MANOJRATNA DUGGIRALA

Posted on Mar 2

Hands-on Android Development: Building Apps with Java & Android Studio

#android #java #kotlin #coding

What is Android Studio?
Android Studio is the official Integrated Development Environment (IDE) for Android app development, built by Google. It provides developers with a powerful and flexible environment to design, develop, test, and debug Android applications efficiently.

Key Features of Android Studio:
✅ Intelligent Code Editor: It supports Java, Kotlin, and C++, offering features like code completion, refactoring, and real-time error checking.

✅ Layout Editor: A drag-and-drop UI designer that helps developers design app interfaces visually without writing XML manually.

✅ Gradle Build System: Automates and optimizes app building, making it easier to manage dependencies and configurations.

✅ Emulator for Testing: Provides a virtual Android device to test applications without needing a physical phone.

✅ APK Analyzer: Helps inspect the app’s APK file size and resources to optimize performance.

✅ Version Control Integration: Supports Git and other version control tools for collaborative development.

✅ Real-time Performance Profiler: Monitors CPU, memory, and network usage to optimize app performance.

Why Developers Love Android Studio?
User-friendly UI with a sleek and intuitive interface.
Deep integration with Google Services, including Firebase and Google Play.
Regular updates with the latest Android features and improvements.
Cross-platform support for Wear OS, Android TV, and more.
Android Studio is the ultimate toolkit for any developer looking to create high-performance Android applications!

In this Workshop, I Have Developed 4 Applications, and here is a detailed Overview of Every Application

1.Simple Counter App

This XML layout defines a simple Tap Counter App UI using a LinearLayout, two Button elements, and a TextView. Let’s break it down step by step.

Root Layout - LinearLayout

<LinearLayout
    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/main"
    android:layout_margin="20sp"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:weightSum="10"
    android:orientation="vertical"
    tools:context=".MainActivity">

Count Button

<Button
    android:layout_width="match_parent"
    android:layout_height="4dp"
    android:layout_weight="1"
    android:text="Count"
    android:onClick="count"
    android:textSize="24sp" />

TextView - Display Counter Value

<TextView
    android:id="@+id/text1"
    android:layout_width="match_parent"
    android:layout_height="0sp"
    android:layout_weight="8"
    android:text="0"
    android:gravity="center"
    android:textSize="200sp"/>

Toast Button

<Button
    android:layout_width="match_parent"
    android:layout_height="0sp"
    android:layout_weight="1"
    android:text="Toast"
    android:onClick="toast"
    android:textSize="24sp"/>

MainActivity.java File

Package and Imports

package com.example.android_workshop;

This defines the package name of APP

import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

Defining Variables and Extending AppCompatActivity

public class MainActivity extends AppCompatActivity {
    TextView t1;
    int count = 0;

onCreate() Method - Initializing the UI

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

Linking TextView from XML to Java

    t1 = this.<TextView>findViewById(R.id.text1);

Handling Window Insets (Edge-to-Edge UI)

    ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
        Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
        v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
        return insets;
    });

count() Method - Increasing the Counter

public void count(View view) {
    count++;
    t1.setText("" + count);
}

toast() Method - Showing a Toast Message

public void toast(View view) {
    Toast.makeText(MainActivity.this, "Hello my dear Connections" + count,
            Toast.LENGTH_LONG).show();
}

How Does the App Works?
1️⃣ Pressing the "Count" button increases the counter and updates the TextView.
2️⃣ Pressing the "Toast" button displays a message showing the current count.

Simple Calculator App

This XML file defines the UI for a simple calculator app in Android using LinearLayout.

Overview:

Dark Theme (android:background="#000") for a stylish look.
Title (TextView): Displays "Calculator" in red text.
Two Input Fields (EditText): Allow users to enter two numbers.
Four Buttons (Button): Perform addition (+), subtraction (-), multiplication (*), and division (/).
Result Display (TextView): Shows the output after a calculation.

