Android Developers Blog

JetPack Compose: Basic TextView Sample in JetPack Compose

2023-07-03T22:15:00.007+05:30

Hi All,

This is the very basic Text View Sample Jetpack compose.

1. Text Color: Change the text color using color parameter

@Composable
fun ColorText() {
    Text("Text in Red Color", color = Color.Red ,  modifier = Modifier
        .padding(8.dp) // margin
        .padding(8.dp) // padding
    )
}

2. Text Size: Change the text size using fontSize parameter
@Composable
fun TextWithSize(label : String, size : TextUnit) {
    Text(label, fontSize = size)
}

//TextWithSize("Big text",40.sp) -- call this method 



3.Bold Text: Use fontWeight parameter to making the bold text
@Composable
fun BoldText() {
    Text("Text in Bold", fontWeight = FontWeight.Bold,  modifier = Modifier
        .padding(8.dp) // margin
        .padding(8.dp)) // padding
}


4. Italic Text: Use fontStyle paramter to making the italic text
@Composable
fun ItalicText() {
    Text("Italic Text", fontStyle = FontStyle.Italic,  modifier = Modifier
        .padding(8.dp) // margin
        .padding(8.dp)) // padding
}


5. Maximum number of lines: To limit the number of visible lines in a
Text composable, set the maxLines parameter,
@Composable
fun MaxLines() {
    Text("Text with Max line 2 ".repeat(50), maxLines = 2, modifier = Modifier
        .padding(8.dp) // margin
        .padding(8.dp)) // padding
}

6. Text Overflow: When limiting a long text, you may want to indicate
a text overflow, which is only shown if the displayed text is truncated.
To do so, set the textOverflow parameter
@Composable
fun OverflowedText() {
    Text("Text with three dot at end, Text Overflow  ".repeat(150),
        maxLines = 3, overflow = TextOverflow.Ellipsis,
        modifier = Modifier
            .padding(8.dp)) // margin
}



Download code from here

Splash Screen API in Android 12 | Android 12 Splash Screen Example | Splash screens in Android 12 | Splash screen demo Using Splash Screen API | Splash Screen API Example

2021-10-21T14:51:00.011+05:30

Hi All,

Today I am going to share a tutotial and a sample demo of Android 12

Splash Screen Api. Android 12 Splash screen api introduce in Android 12.

Android 12 adds the SplashScreen API, which enables a new app launch animation

for all apps when running on a device with Android 12 or higher. This includes an

into-app motion at launch, a splash screen showing your app icon, and a transition

to your app itself.

Note: As Splash Screen introduced in Android 12 so it will work on Android

Api level 31 and above.

We can Customize the Splash Screen Theme:

- With the help of below attribute we can customize our Splash activity theme.

1. android:windowSplashScreenBackground : Used for Splash Screen background color.


#FFFFFF

2. android:windowSplashScreenAnimatedIcon: Used to replace an icon in

the center of the starting window. If the object is animatable and drawable through AnimationDrawable and AnimatedVectorDrawable, you also need to set windowSplashScreenAnimationDuration to play the animation while showing the

starting window.



	@drawable/splash_screen_animateable_icon

3. android:windowSplashScreenAnimationDuration : Used to indicate the duration of the splash screen icon animation. Max duration is 1000ms.

4. android:windowSplashScreenIconBackgroundColor : Used to set a background behind

the splash screen icon. This is useful if there isn’t enough contrast between the window

background and the icon.


#004d28

5. android:windowSplashScreenBrandingImage: We can use this to set an image to be shown at the bottom of the splash screen. The design guidelines recommend against using a branding image.


@drawable/ic_logo_12

Keep the splash screen on-screen for longer periods:

The splash screen is dismissed as soon as your app draws its first frame. If you need to load a small amount of data such as in-app settings from a local disk asynchronously, you can use ViewTreeObserver.OnPreDrawListener to suspend the app to draw its first frame.

If your starting activity finishes before drawing (for example, by not setting the content view and finishing before onResume), the pre-draw listener is not needed.

