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) {}
 }
 @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