import android.Manifest
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.location.Location
import android.location.LocationManager
import android.os.Bundle
import android.widget.Button
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import com.google.android.gms.location.FusedLocationProviderClient
import com.google.android.gms.location.LocationServices

class MainActivity : AppCompatActivity() {

    private lateinit var fusedLocationClient: FusedLocationProviderClient

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

        // Initialize FusedLocationProviderClient
        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this)

        // Request location permissions
        requestLocationPermissions()

        // Setup buttons
        findViewById<Button>(R.id.btnReportCrime).setOnClickListener {
            reportCrime()
        }

        findViewById<Button>(R.id.btnNeighborhoodWatch).setOnClickListener {
            neighborhoodWatch()
        }

        findViewById<Button>(R.id.btnEmergencyAlerts).setOnClickListener {
            emergencyAlerts()
        }

        findViewById<Button>(R.id.btnShareLocation).setOnClickListener {
            shareLocation()
        }

        findViewById<Button>(R.id.btnSendDistressSignal).setOnClickListener {
            sendDistressSignal()
        }
    }

    private fun requestLocationPermissions() {
        val permissions = arrayOf(
            Manifest.permission.ACCESS_FINE_LOCATION,
            Manifest.permission.ACCESS_COARSE_LOCATION
        )
        ActivityCompat.requestPermissions(this, permissions, LOCATION_PERMISSION_REQUEST_CODE)
    }

    private fun reportCrime() {
        // Implement crime reporting functionality
        Toast.makeText(this, "Crime reported", Toast.LENGTH_SHORT).show()
    }

    private fun neighborhoodWatch() {
        // Implement neighborhood watch coordination
        Toast.makeText(this, "Neighborhood watch activated", Toast.LENGTH_SHORT).show()
    }

    private fun emergencyAlerts() {
        // Implement emergency response alerts
        Toast.makeText(this, "Emergency alerts enabled", Toast.LENGTH_SHORT).show()
    }

    private fun shareLocation() {
        if (checkLocationPermission()) {
            fusedLocationClient.lastLocation
                .addOnSuccessListener { location: Location? ->
                    location?.let {
                        val latitude = location.latitude
                        val longitude = location.longitude
                        // Send location to trusted contacts or emergency services
                        Toast.makeText(
                            this,
                            "Location shared: Lat=$latitude, Long=$longitude",
                            Toast.LENGTH_SHORT
                        ).show()
                    }
                }
        }
    }

    private fun sendDistressSignal() {
        // Send distress signal to emergency contacts or authorities
        Toast.makeText(this, "Distress signal sent", Toast.LENGTH_SHORT).show()
    }

    private fun checkLocationPermission(): Boolean {
        return ActivityCompat.checkSelfPermission(
            this,
            Manifest.permission.ACCESS_FINE_LOCATION
        ) == PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(
            this,
            Manifest.permission.ACCESS_COARSE_LOCATION
        ) == PackageManager.PERMISSION_GRANTED
    }

    companion object {
        private const val LOCATION_PERMISSION_REQUEST_CODE = 1001
    }
}
by

Kotlin online compiler

Write, Run & Share Kotlin code online using OneCompiler’s Kotlin online compiler for free. It’s a modern and fast online playground for Kotlin, supporting the latest version and ideal for learning, experimenting, and sharing code instantly.

About Kotlin

Kotlin is a statically typed, modern programming language developed by JetBrains. It runs on the JVM and is fully interoperable with Java. Kotlin is concise, expressive, and safe, and it’s officially supported by Google for Android app development.

Sample Code

The following is a simple Kotlin program that prints a greeting:

fun main() {
    println("Hello, OneCompiler!")
}

Taking inputs (stdin)

OneCompiler’s Kotlin editor supports stdin. You can provide input using the I/O tab. Here's a sample program that reads a line of input and prints a greeting:

fun main() {
    print("Enter your name: ")
    val name = readLine()
    println("Hello, $name")
}

Syntax Basics

Variables

val name: String = "OneCompiler"  // Immutable
var age: Int = 25                 // Mutable

Kotlin supports type inference, so explicit types are optional:

val city = "Hyderabad"
var count = 10

Conditionals

val score = 85
if (score >= 50) {
    println("Pass")
} else {
    println("Fail")
}

Loops

For loop

for (i in 1..5) {
    println(i)
}

While loop

var i = 1
while (i <= 5) {
    println(i)
    i++
}

Do-While loop

var j = 1
do {
    println(j)
    j++
} while (j <= 5)

Functions

fun add(a: Int, b: Int): Int {
    return a + b
}

fun greet(name: String) = "Hello, $name"

Collections

val items = listOf("apple", "banana", "cherry")
for (item in items) {
    println(item)
}

This guide provides a quick reference to Kotlin programming syntax and features. Start coding in Kotlin using OneCompiler’s Kotlin online compiler today!