Converted Autofill sample service to kotlin.

Also modified some kotlin in Autofill client activities.

Bug: 38182790
Test: manual
Change-Id: I09938ae3edf83c7a26855c376a96f69a67f542c1

29 files changed, 1089 insertions, 1459 deletions

diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/build.gradle b/input/autofill/AutofillFramework/kotlinApp/Application/build.gradle
index fa91e606..bd0cded2 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/build.gradle
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/build.gradle
@@ -23,6 +23,7 @@ dependencies {
     compile "com.android.support:support-v13:25.0.1"
     compile "com.android.support:cardview-v7:25.0.1"
     compile "com.android.support:appcompat-v7:25.0.1"
+    compile 'com.google.code.gson:gson:2.7'
     compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
 }
 
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.java
deleted file mode 100644
index 54049902..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework;
-
-import android.os.Bundle;
-
-import java.util.Arrays;
-import java.util.Set;
-
-public final class CommonUtil {
-
-    public static final String TAG = "AutofillSample";
-
-    public static final String EXTRA_DATASET_NAME = "dataset_name";
-    public static final String EXTRA_FOR_RESPONSE = "for_response";
-
-    private static void bundleToString(StringBuilder builder, Bundle data) {
-        final Set<String> keySet = data.keySet();
-        builder.append("[Bundle with ").append(keySet.size()).append(" keys:");
-        for (String key : keySet) {
-            builder.append(' ').append(key).append('=');
-            Object value = data.get(key);
-            if ((value instanceof Bundle)) {
-                bundleToString(builder, (Bundle) value);
-            } else {
-                builder.append((value instanceof Object[])
-                        ? Arrays.toString((Object[]) value) : value);
-            }
-        }
-        builder.append(']');
-    }
-
-    public static String bundleToString(Bundle data) {
-        if (data == null) {
-            return "N/A";
-        }
-        final StringBuilder builder = new StringBuilder();
-        bundleToString(builder, data);
-        return builder.toString();
-    }
-}
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt
new file mode 100644
index 00000000..e2839e92
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework
+
+import android.os.Bundle
+import java.util.Arrays
+
+object CommonUtil {
+
+    val TAG = "AutofillSample"
+
+    val EXTRA_DATASET_NAME = "dataset_name"
+    val EXTRA_FOR_RESPONSE = "for_response"
+
+    private fun bundleToString(builder: StringBuilder, data: Bundle) {
+        val keySet = data.keySet()
+        builder.append("[Bundle with ").append(keySet.size).append(" keys:")
+        for (key in keySet) {
+            builder.append(' ').append(key).append('=')
+            val value = data.get(key)
+            if (value is Bundle) {
+                bundleToString(builder, value)
+            } else {
+                val string = if (value is Array<*>) Arrays.toString(value) else value
+                builder.append(string)
+            }
+        }
+        builder.append(']')
+    }
+
+    fun bundleToString(data: Bundle?): String {
+        if (data == null) {
+            return "N/A"
+        }
+        val builder = StringBuilder()
+        bundleToString(builder, data)
+        return builder.toString()
+    }
+}
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt
index 46fdb72a..9c4121aa 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt
@@ -27,7 +27,7 @@ class CreditCardActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-
+        setContentView(R.layout.credit_card_activity)
 
         // Create an ArrayAdapter using the string array and a default spinner layout
         val dayAdapter = ArrayAdapter.createFromResource(this, R.array.day_array, android.R.layout.simple_spinner_item)
@@ -57,13 +57,12 @@ class CreditCardActivity : AppCompatActivity() {
      * any new data.
      */
     private fun submit() {
-        val intent = WelcomeActivity.getStartActivityIntent(this@CreditCardActivity)
+        val intent = WelcomeActivity.getStartActivityIntent(this)
         startActivity(intent)
         finish()
     }
 
     companion object {
-
         fun getStartActivityIntent(context: Context): Intent {
             val intent = Intent(context, CreditCardActivity::class.java)
             return intent
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt
index 5f66364c..193008b5 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt
@@ -72,21 +72,19 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
     override fun autofill(values: SparseArray<AutofillValue>) {
         // User has just selected a Dataset from the list of Autofill suggestions and the Dataset's
         // AutofillValue gets passed into this method.
-        Log.d(TAG, "autoFill(): " + values)
+        Log.d(TAG, "autofill(): " + values)
         for (i in 0..values.size() - 1) {
             val id = values.keyAt(i)
             val value = values.valueAt(i)
-            val item = mItems.get(id)
-            if (item == null) {
-                Log.w(TAG, "No item for id " + id)
-                return
-            }
-            if (!item.editable) {
-                Log.w(TAG, "Item for id $id is not editable: $item")
-                return
+
+            mItems[id]?.let {
+                if (!it.editable) {
+                    Log.w(TAG, "Item for autofillId $id is not editable: $it")
+                    return@autofill
+                }
+                // Set the item's text to the text wrapped in the AutofillValue.
+                it.text = value.textValue
             }
-            // Set the item's text to the text wrapped in the AutofillValue.
-            item.text = value.textValue
         }
         postInvalidate()
     }
@@ -121,9 +119,8 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
         Log.d(TAG, "onDraw: " + mLines.size + " lines; canvas:" + canvas)
         var x: Float
         var y = (mTopMargin + mLineLength).toFloat()
-        for (i in mLines.indices) {
+        for (line in mLines) {
             x = mLeftMargin.toFloat()
-            val line = mLines[i]
             Log.v(TAG, "Drawing '" + line + "' at " + x + "x" + y)
             mTextPaint.color = if (line.fieldTextItem.focused) mFocusedColor else mUnfocusedColor
             val readOnlyText = line.labelItem.text.toString() + ":  ["
@@ -184,7 +181,9 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
         return line
     }
 
-    private class Item internal constructor(val line: Line, val id: Int, val hints: Array<String>?, val type: Int, var text: CharSequence, val editable: Boolean, val sanitized: Boolean) {
+    private class Item internal constructor(val line: Line, val id: Int, val hints: Array<String>?,
+                                            val type: Int, var text: CharSequence,
+                                            val editable: Boolean, val sanitized: Boolean) {
         var focused = false
 
         override fun toString(): String {
@@ -198,7 +197,8 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
             get() = if (editable) EditText::class.java.name else TextView::class.java.name
     }
 
-    private inner class Line constructor(val idEntry: String, label: String, hints: Array<String>, text: String, sanitized: Boolean) {
+    private inner class Line constructor(val idEntry: String, label: String, hints: Array<String>,
+                                         text: String, sanitized: Boolean) {
 
         // Boundaries of the text field, relative to the CustomView
         internal val bounds = Rect()
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/LoginActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/LoginActivity.kt
index ca146019..bf3fe874 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/LoginActivity.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/LoginActivity.kt
@@ -24,8 +24,8 @@ import android.widget.Toast
 import com.example.android.autofillframework.R
 import kotlinx.android.synthetic.main.login_activity.*
 
