How to Compose Gmail on Button Click in Android Using Java and Kotlin

Composing an email directly from an Android application enhances user experience by integrating email functionality seamlessly. This guide covers how to implement a feature in Android to compose a Gmail message on button click using both Java and Kotlin.

Prerequisites

• Android Studio installed
• Basic understanding of Android development
• Basic knowledge of Java or Kotlin

Step-by-Step Guide

1. Setting Up the Project

Open Android Studio and create a new project with an Empty Activity. Name your project and set the language to either Java or Kotlin.

2. Designing the User Interface

Open activity_main.xml and add a Button that will trigger the email composition.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/composeEmailButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Compose Email"
        android:layout_centerInParent="true"/>
</RelativeLayout>

3. Implementing the Button Click in Java

Open MainActivity.java and implement the button click event to compose an email.

package com.example.composeemail;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

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

        Button composeEmailButton = findViewById(R.id.composeEmailButton);
        composeEmailButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                composeEmail(new String[]{"recipient@example.com"}, "Subject", "Email body text");
            }
        });
    }

    public void composeEmail(String[] addresses, String subject, String body) {
        Intent intent = new Intent(Intent.ACTION_SENDTO);
        intent.setData(Uri.parse("mailto:")); // only email apps should handle this
        intent.putExtra(Intent.EXTRA_EMAIL, addresses);
        intent.putExtra(Intent.EXTRA_SUBJECT, subject);
        intent.putExtra(Intent.EXTRA_TEXT, body);
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }
}

4. Implementing the Button Click in Kotlin

Open MainActivity.kt and implement the button click event to compose an email.

package com.example.composeemail

import android.content.Intent
import android.net.Uri
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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

        composeEmailButton.setOnClickListener {
            composeEmail(arrayOf("recipient@example.com"), "Subject", "Email body text")
        }
    }

    private fun composeEmail(addresses: Array<String>, subject: String, body: String) {
        val intent = Intent(Intent.ACTION_SENDTO).apply {
            data = Uri.parse("mailto:") // only email apps should handle this
            putExtra(Intent.EXTRA_EMAIL, addresses)
            putExtra(Intent.EXTRA_SUBJECT, subject)
            putExtra(Intent.EXTRA_TEXT, body)
        }
        if (intent.resolveActivity(packageManager) != null) {
            startActivity(intent)
        }
    }
}

5. Testing the Application

• Run the application on an Android device or emulator.
• Click the “Compose Email” button.
• Verify that the email composition screen appears with the recipient, subject, and body pre-filled.

Conclusion

By following these steps, you can implement a feature in your Android application that allows users to compose Gmail messages on a button click. This guide provided both Java and Kotlin implementations to suit your preference.