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        mainViewModel = ViewModelProvider(this).get(MainViewModel::class.java)
        content = findViewById(android.R.id.content)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            Log.d("MainActivity", "onCreate: I AM RUNNING ON API 12 or higher")
            content.viewTreeObserver.addOnPreDrawListener(object :
                    ViewTreeObserver.OnPreDrawListener {
                    override fun onPreDraw(): Boolean =
                        when {
                            mainViewModel.mockDataLoading() -> {
                                content.viewTreeObserver.removeOnPreDrawListener(this)
                                true
                            }
                            else -> false
                        }
                })
        }
    }

Customizing Splash Screen Animation: In Android 12 we get the Splash screen

instance by calling getSplashScreen() from Activity class. So we can further customize

the animation of the splash screen through Activity.getSplashScreen().

        splashScreen.setOnExitAnimationListener { splashScreenView ->
            val slideUp = ObjectAnimator.ofFloat(
                splashScreenView,
                View.TRANSLATION_Y,
                0f,
                -splashScreenView.height.toFloat()
            )
            slideUp.interpolator = AnticipateInterpolator()
            slideUp.duration = 200L

            // Call SplashScreenView.remove at the end of your custom animation.
            slideUp.doOnEnd { splashScreenView.remove() }

            // Run your animation.
            slideUp.start()
        }

Code: MainActivity.kt

package com.example.android12splashscreenapi import android.animation.ObjectAnimator import android.os.Build import android.os.Bundle import android.util.Log import android.view.View import android.view.ViewTreeObserver import android.view.animation.AnticipateInterpolator import androidx.appcompat.app.AppCompatActivity import androidx.core.animation.doOnEnd import androidx.lifecycle.ViewModelProvider class MainActivity : AppCompatActivity() { lateinit var content: View lateinit var mainViewModel: MainViewModel override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) mainViewModel = ViewModelProvider(this).get(MainViewModel::class.java) content = findViewById(android.R.id.content) if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) { Log.d("MainActivity", "onCreate: I AM RUNNING ON API 12 or higher") content.viewTreeObserver.addOnPreDrawListener(object : ViewTreeObserver.OnPreDrawListener { override fun onPreDraw(): Boolean = when { mainViewModel.mockDataLoading() -> { content.viewTreeObserver.removeOnPreDrawListener(this) true } else -> false } }) // custom exit on splashScreen splashScreen.setOnExitAnimationListener { splashScreenView -> val slideUp = ObjectAnimator.ofFloat( splashScreenView, View.TRANSLATION_Y, 0f, -splashScreenView.height.toFloat() ) slideUp.interpolator = AnticipateInterpolator() slideUp.duration = 200L // Call SplashScreenView.remove at the end of your custom animation. slideUp.doOnEnd { splashScreenView.remove() } // Run your animation. slideUp.start() } } } }

Reference:

1. https://developer.android.com/guide/topics/ui/splash-screen#suspend-drawing

Note: For updating/migraating your older app for Android 12 please check below

tutorial.

1. https://developer.android.com/guide/topics/ui/splash-screen/migrate

Download Complete Code Here

Hope this will help Someone.

Enjoy Coding .......................... :)

Android Jetpack Compose Toolbar example | Jetpack Compose TopAppBar

2021-09-28T22:29:00.002+05:30

Hi Friends,

Many of us looking for Toolbar example in Jetpack Compose or

TopAppBar example in Jetpack compose. Today I am going to share you

a sample which helps you in creating Toolbar in Jetpack compose.

Also in this tutoriail I am providing you how to create toolbar menu item using

JetPack Compose.

Source Code:

Complete Activity class

Download code from here

Hope this will help someone.

Enjoy Coding............... :)

Android Jetpack Compose Dropdown menu Example | Dropdown menu using DropdownMenu Composable

2021-09-28T13:06:00.001+05:30

Dropdown menu:

We are going to use DropdownMenu Composable for creating dropdown menu.

fun DropdownMenu(
    expanded: Boolean,
    onDismissRequest: () -> Unit,
    modifier: Modifier = Modifier,
    offset: DpOffset = DpOffset(0.dp, 0.dp),
    properties: PopupProperties = PopupProperties(focusable = true),
    content: @Composable ColumnScope.() -> Unit
)

In Above code if expanded is true, the popup menu with dropdown content will be shown.

