เลื่อน

@Composable private fun ScrollBoxes() {     Column(         modifier = Modifier             .background(Color.LightGray)             .size(100.dp)             .verticalScroll(rememberScrollState())     ) {         repeat(10) {             Text("Item $it", modifier = Modifier.padding(2.dp))         }     } }
GesturesSnippets.kt

@Composable private fun ScrollBoxesSmooth() {     // Smoothly scroll 100px on first composition     val state = rememberScrollState()     LaunchedEffect(Unit) { state.animateScrollTo(100) }      Column(         modifier = Modifier             .background(Color.LightGray)             .size(100.dp)             .padding(horizontal = 8.dp)             .verticalScroll(state)     ) {         repeat(10) {             Text("Item $it", modifier = Modifier.padding(2.dp))         }     } }
GesturesSnippets.kt

@Composable private fun ScrollableSample() {     // actual composable state     var offset by remember { mutableStateOf(0f) }     Box(         Modifier             .size(150.dp)             .scrollable(                 orientation = Orientation.Vertical,                 // Scrollable state: describes how to consume                 // scrolling delta and update offset                 state = rememberScrollableState { delta ->                     offset += delta                     delta                 }             )             .background(Color.LightGray),         contentAlignment = Alignment.Center     ) {         Text(offset.toString())     } }
GesturesSnippets.kt

@Composable private fun AutomaticNestedScroll() {     val gradient = Brush.verticalGradient(0f to Color.Gray, 1000f to Color.White)     Box(         modifier = Modifier             .background(Color.LightGray)             .verticalScroll(rememberScrollState())             .padding(32.dp)     ) {         Column {             repeat(6) {                 Box(                     modifier = Modifier                         .height(128.dp)                         .verticalScroll(rememberScrollState())                 ) {                     Text(                         "Scroll here",                         modifier = Modifier                             .border(12.dp, Color.DarkGray)                             .background(brush = gradient)                             .padding(24.dp)                             .height(150.dp)                     )                 }             }         }     } }
GesturesSnippets.kt

val nestedScrollConnection = object : NestedScrollConnection {     override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {         println("Received onPreScroll callback.")         return Offset.Zero     }      override fun onPostScroll(         consumed: Offset,         available: Offset,         source: NestedScrollSource     ): Offset {         println("Received onPostScroll callback.")         return Offset.Zero     } }
GesturesSnippets.kt

val disabledNestedScrollConnection = remember {     object : NestedScrollConnection {         override fun onPostScroll(             consumed: Offset,             available: Offset,             source: NestedScrollSource         ): Offset {             return if (source == NestedScrollSource.SideEffect) {                 available             } else {                 Offset.Zero             }         }     } }
GesturesSnippets.kt

@Composable fun ImageResizeOnScrollExample(     modifier: Modifier = Modifier,     maxImageSize: Dp = 300.dp,     minImageSize: Dp = 100.dp ) {     var currentImageSize by remember { mutableStateOf(maxImageSize) }     var imageScale by remember { mutableFloatStateOf(1f) }      val nestedScrollConnection = remember {         object : NestedScrollConnection {             override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {                 // Calculate the change in image size based on scroll delta                 val delta = available.y                 val newImageSize = currentImageSize + delta.dp                 val previousImageSize = currentImageSize                  // Constrain the image size within the allowed bounds                 currentImageSize = newImageSize.coerceIn(minImageSize, maxImageSize)                 val consumed = currentImageSize - previousImageSize                  // Calculate the scale for the image                 imageScale = currentImageSize / maxImageSize                  // Return the consumed scroll amount                 return Offset(0f, consumed.value)             }         }     }      Box(Modifier.nestedScroll(nestedScrollConnection)) {         LazyColumn(             Modifier                 .fillMaxWidth()                 .padding(15.dp)                 .offset {                     IntOffset(0, currentImageSize.roundToPx())                 }         ) {             // Placeholder list items             items(100, key = { it }) {                 Text(                     text = "Item: $it",                     style = MaterialTheme.typography.bodyLarge                 )             }         }          Image(             painter = ColorPainter(Color.Red),             contentDescription = "Red color image",             Modifier                 .size(maxImageSize)                 .align(Alignment.TopCenter)                 .graphicsLayer {                     scaleX = imageScale                     scaleY = imageScale                     // Center the image vertically as it scales                     translationY = -(maxImageSize.toPx() - currentImageSize.toPx()) / 2f                 }         )     } }
AnimateImageSnippets.kt

