coroutines: use lifecycleScope where appropriate

There's still a bit of GlobalScope lingering around, which might be
removable.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

build.gradle

@@ -10,16 +10,17 @@ buildscript {
         coordinatorLayoutVersion = '1.1.0'
         coreKtxVersion = '1.3.1'
         coroutinesVersion = '1.3.9'
+        desugarVersion = '1.0.10'
         eddsaVersion = '0.3.0'
         fragmentVersion = '1.2.5'
         jsr305Version = '3.0.2'
         junitVersion = '4.13'
         kotlinVersion = '1.4.10'
+        lifecycleRuntimeKtxVersion = '2.3.0-alpha07'
         materialComponentsVersion = '22973ff10305397bfc72fed41684175fee8aeefb'
         mavenPluginVersion = '2.1'
         preferenceVersion = '1.1.1'
         zxingEmbeddedVersion = '3.6.0'
-        desugarVersion = '1.0.10'
 
         groupName = 'com.wireguard.android'
     }

ui/build.gradle

@@ -66,6 +66,7 @@ dependencies {
     implementation "androidx.databinding:databinding-runtime:$agpVersion"
     implementation "androidx.fragment:fragment-ktx:$fragmentVersion"
     implementation "androidx.preference:preference-ktx:$preferenceVersion"
+    implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycleRuntimeKtxVersion"
     implementation "com.github.material-components:material-components-android:$materialComponentsVersion"
     implementation "com.journeyapps:zxing-android-embedded:$zxingEmbeddedVersion"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutinesVersion"

ui/src/main/java/com/wireguard/android/activity/BaseActivity.kt

@@ -7,10 +7,10 @@ package com.wireguard.android.activity
 import android.os.Bundle
 import androidx.databinding.CallbackRegistry
 import androidx.databinding.CallbackRegistry.NotifierCallback
+import androidx.lifecycle.lifecycleScope
 import com.wireguard.android.Application
 import com.wireguard.android.model.ObservableTunnel
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 
 /**
@@ -39,7 +39,7 @@ abstract class BaseActivity : ThemeChangeAwareActivity() {
             else -> null
         }
         if (savedTunnelName != null)
-            GlobalScope.launch(Dispatchers.Main.immediate) { selectedTunnel = Application.getTunnelManager().getTunnels()[savedTunnelName] }
+            lifecycleScope.launch(Dispatchers.Main.immediate) { selectedTunnel = Application.getTunnelManager().getTunnels()[savedTunnelName] }
 
         // The selected tunnel must be set before the superclass method recreates fragments.
         super.onCreate(savedInstanceState)

ui/src/main/java/com/wireguard/android/activity/LogViewerActivity.kt

@@ -26,6 +26,7 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.app.ShareCompat
+import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
@@ -40,10 +41,7 @@ import com.wireguard.android.widget.EdgeToEdge.setUpFAB
 import com.wireguard.android.widget.EdgeToEdge.setUpRoot
 import com.wireguard.android.widget.EdgeToEdge.setUpScrollingContent
 import com.wireguard.crypto.KeyPair
-import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.cancel
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.io.BufferedReader
@@ -68,7 +66,6 @@ class LogViewerActivity : AppCompatActivity() {
     private var rawLogLines = StringBuffer()
     private var recyclerView: RecyclerView? = null
     private var saveButton: MenuItem? = null
-    private val logStreamingScope = CoroutineScope(Dispatchers.IO)
     private val year by lazy {
         val yearFormatter: DateFormat = SimpleDateFormat("yyyy", Locale.US)
         yearFormatter.format(Date())
@@ -115,7 +112,7 @@ class LogViewerActivity : AppCompatActivity() {
             addItemDecoration(DividerItemDecoration(context, LinearLayoutManager.VERTICAL))
         }
 