onDismissRequest will be called when the menu should be dismiss,

@Composable
fun DropdownDemo() {
    var expanded by remember { mutableStateOf(false) }
    val items = listOf(
        "Apple", "Banana", "Cherry", "Grapes",
        "Mango", "Pineapple", "Pear"
    )
    var selectedIndex by remember { mutableStateOf(0) }
    Column(
        modifier = Modifier
            .fillMaxSize()
            .wrapContentSize(Alignment.TopStart)
            .padding(all = 5.dp)
    ) {
        Text(
            items[selectedIndex],
            modifier = Modifier
                .fillMaxWidth()
                .clickable(onClick = { expanded = true })
                .background(
                    Color.Red
                ),
            color = Color.White,
            fontSize = 20.sp,
            textAlign = TextAlign.Start
        )
        DropdownMenu(
            expanded = expanded,
            onDismissRequest = { expanded = false },
            modifier = Modifier
                .fillMaxWidth()
                .background(
                    Color.Gray
                )
        ) {
            items.forEachIndexed { index, s ->
                DropdownMenuItem(onClick = {
                    selectedIndex = index
                    expanded = false
                }) {
                    Text(text = s)
                }
            }
        }
    }
}

Hope this will help someone.
Enjoy Coding.......... :)

Android Jetpack Compose Button Example | How to center a button in jetpack Compose | How to onclick listener on button in Jetpack Compose

2021-09-24T17:37:00.000+05:30

Hi Friends,

Today I am sharing a Sample of Jetpack Compose Button view. I will show you how

to set onclick listener on button in Jetpack Compose. How to style on Button in

Jetpack Compse , how to set height and width of button in Jetpack compose.

Code:

Hope this will help someone.

Enjoy Coding........... :)

Android Jetpack compose- Android Listview using Jetpack compose | Jetpack compose listview clicklistener

2021-09-24T17:35:00.002+05:30

Hello all,

Today I am going to share my anothere Android Jetpack Compose tutoria.

How to set clicklistener on listview in android Jetpack Compses, how to set clicklistener

on button using Jetpack Compse.

I am sharing below code where I am handling list item click in jetpack compose.

Downlaod complete code from here

Hope this will help someone.

Enjoy Coding....... :)

Android Jetpack Compose Alert Dialog Sample | Jetpack Compose Dialog

2021-09-24T13:09:00.002+05:30

Hi Friends,

Today I am sharing the Jetpack Compse Alert Dialog Sample.

What is Alert Dialog?

- Alert dialog is a Dialog which interrupts the user with

urgent information, details or actions.

Code:

Hope this will help someone.

Enjoy Coding........ :)

How to get Context in Jetpack Compose

2021-09-23T22:12:00.001+05:30

Hello All,

Many of us facing issue in using/getting context in JetPack Compose.

Here I am sharing a composbale function where I am using context for showing toast message.

Android Jetpack Compose- An easy way to RecyclerView | How to create a RecyclerView in Jetpack Compose | LazyColumn-JetPack Compose

2021-09-23T20:54:00.000+05:30

Hello Friends,

Today I am going to share a my another JetPack Compose tutorial.

Here I am going to share you the creation of listview/recyclerview using

Compose.

Creating a listview/recyclerview in Compose:

Creating a listview/recyclerview in Compose is easy.

No Adapter. No View holder.

What is LazyColumn?

- A LazyColumn is a vertically scrolling list that only composes and lays out the currently visible items. It’s similar to a Recyclerview in the classic Android View system.

Download code from here

Hope this will help someone.

Enjoy Coding......................... :)

Android Jetpack- Jetpack cardview sample

2021-09-22T14:45:00.005+05:30

Hi All,

Today I am going to share Jetpack CardView sample. Here I am going to create a simple android cardview UI withoutt using the android Xml and layout editor.

We are going to build the UI using Composable funtion(i.e: using Jetpack Compse).

Column : We are going to use Column function for arranging the view vertically.

For arranging the view horizontally you can use Row function.

Check MainActivity.kt file for Code,

Download complete code here

Hope this will help someone.
Enjoy coding.... :)

Android Jetpack- Composable functions

2021-09-21T21:31:00.007+05:30

Jetpack Compose is built around composable functions. These functions

let you define your app's UI programmatically by describing how it

should look and providing data dependencies, rather than

focusing on the process of the UI's construction (initializing an

element, attaching it to a parent, etc.).

To create a composable function, just add the @Composable annotation
to the function name.

Enjoy Coding.... :)

Android Jetpack Compose-Android Gradle plugin requires Java 11 to run. You are currently using Java 1.8

2021-09-04T22:35:00.001+05:30

Hi All,

Many of us facing below issue while running the Android Jetpack

Compose Project.

