bugfix: browse screen back button v3

Author: Lennoard

app/src/main/kotlin/com/androidvip/sysctlgui/ui/main/MainScreen.kt

@@ -1,5 +1,6 @@
 package com.androidvip.sysctlgui.ui.main
 
+import androidx.activity.compose.LocalOnBackPressedDispatcherOwner
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.expandVertically
 import androidx.compose.animation.fadeIn
@@ -52,6 +53,8 @@ private fun MainScreenContent(
     navController: NavHostController,
     snackbarHostState: SnackbarHostState
 ) {
+    val onBackPressedDispatcherOwner = LocalOnBackPressedDispatcherOwner.current
+
     Scaffold(
         topBar = {
             AnimatedVisibility(
@@ -65,7 +68,9 @@ private fun MainScreenContent(
                     showSearch = state.showSearchAction,
                     showBack = state.showBackButton,
                     onSearchPressed = { navController.navigate(UiRoute.Search) },
-                    onBackPressed = { navController.popBackStack() }
+                    onBackPressed = {
+                        onBackPressedDispatcherOwner?.onBackPressedDispatcher?.onBackPressed()
+                    }
                 )
             }
         },

app/src/main/kotlin/com/androidvip/sysctlgui/ui/params/browse/ParamBrowseScreen.kt

@@ -20,6 +20,10 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material.ExperimentalMaterialApi
+import androidx.compose.material.pullrefresh.PullRefreshIndicator
+import androidx.compose.material.pullrefresh.pullRefresh
+import androidx.compose.material.pullrefresh.rememberPullRefreshState
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
@@ -31,6 +35,7 @@ import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
@@ -57,13 +62,16 @@ import com.androidvip.sysctlgui.ui.main.MainViewModel
 import com.androidvip.sysctlgui.ui.main.MainViewState
 import com.androidvip.sysctlgui.ui.params.DocumentationBottomSheet
 import com.androidvip.sysctlgui.utils.browse
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.launch
 import org.koin.compose.viewmodel.koinViewModel
 import java.io.File
+import kotlin.time.Duration.Companion.seconds
 
-@OptIn(ExperimentalMaterial3Api::class)
+@OptIn(ExperimentalMaterialApi::class, ExperimentalMaterial3Api::class)
 @Composable
 fun ParamBrowseScreen(
     mainViewModel: MainViewModel = koinViewModel(),
@@ -115,7 +123,9 @@ fun ParamBrowseScreen(
         backEnabled = state.backEnabled,
         onBackPressed = {
             viewModel.onEvent(ParamBrowseViewEvent.BackRequested)
-        }
+        },
+        isRefreshing = state.loading,
+        onRefresh = { viewModel.onEvent(ParamBrowseViewEvent.RefreshRequested) }
     )
 
     documentation?.let {
@@ -126,6 +136,8 @@ fun ParamBrowseScreen(
     }
 }
 
+
+@OptIn(ExperimentalMaterialApi::class)
 @Composable
 private fun ParamBrowseScreenContent(
     params: List<UiKernelParam>,
@@ -135,8 +147,11 @@ private fun ParamBrowseScreenContent(
     onDocumentationClicked: (ParamDocumentation) -> Unit,
     backEnabled: Boolean = false,
     onBackPressed: () -> Unit,
+    isRefreshing: Boolean,
+    onRefresh: () -> Unit
 ) {
     val listState = rememberLazyListState()
+    val pullRefreshState = rememberPullRefreshState(refreshing = isRefreshing, onRefresh = onRefresh)
     var headerVisible by remember { mutableStateOf(backEnabled) }
 
     BackHandler(enabled = backEnabled, onBack = onBackPressed)
@@ -173,7 +188,11 @@ private fun ParamBrowseScreenContent(
 
     val finalHeaderVisible = (headerVisible || isAtTop) && backEnabled
 
-    Box(modifier = Modifier.fillMaxSize()) {
+    Box(
+        modifier = Modifier
+            .fillMaxSize()
+            .pullRefresh(pullRefreshState),
+    ) {
         val spacerHeight by animateDpAsState(if (finalHeaderVisible) 56.dp else 0.dp)
         LazyColumn(
             state = listState,
@@ -226,6 +245,14 @@ private fun ParamBrowseScreenContent(
                 onClicked = { onDocumentationClicked(documentation!!) }
             )
         }
+
+        PullRefreshIndicator(
+            refreshing = isRefreshing,
+            state = pullRefreshState,
+            modifier = Modifier.align(Alignment.TopCenter),
+            backgroundColor = MaterialTheme.colorScheme.surfaceContainerHighest,
+            contentColor = MaterialTheme.colorScheme.tertiary
+        )
     }
 }
 