-        logStreamingScope.launch { streamingLog() }
+        lifecycleScope.launch(Dispatchers.IO) { streamingLog() }
 
         binding.shareFab.setOnClickListener {
             revokeLastUri()
@@ -136,7 +133,6 @@ class LogViewerActivity : AppCompatActivity() {
 
     override fun onDestroy() {
         super.onDestroy()
-        logStreamingScope.cancel()
     }
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
@@ -159,7 +155,7 @@ class LogViewerActivity : AppCompatActivity() {
                 true
             }
             R.id.save_log -> {
-                GlobalScope.launch { saveLog() }
+                lifecycleScope.launch(Dispatchers.IO) { saveLog() }
                 true
             }
             else -> super.onOptionsItemSelected(item)

ui/src/main/java/com/wireguard/android/activity/SettingsActivity.kt

@@ -12,6 +12,7 @@ import android.util.SparseArray
 import android.view.MenuItem
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
+import androidx.lifecycle.lifecycleScope
 import androidx.preference.Preference
 import androidx.preference.PreferenceFragmentCompat
 import com.wireguard.android.Application
@@ -20,7 +21,6 @@ import com.wireguard.android.backend.WgQuickBackend
 import com.wireguard.android.util.AdminKnobs
 import com.wireguard.android.util.ModuleLoader
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.util.ArrayList
@@ -102,7 +102,7 @@ class SettingsActivity : ThemeChangeAwareActivity() {
                     preferenceManager.findPreference<Preference>("multiple_tunnels")
             ).filterNotNull()
             wgQuickOnlyPrefs.forEach { it.isVisible = false }
-            GlobalScope.launch(Dispatchers.Main.immediate) {
+            lifecycleScope.launch(Dispatchers.Main.immediate) {
                 if (Application.getBackend() is WgQuickBackend) {
                     ++preferenceScreen.initialExpandedChildrenCount
                     wgQuickOnlyPrefs.forEach { it.isVisible = true }
@@ -121,7 +121,7 @@ class SettingsActivity : ThemeChangeAwareActivity() {
                 moduleInstaller?.parent?.removePreference(moduleInstaller)
             } else {
                 kernelModuleDisabler?.parent?.removePreference(kernelModuleDisabler)
-                GlobalScope.launch(Dispatchers.Main.immediate) {
+                lifecycleScope.launch(Dispatchers.Main.immediate) {
                     try {
                         withContext(Dispatchers.IO) { Application.getRootShell().start() }
                         moduleInstaller?.isVisible = true

ui/src/main/java/com/wireguard/android/activity/TunnelToggleActivity.kt

@@ -12,13 +12,13 @@ import android.util.Log
 import android.widget.Toast
 import androidx.annotation.RequiresApi
 import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.lifecycleScope
 import com.wireguard.android.Application
 import com.wireguard.android.QuickTileService
 import com.wireguard.android.R
 import com.wireguard.android.backend.Tunnel
 import com.wireguard.android.util.ErrorMessages
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 
 @RequiresApi(Build.VERSION_CODES.N)
@@ -26,7 +26,7 @@ class TunnelToggleActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         val tunnel = Application.getTunnelManager().lastUsedTunnel ?: return
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 tunnel.setStateAsync(Tunnel.State.TOGGLE)
             } catch (e: Throwable) {

ui/src/main/java/com/wireguard/android/fragment/AppListDialogFragment.kt

@@ -13,6 +13,7 @@ import androidx.appcompat.app.AlertDialog
 import androidx.databinding.Observable
 import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.lifecycleScope
 import com.google.android.material.tabs.TabLayout
 import com.wireguard.android.BR
 import com.wireguard.android.R
@@ -22,7 +23,6 @@ import com.wireguard.android.model.ApplicationData
 import com.wireguard.android.util.ErrorMessages
 import com.wireguard.android.util.requireTargetFragment
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
@@ -36,7 +36,7 @@ class AppListDialogFragment : DialogFragment() {
     private fun loadData() {
         val activity = activity ?: return
         val pm = activity.packageManager
-        GlobalScope.launch(Dispatchers.Default) {
+        lifecycleScope.launch(Dispatchers.Default) {
             try {
                 val applicationData: MutableList<ApplicationData> = ArrayList()
                 withContext(Dispatchers.IO) {

ui/src/main/java/com/wireguard/android/fragment/BaseFragment.kt

@@ -12,6 +12,7 @@ import android.widget.Toast
 import androidx.databinding.DataBindingUtil
 import androidx.databinding.ViewDataBinding
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.lifecycleScope
 import com.google.android.material.snackbar.Snackbar
 import com.wireguard.android.Application
 import com.wireguard.android.R
@@ -24,7 +25,6 @@ import com.wireguard.android.databinding.TunnelListItemBinding
 import com.wireguard.android.model.ObservableTunnel
 import com.wireguard.android.util.ErrorMessages
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 
 /**
@@ -72,7 +72,7 @@ abstract class BaseFragment : Fragment(), OnSelectedTunnelChangedListener {
             is TunnelListItemBinding -> binding.item
             else -> return
         } ?: return
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             if (Application.getBackend() is GoBackend) {
                 val intent = GoBackend.VpnService.prepare(view.context)
                 if (intent != null) {
@@ -87,7 +87,7 @@ abstract class BaseFragment : Fragment(), OnSelectedTunnelChangedListener {
     }
 