> Failed to apply plugin 'com.android.internal.application'.
    > Android Gradle plugin requires Java 11 to run. You are currently using Java 1.8.
    You can try some of the following options:
    - changing the IDE settings.
    - changing the JAVA_HOME environment variable.
    - changing `org.gradle.java.home` in `gradle.properties`.

In order to fix this issue we need to use Java 11. You can find it in Preferences > Build, Execution, Deployment > Build Tools > Gradle > Gradle JDK.

Hope this will help some one.

Enjoy Coding....... :)

Android Jetpack Compose- Android Studio with Jetpack Compose Getting Started | Jetpack Compose Tutoria

2021-09-01T23:22:00.006+05:30

Hi All,

Today I am going to share my first JetPack Compose Tutorial. Here we learn how\nto setup android compose in android studio. We see the rquired dependency and other settings.

Step 1: Installation: First we have to download Android Studio Arctic Fox. That’s because when we use Android Studio to develop our app with Jetpack Compose, we can benefit from smart editor features, such as New Project templates and the ability to immediately
preview our Compose UI.

Step2: Create android app : After the installint of latest android studio from link now lets

create an app.

Open Android Studio > select File > New > New Project from the menu bar.
In the Select a Project Template window, select Empty Compose Activity and click Next.
In the Configure your project window, do the following:
1. Set the Name, Package name, and Save location as you normally would.
2. Note that, in the Language dropdown menu, Kotlin is the only available option because Jetpack Compose works only with classes written in Kotlin.
3. In the Minimum API level dropdown menu, select API level 21 or higher.
Click Finish.

You can see below dependecny in your app build.gradle file which is required for Compose.

For more check this tutorial

While setting it if you are facing issue of "Android Gradle plugin requires Java 11 to run. You are currently using Java 1.8". Plesase check this tutorial

Hope this will help some one.

Enjoy Coding....... :)

Kotlin - Enum Classes in Kotlin | Enum Methods | Enum Properties

2020-05-11T23:03:00.004+05:30

Hello Friend,
Today I am going to share about Enum class in Kotlin

- How to create/initialize enum classes
- methods and properties of enum classes.

Initializing enums –

Now we can easily access the color of fruits,
Enum Methods-

values: This method returns a list of all the constants defined within the enum class.
valueOf: This methods returns the enum constant defined in enum, matching the input string. If the constant, is not present in the enum, then an IllegalArgumentException is thrown.

Enum Properties-

ordinal: This property stores the ordinal value of the constant, which is usually a zero-based index.
name: This property stores the name of the constant.

Below is the example which help us to understand the uses of Enum method and Properties.

Outputs:

Hope this will help some one.
Enjoy Coding... :)

Kotlin - Android notification in kotlin | Android MVP in Kotlin

2020-05-11T15:44:00.000+05:30

Hello Friends,
Lets first tell you what is notification.

Notification is a message that is used to display some short messages outside of our main application. Even if the app is not running, notifications will still work. Notifications have the following contents: an icon, title of notification and some text content.

Now today I am going to share , how create notification in Kotlin.

Download code from here
Hope this will helps someone..
Enjoy Coding.... :)

Mobile World : The next version of Android is officially Android 11 | About android 11 release in 2020 | Android 11 name | Features coming in Android 11

2020-01-03T22:07:00.000+05:30

Android 11: Next Alphabet R Android 11 soon to Arrive

Google is all set to introduce Android 11 after success of its Android 9 and Android 10 in queue. Much of the information is not disclosed for now but is awaited and speculation is that Android 11 will be more oriented on dual display.

Android launch date is expected around September 2020 but rumours had started already. Android 11 will be available for free. After Android Q version this Android 11 will be called Android R as expected alphabetically. Also, the trends of naming their android after desserts is also said to be maintained. Android 10 was in some non-Google company like Oneplus 7T and 7T Pro but possibly it could be different for Android 11. Although it will be available for smart phones who want to be upgrade possibly.

Android 11 in Smart phones

If to put in simple language Android is an open source operating system that powers Google and Smart phones. Also, this operating system is based on a modified version of the Linux Kernel. It’s a decade old and the most popular mobile operating system in world. Android 11 like other Android software is for smart phones and tablets. Although to compare it with iPhones, Androids varies a lot. But today both are multitasking. Android 11 like other old version will be empowering Samsung series, Xperia, HTC series and many more. It is at least believes to be on pixel phones.

