Native Android Development

Required Tools

MainActivity.kt

package com.example.myapp

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.*
import androidx.compose.material3.*
import androidx.compose.runtime.*
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.example.myapp.ui.theme.MyAppTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyAppTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    CounterScreen()
                }
            }
        }
    }
}

@Composable
fun CounterScreen() {
    var count by remember { mutableStateOf(0) }
    
    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(16.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center
    ) {
        Text(
            text = "Count: $count",
            style = MaterialTheme.typography.headlineMedium,
            modifier = Modifier.padding(bottom = 32.dp)
        )
        
        Button(
            onClick = { count++ },
            modifier = Modifier.padding(8.dp)
        ) {
            Text("Increment")
        }
        
        Button(
            onClick = { count-- },
            enabled = count > 0,
            modifier = Modifier.padding(8.dp)
        ) {
            Text("Decrement")
        }
        
        if (count >= 10) {
            Text(
                text = "Great job! You've reached $count!",
                style = MaterialTheme.typography.bodyLarge,
                color = MaterialTheme.colorScheme.primary,
                modifier = Modifier.padding(top = 16.dp)
            )
        }
    }
}

@Preview(showBackground = true)
@Composable
fun CounterScreenPreview() {
    MyAppTheme {
        CounterScreen()
    }
}