     private fun setTunnelStateWithPermissionsResult(tunnel: ObservableTunnel, checked: Boolean) {
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 tunnel.setStateAsync(Tunnel.State.of(checked))
             } catch (e: Throwable) {

ui/src/main/java/com/wireguard/android/fragment/ConfigNamingDialogFragment.kt

@@ -11,13 +11,13 @@ import android.os.Bundle
 import android.view.inputmethod.InputMethodManager
 import androidx.appcompat.app.AlertDialog
 import androidx.fragment.app.DialogFragment
+import androidx.lifecycle.lifecycleScope
 import com.wireguard.android.Application
 import com.wireguard.android.R
 import com.wireguard.android.databinding.ConfigNamingDialogFragmentBinding
 import com.wireguard.config.BadConfigException
 import com.wireguard.config.Config
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import java.io.ByteArrayInputStream
 import java.io.IOException
@@ -31,7 +31,7 @@ class ConfigNamingDialogFragment : DialogFragment() {
     private fun createTunnelAndDismiss() {
         binding?.let {
             val name = it.tunnelNameText.text.toString()
-            GlobalScope.launch(Dispatchers.Main.immediate) {
+            lifecycleScope.launch(Dispatchers.Main.immediate) {
                 try {
                     Application.getTunnelManager().create(name, config)
                     dismiss()

ui/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.kt

@@ -11,6 +11,7 @@ import android.view.MenuInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.databinding.DataBindingUtil
+import androidx.lifecycle.lifecycleScope
 import com.wireguard.android.R
 import com.wireguard.android.backend.Tunnel
 import com.wireguard.android.databinding.TunnelDetailFragmentBinding
@@ -19,7 +20,6 @@ import com.wireguard.android.model.ObservableTunnel
 import com.wireguard.android.widget.EdgeToEdge.setUpRoot
 import com.wireguard.android.widget.EdgeToEdge.setUpScrollingContent
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import java.util.Timer
 import java.util.TimerTask
@@ -82,7 +82,7 @@ class TunnelDetailFragment : BaseFragment() {
     override fun onSelectedTunnelChanged(oldTunnel: ObservableTunnel?, newTunnel: ObservableTunnel?) {
         binding ?: return
         binding!!.tunnel = newTunnel
-        if (newTunnel == null) binding!!.config = null else GlobalScope.launch(Dispatchers.Main.immediate) {
+        if (newTunnel == null) binding!!.config = null else lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 binding!!.config = newTunnel.getConfigAsync()
             } catch (_: Throwable) {
@@ -114,7 +114,7 @@ class TunnelDetailFragment : BaseFragment() {
         val state = tunnel.state
         if (state != Tunnel.State.UP && lastState == state) return
         lastState = state
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 val statistics = tunnel.getStatisticsAsync()
                 for (i in 0 until binding!!.peersLayout.childCount) {

