Optimizing Performance

class MainActivity : AppCompatActivity() {
    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        val view = binding.root
        setContentView(view)

        binding.textView.text = "Hello World"
    }
}

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

        val textView = findViewById<TextView>(R.id.textView)
        textView.text = "Hello World"
    }
}

class MyAdapter(private val dataList: List<String>) : RecyclerView.Adapter<MyAdapter.ViewHolder>() {

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val textView: TextView = itemView.findViewById(R.id.textView)
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(parent.context)
            .inflate(R.layout.item_layout, parent, false)
        return ViewHolder(view)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.textView.text = dataList[position]
    }

    override fun getItemCount(): Int = dataList.size
}

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Hello World"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/image"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/title"
        app:layout_constraintBottom_toBottomOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

val viewStub = findViewById<ViewStub>(R.id.view_stub)
val inflatedView = viewStub.inflate()

val options = BitmapFactory.Options().apply {
    inJustDecodeBounds = true
    BitmapFactory.decodeResource(resources, R.drawable.image, this)
    val height = outHeight
    val width = outWidth
    inSampleSize = calculateInSampleSize(this, 100, 100)
    inJustDecodeBounds = false
}
val bitmap = BitmapFactory.decodeResource(resources, R.drawable.image, options)

val options = BitmapFactory.Options().apply {
    inBitmap = reusedBitmap
}
val bitmap = BitmapFactory.decodeResource(resources, R.drawable.image, options)

class BitmapCache : LruCache<String, Bitmap>(maxSize) {
    override fun sizeOf(key: String, value: Bitmap): Int {
        return value.byteCount
    }
}

val cache = BitmapCache(1024 * 1024) // 1MB max size

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

        // Example of inefficient nested layout
        val parentLayout = findViewById<ViewGroup>(R.id.parent_layout)
        val childView = findViewById<View>(R.id.child_view)

        // This can cause overdraw if child_view has transparency
    }
}

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

        StrictMode.setThreadPolicy(
            StrictMode.ThreadPolicy.Builder()
                .detectAll()
                .penaltyLog()
                .build()
        )
    }
}

# From Android Studio
# Navigate to:
#     Tools > Profiler

# Or use the shortcut:
#     Shift + Alt + A (Windows/Linux)
#     Shift + Option + A (macOS)

import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable

@Composable
fun OptimizedLazyList(items: List<String>) {
    LazyColumn {
        items(items) { item ->
            Text(text = item)
        }
    }
}

LazyColumn {
    items(items, key = { it.id }) { item ->
        Text(text = item.name)
    }
}

class MyActivity : AppCompatActivity() {
    private val contextRef = WeakReference<Context>(this)

    fun doSomething() {
        val context = contextRef.get()
        if (context != null) {
            // Safe to use context here
        }
    }
}

class MyActivity : AppCompatActivity() {
    private val receiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context?, intent: Intent?) { }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        registerReceiver(receiver, IntentFilter("ACTION"))
    }

    override fun onDestroy() {
        super.onDestroy()
        unregisterReceiver(receiver) // Prevents leak
    }
}

android {
    compileSdk 34

    defaultConfig {
        targetSdk 34
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    kotlinOptions {
        jvmTarget = "1.8"
    }

    buildFeatures {
        buildConfig = true
    }
}

android {
    compileSdk 34

    baselineProfile {
        automaticGeneration = true
    }
}