+
 class LoginActivity : AppCompatActivity() {
-    val TAG = "LoginActivity"
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AuthActivity.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AuthActivity.java
deleted file mode 100644
index 768b2ee3..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AuthActivity.java
+++ /dev/null
@@ -1,160 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service;
-
-import android.app.Activity;
-import android.app.PendingIntent;
-import android.app.assist.AssistStructure;
-import android.content.Context;
-import android.content.Intent;
-import android.content.IntentSender;
-import android.os.Bundle;
-import android.service.autofill.Dataset;
-import android.service.autofill.FillResponse;
-import android.support.annotation.Nullable;
-import android.text.Editable;
-import android.util.Log;
-import android.view.View;
-import android.view.View.OnClickListener;
-import android.widget.Button;
-import android.widget.EditText;
-import android.widget.Toast;
-
-import com.example.android.autofillframework.R;
-import com.example.android.autofillframework.service.datasource.LocalAutofillRepository;
-import com.example.android.autofillframework.service.model.AutofillFieldsCollection;
-import com.example.android.autofillframework.service.model.ClientFormData;
-import com.example.android.autofillframework.service.settings.MyPreferences;
-
-import java.util.HashMap;
-
-import static android.view.autofill.AutofillManager.EXTRA_ASSIST_STRUCTURE;
-import static android.view.autofill.AutofillManager.EXTRA_AUTHENTICATION_RESULT;
-import static com.example.android.autofillframework.CommonUtil.EXTRA_DATASET_NAME;
-import static com.example.android.autofillframework.CommonUtil.EXTRA_FOR_RESPONSE;
-import static com.example.android.autofillframework.CommonUtil.TAG;
-
-/**
- * This Activity controls the UI for logging in to the Autofill service.
- * It is launched when an Autofill Response or specific Dataset within the Response requires
- * authentication to access. It bundles the result in an Intent.
- */
-public class AuthActivity extends Activity {
-
-    // Unique id for dataset intents.
-    private static int sDatasetPendingIntentId = 0;
-
-    private EditText mMasterPassword;
-    private Button mCancel;
-    private Button mLogin;
-    private Intent mReplyIntent;
-
-    static IntentSender getAuthIntentSenderForResponse(Context context) {
-        final Intent intent = new Intent(context, AuthActivity.class);
-        return PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT)
-                .getIntentSender();
-    }
-
-    static IntentSender getAuthIntentSenderForDataset(Context context, String datasetName) {
-        final Intent intent = new Intent(context, AuthActivity.class);
-        intent.putExtra(EXTRA_DATASET_NAME, datasetName);
-        intent.putExtra(EXTRA_FOR_RESPONSE, false);
-        return PendingIntent.getActivity(context, ++sDatasetPendingIntentId, intent,
-                PendingIntent.FLAG_CANCEL_CURRENT).getIntentSender();
-    }
-
-    @Override
-    protected void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        setContentView(R.layout.auth_activity);
-        mCancel = findViewById(R.id.cancel);
-        mLogin = findViewById(R.id.login);
-        mMasterPassword = findViewById(R.id.master_password);
-        mLogin.setOnClickListener(new OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                login();
-            }
-
-        });
-
-        mCancel.setOnClickListener(new OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                onFailure();
-                AuthActivity.this.finish();
-            }
-        });
-    }
-
-    private void login() {
-        Editable password = mMasterPassword.getText();
-        if (password.toString()
-                .equals(MyPreferences.getInstance(AuthActivity.this).getMasterPassword())) {
-            onSuccess();
-        } else {
-            Toast.makeText(this, "Password incorrect", Toast.LENGTH_SHORT).show();
-            onFailure();
-        }
-        finish();
-    }
-
-    @Override
-    public void finish() {
-        if (mReplyIntent != null) {
-            setResult(RESULT_OK, mReplyIntent);
-        } else {
-            setResult(RESULT_CANCELED);
-        }
-        super.finish();
-    }
-
-    private void onFailure() {
-        Log.w(TAG, "Failed auth.");
-        mReplyIntent = null;
-    }
-
-    private void onSuccess() {
-        Intent intent = getIntent();
-        boolean forResponse = intent.getBooleanExtra(EXTRA_FOR_RESPONSE, true);
-        AssistStructure structure = intent.getParcelableExtra(EXTRA_ASSIST_STRUCTURE);
-        StructureParser parser = new StructureParser(structure);
-        parser.parse();
-        AutofillFieldsCollection autofillFields = parser.getAutofillFields();
-        int saveTypes = parser.getSaveTypes();
-        mReplyIntent = new Intent();
-        HashMap<String, ClientFormData> clientFormDataMap =
-                LocalAutofillRepository.getInstance(this).getClientFormData
-                        (autofillFields.getFocusedHints(), autofillFields.getAllHints());
-        if (forResponse) {
-            setResponseIntent(AutofillHelper.newResponse
-                    (this, false, autofillFields, saveTypes, clientFormDataMap));
-        } else {
-            String datasetName = intent.getStringExtra(EXTRA_DATASET_NAME);
-            setDatasetIntent(AutofillHelper.newDataset
-                    (this, autofillFields, clientFormDataMap.get(datasetName)));
-        }
-    }
-
-    private void setResponseIntent(FillResponse fillResponse) {
-        mReplyIntent.putExtra(EXTRA_AUTHENTICATION_RESULT, fillResponse);
-    }
-
-    private void setDatasetIntent(Dataset dataset) {
-        mReplyIntent.putExtra(EXTRA_AUTHENTICATION_RESULT, dataset);
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AuthActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AuthActivity.kt
new file mode 100644
index 00000000..b8c3f8b1
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AuthActivity.kt
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service
+
+import android.app.Activity
+import android.app.PendingIntent
+import android.app.assist.AssistStructure
+import android.content.Context
+import android.content.Intent
+import android.content.IntentSender
+import android.os.Bundle
+import android.service.autofill.Dataset
+import android.service.autofill.FillResponse
+import android.util.Log
+import android.view.autofill.AutofillManager.EXTRA_ASSIST_STRUCTURE
+import android.view.autofill.AutofillManager.EXTRA_AUTHENTICATION_RESULT
+import android.widget.Toast
+import com.example.android.autofillframework.CommonUtil.EXTRA_DATASET_NAME
+import com.example.android.autofillframework.CommonUtil.EXTRA_FOR_RESPONSE
+import com.example.android.autofillframework.CommonUtil.TAG
+import com.example.android.autofillframework.R
+import com.example.android.autofillframework.service.datasource.SharedPrefsAutofillRepository
+import com.example.android.autofillframework.service.settings.MyPreferences
+import kotlinx.android.synthetic.main.auth_activity.cancel
+import kotlinx.android.synthetic.main.auth_activity.login
+import kotlinx.android.synthetic.main.auth_activity.master_password
+
+/**
+ * This Activity controls the UI for logging in to the Autofill service.
+ * It is launched when an Autofill Response or specific Dataset within the Response requires
+ * authentication to access. It bundles the result in an Intent.
+ */
+class AuthActivity : Activity() {
+
+    private var mReplyIntent: Intent? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.auth_activity)
+        login.setOnClickListener { login() }
+        cancel.setOnClickListener {
+            onFailure()
+            this@AuthActivity.finish()
+        }
+    }
+
+    private fun login() {
+        val password = master_password.text
+        if (password.toString() == MyPreferences.getMasterPassword(this@AuthActivity)) {
+            onSuccess()
+        } else {
+            Toast.makeText(this, "Password incorrect", Toast.LENGTH_SHORT).show()
+            onFailure()
+        }
+        finish()
+    }
+
+    override fun finish() {
+        if (mReplyIntent != null) {
+            setResult(Activity.RESULT_OK, mReplyIntent)
+        } else {
+            setResult(Activity.RESULT_CANCELED)
+        }
+        super.finish()
+    }
+
+    private fun onFailure() {
+        Log.w(TAG, "Failed auth.")
