fix: weird double push navigation bug

The "Add Install" button was somehow able to push a screen with the same key onto the stack twice, messing up model retrieval downstream.

app/src/main/kotlin/com/aliucord/manager/ui/components/BackButton.kt

@@ -1,29 +1,27 @@
 package com.aliucord.manager.ui.components
 
-import android.app.Activity
 import androidx.activity.compose.LocalActivity
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.platform.LocalInspectionMode
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import cafe.adriel.voyager.navigator.LocalNavigator
-import cafe.adriel.voyager.navigator.Navigator
 import com.aliucord.manager.R
-import com.aliucord.manager.ui.screens.home.HomeScreen
+import com.aliucord.manager.util.back
 
 /**
  * Standalone back button for interacting with the current navigator.
  */
 @Composable
 fun BackButton() {
-    // Support rendering in @Preview
-    val context = if (LocalInspectionMode.current) null else LocalActivity.current
     val navigator = LocalNavigator.current
+    val activity = LocalActivity.current
 
     IconButton(
-        onClick = { if (context != null) navigator?.back(context) },
+        onClick = {
+            navigator?.back(activity)
+        },
     ) {
         Icon(
             painter = painterResource(R.drawable.ic_back),
@@ -31,20 +29,3 @@ fun BackButton() {
         )
     }
 }
-
-/**
- * Custom back logic for handling special screens differently.
- * If on Home, Landing, or Debug then exit immediately otherwise go back one.
- */
-fun Navigator.back(currentActivity: Activity?) {
-    val top = this.lastItemOrNull ?: return
-    val stackSize = this.items.size
-
-    if (stackSize > 1) {
-        pop()
-    } else if (top is HomeScreen) {
-        currentActivity?.finish()
-    } else {
-        replaceAll(HomeScreen())
-    }
-}

app/src/main/kotlin/com/aliucord/manager/ui/screens/home/HomeScreen.kt

@@ -34,6 +34,7 @@ import com.aliucord.manager.ui.screens.plugins.PluginsScreen
 import com.aliucord.manager.ui.util.DiscordVersion
 import com.aliucord.manager.ui.util.paddings.PaddingValuesSides
 import com.aliucord.manager.ui.util.paddings.exclude
+import com.aliucord.manager.util.pushOnce
 import kotlinx.coroutines.launch
 import kotlinx.parcelize.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
@@ -48,7 +49,6 @@ class HomeScreen : Screen, Parcelable {
         val navigator = LocalNavigator.currentOrThrow
         val scope = rememberCoroutineScope()
         val model = koinScreenModel<HomeModel>()
-        val onClickInstall = remember { { navigator.push(PatchOptionsScreen()) } }
 
         // Refresh installations list when the screen changes or activity resumes
         LifecycleResumeEffect(Unit) {
@@ -65,7 +65,7 @@ class HomeScreen : Screen, Parcelable {
                     state = state,
                     supportedVersion = model.supportedVersion,
                     padding = padding,
-                    onClickInstall = onClickInstall,
+                    onClickInstall = { navigator.pushOnce(PatchOptionsScreen()) },
                     onUpdate = {
                         scope.launch {
                             navigator.push(model.createPrefilledPatchOptsScreen(it))
@@ -80,7 +80,7 @@ class HomeScreen : Screen, Parcelable {
 
                 InstallsState.None -> HomeScreenNoneContent(
                     padding = padding,
-                    onClickInstall = onClickInstall,
+                    onClickInstall = { navigator.pushOnce(PatchOptionsScreen()) },
                 )
 
                 InstallsState.Error -> HomeScreenFailureContent(padding = padding)

app/src/main/kotlin/com/aliucord/manager/ui/screens/iconopts/IconOptionsScreen.kt

@@ -23,35 +23,36 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import cafe.adriel.voyager.core.screen.Screen
+import cafe.adriel.voyager.koin.koinScreenModel
+import cafe.adriel.voyager.navigator.LocalNavigator
+import cafe.adriel.voyager.navigator.currentOrThrow
 import coil3.compose.AsyncImage
 import com.aliucord.manager.R
 import com.aliucord.manager.ui.components.*
 import com.aliucord.manager.ui.screens.iconopts.components.*
+import com.aliucord.manager.ui.screens.patchopts.PatchOptionsScreen
 import com.aliucord.manager.ui.util.ColorSaver
 import dev.zt64.compose.pipette.CircularColorPicker
 import dev.zt64.compose.pipette.HsvColor
 import kotlinx.parcelize.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
 
-interface IconOptionsScreenParent : Parcelable {
-    /**
-     * The screen model is elevated outside of this screen
-     * in order to share the state with the parent screen.
-     */
-    @Composable
-    fun getIconModel(): IconOptionsModel
-}
-
 @Parcelize
-class IconOptionsScreen(
-    private val parent: IconOptionsScreenParent,
-) : Screen, Parcelable {
+class IconOptionsScreen : Screen, Parcelable {
     @IgnoredOnParcel
     override val key = "IconOptions"
 
