), firstWord.length(), firstWord.length() +
    lastWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); // set size
textview.setText(spannable);

Output created by the code above:

Spannable typeface: In order to set a different font typeface to some portion of text, a custom

TypefaceSpan can be used, as shown in the following example:

Spannable spannable = new SpannableString(firstWord + lastWord);
spannable.setSpan(new CustomTypefaceSpan("SFUIText-Bold.otf", fontBold), 0,
    firstWord.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new CustomTypefaceSpan("SFUIText-Regular.otf", fontRegular),
    firstWord.length(), firstWord.length() + lastWord.length(),
    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
text.setText(spannable);

However, in order to make the above code working, the class CustomTypefaceSpan has to be derived from

the class TypefaceSpan. This can be done as follows:

public class CustomTypefaceSpan extends TypefaceSpan {
    private final Typeface newType;
    public CustomTypefaceSpan(String family, Typeface type) {
        super(family);
        newType = type;
    }
    @Override
    public void updateDrawState(TextPaint ds) {
        applyCustomTypeFace(ds, newType);
    }
    @Override
    public void updateMeasureState(TextPaint paint) {
        applyCustomTypeFace(paint, newType);
    }
    private static void applyCustomTypeFace(Paint paint, Typeface tf) {
        int oldStyle;
        Typeface old = paint.getTypeface();
        if (old == null) {
            oldStyle = 0;
        } else {
            oldStyle = old.getStyle();
        }
        int fake = oldStyle & ~tf.getStyle();
        if ((fake & Typeface.BOLD) != 0) {
            paint.setFakeBoldText(true);
        }
        if ((fake & Typeface.ITALIC) != 0) {
            paint.setTextSkewX(-0.25 f);
        }
        paint.setTypeface(tf);
    }
}

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Getting Started with Android Navigation Component

Yogesh Choudhary Paliyal — Wed, 15 Jan 2020 15:13:22 +0000

Navigation refers to the interactions that allow users to navigate across, into, and back out from the different pieces of content within your app. Android Jetpack’s Navigation component helps you implement navigation, from simple button clicks to more complex patterns, such as app bars and the navigation drawer.

Source: developer.android.com

The navigation component provides a flexible solution to handle the fragments and maintain the backstack.

Features

Easy to implement.
Handling Up and Back actions correctly by default.
Handling fragment transactions.
Safe Args – a Gradle plugin that provides type safety when navigating and passing data between destinations.
ViewModel support – you can scope a ViewModel to a navigation graph to share UI-related data between the graph’s destinations.

Implementation

Add to build.gradle(project)

classpath "androidx.navigation:navigation-safe-args-gradle-plugin:2.1.0"

apply the plugin to app-level build.gradle

apply plugin: "androidx.navigation.safeargs.kotlin"

Add dependencies

dependencies {
  def nav_version = "2.1.0"

  // Kotlin
  implementation "androidx.navigation:navigation-fragment-ktx:$nav_version"
  implementation "androidx.navigation:navigation-ui-ktx:$nav_version"
}

Navigation without Arguments

Create 2 fragments MainFragment and BasicFragment.

We will navigate to BasicFragment from MainFragment

Create nav_basic.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nav_basic"
    app:startDestination="@id/mainFragment">

    <fragment
        android:id="@+id/mainFragment"
        tools:layout="@layout/fragment_main"
        android:name="com.techpaliyal.androidnavigationcomponent.MainFragment">
        <action android:id="@+id/startBasicFragment"
            app:destination="@id/basicFragment">

        </action>

    </fragment>

    <fragment
        android:id="@+id/basicFragment"
        tools:layout="@layout/fragment_basic"
        android:name="com.techpaliyal.androidnavigationcomponent.BasicFragment"/>

</navigation>

app:startDestination=”@id/mainFragment” this will be the entry point.

action this is used for navigation from mainFragment to basicFragment

Add Navigation fragment to MainActivity

<fragment
    android:id="@+id/nav_host_fragment"
    android:name="androidx.navigation.fragment.NavHostFragment"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    app:defaultNavHost="true"
    app:navGraph="@navigation/nav_basic" />

Navigate from mainFragment to basicFragment using action id

inside MainFragment.kt on button click

findNavController().navigate(R.id.basicFragment)

findNavController() will give reference to the controller in which the fragment is attached.