+        mReplyIntent = null
+    }
+
+    private fun onSuccess() {
+        val intent = intent
+        val forResponse = intent.getBooleanExtra(EXTRA_FOR_RESPONSE, true)
+        val structure = intent.getParcelableExtra<AssistStructure>(EXTRA_ASSIST_STRUCTURE)
+        val parser = StructureParser(structure)
+        parser.parseForFill()
+        val autofillFields = parser.autofillFields
+        mReplyIntent = Intent()
+        val clientFormDataMap = SharedPrefsAutofillRepository
+                .getClientFormData(this, autofillFields.focusedAutofillHints, autofillFields.allAutofillHints)
+        if (forResponse) {
+            AutofillHelper.newResponse(this, false, autofillFields, clientFormDataMap)?.let(this::setResponseIntent)
+        } else {
+            val datasetName = intent.getStringExtra(EXTRA_DATASET_NAME)
+            clientFormDataMap?.let {
+                it[datasetName]?.let {
+                    AutofillHelper.newDataset(this, autofillFields, it)?.let(this::setDatasetIntent)
+                }
+            }
+        }
+    }
+
+    private fun setResponseIntent(fillResponse: FillResponse) {
+        mReplyIntent?.putExtra(EXTRA_AUTHENTICATION_RESULT, fillResponse)
+    }
+
+    private fun setDatasetIntent(dataset: Dataset) {
+        mReplyIntent?.putExtra(EXTRA_AUTHENTICATION_RESULT, dataset)
+    }
+
+    companion object {
+
+        // Unique autofillId for dataset intents.
+        private var sDatasetPendingIntentId = 0
+
+        internal fun getAuthIntentSenderForResponse(context: Context): IntentSender {
+            val intent = Intent(context, AuthActivity::class.java)
+            return PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT)
+                    .intentSender
+        }
+
+        internal fun getAuthIntentSenderForDataset(context: Context, datasetName: String): IntentSender {
+            val intent = Intent(context, AuthActivity::class.java)
+            intent.putExtra(EXTRA_DATASET_NAME, datasetName)
+            intent.putExtra(EXTRA_FOR_RESPONSE, false)
+            return PendingIntent.getActivity(context, ++sDatasetPendingIntentId, intent,
+                    PendingIntent.FLAG_CANCEL_CURRENT).intentSender
+        }
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AutofillHelper.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AutofillHelper.java
deleted file mode 100644
index 460729e6..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AutofillHelper.java
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service;
-
-import android.content.Context;
-import android.content.IntentSender;
-import android.service.autofill.Dataset;
-import android.service.autofill.FillResponse;
-import android.service.autofill.SaveInfo;
-import android.util.Log;
-import android.view.autofill.AutofillId;
-import android.widget.RemoteViews;
-
-import com.example.android.autofillframework.R;
-import com.example.android.autofillframework.service.model.AutofillFieldsCollection;
-import com.example.android.autofillframework.service.model.ClientFormData;
-
-import java.util.HashMap;
-import java.util.Set;
-
-import static com.example.android.autofillframework.CommonUtil.TAG;
-
-/**
- * This is a class containing helper methods for building Autofill Datasets and Responses.
- */
-public final class AutofillHelper {
-
-    /**
-     * Wraps autofill data in a LoginCredential  Dataset object which can then be sent back to the
-     * client View.
-     */
-    public static Dataset newDataset(Context context,
-            AutofillFieldsCollection autofillFields, ClientFormData clientFormData) {
-        Dataset.Builder datasetBuilder = new Dataset.Builder
-                (newRemoteViews(context.getPackageName(), clientFormData.getDatasetName()));
-        boolean setValueAtLeastOnce = clientFormData.applyToFields(autofillFields, datasetBuilder);
-        if (setValueAtLeastOnce) {
-            return datasetBuilder.build();
-        } else {
-            return null;
-        }
-    }
-
-    public static RemoteViews newRemoteViews(String packageName, String remoteViewsText) {
-        RemoteViews presentation = new RemoteViews(packageName, R.layout.list_item);
-        presentation.setTextViewText(R.id.text1, remoteViewsText);
-        return presentation;
-    }
-
-    /**
-     * Wraps autofill data in a Response object (essentially a series of Datasets) which can then
-     * be sent back to the client View.
-     */
-    public static FillResponse newResponse(Context context,
-            boolean datasetAuth, AutofillFieldsCollection autofillFields, int saveType,
-            HashMap<String, ClientFormData> clientFormDataMap) {
-        FillResponse.Builder responseBuilder = new FillResponse.Builder();
-        if (clientFormDataMap != null) {
-            Set<String> datasetNames = clientFormDataMap.keySet();
-            for (String datasetName : datasetNames) {
-                ClientFormData clientFormData = clientFormDataMap.get(datasetName);
-                if (datasetAuth) {
-                    Dataset.Builder datasetBuilder =
-                            new Dataset.Builder(newRemoteViews
-                                    (context.getPackageName(), clientFormData.getDatasetName()));
-                    IntentSender sender = AuthActivity
-                            .getAuthIntentSenderForDataset(context, clientFormData.getDatasetName());
-                    datasetBuilder.setAuthentication(sender);
-                    responseBuilder.addDataset(datasetBuilder.build());
-                } else {
-                    Dataset dataset = newDataset(context, autofillFields, clientFormData);
-                    if (dataset != null) {
-                        responseBuilder.addDataset(dataset);
-                    }
-                }
-            }
-        }
-        if (saveType != 0) {
-            AutofillId[] autofillIds = autofillFields.getAutofillIds();
-            responseBuilder.setSaveInfo(new SaveInfo.Builder(saveType, autofillIds).build());
-            return responseBuilder.build();
-        } else {
-            Log.d(TAG, "These fields are not meant to be saved by autofill.");
-            return null;
-        }
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AutofillHelper.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AutofillHelper.kt
new file mode 100644
index 00000000..b7470d7b
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/AutofillHelper.kt
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service
+
+import android.content.Context
+import android.service.autofill.Dataset
+import android.service.autofill.FillResponse
+import android.service.autofill.SaveInfo
+import android.util.Log
+import android.widget.RemoteViews
+import com.example.android.autofillframework.CommonUtil.TAG
+import com.example.android.autofillframework.R
+import com.example.android.autofillframework.service.model.AutofillFieldsCollection
+import com.example.android.autofillframework.service.model.ClientFormData
+import java.util.HashMap
+
+/**
+ * This is a class containing helper methods for building Autofill Datasets and Responses.
+ */
+object AutofillHelper {
+
+    /**
+     * Wraps autofill data in a [Dataset] object which can then be sent back to the
+     * client View.
+     */
+    fun newDataset(context: Context, autofillFields: AutofillFieldsCollection,
+            clientFormData: ClientFormData): Dataset? {
+        clientFormData.datasetName?.let { datasetName ->
+            val datasetBuilder = Dataset.Builder(newRemoteViews(context.packageName, datasetName))
+            val setValueAtLeastOnce = clientFormData.applyToFields(autofillFields, datasetBuilder)
+            if (setValueAtLeastOnce) {
+                return datasetBuilder.build()
+            }
+        }
+        return null
+    }
+
+    fun newRemoteViews(packageName: String, remoteViewsText: String): RemoteViews {
+        val presentation = RemoteViews(packageName, R.layout.list_item)
+        presentation.setTextViewText(R.id.text1, remoteViewsText)
+        return presentation
+    }
+
+    /**
+     * Wraps autofill data in a [FillResponse] object (essentially a series of Datasets) which can
+     * then be sent back to the client View.
+     */
+    fun newResponse(context: Context,
+            datasetAuth: Boolean, autofillFields: AutofillFieldsCollection,
+            clientFormDataMap: HashMap<String, ClientFormData>?): FillResponse? {