ui/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.kt

@@ -18,6 +18,7 @@ import android.view.WindowManager
 import android.view.inputmethod.InputMethodManager
 import android.widget.EditText
 import android.widget.Toast
+import androidx.lifecycle.lifecycleScope
 import com.google.android.material.snackbar.Snackbar
 import com.wireguard.android.Application
 import com.wireguard.android.R
@@ -33,7 +34,6 @@ import com.wireguard.android.widget.EdgeToEdge.setUpRoot
 import com.wireguard.android.widget.EdgeToEdge.setUpScrollingContent
 import com.wireguard.config.Config
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 
 /**
@@ -141,7 +141,7 @@ class TunnelEditorFragment : BaseFragment(), AppSelectionListener {
                 Snackbar.make(binding!!.mainContainer, error, Snackbar.LENGTH_LONG).show()
                 return false
             }
-            GlobalScope.launch(Dispatchers.Main.immediate) {
+            lifecycleScope.launch(Dispatchers.Main.immediate) {
                 when {
                     tunnel == null -> {
                         Log.d(TAG, "Attempting to create new tunnel " + binding!!.name)
@@ -205,7 +205,7 @@ class TunnelEditorFragment : BaseFragment(), AppSelectionListener {
         binding!!.config = ConfigProxy()
         if (tunnel != null) {
             binding!!.name = tunnel!!.name
-            GlobalScope.launch(Dispatchers.Main.immediate) {
+            lifecycleScope.launch(Dispatchers.Main.immediate) {
                 try {
                     onConfigLoaded(tunnel!!.getConfigAsync())
                 } catch (_: Throwable) {
@@ -242,7 +242,7 @@ class TunnelEditorFragment : BaseFragment(), AppSelectionListener {
             Log.d(TAG, message)
             // Now save the rest of configuration changes.
             Log.d(TAG, "Attempting to save config of renamed tunnel " + tunnel!!.name)
-            GlobalScope.launch(Dispatchers.Main.immediate) {
+            lifecycleScope.launch(Dispatchers.Main.immediate) {
                 try {
                     renamedTunnel.setConfigAsync(newConfig)
                     onConfigSaved(renamedTunnel, null)

ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.kt

@@ -21,6 +21,7 @@ import android.view.animation.Animation
 import android.view.animation.AnimationUtils
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.view.ActionMode
+import androidx.lifecycle.lifecycleScope
 import com.google.android.material.snackbar.Snackbar
 import com.google.zxing.integration.android.IntentIntegrator
 import com.wireguard.android.Application
@@ -38,7 +39,6 @@ import com.wireguard.android.widget.MultiselectableRelativeLayout
 import com.wireguard.config.Config
 import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
@@ -74,7 +74,7 @@ class TunnelListFragment : BaseFragment() {
     }
 
     private fun importTunnel(uri: Uri?) {
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             withContext(Dispatchers.IO) {
                 val activity = activity
                 if (activity == null || uri == null) {
@@ -221,7 +221,7 @@ class TunnelListFragment : BaseFragment() {
 
     override fun onSelectedTunnelChanged(oldTunnel: ObservableTunnel?, newTunnel: ObservableTunnel?) {
         binding ?: return
-        GlobalScope.launch(Dispatchers.Main) {
+        lifecycleScope.launch(Dispatchers.Main) {
             val tunnels = Application.getTunnelManager().getTunnels()
             if (newTunnel != null) viewForTunnel(newTunnel, tunnels).setSingleSelected(true)
             if (oldTunnel != null) viewForTunnel(oldTunnel, tunnels).setSingleSelected(false)
@@ -264,7 +264,7 @@ class TunnelListFragment : BaseFragment() {
         super.onViewStateRestored(savedInstanceState)
         binding ?: return
         binding!!.fragment = this
-        GlobalScope.launch(Dispatchers.Main.immediate) { binding!!.tunnels = Application.getTunnelManager().getTunnels() }
+        lifecycleScope.launch(Dispatchers.Main.immediate) { binding!!.tunnels = Application.getTunnelManager().getTunnels() }
         binding!!.rowConfigurationHandler = object : RowConfigurationHandler<TunnelListItemBinding, ObservableTunnel> {
             override fun onConfigureRow(binding: TunnelListItemBinding, item: ObservableTunnel, position: Int) {
                 binding.fragment = this@TunnelListFragment
@@ -316,7 +316,7 @@ class TunnelListFragment : BaseFragment() {
                         scaleX = 1f
                         scaleY = 1f
                     }
-                    GlobalScope.launch(Dispatchers.Main.immediate) {
+                    lifecycleScope.launch(Dispatchers.Main.immediate) {
                         try {
                             val tunnels = Application.getTunnelManager().getTunnels()
                             val tunnelsToDelete = ArrayList<ObservableTunnel>()
@@ -332,7 +332,7 @@ class TunnelListFragment : BaseFragment() {
                     true
                 }
                 R.id.menu_action_select_all -> {
-                    GlobalScope.launch(Dispatchers.Main.immediate) {
+                    lifecycleScope.launch(Dispatchers.Main.immediate) {
                         val tunnels = Application.getTunnelManager().getTunnels()
                         for (i in 0 until tunnels.size) {
                             setItemChecked(i, true)

ui/src/main/java/com/wireguard/android/preference/KernelModuleDisablerPreference.kt

