Fix bug around restoring InsertFieldDialog

AnkiDroid/src/main/java/com/ichi2/anki/CardTemplateEditor.kt

@@ -41,14 +41,12 @@ import com.google.android.material.bottomnavigation.BottomNavigationView
 import com.google.android.material.tabs.TabLayout
 import com.google.android.material.tabs.TabLayoutMediator
 import com.ichi2.anim.ActivityTransitionAnimation.Direction.*
-import com.ichi2.anki.dialogs.ConfirmationDialog
-import com.ichi2.anki.dialogs.DeckSelectionDialog
+import com.ichi2.anki.dialogs.*
 import com.ichi2.anki.dialogs.DeckSelectionDialog.DeckSelectionListener
 import com.ichi2.anki.dialogs.DeckSelectionDialog.SelectableDeck
-import com.ichi2.anki.dialogs.DiscardChangesDialog
-import com.ichi2.anki.dialogs.InsertFieldDialog.InsertFieldListener
-import com.ichi2.anki.dialogs.InsertFieldDialogFactory
+import com.ichi2.anki.dialogs.InsertFieldDialog.Companion.REQUEST_FIELD_INSERT
 import com.ichi2.anki.exception.ConfirmModSchemaException
+import com.ichi2.annotations.NeedsTest
 import com.ichi2.async.TaskListenerWithContext
 import com.ichi2.libanki.*
 import com.ichi2.libanki.Collection
@@ -428,20 +426,13 @@ open class CardTemplateEditor : AnkiActivity(), DeckSelectionListener {
             }
         }
 
+        @NeedsTest(
+            "the kotlin migration made this method crash due to a recursive call when the dialog would return its data"
+        )
         private fun showInsertFieldDialog() {
-            if (mTemplateEditor.mFieldNames == null) {
-                return
+            mTemplateEditor.mFieldNames?.let { fieldNames ->
+                mTemplateEditor.showDialogFragment(InsertFieldDialog.newInstance(fieldNames))
             }
-            val insertFieldDialogFactory = InsertFieldDialogFactory(
-                object : InsertFieldListener {
-                    override fun insertField(field: String?) {
-                        insertField(field)
-                    }
-                }).attachToActivity<InsertFieldDialogFactory>(mTemplateEditor)
-            val insertFieldDialog = insertFieldDialogFactory
-                .newInsertFieldDialog()
-                .withArguments(mTemplateEditor.mFieldNames!!)
-            mTemplateEditor.showDialogFragment(insertFieldDialog)
         }
 
         @Suppress("unused")
@@ -463,6 +454,12 @@ open class CardTemplateEditor : AnkiActivity(), DeckSelectionListener {
 
         override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
             initTabLayoutMediator()
+            parentFragmentManager.setFragmentResultListener(REQUEST_FIELD_INSERT, viewLifecycleOwner) { key, bundle ->
+                if (key == REQUEST_FIELD_INSERT) {
+                    // this is guaranteed to be non null, as we put a non null value on the other side
+                    insertField(bundle.getString(InsertFieldDialog.KEY_INSERTED_FIELD)!!)
+                }
+            }
         }
 
         private fun initTabLayoutMediator() {

AnkiDroid/src/main/java/com/ichi2/anki/dialogs/InsertFieldDialog.kt

@@ -19,32 +19,30 @@ package com.ichi2.anki.dialogs
 import android.os.Bundle
 import android.view.ViewGroup
 import android.widget.TextView
+import androidx.core.os.bundleOf
 import androidx.fragment.app.DialogFragment
 import androidx.recyclerview.widget.RecyclerView
 import com.afollestad.materialdialogs.MaterialDialog
+import com.ichi2.anki.CardTemplateEditor
 import com.ichi2.anki.R
 import java.util.*
 
 /**
- * This is a reusable convenience class which makes it easy to show a insert field dialog as a DialogFragment.
- * Create a new instance with required fields list, then show it via the fragment manager as usual.
+ * Dialog fragment used to show the fields that the user can insert in the card editor. This
+ * fragment can notify other fragments from the same activity about an inserted field.
+ *
+ * @see [CardTemplateEditor.CardTemplateFragment]
  */
-class InsertFieldDialog(private val insertFieldListener: InsertFieldListener) : DialogFragment() {
+class InsertFieldDialog : DialogFragment() {
     private lateinit var mDialog: MaterialDialog
     private lateinit var mFieldList: List<String>
-    fun withArguments(fieldItems: List<String>): InsertFieldDialog {
-        val args = Bundle()
-        args.putStringArrayList("fieldItems", ArrayList(fieldItems))
-        this.arguments = args
-        return this
-    }
 
     /**
      * A dialog for inserting field in card template editor
      */
     override fun onCreateDialog(savedInstanceState: Bundle?): MaterialDialog {
         super.onCreate(savedInstanceState)
-        mFieldList = requireArguments().getStringArrayList("fieldItems")!!
+        mFieldList = requireArguments().getStringArrayList(KEY_FIELD_ITEMS)!!
         val adapter: RecyclerView.Adapter<*> = object : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
             override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
                 val root = layoutInflater.inflate(R.layout.material_dialog_list_item, parent, false)
@@ -70,11 +68,28 @@ class InsertFieldDialog(private val insertFieldListener: InsertFieldListener) :
     }
 
     private fun selectFieldAndClose(textView: TextView) {
-        insertFieldListener.insertField(textView.text.toString())
+        parentFragmentManager.setFragmentResult(
+            REQUEST_FIELD_INSERT,
+            bundleOf(KEY_INSERTED_FIELD to textView.text.toString())
+        )
         mDialog.dismiss()
     }
 
-    interface InsertFieldListener {
-        fun insertField(field: String?)
+    companion object {
+        /**
+         * Other fragments sharing the activity can use this with
+         * [androidx.fragment.app.FragmentManager.setFragmentResultListener] to get a result back.
+         */
+        const val REQUEST_FIELD_INSERT = "request_field_insert"
+
+        /**
+         * This fragment requires that a list of fields names to be passed in.
+         */
+        const val KEY_INSERTED_FIELD = "key_inserted_field"
+        private const val KEY_FIELD_ITEMS = "key_field_items"
+
+        fun newInstance(fieldItems: List<String>): InsertFieldDialog = InsertFieldDialog().apply {
+            arguments = bundleOf(KEY_FIELD_ITEMS to ArrayList(fieldItems))
+        }
     }
 }