Messenger Activity in Android to Chat Process

Messenger Activity in Android

I am going to tell you what Messenger is and how to create a Messenger Activity in an application in Android.

Also how to work with it when we are on chat.

Messenger is a Java class and we use this in Android by extending the Activity class.

This class allows us to implement message-based communication between processes

by creating a Messenger pointing to the handler in one process and handing that Messenger in another process.

Step 1

Create a new project by "File" -> "New" -> "Android Application Project". Its name is MessengerActivity.

Step 2

Write the following code in "values/string.xml":

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

<resources>

    <string name="app_name">MessengerActivity</string>

    <string name="hello_world">Hello world!</string>

    <string name="menu_settings">Settings</string>

    <string name="title_activity_rotations_exercises">Rotations Exercises</string>

    <string name="message_prompt">Message:</string>

    <string name="font_size_prompt">Font size:</string>

    <string name="add_message_button_label">Send Messege</string>

    <string name="message_hint">Your Message</string>

</resources>

Step 3

Write the following code in "activity_main.xml":

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

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

    android:id="@+id/mainLayout"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

  <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content" >

        <TextView

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="@string/message_prompt"

            android:textAppearance="?android:attr/textAppearanceMedium" />

        <EditText

            android:id="@+id/message_field"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:ems="10"

            android:hint="@string/message_hint" >

            <requestFocus />

        </EditText>

    </LinearLayout>

    <Button

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="@string/add_message_button_label"

        android:onClick="SendMessege" />

</LinearLayout>

Step 4

Write the following code in MessengerActivity.java:

package com.example.Messenger.Activity;

import java.util.ArrayList;

import com.message.sending.MainActivity.R;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.EditText;

import android.widget.LinearLayout;

import android.widget.TextView;

public class MessengerActivity extends Activity {

    private LinearLayout mMainLayout;

    private EditText mMessageField;

    private ArrayList<String> mMessages = new ArrayList<String>();

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mMainLayout = (LinearLayout)findViewById(R.id.mainLayout);

        mMessageField = (EditText)findViewById(R.id.message_field);

    }

    @Override

    protected void onSaveInstanceState(Bundle outState) {

        super.onSaveInstanceState(outState);

        outState.putStringArrayList("messages", mMessages);

    }

    @Override

    protected void onRestoreInstanceState(Bundle savedInstanceState) {

        super.onRestoreInstanceState(savedInstanceState);

        mMessages = savedInstanceState.getStringArrayList("messages");

        for(String message: mMessages) {

         //   SendMessege(message);

        }

    }

     @SuppressLint("NewApi")

      public void SendMessege(View clickedButton) {

       String message = mMessageField.getText().toString();

        if (!message.isEmpty()) {

            mMessages.add(message);

        }

    }

     private void SendMessege(String message) {

        TextView textV = new TextView(this);

        textV.setText(message);

        mMainLayout.addView(textV); 

    }

}

Step 5

Compile the project by "Android Virtual Device" and see the output.

Starting output window

 

 Running output window