Android: Make SettingViewHolder a LifecycleOwner

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/ui/SettingsAdapter.kt

@@ -16,6 +16,7 @@ import androidx.annotation.ColorInt
 import androidx.appcompat.app.AlertDialog
 import androidx.core.content.ContextCompat
 import androidx.fragment.app.FragmentActivity
+import androidx.lifecycle.Lifecycle
 import androidx.recyclerview.widget.RecyclerView
 import com.google.android.material.color.MaterialColors
 import com.google.android.material.datepicker.CalendarConstraints
@@ -543,6 +544,25 @@ class SettingsAdapter(
         }
     }
 
+    override fun onViewRecycled(holder: SettingViewHolder) {
+        super.onViewRecycled(holder)
+        holder.onViewRecycled()
+    }
+
+    override fun onViewAttachedToWindow(holder: SettingViewHolder) {
+        super.onViewAttachedToWindow(holder)
+        holder.onViewAttachedToWindow()
+    }
+
+    override fun onViewDetachedFromWindow(holder: SettingViewHolder) {
+        super.onViewDetachedFromWindow(holder)
+        holder.onViewDetachedFromWindow()
+    }
+
+    fun getFragmentLifecycle(): Lifecycle {
+        return fragmentView.getFragmentLifecycle()
+    }
+
     private fun getValueForSingleChoiceSelection(item: SingleChoiceSetting, which: Int): Int {
         val valuesId = item.valuesId
 

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/ui/SettingsFragment.kt

@@ -18,6 +18,7 @@ import androidx.core.view.updatePadding
 import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
+import androidx.lifecycle.Lifecycle
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import com.google.android.material.snackbar.Snackbar
@@ -25,7 +26,6 @@ import org.dolphinemu.dolphinemu.R
 import org.dolphinemu.dolphinemu.databinding.FragmentSettingsBinding
 import org.dolphinemu.dolphinemu.features.settings.model.Settings
 import org.dolphinemu.dolphinemu.features.settings.model.view.SettingsItem
-import org.dolphinemu.dolphinemu.ui.main.MainActivity
 import org.dolphinemu.dolphinemu.ui.main.MainPresenter
 import org.dolphinemu.dolphinemu.utils.GpuDriverInstallResult
 import org.dolphinemu.dolphinemu.utils.SerializableHelper.serializable
@@ -200,6 +200,10 @@ class SettingsFragment : Fragment(), SettingsFragmentView {
             .show()
     }
 
+    override fun getFragmentLifecycle(): Lifecycle {
+        return lifecycle
+    }
+
     private fun askForDriverFile() {
         val intent = Intent(Intent.ACTION_GET_CONTENT).apply {
             addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/ui/SettingsFragmentView.kt

@@ -4,6 +4,7 @@ package org.dolphinemu.dolphinemu.features.settings.ui
 
 import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.FragmentActivity
+import androidx.lifecycle.Lifecycle
 import org.dolphinemu.dolphinemu.features.settings.model.Settings
 import org.dolphinemu.dolphinemu.features.settings.model.view.SettingsItem
 import org.dolphinemu.dolphinemu.utils.GpuDriverInstallResult
@@ -119,4 +120,9 @@ interface SettingsFragmentView {
      * Shows a dialog asking the user to install or uninstall a GPU driver
      */
     fun showGpuDriverDialog()
+
+    /**
+     * Returns the Lifecycle for the Fragment.
+     */
+    fun getFragmentLifecycle(): Lifecycle
 }

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/ui/viewholder/SettingViewHolder.kt

@@ -9,15 +9,17 @@ import android.view.View
 import android.view.View.OnLongClickListener
 import android.widget.TextView
 import android.widget.Toast
-import androidx.recyclerview.widget.RecyclerView
+import androidx.lifecycle.LifecycleOwner
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import org.dolphinemu.dolphinemu.DolphinApplication
 import org.dolphinemu.dolphinemu.R
 import org.dolphinemu.dolphinemu.features.settings.model.view.SettingsItem
 import org.dolphinemu.dolphinemu.features.settings.ui.SettingsAdapter
+import org.dolphinemu.dolphinemu.utils.LifecycleViewHolder
 
 abstract class SettingViewHolder(itemView: View, protected val adapter: SettingsAdapter) :
-    RecyclerView.ViewHolder(itemView), View.OnClickListener, OnLongClickListener {
+    LifecycleViewHolder(itemView, adapter.getFragmentLifecycle()),
+    LifecycleOwner, View.OnClickListener, OnLongClickListener {
 
     init {
         itemView.setOnClickListener(this)

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/LifecycleViewHolder.kt

@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package org.dolphinemu.dolphinemu.utils
+
+import android.view.View
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.LifecycleRegistry
+import androidx.recyclerview.widget.RecyclerView
+
+/**
+ * A ViewHolder with an attached Lifecycle.
+ *
+ * @param itemView The view held by the ViewHolder.
+ * @param parentLifecycle If the passed-in Lifecycle changes state to DESTROYED, this ViewHolder
+ *                        will also change state to DESTROYED. This should normally be set to the
+ *                        Lifecycle of the containing Fragment or Activity to prevent instances
+ *                        of this class from leaking.
+ */
+abstract class LifecycleViewHolder(itemView: View, parentLifecycle: Lifecycle) :
+    RecyclerView.ViewHolder(itemView), LifecycleOwner {
+
+    private val lifecycleRegistry = LifecycleRegistry(this)
+
+    override val lifecycle: Lifecycle
+        get() = lifecycleRegistry
+
+    init {
+        lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE)
+        parentLifecycle.addObserver(object : DefaultLifecycleObserver {
+            override fun onDestroy(owner: LifecycleOwner) {
+                // Make sure this ViewHolder doesn't leak if its lifecycle has observers
+                lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_DESTROY)
+            }
+        })
+    }
+
+    /**
+     * To be called from a function overriding [RecyclerView.Adapter.onViewRecycled].
+     */
+    fun onViewRecycled() {
+        lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP)
+    }
+
+    /**
+     * To be called from a function overriding [RecyclerView.Adapter.onViewAttachedToWindow].
+     */
+    fun onViewAttachedToWindow() {
+        lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_RESUME)
+    }
+
+    /**
+     * To be called from a function overriding [RecyclerView.Adapter.onViewDetachedFromWindow].
+     */
+    fun onViewDetachedFromWindow() {
+        lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP)
+    }
+}