Develop Tip Calculator App with a working Calculate button.

Develop Tip Calculator App with a working Calculate button.

Activity_Main.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="186dp"
        android:layout_height="45dp"
        android:text=""
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.497"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.816" />

    <EditText
        android:id="@+id/cost"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="Cost"
        android:inputType="textPersonName"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.417"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.023"
        tools:ignore="TouchTargetSizeCheck" />

    <RadioGroup
        android:id="@+id/RG"
        android:layout_width="200dp"
        android:layout_height="144dp"
        app:layout_constraintBottom_toTopOf="@+id/switch1"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.44"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/cost"
        app:layout_constraintVertical_bias="0.385">

        <RadioButton
            android:id="@+id/radio15"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Awesome (20)" />

        <RadioButton
            android:id="@+id/radio18"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Good (18)" />

        <RadioButton
            android:id="@+id/radio20"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Average (15)" />
    </RadioGroup>


//for round tip enable/disable

    <Switch
        android:id="@+id/switch1"
        android:layout_width="409dp"
        android:layout_height="56dp"
        android:layout_marginTop="240dp"
        android:text="Round Up Tip"
        app:layout_constraintBottom_toTopOf="@+id/textView"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/cost"
        app:layout_constraintVertical_bias="0.0"
        tools:ignore="HardcodedText,UseSwitchCompatOrMaterialXml" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Calculate Tip"
        app:layout_constraintBottom_toTopOf="@+id/textView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/switch1" />

</androidx.constraintlayout.widget.ConstraintLayout>


MainActivity.kt
package com.example.calculatetip

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.calculatetip.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    lateinit var binding: ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.button.setOnClickListener() {
            calculateTip()
        }
    }
    fun calculateTip()
    {
        val cost=(binding.cost.text.toString()).toDouble()
        val selected=binding.RG.checkedRadioButtonId
        val tipPercent=when(selected)
        {
            R.id.radio15 -> 0.15
            R.id.radio18 -> 0.18
            else -> 0.20
        }
        var tip=tipPercent*cost
        if(binding.switch1.isChecked)
        {
            tip=kotlin.math.ceil(tip)
        }
        binding.textView.text=tip.toString()
    }
}



build.gradle:

In  gradle  scripts -> select build.gradle(Module:app) file -> update the higlighted build features lines of code.
Finally Sync Now .

Then Run the emulator


plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
}

android {
    namespace 'com.example.calculatetip'
    compileSdk 33

    defaultConfig {
        applicationId "com.example.calculatetip"
        minSdk 24
        targetSdk 33
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
    buildFeatures{
        viewBinding="true"
    }
}

dependencies {

    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.6.1'
    implementation 'com.google.android.material:material:1.9.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
}