manager: change FAB visibility with scrolling gestures on module screen list

manager/app/src/main/java/com/rifsxd/ksunext/ui/screen/Module.kt

@@ -77,6 +77,12 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.animation.scaleIn
+import androidx.compose.animation.scaleOut
+import androidx.compose.animation.core.tween
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
@@ -164,6 +170,30 @@ fun ModuleScreen(navigator: DestinationsNavigator) {
         contract = ActivityResultContracts.StartActivityForResult()
     ) { viewModel.fetchModuleList() }
 
+    val listState = rememberLazyListState()
+    var showFab by remember { mutableStateOf(true) }
+
+    LaunchedEffect(listState) {
+        var lastIndex = listState.firstVisibleItemIndex
+        var lastOffset = listState.firstVisibleItemScrollOffset
+
+        snapshotFlow { listState.firstVisibleItemIndex to listState.firstVisibleItemScrollOffset }
+            .collect { (currIndex, currOffset) ->
+                val isScrollingDown = currIndex > lastIndex ||
+                    (currIndex == lastIndex && currOffset > lastOffset + 4)
+                val isScrollingUp = currIndex < lastIndex ||
+                    (currIndex == lastIndex && currOffset < lastOffset - 4)
+
+                when {
+                    isScrollingDown && showFab -> showFab = false
+                    isScrollingUp && !showFab -> showFab = true
+                }
+
+                lastIndex = currIndex
+                lastOffset = currOffset
+            }
+    }
+
     Scaffold(
         topBar = {
             SearchAppBar(
@@ -289,6 +319,17 @@ fun ModuleScreen(navigator: DestinationsNavigator) {
         },
         floatingActionButton = {
             if (!hideInstallButton) {
+                AnimatedVisibility(
+                    visible = showFab,
+                    enter = scaleIn(
+                        animationSpec = tween(200),
+                        initialScale = 0.8f
+                    ) + fadeIn(animationSpec = tween(400)),
+                    exit = scaleOut(
+                        animationSpec = tween(200),
+                        targetScale = 0.8f
+                    ) + fadeOut(animationSpec = tween(400))
+                ) {
                     val moduleInstall = stringResource(id = R.string.module_install)
                     val selectZipLauncher = rememberLauncherForActivityResult(
                         contract = ActivityResultContracts.StartActivityForResult()
@@ -330,6 +371,7 @@ fun ModuleScreen(navigator: DestinationsNavigator) {
                         text = { Text(text = moduleInstall) },
                     )
                 }
+            }
         },
         contentWindowInsets = WindowInsets.safeDrawing.only(WindowInsetsSides.Top + WindowInsetsSides.Horizontal),
         snackbarHost = { SnackbarHost(hostState = snackBarHost) }
@@ -370,7 +412,8 @@ fun ModuleScreen(navigator: DestinationsNavigator) {
                         }
                     },
                     context = context,
-                    snackBarHost = snackBarHost
+                    snackBarHost = snackBarHost,
+                    listState = listState
                 )
             }
         }
@@ -388,6 +431,7 @@ private fun ModuleList(
     onClickModule: (id: String, name: String, hasWebUi: Boolean) -> Unit,
     context: Context,
     snackBarHost: SnackbarHostState,
+    listState: LazyListState
 ) {
     val failedEnable = stringResource(R.string.module_failed_to_enable)
     val failedDisable = stringResource(R.string.module_failed_to_disable)
@@ -560,6 +604,7 @@ private fun ModuleList(
         isRefreshing = viewModel.isRefreshing
     ) {
         LazyColumn(
+            state = listState,
             modifier = modifier,
             verticalArrangement = Arrangement.spacedBy(16.dp),
             contentPadding = remember {
@@ -567,7 +612,7 @@ private fun ModuleList(
                     start = 16.dp,
                     top = 16.dp,
                     end = 16.dp,
-                    bottom = 16.dp + 56.dp + 16.dp + 48.dp + 6.dp /* Scaffold Fab Spacing + Fab container height + SnackBar height */
+                    bottom = 16.dp
                 )
             },
         ) {