Next step? Implement logic in MainActivity.java to perform calculations when buttons are clicked!

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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/main"
    android:orientation="vertical"
    android:background="#000"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Calculator"
        android:textSize="24sp"
        android:textColor="@color/design_default_color_error"
        android:layout_margin="20sp"
        android:gravity="center"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/edit1"
        android:hint="Enter First Value "
        android:textSize="24sp"
        android:layout_margin="10sp"
        android:textColor="@color/design_default_color_error"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/edit2"
        android:hint="Enter Second Value "
        android:textSize="24sp"
        android:layout_margin="10sp"
        android:textColor="@color/design_default_color_error"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center"
        android:layout_margin="10dp">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="+"
        android:onClick="Pluse"
        android:textSize="24sp"
        android:gravity="center" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="-"
        android:onClick="Minus"
        android:textSize="24sp"
        android:gravity="center" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="*"
        android:onClick="Multiplication"
        android:textSize="24sp"
        android:gravity="center" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="/"
        android:onClick="Division"
        android:textSize="24sp"
        android:gravity="center" />


</LinearLayout>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/text1"
        android:text="Result"
        android:textSize="24sp"
        android:layout_margin="30sp"
        android:gravity="center"/>
</LinearLayout>

This Java class defines the logic for a simple calculator app in Android. It handles basic arithmetic operations (+, -, *, /) based on user input.

Key Highlights:
UI Elements:
EditText e1, e2; → Input fields for user-entered numbers.
TextView t1; → Displays the result.
Arithmetic Operations:
Addition (Pluse) – Adds two numbers.
Subtraction (Minus) – Subtracts second number from the first.
Multiplication (Multiplication) – Multiplies two numbers.
Division (Division) – Divides first number by second.
EdgeToEdge & Insets Handling: Ensures UI adapts to system bars.
Event Handling: Click events trigger calculations when users press buttons.
💡 Possible Improvements:
✔️ Handle division by zero to prevent app crashes.
✔️ Use try-catch to prevent errors when fields are empty.

Next step? Improve UI and add more features like clear/reset buttons!

package com.example.simplecaluclator;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {
    EditText e1,e2;
    TextView t1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        e1=this.<EditText>findViewById(R.id.edit1);
        e2=this.<EditText>findViewById(R.id.edit2);
        t1=this.<TextView>findViewById(R.id.text1);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
    }

    public void Pluse(View view) {
        int a,b,c;
        a=Integer.parseInt(e1.getText().toString());
        b=Integer.parseInt(e2.getText().toString());
        c=a+b;
        t1.setText(""+c);
    }

    public void Minus(View view) {
        int a,b,c;
        a=Integer.parseInt(e1.getText().toString());
        b=Integer.parseInt(e2.getText().toString());
        c=a-b;
        t1.setText(""+c);
    }

    public void Multiplication(View view) {
        int a,b,c;
        a=Integer.parseInt(e1.getText().toString());
        b=Integer.parseInt(e2.getText().toString());
        c=a*b;
        t1.setText(""+c);
    }

    public void Division(View view) {
        int a,b,c;
        a=Integer.parseInt(e1.getText().toString());
        b=Integer.parseInt(e2.getText().toString());
        c=a/b;
        t1.setText(""+c);
    }
}

And This is How it Works;

During my Android Development Workshop, I explored and built some amazing applications that truly enhanced my skills. Here are my top projects:

✅ 📱 Simple Calculator App – A clean, functional UI with basic arithmetic operations.
✅ 🗣️ Text-to-Speech App – Convert text into speech with a simple click!
✅ 🔀 Intent Application – Seamlessly navigate between activities in Android apps.

These projects gave me hands-on experience with Java & Android Studio, and I loved the process of bringing ideas to life.

👀 More details? I’ll be sharing an in-depth blog soon. Stay tuned!

🔗 Let's connect on LinkedIn! Feel free to DM me to discuss Android development and more.

AndroidDevelopment #AndroidStudio #Java #DevCommunity

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