     @Composable
     override fun Content() {
-        val model = parent.getIconModel()
+        // Retrieves a global model owned by the navigator
+        val navigator = LocalNavigator.currentOrThrow
+        val modelScreen by remember {
+            derivedStateOf {
+                navigator.items.lastOrNull { it is PatchOptionsScreen }
+                    ?: error("No PatchOptionsScreen in stack")
+            }
+        }
+        val model = modelScreen.koinScreenModel<IconOptionsModel>() // Parameters are already injected in PatchOptionsScreen
 
         IconOptionsScreenContent(
             mode = model.mode,

app/src/main/kotlin/com/aliucord/manager/ui/screens/log/LogScreen.kt

@@ -16,9 +16,9 @@ import cafe.adriel.voyager.navigator.currentOrThrow
 import com.aliucord.manager.R
 import com.aliucord.manager.manager.InstallLogData
 import com.aliucord.manager.ui.components.Label
-import com.aliucord.manager.ui.components.back
 import com.aliucord.manager.ui.screens.log.components.LogAppBar
 import com.aliucord.manager.ui.screens.log.components.LogTextArea
+import com.aliucord.manager.util.back
 import kotlinx.parcelize.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
 import org.koin.core.parameter.parametersOf

app/src/main/kotlin/com/aliucord/manager/ui/screens/patching/PatchingScreen.kt

@@ -38,6 +38,7 @@ import com.aliucord.manager.ui.screens.patchopts.PatchOptions
 import com.aliucord.manager.ui.util.paddings.*
 import com.aliucord.manager.ui.util.spacedByLastAtBottom
 import com.aliucord.manager.ui.util.thenIf
+import com.aliucord.manager.util.back
 import com.aliucord.manager.util.isIgnoringBatteryOptimizations
 import kotlinx.collections.immutable.persistentListOf
 import kotlinx.coroutines.flow.filter

app/src/main/kotlin/com/aliucord/manager/ui/screens/patchopts/PatchOptionsScreen.kt

@@ -22,7 +22,8 @@ import com.aliucord.manager.R
 import com.aliucord.manager.ui.components.TextDivider
 import com.aliucord.manager.ui.components.dialogs.NetworkWarningDialog
 import com.aliucord.manager.ui.components.dialogs.UnknownSourcesPermissionDialog
-import com.aliucord.manager.ui.screens.iconopts.*
+import com.aliucord.manager.ui.screens.iconopts.IconOptionsModel
+import com.aliucord.manager.ui.screens.iconopts.IconOptionsScreen
 import com.aliucord.manager.ui.screens.patching.PatchingScreen
 import com.aliucord.manager.ui.screens.patchopts.components.PackageNameStateLabel
 import com.aliucord.manager.ui.screens.patchopts.components.PatchOptionsAppBar
@@ -39,15 +40,10 @@ import org.koin.core.parameter.parametersOf
 @Parcelize
 class PatchOptionsScreen(
     private val prefilledOptions: PatchOptions? = null,
-) : Screen, Parcelable, IconOptionsScreenParent {
+) : Screen, Parcelable {
     @IgnoredOnParcel
     override val key = "PatchOptions"
 
-    @Composable
-    override fun getIconModel(): IconOptionsModel {
-        return koinScreenModel<IconOptionsModel>()
-    }
-
     @Composable
     override fun Content() {
         val context = LocalContext.current
@@ -85,7 +81,7 @@ class PatchOptionsScreen(
             debuggable = model.debuggable,
             setDebuggable = model::changeDebuggable,
 
-            onOpenIconOptions = { navigator.push(IconOptionsScreen(this@PatchOptionsScreen)) },
+            onOpenIconOptions = { navigator.push(IconOptionsScreen()) },
 
             appName = model.appName,
             appNameIsError = model.appNameIsError,

app/src/main/kotlin/com/aliucord/manager/util/Navigation.kt

@@ -0,0 +1,33 @@
+package com.aliucord.manager.util
+
+import android.app.Activity
+import cafe.adriel.voyager.core.screen.Screen
+import cafe.adriel.voyager.core.stack.Stack
+import com.aliucord.manager.ui.screens.home.HomeScreen
+
+/**
+ * Custom back logic for handling special screens differently.
+ * If on Home, Landing, or Debug then exit immediately otherwise go back one.
+ */
+fun Stack<Screen>.back(currentActivity: Activity?) {
+    val top = this.lastItemOrNull ?: return
+    val stackSize = this.items.size
+
+    if (stackSize > 1) {
+        pop()
+    } else if (top is HomeScreen) {
+        currentActivity?.finish()
+    } else {
+        replaceAll(HomeScreen())
+    }
+}
+
+/**
+ * Workaround for an issue where a button can push a screen with the same key twice onto the stack.
+ * https://github.com/adrielcafe/voyager/issues/474#issuecomment-2907701009
+ */
+infix fun Stack<Screen>.pushOnce(item: Screen) {
+    if (lastItemOrNull?.key != item.key) {
+        push(item)
+    }
+}