<androidx.coordinatorlayout.widget.CoordinatorLayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     android:layout_width="match_parent"     android:layout_height="match_parent">      <com.google.android.material.appbar.AppBarLayout         android:id="@+id/app_bar"         android:layout_width="match_parent"         android:layout_height="100dp"         android:fitsSystemWindows="true">          <com.google.android.material.appbar.CollapsingToolbarLayout             android:id="@+id/collapsing_toolbar_layout"             android:layout_width="match_parent"             android:layout_height="match_parent"             android:fitsSystemWindows="true"             app:layout_scrollFlags="scroll|exitUntilCollapsed">              <!--...-->          </com.google.android.material.appbar.CollapsingToolbarLayout>      </com.google.android.material.appbar.AppBarLayout>      <androidx.compose.ui.platform.ComposeView         android:id="@+id/compose_view"         app:layout_behavior="@string/appbar_scrolling_view_behavior"         android:layout_width="match_parent"         android:layout_height="match_parent"/>  </androidx.coordinatorlayout.widget.CoordinatorLayout>
touchinput_gestures_nested_scroll_interop.xml

open class MainActivity : ComponentActivity() {     override fun onCreate(savedInstanceState: Bundle?) {         super.onCreate(savedInstanceState)         setContentView(R.layout.activity_main)         findViewById<ComposeView>(R.id.compose_view).apply {             setContent {                 val nestedScrollInterop = rememberNestedScrollInteropConnection()                 // Add the nested scroll connection to your top level @Composable element                 // using the nestedScroll modifier.                 LazyColumn(modifier = Modifier.nestedScroll(nestedScrollInterop)) {                     items(20) { item ->                         Box(                             modifier = Modifier                                 .padding(16.dp)                                 .height(56.dp)                                 .fillMaxWidth()                                 .background(Color.Gray),                             contentAlignment = Alignment.Center                         ) {                             Text(item.toString())                         }                     }                 }             }         }     } }
GesturesSnippets.kt

@Composable private fun NestedScrollInteropComposeParentWithAndroidChildExample() {     val toolbarHeightPx = with(LocalDensity.current) { ToolbarHeight.roundToPx().toFloat() }     val toolbarOffsetHeightPx = remember { mutableStateOf(0f) }      // Sets up the nested scroll connection between the Box composable parent     // and the child AndroidView containing the RecyclerView     val nestedScrollConnection = remember {         object : NestedScrollConnection {             override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {                 // Updates the toolbar offset based on the scroll to enable                 // collapsible behaviour                 val delta = available.y                 val newOffset = toolbarOffsetHeightPx.value + delta                 toolbarOffsetHeightPx.value = newOffset.coerceIn(-toolbarHeightPx, 0f)                 return Offset.Zero             }         }     }      Box(         Modifier             .fillMaxSize()             .nestedScroll(nestedScrollConnection)     ) {         TopAppBar(             modifier = Modifier                 .height(ToolbarHeight)                 .offset { IntOffset(x = 0, y = toolbarOffsetHeightPx.value.roundToInt()) }         )          AndroidView(             { context ->                 LayoutInflater.from(context)                     .inflate(R.layout.view_in_compose_nested_scroll_interop, null).apply {                         with(findViewById<RecyclerView>(R.id.main_list)) {                             layoutManager = LinearLayoutManager(context, VERTICAL, false)                             adapter = NestedScrollInteropAdapter()                         }                     }.also {                         // Nested scrolling interop is enabled when                         // nested scroll is enabled for the root View                         ViewCompat.setNestedScrollingEnabled(it, true)                     }             },             // ...         )     } }  private class NestedScrollInteropAdapter :     Adapter<NestedScrollInteropAdapter.NestedScrollInteropViewHolder>() {     val items = (1..10).map { it.toString() }      override fun onCreateViewHolder(         parent: ViewGroup,         viewType: Int     ): NestedScrollInteropViewHolder {         return NestedScrollInteropViewHolder(             LayoutInflater.from(parent.context)                 .inflate(R.layout.list_item, parent, false)         )     }      override fun onBindViewHolder(holder: NestedScrollInteropViewHolder, position: Int) {         // ...     }      class NestedScrollInteropViewHolder(view: View) : ViewHolder(view) {         fun bind(item: String) {             // ...         }     }     // ... } 

@Composable fun ViewInComposeNestedScrollInteropExample() {     Box(         Modifier             .fillMaxSize()             .scrollable(rememberScrollableState {                 // View component deltas should be reflected in Compose                 // components that participate in nested scrolling                 it             }, Orientation.Vertical)     ) {         AndroidView(             { context ->                 LayoutInflater.from(context)                     .inflate(android.R.layout.list_item, null)                     .apply {                         // Nested scrolling interop is enabled when                         // nested scroll is enabled for the root View                         ViewCompat.setNestedScrollingEnabled(this, true)                     }             }         )     } } 

class BottomSheetFragment : BottomSheetDialogFragment() {      override fun onCreateView(         inflater: LayoutInflater,         container: ViewGroup?,         savedInstanceState: Bundle?     ): View {         val rootView: View = inflater.inflate(R.layout.fragment_bottom_sheet, container, false)          rootView.findViewById<ComposeView>(R.id.compose_view).apply {             setContent {                 val nestedScrollInterop = rememberNestedScrollInteropConnection()                 LazyColumn(                     Modifier                         .nestedScroll(nestedScrollInterop)                         .fillMaxSize()                 ) {                     item {                         Text(text = "Bottom sheet title")                     }                     items(10) {                         Text(                             text = "List item number $it",                             modifier = Modifier.fillMaxWidth()                         )                     }                 }             }             return rootView         }     } }