ui: queue up tunnel mutating on activity scope instead of fragment scope

Fragment scopes get cancelled when the fragment goes away, but we don't
actually want to cancel an in-flight transition in that case. Also,
before when the fragment would cancel, there'd be an exception, and the
exception handler would call Fragment::getString, which in turn called
requireContext, which caused an exception. Work around this by using the
`activity ?: Application.get()` idiom to always have a context for
strings and toasts.

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

6 files changed, 80 insertions, 69 deletions

diff --git a/ui/src/main/java/com/wireguard/android/fragment/BaseFragment.kt b/ui/src/main/java/com/wireguard/android/fragment/BaseFragment.kt
index 10239e6e..90943f0a 100644
--- a/ui/src/main/java/com/wireguard/android/fragment/BaseFragment.kt
+++ b/ui/src/main/java/com/wireguard/android/fragment/BaseFragment.kt
@@ -31,7 +31,6 @@ import kotlinx.coroutines.launch
  * attached to a `BaseActivity`.
  */
 abstract class BaseFragment : Fragment(), OnSelectedTunnelChangedListener {
-    private var baseActivity: BaseActivity? = null
     private var pendingTunnel: ObservableTunnel? = null
     private var pendingTunnelUp: Boolean? = null
     private val permissionActivityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
@@ -44,24 +43,18 @@ abstract class BaseFragment : Fragment(), OnSelectedTunnelChangedListener {
     }
 
     protected var selectedTunnel: ObservableTunnel?
-        get() = baseActivity?.selectedTunnel
+        get() = (activity as? BaseActivity)?.selectedTunnel
         protected set(tunnel) {
-            baseActivity?.selectedTunnel = tunnel
+            (activity as? BaseActivity)?.selectedTunnel = tunnel
         }
 
     override fun onAttach(context: Context) {
         super.onAttach(context)
-        if (context is BaseActivity) {
-            baseActivity = context
-            baseActivity?.addOnSelectedTunnelChangedListener(this)
-        } else {
-            baseActivity = null
-        }
+        (activity as? BaseActivity)?.addOnSelectedTunnelChangedListener(this)
     }
 
     override fun onDetach() {
-        baseActivity?.removeOnSelectedTunnelChangedListener(this)
-        baseActivity = null
+        (activity as? BaseActivity)?.removeOnSelectedTunnelChangedListener(this)
         super.onDetach()
     }
 
@@ -71,9 +64,10 @@ abstract class BaseFragment : Fragment(), OnSelectedTunnelChangedListener {
             is TunnelListItemBinding -> binding.item
             else -> return
         } ?: return
-        lifecycleScope.launch {
+        val activity = activity ?: return
+        activity.lifecycleScope.launch {
             if (Application.getBackend() is GoBackend) {
-                val intent = GoBackend.VpnService.prepare(view.context)
+                val intent = GoBackend.VpnService.prepare(activity)
                 if (intent != null) {
                     pendingTunnel = tunnel
                     pendingTunnelUp = checked
@@ -86,20 +80,21 @@ abstract class BaseFragment : Fragment(), OnSelectedTunnelChangedListener {
     }
 
     private fun setTunnelStateWithPermissionsResult(tunnel: ObservableTunnel, checked: Boolean) {
-        lifecycleScope.launch {
+        val activity = activity ?: return
+        activity.lifecycleScope.launch {
             try {
                 tunnel.setStateAsync(Tunnel.State.of(checked))
             } catch (e: Throwable) {
                 val error = ErrorMessages[e]
                 val messageResId = if (checked) R.string.error_up else R.string.error_down
-                val message = getString(messageResId, error)
+                val message = activity.getString(messageResId, error)
                 val view = view
                 if (view != null)
                     Snackbar.make(view, message, Snackbar.LENGTH_LONG)
                             .setAnchorView(view.findViewById(R.id.create_fab))
                             .show()
                 else
-                    Toast.makeText(activity ?: Application.get(), message, Toast.LENGTH_LONG).show()
+                    Toast.makeText(activity, message, Toast.LENGTH_LONG).show()
                 Log.e(TAG, message, e)
             }
         }
diff --git a/ui/src/main/java/com/wireguard/android/fragment/ConfigNamingDialogFragment.kt b/ui/src/main/java/com/wireguard/android/fragment/ConfigNamingDialogFragment.kt
index cd2431c9..0919f5ea 100644
--- a/ui/src/main/java/com/wireguard/android/fragment/ConfigNamingDialogFragment.kt
+++ b/ui/src/main/java/com/wireguard/android/fragment/ConfigNamingDialogFragment.kt
@@ -29,15 +29,15 @@ class ConfigNamingDialogFragment : DialogFragment() {
     private var imm: InputMethodManager? = null
 