+        val responseBuilder = FillResponse.Builder()
+        clientFormDataMap?.keys?.let { datasetNames ->
+            for (datasetName in datasetNames) {
+                clientFormDataMap[datasetName]?.let { clientFormData ->
+                    if (datasetAuth) {
+                        clientFormData.datasetName?.let {
+                            val datasetBuilder = Dataset.Builder(newRemoteViews(context.packageName, it))
+                            val sender = AuthActivity
+                                    .getAuthIntentSenderForDataset(context, it)
+                            datasetBuilder.setAuthentication(sender)
+                            responseBuilder.addDataset(datasetBuilder.build())
+                        }
+                    } else {
+                        val dataset = newDataset(context, autofillFields, clientFormData)
+                        dataset?.let(responseBuilder::addDataset)
+                    }
+                }
+            }
+        }
+        if (autofillFields.saveType != 0) {
+            val autofillIds = autofillFields.autofillIds
+            responseBuilder.setSaveInfo(SaveInfo.Builder(autofillFields.saveType,
+                    autofillIds.toTypedArray()).build())
+            return responseBuilder.build()
+        } else {
+            Log.d(TAG, "These fields are not meant to be saved by autofill.")
+            return null
+        }
+    }
+}
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/MyAutofillService.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/MyAutofillService.java
deleted file mode 100644
index 61e42050..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/MyAutofillService.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service;
-
-import android.app.assist.AssistStructure;
-import android.content.IntentSender;
-import android.os.Bundle;
-import android.os.CancellationSignal;
-import android.service.autofill.AutofillService;
-import android.service.autofill.FillCallback;
-import android.service.autofill.FillContext;
-import android.service.autofill.FillRequest;
-import android.service.autofill.FillResponse;
-import android.service.autofill.SaveCallback;
-import android.service.autofill.SaveRequest;
-import android.util.Log;
-import android.widget.RemoteViews;
-
-import com.example.android.autofillframework.R;
-import com.example.android.autofillframework.service.datasource.LocalAutofillRepository;
-import com.example.android.autofillframework.service.model.AutofillFieldsCollection;
-import com.example.android.autofillframework.service.model.ClientFormData;
-import com.example.android.autofillframework.service.settings.MyPreferences;
-
-import java.util.HashMap;
-import java.util.List;
-
-import static com.example.android.autofillframework.CommonUtil.TAG;
-import static com.example.android.autofillframework.CommonUtil.bundleToString;
-
-public class MyAutofillService extends AutofillService {
-
-    @Override
-    public void onFillRequest(AssistStructure assistStructure, Bundle bundle, int i,
-            CancellationSignal cancellationSignal, FillCallback fillCallback) {
-        /* Deprecated, ignore */
-    }
-
-    @Override
-    public void onSaveRequest(AssistStructure assistStructure, Bundle bundle,
-            SaveCallback saveCallback) {
-        /* Deprecated, ignore */
-    }
-
-    @Override
-    public void onFillRequest(FillRequest request, CancellationSignal cancellationSignal,
-            FillCallback callback) {
-        AssistStructure structure = request.getStructure();
-        final Bundle data = request.getClientState();
-        Log.d(TAG, "onFillRequest(): data=" + bundleToString(data));
-
-        // Temporary hack for disabling autofill for components in this autofill service.
-        // i.e. we don't want to autofill components in AuthActivity.
-        if (structure.getActivityComponent().toShortString()
-                .contains("com.example.android.autofillframework.service")) {
-            callback.onSuccess(null);
-            return;
-        }
-        cancellationSignal.setOnCancelListener(new CancellationSignal.OnCancelListener() {
-            @Override
-            public void onCancel() {
-                Log.w(TAG, "Cancel autofill not implemented in this sample.");
-            }
-        });
-        // Parse AutoFill data in Activity
-        StructureParser parser = new StructureParser(structure);
-        parser.parse();
-        AutofillFieldsCollection autofillFields = parser.getAutofillFields();
-        int saveTypes = parser.getSaveTypes();
-
-        FillResponse.Builder responseBuilder = new FillResponse.Builder();
-        // Check user's settings for authenticating Responses and Datasets.
-        boolean responseAuth = MyPreferences.getInstance(this).isResponseAuth();
-        if (responseAuth) {
-            // If the entire Autofill Response is authenticated, AuthActivity is used
-            // to generate Response.
-            IntentSender sender = AuthActivity.getAuthIntentSenderForResponse(this);
-            RemoteViews presentation = AutofillHelper
-                    .newRemoteViews(getPackageName(), getString(R.string.autofill_sign_in_prompt));
-            responseBuilder
-                    .setAuthentication(autofillFields.getAutofillIds(), sender, presentation);
-            callback.onSuccess(responseBuilder.build());
-        } else {
-            boolean datasetAuth = MyPreferences.getInstance(this).isDatasetAuth();
-            HashMap<String, ClientFormData> clientFormDataMap =
-                    LocalAutofillRepository.getInstance(this).getClientFormData
-                            (autofillFields.getFocusedHints(), autofillFields.getAllHints());
-            FillResponse response = AutofillHelper.newResponse
-                    (this, datasetAuth, autofillFields, saveTypes, clientFormDataMap);
-            callback.onSuccess(response);
-        }
-    }
-
-    @Override
-    public void onSaveRequest(SaveRequest request, SaveCallback callback) {
-        List<FillContext> context = request.getFillContexts();
-        final AssistStructure structure = context.get(context.size() - 1).getStructure();
-        final Bundle data = request.getClientState();
-        Log.d(TAG, "onSaveRequest(): data=" + bundleToString(data));
-        StructureParser parser = new StructureParser(structure);
-        parser.parse();
-        ClientFormData clientFormData = parser.getClientFormData();
-        LocalAutofillRepository.getInstance(this).saveClientFormData(clientFormData);
-    }
-
-    @Override
-    public void onConnected() {
-        Log.d(TAG, "onConnected");
-    }
-
-    @Override
-    public void onDisconnected() {
-        Log.d(TAG, "onDisconnected");
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/MyAutofillService.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/MyAutofillService.kt
new file mode 100644
index 00000000..9bc2a8c2
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/MyAutofillService.kt
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service
+
+import android.app.assist.AssistStructure
+import android.os.Bundle
+import android.os.CancellationSignal
+import android.service.autofill.AutofillService
+import android.service.autofill.FillCallback
+import android.service.autofill.FillRequest
+import android.service.autofill.FillResponse
+import android.service.autofill.SaveCallback
+import android.service.autofill.SaveRequest
+import android.util.Log
+import com.example.android.autofillframework.CommonUtil.TAG
+import com.example.android.autofillframework.CommonUtil.bundleToString
+import com.example.android.autofillframework.R
+import com.example.android.autofillframework.service.datasource.SharedPrefsAutofillRepository
+import com.example.android.autofillframework.service.settings.MyPreferences
+
+class MyAutofillService : AutofillService() {
+
+    override fun onFillRequest(assistStructure: AssistStructure, bundle: Bundle, i: Int,
+            cancellationSignal: CancellationSignal, fillCallback: FillCallback) {
+        /* Deprecated, ignore */
+    }
+
+    override fun onSaveRequest(assistStructure: AssistStructure, bundle: Bundle,
+            saveCallback: SaveCallback) {
+        /* Deprecated, ignore */
+    }
+
+    override fun onFillRequest(request: FillRequest, cancellationSignal: CancellationSignal,
+            callback: FillCallback) {
+        val structure = request.structure
+        val data = request.clientState