Android 11 features

Now if talking about Android 11 features, most of it is unknown for now and soon expected to be disclosed but expectation are “Scoped Storage” which is supposed to be in Android 10 but Google pushed it back due to complaints from Android developers. This feature makes memory read speeds much quicker, improves security, and stops you needing to give every new apps permission. Also all those features which is gone missing or not as expected in Android 10 will be anticipated to be there in Android 11. Just to name few:

1. Near field Communication (NFC)

NFC determines how your Android phone connects or interacts with the nearest device. This connection does not depend on Wi-Fi, 3G or LTE. It helped users to share videos, photos, music by not using any apps but by pressing phone against each other. But this feature is gone now and causes hindrance to share. NFC is expected in Android 11 to get away with this problem of sharing.

2. Improvement in Dark Mode

Using phone in darker made is a treat to eye. It makes different apps look way far better than it is normally. Android 10 has lots of problem regarding it. Every app does not have to have its darker mode feature, so if smart phone has it already it will reduce much inconvenience of jumping to different apps. Also on apps that do have dark mode some text aren’t colour wrapped and go invisible. Having better dark mode option is what in line of expectation from Android 11.

3. Easy access like “Chat bubbles”

Chat bubbles over the top of the apps which enables you to see your whole conversations while you are on other apps. Isn’t amazing feature? Like Facebook messenger, it should be an Android feature as well. It allows you to use other apps while chatting. User does not have to dodge every time they get a message. It’s of utmost use when we need notification while working on other apps. Especially with Instagram, , Twitter, WhatsApp, Facebook . You can easily continue with your conversation anytime.

Android 11 Updates over different phones

So the phone that going to have this Android version is:

Ø Nokia: After google, Nokia is the next original equipment

Manufacturer (OEM) which is expected to do software

upgrade. Their 'Android R' OTA update is to be done

is – Nokia 9 Pure View

Nokia 6.2

Nokia 7.2

Ø Samsung: Needless to mention that Samsung Galaxy S10 and

Samsung Galaxy Note 10 will going to be upgraded

to Android 11 Features.

ØXiaomi: The MIUI 12 will be expected to be based on

Android R version.

Hope you like this article.

Enjoy reading article :)

Android MVP template | Android MVP Plugin

2019-10-08T21:06:00.002+05:30

Hello Friends,
Today I am sharing the android MVP template which make the development
Faster. This is an android studio template inspired by android view-model template.

When we follow Android MVP architecture in any project, for each module or feature
we need to create an Activity/Fragment, a Presenter and a Contract class and also
a layout file corresponding to them. This is really an time taking process.

So Taking advantage of Android Studio template I created a MVP template
which creates all this file at the start.

Getting Started

1. Download the MVPActivity Teamplate ,which you found at the bottom of this blog.
2. For WINDOW, Just copy directory MVPActivity
to $ANDROID_STUDIO_FOLDER$\plugins\android\lib\templates\activities\
3. For Mac, Just copy directory MVPActivity
to $ANDROID_STUDIO_FOLDER$/Contents/plugins/android/lib/templates/activities/

4. Below are the few common files,

A. template.xml – This will contain information about the template

name, minSdkVersion, etc

B. recipe.xml.ftl - This will contain instructions explaining how to
create the template, including what variables to ask the user for and
what should be done with those variables.
C. globals.xml.ftl – This defines global variables

D. root/ folder – this will contain the template code.

Download code from here

Hope this will helps some one...

Enjoy Coding........... :)

Kotlin Android - RecyclerView Example

2019-10-07T18:07:00.002+05:30

Hello Friends,
Today I am sharing the demo of RecyclerView in Kotlin.
A RecyclerView is essentially a ViewGroup of containers called ViewHolders which
populate a particular item.

So lets first familiar with RecyclerView and What RecyclerView requires:
1. It requires a set of data objects to work with
2. An xml file of the individual view item
3. An adapter to bind that data to the views shown in the ViewHolders
4. ViewHolder to populate the UI from the xml item file

Getting Started

Download code from here
Hope this will helps someone.
Enjoy coding.... :)

Kotlin Android – AlertDialog – Example

2019-10-05T23:10:00.001+05:30

Hello Friends,
Here is the demo Alert Dialog in Kotlin. Android AlertDialog class
is used to display a dialog box to user with positive and negative buttons.
It Appears on top of the activity layout. You may not physically access any other
UI components of activity. It will be run on UI thread.