     private fun createTunnelAndDismiss() {
-        binding?.let {
-            val name = it.tunnelNameText.text.toString()
-            lifecycleScope.launch {
-                try {
-                    Application.getTunnelManager().create(name, config)
-                    dismiss()
-                } catch (e: Throwable) {
-                    it.tunnelNameTextLayout.error = e.message
-                }
+        val binding = binding ?: return
+        val activity = activity ?: return
+        val name = binding.tunnelNameText.text.toString()
+        activity.lifecycleScope.launch {
+            try {
+                Application.getTunnelManager().create(name, config)
+                dismiss()
+            } catch (e: Throwable) {
+                binding.tunnelNameTextLayout.error = e.message
             }
         }
     }
diff --git a/ui/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.kt b/ui/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.kt
index e035210a..f002c085 100644
--- a/ui/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.kt
+++ b/ui/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.kt
@@ -39,24 +39,27 @@ class TunnelEditorFragment : BaseFragment() {
     private var haveShownKeys = false
     private var binding: TunnelEditorFragmentBinding? = null
     private var tunnel: ObservableTunnel? = null
+
     private fun onConfigLoaded(config: Config) {
         binding?.config = ConfigProxy(config)
     }
 
     private fun onConfigSaved(savedTunnel: Tunnel, throwable: Throwable?) {
-        val message: String
+        val ctx = activity ?: Application.get()
         if (throwable == null) {
-            message = getString(R.string.config_save_success, savedTunnel.name)
+            val message = ctx.getString(R.string.config_save_success, savedTunnel.name)
             Log.d(TAG, message)
-            Toast.makeText(activity ?: Application.get(), message, Toast.LENGTH_SHORT).show()
+            Toast.makeText(ctx, message, Toast.LENGTH_SHORT).show()
             onFinished()
         } else {
             val error = ErrorMessages[throwable]
-            message = getString(R.string.config_save_error, savedTunnel.name, error)
+            val message = ctx.getString(R.string.config_save_error, savedTunnel.name, error)
             Log.e(TAG, message, throwable)
-            binding?.let {
-                Snackbar.make(it.mainContainer, message, Snackbar.LENGTH_LONG).show()
-            }
+            val binding = binding
+            if (binding != null)
+                Snackbar.make(binding.mainContainer, message, Snackbar.LENGTH_LONG).show()
+            else
+                Toast.makeText(ctx, message, Toast.LENGTH_SHORT).show()
         }
     }
 
@@ -115,7 +118,8 @@ class TunnelEditorFragment : BaseFragment() {
                 Snackbar.make(binding!!.mainContainer, error, Snackbar.LENGTH_LONG).show()
                 return false
             }
-            lifecycleScope.launch {
+            val activity = requireActivity()
+            activity.lifecycleScope.launch {
                 when {
                     tunnel == null -> {
                         Log.d(TAG, "Attempting to create new tunnel " + binding!!.name)
@@ -209,46 +213,48 @@ class TunnelEditorFragment : BaseFragment() {
     }
 
     private fun onTunnelCreated(newTunnel: ObservableTunnel?, throwable: Throwable?) {
-        val message: String
+        val ctx = activity ?: Application.get()
         if (throwable == null) {
             tunnel = newTunnel
-            message = getString(R.string.tunnel_create_success, tunnel!!.name)
+            val message = ctx.getString(R.string.tunnel_create_success, tunnel!!.name)
             Log.d(TAG, message)
-            Toast.makeText(activity ?: Application.get(), message, Toast.LENGTH_SHORT).show()
+            Toast.makeText(ctx, message, Toast.LENGTH_SHORT).show()
             onFinished()
         } else {
             val error = ErrorMessages[throwable]
-            message = getString(R.string.tunnel_create_error, error)
+            val message = ctx.getString(R.string.tunnel_create_error, error)
             Log.e(TAG, message, throwable)
-            binding?.let {
-                Snackbar.make(it.mainContainer, message, Snackbar.LENGTH_LONG).show()
-            }
+            val binding = binding
+            if (binding != null)
+                Snackbar.make(binding.mainContainer, message, Snackbar.LENGTH_LONG).show()
+            else
+                Toast.makeText(ctx, message, Toast.LENGTH_SHORT).show()
         }
     }
 