+        Log.d(TAG, "onFillRequest(): data=" + bundleToString(data))
+
+        // Temporary hack for disabling autofill for components in this autofill service.
+        // i.e. we don't want to autofill components in AuthActivity.
+        if (structure.activityComponent.toShortString()
+                .contains("com.example.android.autofillframework.service")) {
+            callback.onSuccess(null)
+            return
+        }
+        cancellationSignal.setOnCancelListener { Log.w(TAG, "Cancel autofill not implemented in this sample.") }
+        // Parse AutoFill data in Activity
+        val parser = StructureParser(structure)
+        parser.parseForFill()
+        val autofillFields = parser.autofillFields
+
+        val responseBuilder = FillResponse.Builder()
+        // Check user's settings for authenticating Responses and Datasets.
+        val responseAuth = MyPreferences.isResponseAuth(this)
+        if (responseAuth) {
+            // If the entire Autofill Response is authenticated, AuthActivity is used
+            // to generate Response.
+            val sender = AuthActivity.getAuthIntentSenderForResponse(this)
+            val presentation = AutofillHelper
+                    .newRemoteViews(packageName, getString(R.string.autofill_sign_in_prompt))
+            responseBuilder
+                    .setAuthentication(autofillFields.autofillIds.toTypedArray(), sender, presentation)
+            callback.onSuccess(responseBuilder.build())
+        } else {
+            val datasetAuth = MyPreferences.isDatasetAuth(this)
+            val clientFormDataMap = SharedPrefsAutofillRepository.getClientFormData(this, autofillFields.focusedAutofillHints, autofillFields.allAutofillHints)
+            val response = AutofillHelper.newResponse(this, datasetAuth, autofillFields, clientFormDataMap)
+            callback.onSuccess(response)
+        }
+    }
+
+    override fun onSaveRequest(request: SaveRequest, callback: SaveCallback) {
+        val context = request.fillContexts
+        val structure = context[context.size - 1].structure
+        val data = request.clientState
+        Log.d(TAG, "onSaveRequest(): data=" + bundleToString(data))
+        val parser = StructureParser(structure)
+        parser.parseForSave()
+        SharedPrefsAutofillRepository.saveClientFormData(this, parser.clientFormData)
+    }
+
+    override fun onConnected() {
+        Log.d(TAG, "onConnected")
+    }
+
+    override fun onDisconnected() {
+        Log.d(TAG, "onDisconnected")
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/StructureParser.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/StructureParser.java
deleted file mode 100644
index b6294449..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/StructureParser.java
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service;
-
-import android.app.assist.AssistStructure;
-import android.app.assist.AssistStructure.ViewNode;
-import android.app.assist.AssistStructure.WindowNode;
-import android.util.Log;
-
-import com.example.android.autofillframework.service.model.AutofillField;
-import com.example.android.autofillframework.service.model.AutofillFieldsCollection;
-import com.example.android.autofillframework.service.model.ClientFormData;
-import com.example.android.autofillframework.service.model.SavedAutofillValue;
-
-import static com.example.android.autofillframework.CommonUtil.TAG;
-
-/**
- * Parser for an AssistStructure object. This is invoked when the Autofill Service receives an
- * AssistStructure from the client Activity, representing its View hierarchy. In this
- * sample, it parses the hierarchy and records
- */
-final class StructureParser {
-    private final AutofillFieldsCollection mAutofillFields = new AutofillFieldsCollection();
-    private final AssistStructure mStructure;
-    private ClientFormData mClientFormData;
-
-    StructureParser(AssistStructure structure) {
-        mStructure = structure;
-
-    }
-
-    /**
-     * Traverse AssistStructure and add ViewNode metadata to a flat list.
-     */
-    void parse() {
-        Log.d(TAG, "Parsing structure for " + mStructure.getActivityComponent());
-        int nodes = mStructure.getWindowNodeCount();
-        mClientFormData = new ClientFormData();
-        for (int i = 0; i < nodes; i++) {
-            WindowNode node = mStructure.getWindowNodeAt(i);
-            ViewNode view = node.getRootViewNode();
-            parseLocked(view);
-        }
-    }
-
-    private void parseLocked(ViewNode viewNode) {
-        if (viewNode.getAutofillHints() != null && viewNode.getAutofillHints().length > 0) {
-            //TODO check to make sure hints are supported by service.
-            mAutofillFields.add(new AutofillField(viewNode));
-            mClientFormData
-                    .set(viewNode.getAutofillHints(), SavedAutofillValue.fromViewNode(viewNode));
-        }
-        int childrenSize = viewNode.getChildCount();
-        if (childrenSize > 0) {
-            for (int i = 0; i < childrenSize; i++) {
-                parseLocked(viewNode.getChildAt(i));
-            }
-        }
-    }
-
-    public AutofillFieldsCollection getAutofillFields() {
-        return mAutofillFields;
-    }
-
-    public int getSaveTypes() {
-        return mAutofillFields.getSaveType();
-    }
-
-    public ClientFormData getClientFormData() {
-        return mClientFormData;
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/StructureParser.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/StructureParser.kt
new file mode 100644
index 00000000..e05a2d51
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/StructureParser.kt
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service
+
+import android.app.assist.AssistStructure
+import android.app.assist.AssistStructure.ViewNode
+import android.util.Log
+import com.example.android.autofillframework.CommonUtil.TAG
+import com.example.android.autofillframework.service.model.AutofillField
+import com.example.android.autofillframework.service.model.AutofillFieldsCollection
+import com.example.android.autofillframework.service.model.ClientFormData
+import com.example.android.autofillframework.service.model.MutableAutofillValue
+
+/**
+ * Parser for an AssistStructure object. This is invoked when the Autofill Service receives an
+ * AssistStructure from the client Activity, representing its View hierarchy. In this
+ * sample, it parses the hierarchy and records
+ */
+internal class StructureParser(private val mStructure: AssistStructure) {
+    val autofillFields = AutofillFieldsCollection()
+    var clientFormData: ClientFormData = ClientFormData()
+        private set
+
+
+    fun parseForFill() {
+        parse(true)
+    }
+
+    fun parseForSave() {
+        parse(false)
+    }
+
+    /**
+     * Traverse AssistStructure and add ViewNode metadata to a flat list.
+     */
+    private fun parse(forFill: Boolean) {
+        Log.d(TAG, "Parsing structure for " + mStructure.activityComponent)
+        val nodes = mStructure.windowNodeCount
+        clientFormData = ClientFormData()
+        for (i in 0..nodes - 1) {
+            val node = mStructure.getWindowNodeAt(i)
+            val view = node.rootViewNode
+            parseLocked(forFill, view)
+        }
+    }
+
+    private fun parseLocked(forFill: Boolean, viewNode: ViewNode) {
+        viewNode.autofillHints?.let { autofillHints ->
+            if (autofillHints.isNotEmpty()) {
+                if (forFill) {
+                    autofillFields.add(AutofillField(viewNode))
+                } else {
+                    clientFormData.setAutofillValuesForHints(viewNode.autofillHints,
+                            MutableAutofillValue(viewNode))
+                }
+            }
+        }
+        val childrenSize = viewNode.childCount
+        if (childrenSize > 0) {
+            for (i in 0..childrenSize - 1) {
+                parseLocked(forFill, viewNode.getChildAt(i))
+            }
+        }
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/AutofillRepository.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/AutofillRepository.kt
index 8de8b647..f335187e 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/AutofillRepository.java
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/AutofillRepository.kt
@@ -13,29 +13,28 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.example.android.autofillframework.service.datasource;
+package com.example.android.autofillframework.service.datasource
 