To Create an AlertDialog, step by step process is :

1. Create an AlertDialog Builder using the activity’s context.
2. Set message content using the builder.
3. Set Positive Button Text and Action to be taken when the button is clicked using the builder.
4. Set Negative Button Text and Action to be taken when the button is clicked using the builder.
5. Create AlertDialog from the builder.
6. You may set the title to the AlertDialog box using setTitle() method.

1. MainActivity.kt

package com.android.developer.soulutions.myapplication

import android.content.DialogInterface
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.v7.app.AlertDialog
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        btnShowAlert.setOnClickListener {
            // build alert dialog
            val dialogBuilder = AlertDialog.Builder(this)

            // set message of alert dialog
            dialogBuilder.setMessage("Do you want to close this  ?")
                    // if the dialog is cancelable
                    .setCancelable(false)
                    // positive button text and action
                    .setPositiveButton("OK", DialogInterface.OnClickListener { dialog, id ->
                        finish()
                    })
                    // negative button text and action
                    .setNegativeButton("Cancel", DialogInterface.OnClickListener { dialog, id ->
                        dialog.cancel()
                    })

            // create dialog box
            val alert = dialogBuilder.create()
            // set title for alert dialog box
            alert.setTitle("AlertDialogExample")
            // show alert dialog
            alert.show()
        };
    }
}

Download the code from here

Hope this will helps someone.
Enjoy Coding................... :)

React Native- Invariant Violation: The navigation prop is missing for this navigator | react-navigation 3- navigation prop is missing for this navigator.

2018-12-14T17:26:00.002+05:30

Hello Friend,
Recently I faced few issue while implementing the react-navigation in my app.
I spent lots of time in it and then finally I found the actual cause of it.

1. undefined is not an object (evaluating 'RNGestureHandlerModule.State')

Then I follow following steps to resolve this,

remove node_modules and package-lock.json
npm install
npm install --save react-navigation
npm install --save react-native-gesture-handler
react-native link

After following this I face another issue i:e,

2. Invariant Violation: The navigation prop is missing for this navigator. In
react-navigation 3 you must set up your app container directly. More info:
https://reactnavigation.org/docs/en/app-containers.html

Note : This is an react-navigation 3.0 bug. You can go through the below link for more details.

- React Navigation 3.0 has a number of breaking changes including an explicit app container required for the root navigator.

In the past, any navigator could act as the navigation container at the top-level of your app because they were all wrapped in “navigation containers”. The navigation container, now known as an app container, is a higher-order-component that maintains the navigation state of your app and handles interacting with the outside world to turn linking events into navigation actions and so on.

In v2 and earlier, the containers in React Navigation are automatically provided by the create Navigator functions. As of v3, you are required to use the container directly. In v3 we also renamed createNavigationContainer to createAppContainer.

Below are the complete code,

/**
 * This is an example code for Navigator
 */
import React, { Component } from 'react';
import {createStackNavigator,createAppContainer} from 'react-navigation';
 
import FirstPage from './src/component/FirstPage';
import SecondPage from './src/component/SecondPage';
//import all the screens we are going to switch 
 
const RootStack = createStackNavigator({
    //Constant which holds all the screens like index of any book 
    FirstPage: { screen: FirstPage }, 
    //First entry by default be our first screen if we do not define initialRouteName
    SecondPage: { screen: SecondPage }, 
  },
  {
    initialRouteName: 'FirstPage',
  }
);
const App = createAppContainer(RootStack);

Download complet code from here
Hope this will helps someone........

Enjoy coding..... :)

Kotlin-Create TextView Programatically

2018-12-05T17:16:00.004+05:30

Hello Friends,
In this tutorial I am going create a textview dynamically in kotlin and add it to Linearlayout layout.

1. activity_main.xml: Following is the activity_main.xml containing the TextView with the text .

<?xml version="1.0" encoding="utf-8"?>  
 <android.support.constraint.ConstraintLayout xmlns:android="https://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=".TextViewSample">  
  <LinearLayout  
   android:id="@+id/ll_main_layout"  
   android:layout_width="match_parent"  
   android:layout_height="wrap_content"  
   android:orientation="vertical">  
   <TextView  
    android:id="@+id/tv_static"  
    android:layout_width="wrap_content"  
    android:layout_height="wrap_content"  
    android:textSize="20sp"  
    android:padding="20sp"  
    android:justificationMode="inter_word"  
    android:text="This textview is created from xml"/>  
  </LinearLayout>  
 </android.support.constraint.ConstraintLayout>

