feat: Collapse ExtendedFAB on scroll (#1630)

app/src/main/java/app/revanced/manager/ui/screen/PatchesSelectorScreen.kt

@@ -10,6 +10,7 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyListScope
 import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.foundation.pager.HorizontalPager
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.material.icons.Icons
@@ -69,6 +70,7 @@ import app.revanced.manager.ui.viewmodel.PatchesSelectorViewModel.Companion.SHOW
 import app.revanced.manager.ui.viewmodel.PatchesSelectorViewModel.Companion.SHOW_UNSUPPORTED
 import app.revanced.manager.util.Options
 import app.revanced.manager.util.PatchSelection
+import app.revanced.manager.util.isScrollingUp
 import kotlinx.coroutines.launch
 import org.koin.compose.rememberKoinInject
 
@@ -273,7 +275,7 @@ fun PatchesSelectorScreen(
         }
     }
 
-
+    val patchLazyListState = rememberLazyListState()
     Scaffold(
         topBar = {
             AppTopBar(
@@ -302,6 +304,7 @@ fun PatchesSelectorScreen(
             ExtendedFloatingActionButton(
                 text = { Text(stringResource(R.string.save)) },
                 icon = { Icon(Icons.Outlined.Save, null) },
+                expanded = patchLazyListState.isScrollingUp,
                 onClick = {
                     // TODO: only allow this if all required options have been set.
                     onSave(vm.getCustomSelection(), vm.getOptions())
@@ -344,7 +347,8 @@ fun PatchesSelectorScreen(
                     val bundle = bundles[index]
 
                     LazyColumnWithScrollbar(
-                        modifier = Modifier.fillMaxSize()
+                        modifier = Modifier.fillMaxSize(),
+                        state = patchLazyListState
                     ) {
                         patchList(
                             uid = bundle.uid,

app/src/main/java/app/revanced/manager/ui/screen/VersionSelectorScreen.kt

@@ -6,6 +6,8 @@ import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Check
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -32,11 +34,12 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import app.revanced.manager.R
 import app.revanced.manager.data.room.apps.installed.InstallType
 import app.revanced.manager.ui.component.AppTopBar
-import app.revanced.manager.ui.component.ColumnWithScrollbar
 import app.revanced.manager.ui.component.GroupHeader
+import app.revanced.manager.ui.component.LazyColumnWithScrollbar
 import app.revanced.manager.ui.component.LoadingIndicator
 import app.revanced.manager.ui.model.SelectedApp
 import app.revanced.manager.ui.viewmodel.VersionSelectorViewModel
+import app.revanced.manager.util.isScrollingUp
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -63,6 +66,7 @@ fun VersionSelectorScreen(
 
     var selectedVersion: SelectedApp? by rememberSaveable { mutableStateOf(null) }
 
+    val lazyListState = rememberLazyListState()
     Scaffold(
         topBar = {
             AppTopBar(
@@ -74,38 +78,47 @@ fun VersionSelectorScreen(
             ExtendedFloatingActionButton(
                 text = { Text(stringResource(R.string.select_version)) },
                 icon = { Icon(Icons.Default.Check, null) },
+                expanded = lazyListState.isScrollingUp,
                 onClick = { selectedVersion?.let(onAppClick) }
             )
         }
     ) { paddingValues ->
-        ColumnWithScrollbar(
+        LazyColumnWithScrollbar(
             modifier = Modifier
                 .padding(paddingValues)
                 .fillMaxSize(),
-            horizontalAlignment = Alignment.CenterHorizontally
+            horizontalAlignment = Alignment.CenterHorizontally,
+            state = lazyListState
         ) {
             viewModel.installedApp?.let { (packageInfo, installedApp) ->
                 SelectedApp.Installed(
                     packageName = viewModel.packageName,
                     version = packageInfo.versionName
                 ).let {
-                    SelectedAppItem(
-                        selectedApp = it,
-                        selected = selectedVersion == it,
-                        onClick = { selectedVersion = it },
-                        patchCount = supportedVersions[it.version],
-                        enabled =
+                    item {
+                        SelectedAppItem(
+                            selectedApp = it,
+                            selected = selectedVersion == it,
+                            onClick = { selectedVersion = it },
+                            patchCount = supportedVersions[it.version],
+                            enabled =
                             !(installedApp?.installType == InstallType.ROOT && !viewModel.rootInstaller.hasRootAccess()),
-                        alreadyPatched = installedApp != null && installedApp.installType != InstallType.ROOT
-                    )
+                            alreadyPatched = installedApp != null && installedApp.installType != InstallType.ROOT
+                        )
+                    }
                 }
             }
 
-            Row(Modifier.fillMaxWidth()) {
-                GroupHeader(stringResource(R.string.downloadable_versions))
+            item {
+                Row(Modifier.fillMaxWidth()) {
+                    GroupHeader(stringResource(R.string.downloadable_versions))
+                }
             }
 
-            list.forEach {
+            items(
+                items = list,
+                key = { it.packageName }
+            ) {
                 SelectedAppItem(
                     selectedApp = it,
                     selected = selectedVersion == it,
@@ -115,19 +128,23 @@ fun VersionSelectorScreen(
             }
 
             if (viewModel.errorMessage != null) {
-                Column(
-                    modifier = Modifier.fillMaxWidth(),
-                    horizontalAlignment = Alignment.CenterHorizontally
-                ) {
-                    Text(stringResource(R.string.error_occurred))
-                    Text(
-                        text = viewModel.errorMessage!!,
-                        modifier = Modifier.padding(horizontal = 15.dp)
-                    )
+                item {
+                    Column(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalAlignment = Alignment.CenterHorizontally
+                    ) {
+                        Text(stringResource(R.string.error_occurred))
+                        Text(
+                            text = viewModel.errorMessage!!,
+                            modifier = Modifier.padding(horizontal = 15.dp)
+                        )
+                    }
                 }
-            } else if (viewModel.isLoading)
-                LoadingIndicator()
-
+            } else if (viewModel.isLoading) {
+                item {
+                    LoadingIndicator()
+                }
+            }
         }
     }
 }

app/src/main/java/app/revanced/manager/util/Util.kt

@@ -11,6 +11,14 @@ import android.os.Build
 import android.util.Log
 import android.widget.Toast
 import androidx.annotation.StringRes
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.State
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.graphics.Color
 import androidx.core.net.toUri
 import androidx.lifecycle.Lifecycle
@@ -165,4 +173,25 @@ fun String.relativeTime(context: Context): String {
     } catch (e: DateTimeParseException) {
         return context.getString(R.string.invalid_date)
     }
-}
+}
+
+@Composable
+fun LazyListState.isScrollingUp(): State<Boolean> {
+    return remember(this) {
+        var previousIndex by mutableIntStateOf(firstVisibleItemIndex)
+        var previousScrollOffset by mutableIntStateOf(firstVisibleItemScrollOffset)
+
+        derivedStateOf {
+            if (previousIndex != firstVisibleItemIndex) {
+                previousIndex > firstVisibleItemIndex
+            } else {
+                previousScrollOffset >= firstVisibleItemScrollOffset
+            }.also {
+                previousIndex = firstVisibleItemIndex
+                previousScrollOffset = firstVisibleItemScrollOffset
+            }
+        }
+    }
+}
+
+val LazyListState.isScrollingUp: Boolean @Composable get() = this.isScrollingUp().value