-import com.example.android.autofillframework.service.model.ClientFormData;
+import android.content.Context
+import com.example.android.autofillframework.service.model.ClientFormData
+import java.util.HashMap
 
-import java.util.HashMap;
-import java.util.List;
-
-public interface AutofillRepository {
+interface AutofillRepository {
 
     /**
      * Gets saved ClientFormData that contains some objects that can autofill fields with these
-     * {@code autofillHints}.
+     * `autofillHints`.
      */
-    HashMap<String, ClientFormData> getClientFormData(List<String> focusedAutofillHints,
-            List<String> allAutofillHints);
+    fun getClientFormData(context: Context, focusedAutofillHints: List<String>,
+            allAutofillHints: List<String>): HashMap<String, ClientFormData>?
 
     /**
      * Saves LoginCredential under this datasetName.
      */
-    void saveClientFormData(ClientFormData clientFormData);
+    fun saveClientFormData(context: Context, clientFormData: ClientFormData)
 
     /**
      * Clears all data.
      */
-    void clear();
+    fun clear(context: Context)
 }
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/LocalAutofillRepository.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/LocalAutofillRepository.java
deleted file mode 100644
index 8336fe1e..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/LocalAutofillRepository.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.datasource;
-
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.util.ArraySet;
-
-import com.example.android.autofillframework.service.model.ClientFormData;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-
-import java.util.HashMap;
-import java.util.List;
-import java.util.Set;
-
-/**
- * Singleton autofill data repository, that stores autofill fields to SharedPreferences.
- * DISCLAIMER, you should not store sensitive fields like user data unencrypted. This is only done
- * here for simplicity and learning purposes.
- */
-public class LocalAutofillRepository implements AutofillRepository {
-    private static final String SHARED_PREF_KEY = "com.example.android.autofillframework.service";
-    private static final String CLIENT_FORM_DATA_KEY = "loginCredentialDatasets";
-    private static final String DATASET_NUMBER_KEY = "datasetNumber";
-
-    private static LocalAutofillRepository sInstance;
-
-    private final SharedPreferences mPrefs;
-
-    // TODO prepend with autofill data set in Settings.
-    private LocalAutofillRepository(Context context) {
-        mPrefs = context.getApplicationContext()
-                .getSharedPreferences(SHARED_PREF_KEY, Context.MODE_PRIVATE);
-    }
-
-    public static LocalAutofillRepository getInstance(Context context) {
-        if (sInstance == null) {
-            sInstance = new LocalAutofillRepository(context);
-        }
-        return sInstance;
-    }
-
-    @Override
-    public HashMap<String, ClientFormData> getClientFormData(List<String> focusedAutofillHints,
-            List<String> allAutofillHints) {
-        try {
-            // TODO use sqlite instead.
-            boolean hasDataForFocusedAutofillHints = false;
-            HashMap<String, ClientFormData> clientFormDataMap = new HashMap<>();
-            Set<String> clientFormDataStringSet = getAllAutofillDataStringSet();
-            for (String clientFormDataString : clientFormDataStringSet) {
-                ClientFormData clientFormData = ClientFormData
-                        .fromJson(new JSONObject(clientFormDataString));
-                if (clientFormData != null) {
-                    if (clientFormData.helpsWithHints(focusedAutofillHints)) {
-                        hasDataForFocusedAutofillHints = true;
-                    }
-                    if (clientFormData.helpsWithHints(allAutofillHints)) {
-                        clientFormDataMap.put(clientFormData.getDatasetName(), clientFormData);
-                    }
-                }
-            }
-            if (hasDataForFocusedAutofillHints) {
-                return clientFormDataMap;
-            } else {
-                return null;
-            }
-        } catch (JSONException e) {
-            return null;
-        }
-    }
-
-    @Override
-    public void saveClientFormData(ClientFormData clientFormData) {
-        //TODO use sqlite instead.
-        String datasetName = "dataset-" + getDatasetNumber();
-        clientFormData.setDatasetName(datasetName);
-        Set<String> allAutofillData = getAllAutofillDataStringSet();
-        allAutofillData.add(clientFormData.toJson().toString());
-        saveAllAutofillDataStringSet(allAutofillData);
-        incrementDatasetNumber();
-    }
-
-    @Override
-    public void clear() {
-        mPrefs.edit().remove(CLIENT_FORM_DATA_KEY).apply();
-    }
-
-    private Set<String> getAllAutofillDataStringSet() {
-        return mPrefs.getStringSet(CLIENT_FORM_DATA_KEY, new ArraySet<String>());
-    }
-
-    private void saveAllAutofillDataStringSet(Set<String> allAutofillDataStringSet) {
-        mPrefs.edit().putStringSet(CLIENT_FORM_DATA_KEY, allAutofillDataStringSet).apply();
-    }
-
-    /**
-     * For simplicity, datasets will be named in the form "dataset-X" where X means
-     * this was the Xth dataset saved.
-     */
-    private int getDatasetNumber() {
-        return mPrefs.getInt(DATASET_NUMBER_KEY, 0);
-    }
-
-    /**
-     * Every time a dataset is saved, this should be called to increment the dataset number.
-     * (only important for this service's dataset naming scheme).
-     */
-    private void incrementDatasetNumber() {
-        mPrefs.edit().putInt(DATASET_NUMBER_KEY, getDatasetNumber() + 1).apply();
-    }
-}
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/SharedPrefsAutofillRepository.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/SharedPrefsAutofillRepository.kt
new file mode 100644
index 00000000..a7eadc96
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/datasource/SharedPrefsAutofillRepository.kt
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.datasource
+
+import android.content.Context
+import android.content.SharedPreferences
+import android.util.ArraySet
+import com.example.android.autofillframework.service.model.ClientFormData
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+
+
+/**
+ * Singleton autofill data repository, that stores autofill fields to SharedPreferences.
+ * DISCLAIMER, you should not store sensitive fields like user data unencrypted. This is only done
+ * here for simplicity and learning purposes.
+ */
+object SharedPrefsAutofillRepository : AutofillRepository {
+    private val SHARED_PREF_KEY = "com.example.android.autofillframework.service"
+    private val CLIENT_FORM_DATA_KEY = "loginCredentialDatasets"
+    private val DATASET_NUMBER_KEY = "datasetNumber"
+
+    private fun getPrefs(context: Context): SharedPreferences {
+        return context.applicationContext.getSharedPreferences(SHARED_PREF_KEY, Context.MODE_PRIVATE)
+    }
+
+    override fun getClientFormData(context: Context, focusedAutofillHints: List<String>,
+            allAutofillHints: List<String>): HashMap<String, ClientFormData>? {
+        var hasDataForFocusedAutofillHints = false
+        val clientFormDataMap = HashMap<String, ClientFormData>()
+        val clientFormDataStringSet = getAllAutofillDataStringSet(context)
+        for (clientFormDataString in clientFormDataStringSet) {
+            val type = object : TypeToken<ClientFormData>() {}.type
+            Gson().fromJson<ClientFormData>(clientFormDataString, type)?.let { clientFormData ->
+                if (clientFormData.helpsWithHints(focusedAutofillHints)) {
+                    hasDataForFocusedAutofillHints = true
+                    clientFormData.datasetName?.let { datasetName ->
+                        if (clientFormData.helpsWithHints(allAutofillHints)) {
+                            clientFormDataMap.put(datasetName, clientFormData)
+                        }
+                    }
+                }
+            }
+        }
+        if (hasDataForFocusedAutofillHints) {