2. Creation of textview dynamically,

val tv_programtically = TextView(this)
tv_programtically.textSize = 20f
tv_programtically.text = "This textview is an dynamic textview in kotlin"

3. Finally the complete code is:

TextViewSample.kt

package com.android.developer.kotlinsample

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.LinearLayout
import android.widget.TextView
class TextViewSample : AppCompatActivity() {

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_text_view_sample)

    /** Dynamic creation of text view */
    val tv_programtically = TextView(this)
    tv_programtically.textSize = 20f
    tv_programtically.text = "This textview is an dynamic textview in kotlin"
    /**------end--------**/

    // add TextView to LinearLayout
    val ll_main_layout = findViewById(R.id.ll_main_layout) as LinearLayout
    ll_main_layout.addView(tv_programtically)
  }
}

Hope this will help some one. Enjoy Coding.... :)

Kotlin-bind OnClickListener on view

2018-12-05T17:16:00.002+05:30

Hello Friends,
In this tutorial I am showing you how to bind the click listener on View in Kotlin.

1. Code snippet to set OnClickListener on Textview in Kotlin Android

val tvStatic = findViewById(R.id.tv_static) as TextView
tvStatic.setOnClickListener {
 // your code to perform when the user clicks on the TextView
 Toast.makeText(this, "You clicked on TextView 'Click Me'.", Toast.LENGTH_SHORT).show()
}

2. Code snippet to set OnClickListener on Button in Kotlin Android

// get reference to button
val btn_click = findViewById(R.id.btn_click_me) as Button
// set on-click listener
btn_click.setOnClickListener {
    Toast.makeText(this@MainActivity, "You clicked on Button.", Toast.LENGTH_SHORT).show()
}

3. Code snippet to set OnClickListener on ImageView in Kotlin Android

// get reference to ImageView
val iv_profile = findViewById(R.id.image_view) as ImageView
// set on-click listener for ImageView
iv_profile.setOnClickListener {
    // your code here
}

Hope this will help someone.
Enjoy Coding..... :)

Android Live Data Tutorial | Live Data | Data Binding | Architecture Components

2018-06-23T22:13:00.002+05:30

Hello Friends,
Today I am going to share me small tutorial of LiveData with Data Binding.

-What is LiveData?
LiveData is an observable data holder class that can be observed within
a given lifecycle. It lets the components in your app, usually the UI,
observe LiveData objects for changes.

-The advantages of using LiveData

Ensures your UI matches your data state
No memory leaks
No crashes due to stopped activities
No more manual lifecycle handling
Always up to date data
Proper configuration changes
Sharing resources

-How to use it in our app

a. Add below dependency in app/build.gradle

implementation "android.arch.lifecycle:extensions:1.1.1"

b. UserViewModel.java : Creating a ViewModel class

package com.android.developer.livedatademo.model;

import android.arch.lifecycle.MutableLiveData;
import android.arch.lifecycle.ViewModel;

/**
 * Created by mukesh on 13/6/18.
 */
public class UserViewModel extends ViewModel {

    // Create a LiveData with a String
    private MutableLiveData mUser;

    public MutableLiveData getUser() {
        if (mUser == null) {
            mUser = new MutableLiveData();
        }
        return mUser;
    }
}

In Activity class we creates an observer which updates the ui.

final Observer nameObserver = new Observer() {
      @Override
      public void onChanged(@Nullable final User user) {
      // Update the UI, in this case, a TextView.
      binding.tvUserName.setText(user.getName());
    }
};

Next step is observe the livedata, passing in the activity as a LifecycleOwner and the Observer.

userViewModel.getUser().observe(this, nameObserver);
binding.btnClick.setOnClickListener(this);

The complete code,

package com.android.developer.livedatademo;

import android.arch.lifecycle.Observer;
import android.arch.lifecycle.ViewModelProviders;
import android.databinding.DataBindingUtil;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

import com.android.developer.livedatademo.databinding.ActivityMainBinding;
import com.android.developer.livedatademo.model.User;
import com.android.developer.livedatademo.model.UserViewModel;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    UserViewModel userViewModel;
    ActivityMainBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
        // Get the ViewModel.
        userViewModel = ViewModelProviders.of(this).get(UserViewModel.class);
        // Create the observer which updates the UI.
        final Observer nameObserver = new Observer() {
            @Override
            public void onChanged(@Nullable final User user) {
                // Update the UI, in this case, a TextView.
                binding.tvUserName.setText(user.getName());
            }
        };