Navigation with Arguments

Define arguments in nav_basic.xml

<fragment
    android:id="@+id/argumentedFragment"
    tools:layout="@layout/fragment_argumented"
    android:name="com.techpaliyal.androidnavigationcomponent.ArgumentedFragment">
    <argument
        android:name="first_name"
        app:argType="string" />
</fragment>

Send argument from BasicFragment to ArgumentedFragment

val action = MainFragmentDirections.startArgumentedFragment("Yogesh")
            findNavController().navigate(action)

Get arguments in ArgumentedFragment

val params : ArgumentedFragmentArgs by navArgs()

You can check the full code on Github.

Comment for suggestions and issues.

Source Code on Github

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Kotlin Coroutines | QA

Yogesh Choudhary Paliyal — Fri, 10 Jan 2020 19:02:49 +0000

What is kotlin coroutines?

Kotlin coroutines are one of the most exciting features in Kotlin. With them, you can simplify the work of asynchronous tasks in an impressive way, and make the code much more readable and easy to understand.

How are kotlin coroutines implemented?

dependencies {
  ...
  implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:x.x.x"
  implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:x.x.x"
}

Why use kotlin coroutines?

Coroutines are a great way to write asynchronous code that is perfectly readable and maintainable.

The post Kotlin Coroutines | QA appeared first on TechPaliyal.

Firebase Messaging with Image in Android | Android Kotlin push notification

Yogesh Choudhary Paliyal — Sun, 13 Oct 2019 16:42:15 +0000

Hello friends, I came back with a new post.

In this post, we are going to learn how to handle notifications with an image from the firebase console.

Here are a few steps I think we can skip.

Login/Register to the firebase.
Setup your project in the android studio.
Create a project on the firebase console.
Add firebase to your project.

Add dependency (in “app/build.gradle”)

implementation 'com.google.firebase:firebase-messaging:20.0.0'

Create a class that extends FirebaseMessangingService in my case it is “MyFirebaseMessangingService”

Your class look like this initially

class MyFirebaseMessangingService : FirebaseMessagingService(){ 
   override fun onNewToken(p0: String) {
        super.onNewToken(p0)

    }
    override fun onMessageReceived(remoteMessage: RemoteMessage) {
        super.onMessageReceived(remoteMessage)
    }
}

“ onNewToken “: Function will be called when firebase creates/update a unique token for a particular user.

This can be updated periodically, reinstall the app, clear data, etc.

“ onMessageReceived “: This is a special function that is called when a message is received from the firebase console or by your app’s backend, in this function you have to create and show the notification.

Note : This function only triggers when your app is in the foreground state.

Q. What happens when the app is in the background & how to show notification in that condition?

Ans: Firebase will handle itself and show the notification & on click on that notification it will open the very first activity of your projects like Splash or Dashboard.

Add Firebase messaging service to Manifest.xml inside the application tag.

<service
    android:name=".java.MyFirebaseMessagingService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

Show Notification (first download image to bitmap and then show notification)

private fun downloadImage(notification: RemoteMessage.Notification?) {
        Observable.fromCallable(object : Callable<Bitmap?> {
            override fun call(): Bitmap? {
                val future = Glide.with(applicationContext).asBitmap()
                        .load(notification?.imageUrl).submit()
                return future.get()
            }
        }).subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(object : Observer<Bitmap?> {
                    override fun onComplete() {

                    }

                    override fun onSubscribe(d: Disposable) {

                    }

                    override fun onNext(t: Bitmap) {
                        showNotification(notification,t)
                    }

                    override fun onError(e: Throwable) {
                        showNotification(notification,null)
                    }

                })

    }

Note: I used RxJava here for threading, you can use any method you want.

Show the notification

private fun showNotification(notification: RemoteMessage.Notification?, image: Bitmap?) {

        val notificationManager = applicationContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = getString(R.string.notification_channel_id)
        val channelName = getString(R.string.notification_channel_name)
        val importance = NotificationManager.IMPORTANCE_LOW

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val mChannel = NotificationChannel(channelId, channelName, importance)
            notificationManager.createNotificationChannel(mChannel)
        }

        val intent = Intent(applicationContext, MainActivity::class.java)
        val pendingIntent = PendingIntent.getService(applicationContext, 1, intent, 0)
        var builder: Notification.Builder? = null
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            builder = Notification.Builder(applicationContext, channelId)
        } else {
            builder = Notification.Builder(applicationContext)
        }

