Jetpack Compose 1.7 Performance: Strong Skipping + Stability

1@Composable
2fun ProductList(products: List) {
3    // List unstable (runtime type erasure)
4    // → Parent recompose olduğunda bu da recompose
5    products.forEach { ProductCard(it) }
6}

1@Composable
2fun ProductList(products: List) {
3    // Strong skipping: products değişmediyse skip
4    // Reference equality kontrolü otomatik
5    products.forEach { ProductCard(it) }
6}

1// Otomatik stable infer edilir
2data class User(val id: String, val name: String)
3 
4// Explicit @Stable gerekmez — compiler infer eder
5 
6// Ama external class'lar için yine explicit
7@Stable
8class ExternalWrapper(val value: Int)

1// Kotlin collections default stable değil (mutability)
2// ImmutableList kullan:
3import kotlinx.collections.immutable.*
4 
5@Composable
6fun Screen(items: ImmutableList) {
7    // items stable, skip OK
8    LazyColumn {
9        items(items) { ItemRow(it) }
10    }
11}

1// Old Modifier (deprecated)
2fun Modifier.customPadding(value: Dp) = this.then(
3    PaddingModifier(value)  // Allocation heavy
4)
5 
6// New Modifier.Node
7fun Modifier.customPadding(value: Dp) = this.then(
8    CustomPaddingElement(value)
9)
10 
11class CustomPaddingElement(val value: Dp) : ModifierNodeElement() {
12    override fun create() = CustomPaddingNode(value)
13    override fun update(node: CustomPaddingNode) {
14        node.value = value
15    }
16}
17 
18class CustomPaddingNode(var value: Dp) : Modifier.Node(), LayoutModifierNode {
19    override fun MeasureScope.measure(...) {
20        // Optimized implementation
21    }
22}

1// baseline-profile/BaselineProfileGenerator.kt
2@OptIn(ExperimentalBaselineProfilesApi::class)
3class BaselineProfileGenerator {
4    @get:Rule
5    val rule = BaselineProfileRule()
6 
7    @Test
8    fun generate() = rule.collectBaselineProfile(
9        packageName = "com.myapp",
10        profileBlock = {
11            pressHome()
12            startActivityAndWait()
13            // Navigate critical paths
14            device.findObject(By.text("Profile")).click()
15            device.wait(Until.hasObject(By.text("Settings")), 5000)
16        }
17    )
18}

1val LocalTheme = compositionLocalOf { Theme.default }
2 
3@Composable
4fun Screen() {
5    // 1.7: read cached, less recomposition trigger
6    val theme = LocalTheme.current
7    // ... use theme
8}

1LazyColumn(
2    state = rememberLazyListState(),
3    userScrollEnabled = true,
4    // 1.7: automatic prefetch distance based on scroll velocity
5) {
6    items(items, key = { it.id }) { item ->
7        ItemRow(item)
8    }
9}

1// Build Profile
2val recomposeCount = RecomposeCountReport()
3 
4@Composable
5fun App() {
6    // Wrap root with performance monitor
7    PerformanceMonitor(onReport = { report ->
8        Log.d("Compose", "Recomposition: ${report.composableName} - ${report.count}")
9    }) {
10        RootNavHost()
11    }
12}