        // Observe the LiveData, passing in this activity as the LifecycleOwner and the observer.
        userViewModel.getUser().observe(this, nameObserver);
        binding.btnClick.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        User user = new User();
        user.setName("Mukesh Yadav");
        user.setAge("25");
        userViewModel.getUser().setValue(user);
    }
}

Download the complete code here

Hope this will helps someone.
Enjoy Coding... :)

Android MVP for Beginners | Android MVP tutorial | Model-View-Presenter: Android | Android Architecture with MVP

2017-12-17T12:09:00.001+05:30

Hello Friends,
Today I am going to share a very simple example of Android MVP.
In this sample I am using MVP pattern for network call and and user
form(login form) data validation which is mainly used in most of the android
application.

Model View Presenter divides application into three layers i.e: Model, View and Presenter.

Model: This handles the data part of our application
Presenter: It acts as a bridge that connects a Model and a View.
View: This is responsible for laying out views with the relevant data as instructed by the Presenter

Note: The View never communicates with Model directly

1. LoginActivity.java

package android.developer.solutions.androidmvp.activity.login.view;

import android.content.Intent;
import android.developer.solutions.androidmvp.R;
import android.developer.solutions.androidmvp.activity.home.view.HomeActivity;
import android.developer.solutions.androidmvp.activity.login.interactor.LoginInteractorImpl;
import android.developer.solutions.androidmvp.activity.login.presenter.ILoginPresenter;
import android.developer.solutions.androidmvp.activity.login.presenter.LoginPresenterImpl;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;

public class LoginActivity extends AppCompatActivity implements ILoginView {
    EditText username;
    EditText password;
    ProgressBar progress;
    Button button;
    private ILoginPresenter presenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        progress = (ProgressBar) findViewById(R.id.progress);
        button = (Button) findViewById(R.id.btnLogin);
        password = (EditText) findViewById(R.id.password);
        username = (EditText) findViewById(R.id.username);
        presenter = new LoginPresenterImpl(this, new LoginInteractorImpl());
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                presenter.validateCredentials(username.getText().toString(), password.getText().toString());
            }
        });
    }

    @Override
    protected void onDestroy() {
        presenter.onDestroy();
        super.onDestroy();
    }

    @Override
    public void showProgress() {
        progress.setVisibility(View.VISIBLE);
    }

    @Override
    public void hideProgress() {
        progress.setVisibility(View.GONE);
    }

    @Override
    public void setUsernameError() {
        username.setError("Invalid user name");
    }

    @Override
    public void setPasswordError() {
        password.setError("Invalid password");
    }

    @Override
    public void navigateToHome() {
        startActivity(new Intent(this, HomeActivity.class));
        finish();
    }
}

2. ILoginView.java

package android.developer.solutions.androidmvp.activity.login.view;

/**
 * Created by Mukesh on 12/16/2017.
 * androiddevelopersolutions.com
 */
public interface ILoginView {
    void showProgress();
    void hideProgress();
    void setUsernameError();
    void setPasswordError();
    void navigateToHome();
}

Download complete code from here

Hope this will helps some one.
Enjoy Coding............ :)

Android O: Fonts – Part 1 | Working with custom font Android O | Custom font | Fonts in XML

2017-11-27T15:32:00.002+05:30

Hello Friends,
Android 8.0 (API level 26) introduces a new feature, Fonts in XML, which lets you use fonts as resources. You can add the font file in the res/font/ folder to bundle fonts as resources. These fonts are compiled in your R file and are automatically available in Android Studio. You can access the font resources with the help of a new resource type, font. For example, to access a font resource, use @font/myfont, or R.font.myfont.

To use the Fonts in XML feature on devices running Android API version 14 and higher, use the Support Library 26. For more information on using the support library, refer to the Using the support library section.

Steps

To add fonts as resources, perform the following steps in the Android Studio

Right-click the res folder and go to New > Android resource directory

The New Resource Directory window appears.

In the Resource type list, select font, and then click OK.

Note: The name of the resource directory must be font.

Using fonts in XML layouts

In the layout XML file, set the font Family attribute to the font file you want to access.

Download Complete code from here.

Hope this will help some one.

Enjoy coding.................. ;)

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Right-click the res folder and go to New > Android resource directory The New Resource Directory window appears.

Right-click the res folder and go to New > Android resource directory

The New Resource Directory window appears.