-    private fun onTunnelRenamed(renamedTunnel: ObservableTunnel, newConfig: Config,
-                                throwable: Throwable?) {
-        val message: String
+    private suspend fun onTunnelRenamed(renamedTunnel: ObservableTunnel, newConfig: Config,
+                                        throwable: Throwable?) {
+        val ctx = activity ?: Application.get()
         if (throwable == null) {
-            message = getString(R.string.tunnel_rename_success, renamedTunnel.name)
+            val message = ctx.getString(R.string.tunnel_rename_success, renamedTunnel.name)
             Log.d(TAG, message)
             // Now save the rest of configuration changes.
             Log.d(TAG, "Attempting to save config of renamed tunnel " + tunnel!!.name)
-            lifecycleScope.launch {
-                try {
-                    renamedTunnel.setConfigAsync(newConfig)
-                    onConfigSaved(renamedTunnel, null)
-                } catch (e: Throwable) {
-                    onConfigSaved(renamedTunnel, e)
-                }
+            try {
+                renamedTunnel.setConfigAsync(newConfig)
+                onConfigSaved(renamedTunnel, null)
+            } catch (e: Throwable) {
+                onConfigSaved(renamedTunnel, e)
             }
         } else {
             val error = ErrorMessages[throwable]
-            message = getString(R.string.tunnel_rename_error, error)
+            val message = ctx.getString(R.string.tunnel_rename_error, error)
             Log.e(TAG, message, throwable)
-            binding?.let {
-                Snackbar.make(it.mainContainer, message, Snackbar.LENGTH_LONG).show()
-            }
+            val binding = binding
+            if (binding != null)
+                Snackbar.make(binding.mainContainer, message, Snackbar.LENGTH_LONG).show()
+            else
+                Toast.makeText(ctx, message, Toast.LENGTH_SHORT).show()
         }
     }
 
diff --git a/ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.kt b/ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.kt
index 9c9d0ecd..3fbc3451 100644
--- a/ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.kt
+++ b/ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.kt
@@ -15,6 +15,7 @@ import android.view.View
 import android.view.ViewGroup
 import android.view.animation.Animation
 import android.view.animation.AnimationUtils
+import android.widget.Toast
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.view.ActionMode
@@ -46,9 +47,10 @@ class TunnelListFragment : BaseFragment() {
     private var actionMode: ActionMode? = null
     private var binding: TunnelListFragmentBinding? = null
     private val tunnelFileImportResultLauncher = registerForActivityResult(ActivityResultContracts.GetContent()) { data ->
-        lifecycleScope.launch {
-            if (data == null) return@launch
-            val contentResolver = activity?.contentResolver ?: return@launch
+        if (data == null) return@registerForActivityResult
+        val activity = activity ?: return@registerForActivityResult
+        val contentResolver = activity.contentResolver ?: return@registerForActivityResult
+        activity.lifecycleScope.launch {
             TunnelImporter.importTunnel(contentResolver, data) { showSnackbar(it) }
         }
     }
@@ -56,7 +58,9 @@ class TunnelListFragment : BaseFragment() {
     private val qrImportResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
         val qrCode = IntentIntegrator.parseActivityResult(result.resultCode, result.data)?.contents
                 ?: return@registerForActivityResult
-        lifecycleScope.launch { TunnelImporter.importTunnel(parentFragmentManager, qrCode) { showSnackbar(it) } }
+        val activity = activity ?: return@registerForActivityResult
+        val fragManager = parentFragmentManager
+        activity.lifecycleScope.launch { TunnelImporter.importTunnel(fragManager, qrCode) { showSnackbar(it) } }
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
@@ -121,11 +125,12 @@ class TunnelListFragment : BaseFragment() {
 
     private fun onTunnelDeletionFinished(count: Int, throwable: Throwable?) {
         val message: String
+        val ctx = activity ?: Application.get()
         if (throwable == null) {
-            message = resources.getQuantityString(R.plurals.delete_success, count, count)
+            message = ctx.resources.getQuantityString(R.plurals.delete_success, count, count)
         } else {
             val error = ErrorMessages[throwable]
-            message = resources.getQuantityString(R.plurals.delete_error, count, count, error)
+            message = ctx.resources.getQuantityString(R.plurals.delete_error, count, count, error)
             Log.e(TAG, message, throwable)
         }
         showSnackbar(message)
@@ -159,11 +164,13 @@ class TunnelListFragment : BaseFragment() {
     }
 
