ui: refactor AppListDialogFragment's selection communication

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

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

@@ -10,9 +10,10 @@ import android.os.Bundle
 import android.widget.Button
 import android.widget.Toast
 import androidx.appcompat.app.AlertDialog
+import androidx.core.os.bundleOf
 import androidx.databinding.Observable
 import androidx.fragment.app.DialogFragment
-import androidx.fragment.app.Fragment
+import androidx.fragment.app.setFragmentResult
 import androidx.lifecycle.lifecycleScope
 import com.google.android.material.tabs.TabLayout
 import com.wireguard.android.BR
@@ -21,7 +22,6 @@ import com.wireguard.android.databinding.AppListDialogFragmentBinding
 import com.wireguard.android.databinding.ObservableKeyedArrayList
 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.launch
 import kotlinx.coroutines.withContext
@@ -73,7 +73,6 @@ class AppListDialogFragment : DialogFragment() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        require(requireTargetFragment() is AppSelectionListener) { "${requireTargetFragment()} must implement AppSelectionListener" }
         currentlySelectedApps = (arguments?.getStringArrayList(KEY_SELECTED_APPS) ?: emptyList())
         initiallyExcluded = arguments?.getBoolean(KEY_IS_EXCLUDED) ?: true
     }
@@ -130,23 +129,22 @@ class AppListDialogFragment : DialogFragment() {
                 selectedApps.add(data.packageName)
             }
         }
-        (requireTargetFragment() as AppSelectionListener).onSelectedAppsSelected(selectedApps, tabs?.selectedTabPosition == 0)
+        setFragmentResult(REQUEST_SELECTION, bundleOf(
+                KEY_SELECTED_APPS to selectedApps.toTypedArray(),
+                KEY_IS_EXCLUDED to (tabs?.selectedTabPosition == 0)
+        ))
         dismiss()
     }
 
-    interface AppSelectionListener {
-        fun onSelectedAppsSelected(selectedApps: List<String>, isExcluded: Boolean)
-    }
-
     companion object {
-        private const val KEY_SELECTED_APPS = "selected_apps"
+        const val KEY_SELECTED_APPS = "selected_apps"
-        private const val KEY_IS_EXCLUDED = "is_excluded"
+        const val KEY_IS_EXCLUDED = "is_excluded"
-        fun <T> newInstance(selectedApps: ArrayList<String?>?, isExcluded: Boolean, target: T): AppListDialogFragment where T : Fragment?, T : AppSelectionListener? {
+        const val REQUEST_SELECTION = "request_selection"
+        fun newInstance(selectedApps: ArrayList<String?>?, isExcluded: Boolean): AppListDialogFragment {
             val extras = Bundle()
             extras.putStringArrayList(KEY_SELECTED_APPS, selectedApps)
             extras.putBoolean(KEY_IS_EXCLUDED, isExcluded)
             val fragment = AppListDialogFragment()
-            fragment.setTargetFragment(target, 0)
             fragment.arguments = extras
             return fragment
         }

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

@@ -24,7 +24,6 @@ import com.wireguard.android.Application
 import com.wireguard.android.R
 import com.wireguard.android.backend.Tunnel
 import com.wireguard.android.databinding.TunnelEditorFragmentBinding
-import com.wireguard.android.fragment.AppListDialogFragment.AppSelectionListener
 import com.wireguard.android.model.ObservableTunnel
 import com.wireguard.android.util.AdminKnobs
 import com.wireguard.android.util.BiometricAuthenticator
@@ -38,7 +37,7 @@ import kotlinx.coroutines.launch
 /**
  * Fragment for editing a WireGuard configuration.
  */
-class TunnelEditorFragment : BaseFragment(), AppSelectionListener {
+class TunnelEditorFragment : BaseFragment() {
     private var haveShownKeys = false
     private var binding: TunnelEditorFragmentBinding? = null
     private var tunnel: ObservableTunnel? = null
@@ -91,23 +90,6 @@ class TunnelEditorFragment : BaseFragment(), AppSelectionListener {
         super.onDestroyView()
     }
 
-    override fun onSelectedAppsSelected(selectedApps: List<String>, isExcluded: Boolean) {
-        requireNotNull(binding) { "Tried to set excluded/included apps while no view was loaded" }
-        if (isExcluded) {
-            binding!!.config!!.`interface`.includedApplications.clear()
-            binding!!.config!!.`interface`.excludedApplications.apply {
-                clear()
-                addAll(selectedApps)
-            }
-        } else {
-            binding!!.config!!.`interface`.excludedApplications.clear()
-            binding!!.config!!.`interface`.includedApplications.apply {
-                clear()
-                addAll(selectedApps)
-            }
-        }
-    }
-
     private fun onFinished() {
         // Hide the keyboard; it rarely goes away on its own.
         val activity = activity ?: return
@@ -183,8 +165,26 @@ class TunnelEditorFragment : BaseFragment(), AppSelectionListener {
                 if (selectedApps.isNotEmpty())
                     isExcluded = false
             }
-            val fragment = AppListDialogFragment.newInstance(selectedApps, isExcluded, this)
+            val fragment = AppListDialogFragment.newInstance(selectedApps, isExcluded)
-            fragment.show(parentFragmentManager, null)
+            childFragmentManager.setFragmentResultListener(AppListDialogFragment.REQUEST_SELECTION, viewLifecycleOwner) { _, bundle ->
+                requireNotNull(binding) { "Tried to set excluded/included apps while no view was loaded" }
+                val newSelections = requireNotNull(bundle.getStringArray(AppListDialogFragment.KEY_SELECTED_APPS))
+                val excluded = requireNotNull(bundle.getBoolean(AppListDialogFragment.KEY_IS_EXCLUDED))
+                if (excluded) {
+                    binding!!.config!!.`interface`.includedApplications.clear()
+                    binding!!.config!!.`interface`.excludedApplications.apply {
+                        clear()
+                        addAll(newSelections)
+                    }
+                } else {
+                    binding!!.config!!.`interface`.excludedApplications.clear()
+                    binding!!.config!!.`interface`.includedApplications.apply {
+                        clear()
+                        addAll(newSelections)
+                    }
+                }
+            }
+            fragment.show(childFragmentManager, null)
         }
     }