+            return clientFormDataMap
+        } else {
+            return null
+        }
+    }
+
+    override fun saveClientFormData(context: Context, clientFormData: ClientFormData) {
+        val datasetName = "dataset-" + getDatasetNumber(context)
+        clientFormData.datasetName = datasetName
+        val allAutofillData = getAllAutofillDataStringSet(context)
+        allAutofillData.add(Gson().toJson(clientFormData).toString())
+        saveAllAutofillDataStringSet(context, allAutofillData)
+        incrementDatasetNumber(context)
+    }
+
+    override fun clear(context: Context) {
+        getPrefs(context).edit().remove(CLIENT_FORM_DATA_KEY).remove(DATASET_NUMBER_KEY).apply()
+    }
+
+    private fun getAllAutofillDataStringSet(context: Context): MutableSet<String> {
+        return getPrefs(context).getStringSet(CLIENT_FORM_DATA_KEY, ArraySet<String>())
+    }
+
+    private fun saveAllAutofillDataStringSet(context: Context, allAutofillDataStringSet: Set<String>) {
+        getPrefs(context).edit().putStringSet(CLIENT_FORM_DATA_KEY, allAutofillDataStringSet).apply()
+    }
+
+    /**
+     * For simplicity, datasets will be named in the form "dataset-X" where X means
+     * this was the Xth dataset saved.
+     */
+    private fun getDatasetNumber(context: Context): Int {
+        return getPrefs(context).getInt(DATASET_NUMBER_KEY, 0)
+    }
+
+    /**
+     * Every time a dataset is saved, this should be called to increment the dataset number.
+     * (only important for this service's dataset naming scheme).
+     */
+    private fun incrementDatasetNumber(context: Context) {
+        getPrefs(context).edit().putInt(DATASET_NUMBER_KEY, getDatasetNumber(context) + 1).apply()
+    }
+}
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillField.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillField.java
deleted file mode 100644
index 77f0a182..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillField.java
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.model;
-
-import android.app.assist.AssistStructure;
-import android.service.autofill.SaveInfo;
-import android.view.View;
-import android.view.autofill.AutofillId;
-
-/**
- * Class that represents a field that can be autofilled. It will contain a description
- * (what type data the field holds), an AutoFillId (an ID unique to the rest of the ViewStructure),
- * and a value (what data is currently in the field).
- */
-public class AutofillField {
-    private int mSaveType = 0;
-    private String[] mHints;
-    private AutofillId mId;
-    private int mAutofillType;
-    private String[] mAutofillOptions;
-    private boolean mFocused;
-
-    public AutofillField(AssistStructure.ViewNode view) {
-        mId = view.getAutofillId();
-        setHints(view.getAutofillHints());
-        mAutofillType = view.getAutofillType();
-        mAutofillOptions = view.getAutofillOptions();
-        mFocused = view.isFocused();
-    }
-
-    public String[] getHints() {
-        return mHints;
-    }
-
-    public void setHints(String[] hints) {
-        mHints = hints;
-        updateSaveTypeFromHints();
-    }
-
-    public int getSaveType() {
-        return mSaveType;
-    }
-
-    public AutofillId getId() {
-        return mId;
-    }
-
-    public void setId(AutofillId id) {
-        mId = id;
-    }
-
-    public int getAutofillType() {
-        return mAutofillType;
-    }
-
-    public int getAutofillOptionIndex(String value) {
-        for (int i = 0; i < mAutofillOptions.length; i++) {
-            if (mAutofillOptions[i].equals(value)) {
-                return i;
-            }
-        }
-        return -1;
-    }
-
-    public boolean isFocused() {
-        return mFocused;
-    }
-
-    private void updateSaveTypeFromHints() {
-        mSaveType = 0;
-        if (mHints == null) {
-            return;
-        }
-        for (String hint : mHints) {
-            switch (hint) {
-                case View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE:
-                case View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DAY:
-                case View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH:
-                case View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR:
-                case View.AUTOFILL_HINT_CREDIT_CARD_NUMBER:
-                case View.AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE:
-                    mSaveType |= SaveInfo.SAVE_DATA_TYPE_CREDIT_CARD;
-                    break;
-                case View.AUTOFILL_HINT_EMAIL_ADDRESS:
-                    mSaveType |= SaveInfo.SAVE_DATA_TYPE_EMAIL_ADDRESS;
-                    break;
-                case View.AUTOFILL_HINT_PHONE:
-                case View.AUTOFILL_HINT_NAME:
-                    mSaveType |= SaveInfo.SAVE_DATA_TYPE_GENERIC;
-                    break;
-                case View.AUTOFILL_HINT_PASSWORD:
-                    mSaveType |= SaveInfo.SAVE_DATA_TYPE_PASSWORD;
-                    mSaveType &= ~SaveInfo.SAVE_DATA_TYPE_EMAIL_ADDRESS;
-                    mSaveType &= ~SaveInfo.SAVE_DATA_TYPE_USERNAME;
-                    break;
-                case View.AUTOFILL_HINT_POSTAL_ADDRESS:
-                case View.AUTOFILL_HINT_POSTAL_CODE:
-                    mSaveType |= SaveInfo.SAVE_DATA_TYPE_ADDRESS;
-                    break;
-                case View.AUTOFILL_HINT_USERNAME:
-                    mSaveType |= SaveInfo.SAVE_DATA_TYPE_USERNAME;
-                    break;
-            }
-        }
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillField.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillField.kt
new file mode 100644
index 00000000..315299be
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillField.kt
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.model
+
+import android.app.assist.AssistStructure.ViewNode;
+import android.service.autofill.SaveInfo
+import android.view.View
+import android.view.autofill.AutofillId
+
+/**
+ * A stripped down version of a [ViewNode] that contains only autofill-relevant metadata. It also
+ * contains a `saveType` flag that is calculated based on the [ViewNode]'s autofill hints.
+ */
+class AutofillField(view: ViewNode) {
+    var saveType = 0
+        private set
+
+    val autofillHints: Array<String> = view.autofillHints
+    val autofillId: AutofillId = view.autofillId
+    val autofillType: Int = view.autofillType
+    val autofillOptions: Array<String>? = view.autofillOptions
+    val isFocused: Boolean = view.isFocused
+
+    init {
+        updateSaveTypeFromHints()
+    }
+
+    /**
+     * When the [ViewNode] is a list that the user needs to choose a string from (i.e. a spinner),
+     * this is called to return the index of a specific item in the list.
+     */
+    fun getAutofillOptionIndex(value: String): Int? {
+        return autofillOptions?.indexOf(value)
+    }
+
+    private fun updateSaveTypeFromHints() {
+        saveType = 0
+        for (hint in autofillHints) {
+            when (hint) {
+                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE,
+                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DAY,
+                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH,
+                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR,
+                View.AUTOFILL_HINT_CREDIT_CARD_NUMBER,
+                View.AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE -> {
+                    saveType = saveType or SaveInfo.SAVE_DATA_TYPE_CREDIT_CARD
+                }
+                View.AUTOFILL_HINT_EMAIL_ADDRESS -> {
+                    saveType = saveType or SaveInfo.SAVE_DATA_TYPE_EMAIL_ADDRESS
+                }
+                View.AUTOFILL_HINT_PHONE, View.AUTOFILL_HINT_NAME -> {
+                    saveType = saveType or SaveInfo.SAVE_DATA_TYPE_GENERIC
+                }
+                View.AUTOFILL_HINT_PASSWORD -> {
+                    saveType = saveType or SaveInfo.SAVE_DATA_TYPE_PASSWORD
+                    saveType = saveType and SaveInfo.SAVE_DATA_TYPE_EMAIL_ADDRESS.inv()