@@ -15,8 +15,8 @@ import com.wireguard.android.R
 import com.wireguard.android.activity.SettingsActivity
 import com.wireguard.android.backend.Tunnel
 import com.wireguard.android.backend.WgQuickBackend
+import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
@@ -28,7 +28,7 @@ class KernelModuleDisablerPreference(context: Context, attrs: AttributeSet?) : P
     private var state = State.UNKNOWN
     init {
         isVisible = false
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             setState(if (Application.getBackend() is WgQuickBackend) State.ENABLED else State.DISABLED)
         }
     }
@@ -46,7 +46,7 @@ class KernelModuleDisablerPreference(context: Context, attrs: AttributeSet?) : P
             setState(State.DISABLING)
             Application.getSharedPreferences().edit().putBoolean("disable_kernel_module", true).commit()
         }
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             val observableTunnels = Application.getTunnelManager().getTunnels()
                 val downings = observableTunnels.map { async(SupervisorJob()) { it.setStateAsync(Tunnel.State.DOWN) } }
             try {

ui/src/main/java/com/wireguard/android/preference/ModuleDownloaderPreference.kt

@@ -15,8 +15,8 @@ import com.wireguard.android.Application
 import com.wireguard.android.R
 import com.wireguard.android.activity.SettingsActivity
 import com.wireguard.android.util.ErrorMessages
+import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlin.system.exitProcess
@@ -30,21 +30,19 @@ class ModuleDownloaderPreference(context: Context, attrs: AttributeSet?) : Prefe
     @SuppressLint("ApplySharedPref")
     override fun onClick() {
         setState(State.WORKING)
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 when (withContext(Dispatchers.IO) { Application.getModuleLoader().download() }) {
                     OsConstants.ENOENT -> setState(State.NOTFOUND)
                     OsConstants.EXIT_SUCCESS -> {
                         setState(State.SUCCESS)
                         Application.getSharedPreferences().edit().remove("disable_kernel_module").commit()
-                        GlobalScope.launch(Dispatchers.Main.immediate) {
+                        withContext(Dispatchers.IO) {
-                            withContext(Dispatchers.IO) {
+                            val restartIntent = Intent(context, SettingsActivity::class.java)
-                                val restartIntent = Intent(context, SettingsActivity::class.java)
+                            restartIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
-                                restartIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
+                            restartIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
-                                restartIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+                            Application.get().startActivity(restartIntent)
-                                Application.get().startActivity(restartIntent)
+                            exitProcess(0)
-                                exitProcess(0)
-                            }
                         }
                     }
                     else -> setState(State.FAILURE)

ui/src/main/java/com/wireguard/android/preference/ToolsInstallerPreference.kt

@@ -10,8 +10,8 @@ import androidx.preference.Preference
 import com.wireguard.android.Application
 import com.wireguard.android.R
 import com.wireguard.android.util.ToolsInstaller
+import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
@@ -27,7 +27,7 @@ class ToolsInstallerPreference(context: Context, attrs: AttributeSet?) : Prefere
 
     override fun onAttached() {
         super.onAttached()
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 val state = withContext(Dispatchers.IO) { Application.getToolsInstaller().areInstalled() }
                 when {
@@ -45,7 +45,7 @@ class ToolsInstallerPreference(context: Context, attrs: AttributeSet?) : Prefere
 
     override fun onClick() {
         setState(State.WORKING)
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             try {
                 val result = withContext(Dispatchers.IO) { Application.getToolsInstaller().install() }
                 when {

ui/src/main/java/com/wireguard/android/preference/VersionPreference.kt

@@ -16,8 +16,8 @@ import com.wireguard.android.R
 import com.wireguard.android.backend.Backend
 import com.wireguard.android.backend.GoBackend
 import com.wireguard.android.backend.WgQuickBackend
+import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.util.Locale
@@ -47,7 +47,7 @@ class VersionPreference(context: Context, attrs: AttributeSet?) : Preference(con
     }
 
     init {
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             val backend = Application.getBackend()
             versionSummary = getContext().getString(R.string.version_summary_checking, getBackendPrettyName(context, backend).toLowerCase(Locale.ENGLISH))
             notifyChanged()