     private fun showSnackbar(message: CharSequence) {
-        binding?.let {
-            Snackbar.make(it.mainContainer, message, Snackbar.LENGTH_LONG)
-                    .setAnchorView(it.createFab)
+        val binding = binding
+        if (binding != null)
+            Snackbar.make(binding.mainContainer, message, Snackbar.LENGTH_LONG)
+                    .setAnchorView(binding.createFab)
                     .show()
-        }
+        else
+            Toast.makeText(activity ?: Application.get(), message, Toast.LENGTH_SHORT).show()
     }
 
     private fun viewForTunnel(tunnel: ObservableTunnel, tunnels: List<*>): MultiselectableRelativeLayout? {
@@ -181,13 +188,14 @@ class TunnelListFragment : BaseFragment() {
         override fun onActionItemClicked(mode: ActionMode, item: MenuItem): Boolean {
             return when (item.itemId) {
                 R.id.menu_action_delete -> {
+                    val activity = activity ?: return true
                     val copyCheckedItems = HashSet(checkedItems)
                     binding?.createFab?.apply {
                         visibility = View.VISIBLE
                         scaleX = 1f
                         scaleY = 1f
                     }
-                    lifecycleScope.launch {
+                    activity.lifecycleScope.launch {
                         try {
                             val tunnels = Application.getTunnelManager().getTunnels()
                             val tunnelsToDelete = ArrayList<ObservableTunnel>()
diff --git a/ui/src/main/java/com/wireguard/android/preference/KernelModuleDisablerPreference.kt b/ui/src/main/java/com/wireguard/android/preference/KernelModuleDisablerPreference.kt
index 5d21a541..2b1e8e4e 100644
--- a/ui/src/main/java/com/wireguard/android/preference/KernelModuleDisablerPreference.kt
+++ b/ui/src/main/java/com/wireguard/android/preference/KernelModuleDisablerPreference.kt
@@ -8,6 +8,7 @@ import android.content.Context
 import android.content.Intent
 import android.util.AttributeSet
 import android.util.Log
+import androidx.lifecycle.lifecycleScope
 import androidx.preference.Preference
 import com.wireguard.android.Application
 import com.wireguard.android.R
@@ -15,6 +16,7 @@ import com.wireguard.android.activity.SettingsActivity
 import com.wireguard.android.backend.Tunnel
 import com.wireguard.android.backend.WgQuickBackend
 import com.wireguard.android.util.UserKnobs
+import com.wireguard.android.util.activity
 import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -39,7 +41,7 @@ class KernelModuleDisablerPreference(context: Context, attrs: AttributeSet?) : P
     override fun getTitle() = if (state == State.UNKNOWN) "" else context.getString(state.titleResourceId)
 
     override fun onClick() {
-        lifecycleScope.launch {
+        activity.lifecycleScope.launch {
             if (state == State.DISABLED) {
                 setState(State.ENABLING)
                 UserKnobs.setDisableKernelModule(false)
diff --git a/ui/src/main/java/com/wireguard/android/util/ErrorMessages.kt b/ui/src/main/java/com/wireguard/android/util/ErrorMessages.kt
index d8ac94d9..1ee0dafc 100644
--- a/ui/src/main/java/com/wireguard/android/util/ErrorMessages.kt
+++ b/ui/src/main/java/com/wireguard/android/util/ErrorMessages.kt
@@ -6,7 +6,7 @@ package com.wireguard.android.util
 
 import android.content.res.Resources
 import android.os.RemoteException
-import com.wireguard.android.Application.Companion.get
+import com.wireguard.android.Application
 import com.wireguard.android.R
 import com.wireguard.android.backend.BackendException
 import com.wireguard.android.util.RootShell.RootShellException
@@ -63,7 +63,7 @@ object ErrorMessages {
     )
 
     operator fun get(throwable: Throwable?): String {
-        val resources = get().resources
+        val resources = Application.get().resources
         if (throwable == null) return resources.getString(R.string.unknown_error)
         val rootCause = rootCause(throwable)
         return when {