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            builder.setSmallIcon(R.mipmap.ic_launcher)
        } else {
            builder.setSmallIcon(R.mipmap.ic_launcher)
        }

        val title = if (notification?.title.toString().isNullOrEmpty()) {
            getString(R.string.app_name)
        }else{
            notification?.title
        }

        val content = if (notification?.body.isNullOrEmpty()) {
            getString(R.string.app_name)
        }else{
            notification?.body
        }

        builder.setContentTitle(title)
                .setContentText(content)
                .setDeleteIntent(pendingIntent)

        if (image != null) {
            builder.setStyle(Notification.BigPictureStyle().bigPicture(image))
        }

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            builder.setVisibility(Notification.VISIBILITY_PUBLIC)
        }

        notificationManager.notify((0..100).random(), builder.build())

    }

Here is the whole file code:

import android.app.Notification import android.app.NotificationChannel import android.app.NotificationManager import android.app.PendingIntent import android.content.Context import android.content.Intent import android.graphics.Bitmap import android.os.Build import android.util.Log import com.bumptech.glide.Glide import com.google.firebase.messaging.FirebaseMessagingService import com.google.firebase.messaging.RemoteMessage import com.techpaliyal.uniquegallery.R import com.techpaliyal.uniquegallery.activities.MainActivity import io.reactivex.Observable import io.reactivex.Observer import io.reactivex.android.schedulers.AndroidSchedulers import io.reactivex.disposables.Disposable import io.reactivex.schedulers.Schedulers import java.util.concurrent.Callable

class MyFirebaseMessangingService : FirebaseMessagingService(){
    override fun onNewToken(p0: String) {
        super.onNewToken(p0)
        Log.d("TestingNotification",""+p0)
    }
    override fun onMessageReceived(remoteMessage: RemoteMessage) {
        super.onMessageReceived(remoteMessage)
        downloadImage(remoteMessage.notification)
    }

    private fun downloadImage(notification: RemoteMessage.Notification?) {
        Observable.fromCallable(object : Callable<Bitmap?> {
            override fun call(): Bitmap? {
                val future = Glide.with(applicationContext).asBitmap()
                        .load(notification?.imageUrl).submit()
                return future.get()
            }
        }).subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(object : Observer<Bitmap?> {
                    override fun onComplete() {

                    }

                    override fun onSubscribe(d: Disposable) {

                    }

                    override fun onNext(t: Bitmap) {
                        showNotification(notification,t)
                    }

                    override fun onError(e: Throwable) {
                        showNotification(notification,null)
                    }

                })

    }

    private fun showNotification(notification: RemoteMessage.Notification?, image: Bitmap?) {

        val notificationManager = applicationContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = getString(R.string.notification_channel_id)
        val channelName = getString(R.string.notification_channel_name)
        val importance = NotificationManager.IMPORTANCE_LOW

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val mChannel = NotificationChannel(channelId, channelName, importance)
            notificationManager.createNotificationChannel(mChannel)
        }

        val intent = Intent(applicationContext, MainActivity::class.java)
        val pendingIntent = PendingIntent.getService(applicationContext, 1, intent, 0)
        var builder: Notification.Builder? = null
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            builder = Notification.Builder(applicationContext, channelId)
        } else {
            builder = Notification.Builder(applicationContext)
        }

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            builder.setSmallIcon(R.mipmap.ic_launcher)
        } else {
            builder.setSmallIcon(R.mipmap.ic_launcher)
        }

        val title = if (notification?.title.toString().isNullOrEmpty()) {
            getString(R.string.app_name)
        }else{
            notification?.title
        }

        val content = if (notification?.body.isNullOrEmpty()) {
            getString(R.string.app_name)
        }else{
            notification?.body
        }

        builder.setContentTitle(title)
                .setContentText(content)
                .setDeleteIntent(pendingIntent)

        if (image != null) {
            builder.setStyle(Notification.BigPictureStyle().bigPicture(image))
        }

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            builder.setVisibility(Notification.VISIBILITY_PUBLIC)
        }

        notificationManager.notify((0..100).random(), builder.build())

    }
}

If having any question/doubts or feedback please comment below.

The post Firebase Messaging with Image in Android | Android Kotlin push notification appeared first on TechPaliyal.