ui/src/main/java/com/wireguard/android/preference/ZipExporterPreference.kt

@@ -17,9 +17,9 @@ import com.wireguard.android.util.AdminKnobs
 import com.wireguard.android.util.BiometricAuthenticator
 import com.wireguard.android.util.DownloadsFileSaver
 import com.wireguard.android.util.ErrorMessages
-import com.wireguard.android.util.FragmentUtils
+import com.wireguard.android.util.activity
+import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
@@ -35,7 +35,7 @@ import java.util.zip.ZipOutputStream
 class ZipExporterPreference(context: Context, attrs: AttributeSet?) : Preference(context, attrs) {
     private var exportedFilePath: String? = null
     private fun exportZip() {
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             val tunnels = Application.getTunnelManager().getTunnels()
             try {
                 exportedFilePath = withContext(Dispatchers.IO) {
@@ -64,7 +64,7 @@ class ZipExporterPreference(context: Context, attrs: AttributeSet?) : Preference
                 val message = context.getString(R.string.zip_export_error, error)
                 Log.e(TAG, message, e)
                 Snackbar.make(
-                        FragmentUtils.getPrefActivity(this@ZipExporterPreference).findViewById(android.R.id.content),
+                        activity.findViewById(android.R.id.content),
                         message, Snackbar.LENGTH_LONG).show()
                 isEnabled = true
             }
@@ -77,13 +77,12 @@ class ZipExporterPreference(context: Context, attrs: AttributeSet?) : Preference
 
     override fun onClick() {
         if (AdminKnobs.disableConfigExport) return
-        val prefActivity = FragmentUtils.getPrefActivity(this)
+        val fragment = activity.supportFragmentManager.fragments.first()
-        val fragment = prefActivity.supportFragmentManager.fragments.first()
         BiometricAuthenticator.authenticate(R.string.biometric_prompt_zip_exporter_title, fragment) {
             when (it) {
                 // When we have successful authentication, or when there is no biometric hardware available.
                 is BiometricAuthenticator.Result.Success, is BiometricAuthenticator.Result.HardwareUnavailableOrDisabled -> {
-                    prefActivity.ensurePermissions(arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE)) { _, grantResults ->
+                    activity.ensurePermissions(arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE)) { _, grantResults ->
                         if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                             isEnabled = false
                             exportZip()
@@ -92,7 +91,7 @@ class ZipExporterPreference(context: Context, attrs: AttributeSet?) : Preference
                 }
                 is BiometricAuthenticator.Result.Failure -> {
                     Snackbar.make(
-                            prefActivity.findViewById(android.R.id.content),
+                            activity.findViewById(android.R.id.content),
                             it.message,
                             Snackbar.LENGTH_SHORT
                     ).show()

ui/src/main/java/com/wireguard/android/util/Extensions.kt

@@ -9,6 +9,10 @@ import android.content.Context
 import android.util.TypedValue
 import androidx.annotation.AttrRes
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.lifecycleScope
+import androidx.preference.Preference
+import com.wireguard.android.activity.SettingsActivity
+import kotlinx.coroutines.CoroutineScope
 
 fun Context.resolveAttribute(@AttrRes attrRes: Int): Int {
     val typedValue = TypedValue()
@@ -19,3 +23,9 @@ fun Context.resolveAttribute(@AttrRes attrRes: Int): Int {
 fun Fragment.requireTargetFragment(): Fragment {
     return requireNotNull(targetFragment) { "A target fragment should always be set for $this" }
 }
+
+val Preference.activity: SettingsActivity
+    get() = if (this.context is SettingsActivity) this.context as SettingsActivity else throw IllegalStateException("Failed to resolve SettingsActivity")
+
+val Preference.lifecycleScope: CoroutineScope
+    get() = this.activity.lifecycleScope

ui/src/main/java/com/wireguard/android/util/FragmentUtils.kt

@@ -1,21 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-package com.wireguard.android.util
-
-import android.view.ContextThemeWrapper
-import androidx.preference.Preference
-import com.wireguard.android.activity.SettingsActivity
-
-object FragmentUtils {
-    fun getPrefActivity(preference: Preference): SettingsActivity {
-        val context = preference.context
-        if (context is ContextThemeWrapper) {
-            if (context is SettingsActivity) {
-                return context
-            }
-        }
-        throw IllegalStateException("Failed to resolve SettingsActivity")
-    }
-}