@@ -287,6 +314,8 @@ internal fun ParamBrowseScreenContentPreview() {
     var params by remember(currentPath) {
         mutableStateOf(mapFilesToParams(File(currentPath).listFiles()))
     }
+    var isRefreshingPreview by remember { mutableStateOf(false) }
+    val scope = rememberCoroutineScope()
 
     SysctlGuiTheme(dynamicColor = true) {
         Box(modifier = Modifier.background(MaterialTheme.colorScheme.background)) {
@@ -307,6 +336,14 @@ internal fun ParamBrowseScreenContentPreview() {
                 onDocumentationClicked = {},
                 backEnabled = currentPath != root.path,
                 onBackPressed = { currentPath = File(currentPath).parent ?: root.path },
+                isRefreshing = isRefreshingPreview,
+                onRefresh = {
+                    scope.launch {
+                        isRefreshingPreview = true
+                        delay(2.seconds)
+                        isRefreshingPreview = false
+                    }
+                }
             )
         }
     }

app/src/main/kotlin/com/androidvip/sysctlgui/ui/params/browse/ParamBrowseState.kt

@@ -4,6 +4,7 @@ import com.androidvip.sysctlgui.domain.models.ParamDocumentation
 import com.androidvip.sysctlgui.models.UiKernelParam
 
 data class ParamBrowseState(
+    val loading: Boolean = false,
     val params: List<UiKernelParam> = emptyList(),
     val currentPath: String = "",
     val backEnabled: Boolean = false,
@@ -20,4 +21,5 @@ sealed interface ParamBrowseViewEvent {
     data class ParamClicked(val param: UiKernelParam) : ParamBrowseViewEvent
     data class DocumentationClicked(val docs: ParamDocumentation) : ParamBrowseViewEvent
     object BackRequested : ParamBrowseViewEvent
+    object RefreshRequested : ParamBrowseViewEvent
 }

app/src/main/kotlin/com/androidvip/sysctlgui/ui/params/browse/ParamBrowseViewModel.kt

@@ -27,13 +27,15 @@ class ParamBrowseViewModel(
 
     init {
         viewModelScope.launch {
+            setState { copy(loading = true) }
             val startingDirectory = File(Consts.PROC_SYS)
             val params = getParams(startingDirectory)
 
             setState {
                 copy(
                     params = params,
-                    currentPath = startingDirectory.absolutePath
+                    currentPath = startingDirectory.absolutePath,
+                    loading = false
                 )
             }
         }
@@ -47,11 +49,20 @@ class ParamBrowseViewModel(
 
             ParamBrowseViewEvent.BackRequested -> onBackRequested()
             is ParamBrowseViewEvent.ParamClicked -> onParamClicked(event.param)
+            ParamBrowseViewEvent.RefreshRequested -> handleRefreshRequested()
         }
     }
 
+    private fun handleRefreshRequested() {
+        val currentPath = currentState.currentPath
+        if (currentPath == Consts.PROC_SYS) return
+
+        fetchChildParams(currentPath)
+    }
+
     private fun fetchChildParams(parentParam: UiKernelParam) {
         viewModelScope.launch {
+            setState { copy(loading = true) }
             runCatching {
                 val newParamsDeferred = async { getParams(File(parentParam.path)) }
                 val directoryDocumentationDeferred = async { getParamDocumentation(parentParam) }
@@ -64,11 +75,13 @@ class ParamBrowseViewModel(
                         params = newParams,
                         currentPath = parentParam.path,
                         backEnabled = parentParam.path != Consts.PROC_SYS,
-                        documentation = directoryDocumentation
+                        documentation = directoryDocumentation,
+                        loading = false
                     )
                 }
             }.onFailure {
                 setEffect { ParamBrowseViewEffect.ShowError(it.message ?: "Unknown error") }
+                setState { copy(loading = false) }
             }
         }
     }