+                    saveType = saveType and SaveInfo.SAVE_DATA_TYPE_USERNAME.inv()
+                }
+                View.AUTOFILL_HINT_POSTAL_ADDRESS,
+                View.AUTOFILL_HINT_POSTAL_CODE -> {
+                    saveType = saveType or SaveInfo.SAVE_DATA_TYPE_ADDRESS
+                }
+                View.AUTOFILL_HINT_USERNAME -> {
+                    saveType = saveType or SaveInfo.SAVE_DATA_TYPE_USERNAME
+                }
+            }
+        }
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillFieldsCollection.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillFieldsCollection.java
deleted file mode 100644
index 0354b989..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillFieldsCollection.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.model;
-
-import android.view.autofill.AutofillId;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-
-public final class AutofillFieldsCollection {
-
-    private final List<AutofillId> mAutofillIds = new ArrayList<>();
-    private final HashMap<String, List<AutofillField>> mAutofillHintsToFieldsMap = new HashMap<>();
-    private final List<String> mAllAutofillHints = new ArrayList<>();
-    private final List<String> mFocusedAutofillHints = new ArrayList<>();
-    private int size = 0;
-    private int mSaveType = 0;
-
-    public void add(AutofillField autofillField) {
-        mSaveType |= autofillField.getSaveType();
-        size++;
-        mAutofillIds.add(autofillField.getId());
-        List<String> hintsList = Arrays.asList(autofillField.getHints());
-        mAllAutofillHints.addAll(hintsList);
-        if (autofillField.isFocused()) {
-            mFocusedAutofillHints.addAll(hintsList);
-        }
-        for (String hint : autofillField.getHints()) {
-            if (mAutofillHintsToFieldsMap.get(hint) == null) {
-                mAutofillHintsToFieldsMap.put(hint, new ArrayList<AutofillField>());
-            }
-            mAutofillHintsToFieldsMap.get(hint).add(autofillField);
-        }
-    }
-
-    public int getSaveType() {
-        return mSaveType;
-    }
-
-    public AutofillId[] getAutofillIds() {
-        return mAutofillIds.toArray(new AutofillId[size]);
-    }
-
-    public List<AutofillField> getFieldsForHint(String hint) {
-        return mAutofillHintsToFieldsMap.get(hint);
-    }
-
-    public List<String> getFocusedHints() {
-        return mFocusedAutofillHints;
-    }
-
-    public List<String> getAllHints() {
-        return mAllAutofillHints;
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillFieldsCollection.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillFieldsCollection.kt
new file mode 100644
index 00000000..371934da
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/AutofillFieldsCollection.kt
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.model
+
+import android.view.autofill.AutofillId
+import java.util.ArrayList
+import java.util.HashMap
+
+/**
+ * Data structure that stores a collection of `AutofillField`s. Contains all of the client's `View`
+ * hierarchy autofill-relevant metadata.
+ */
+data class AutofillFieldsCollection(val autofillIds: ArrayList<AutofillId> = ArrayList<AutofillId>(),
+        val allAutofillHints: ArrayList<String> = ArrayList<String>(),
+        val focusedAutofillHints: ArrayList<String> = ArrayList<String>()) {
+
+    private val autofillHintsToFieldsMap = HashMap<String, MutableList<AutofillField>>()
+    var saveType = 0
+        private set
+
+    fun add(autofillField: AutofillField) {
+        saveType = saveType or autofillField.saveType
+        autofillIds.add(autofillField.autofillId)
+        val hintsList = autofillField.autofillHints
+        allAutofillHints.addAll(hintsList)
+        if (autofillField.isFocused) {
+            focusedAutofillHints.addAll(hintsList)
+        }
+        autofillField.autofillHints.forEach { autofillHint ->
+            autofillHintsToFieldsMap[autofillHint] = autofillHintsToFieldsMap[autofillHint] ?: ArrayList<AutofillField>()
+            autofillHintsToFieldsMap[autofillHint]?.add(autofillField)
+        }
+    }
+
+    fun getFieldsForHint(hint: String): MutableList<AutofillField>? {
+        return autofillHintsToFieldsMap[hint]
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/ClientFormData.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/ClientFormData.java
deleted file mode 100644
index aa57e935..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/ClientFormData.java
+++ /dev/null
@@ -1,184 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.model;
-
-import android.service.autofill.Dataset;
-import android.support.annotation.NonNull;
-import android.util.Log;
-import android.view.View;
-import android.view.autofill.AutofillId;
-import android.view.autofill.AutofillValue;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Set;
-
-/**
- * ClientFormData is the model that holds all of the data on a client app's page, plus the dataset
- * name associated with it.
- */
-public final class ClientFormData {
-    private static final String TAG = "ClientFormData";
-    private final HashMap<String, SavedAutofillValue> hintMap;
-    private String datasetName;
-
-    public ClientFormData() {
-        this(null, new HashMap<String, SavedAutofillValue>());
-    }
-
-    public ClientFormData(String datasetName, HashMap<String, SavedAutofillValue> hintMap) {
-        this.hintMap = hintMap;
-        this.datasetName = datasetName;
-    }
-
-    public static ClientFormData fromJson(JSONObject jsonObject) {
-        HashMap<String, SavedAutofillValue> hintMap = new HashMap<>();
-        try {
-            String datasetName = jsonObject.has("datasetName") ?
-                    jsonObject.getString("datasetName") : null;
-            JSONObject valuesJson = jsonObject.getJSONObject("values");
-            Iterator<String> hints = valuesJson.keys();
-            while (hints.hasNext()) {
-                String hint = hints.next();
-                JSONObject valueAsJson = valuesJson
-                        .getJSONObject(hint);
-                if (valueAsJson != null) {
-                    SavedAutofillValue savedAutofillValue = SavedAutofillValue.fromJson(valueAsJson);
-                    hintMap.put(hint, savedAutofillValue);
-                }
-            }
-            return new ClientFormData(datasetName, hintMap);
-        } catch (JSONException e) {
-            Log.d(TAG, e.getMessage());
-            return null;
-        }
-    }
-
-    /**
-     * Returns the name of the {@link Dataset}.
-     */
-    public String getDatasetName() {
-        return this.datasetName;
-    }
-
-    /**
-     * Sets the {@link Dataset} name.
-     */
-    public void setDatasetName(String datasetName) {
-        this.datasetName = datasetName;
-    }
-
-    /**
-     * Sets values for a list of hints.
-     */
-    public void set(@NonNull String[] autofillHints, @NonNull SavedAutofillValue autofillValue) {
-        if (autofillHints.length < 1) {
-            return;
-        }
-        for (int i = 0; i < autofillHints.length; i++) {
-            hintMap.put(autofillHints[i], autofillValue);
-        }
-    }
-
-    /**
-     * Populates a {@link Dataset.Builder} with appropriate values for each {@link AutofillId}
-     * in a {@code AutofillFieldsCollection}.
-     */
-    public boolean applyToFields(AutofillFieldsCollection autofillFieldsCollection,
-            Dataset.Builder datasetBuilder) {
-        boolean setValueAtLeastOnce = false;
-        List<String> allHints = autofillFieldsCollection.getAllHints();
-        for (int hintIndex = 0; hintIndex < allHints.size(); hintIndex++) {
-            String hint = allHints.get(hintIndex);
-            List<AutofillField> autofillFields = autofillFieldsCollection.getFieldsForHint(hint);
-            if (autofillFields == null) {
-                continue;
-            }
-            for (int autofillFieldIndex = 0; autofillFieldIndex < autofillFields.size(); autofillFieldIndex++) {
-                AutofillField autofillField = autofillFields.get(autofillFieldIndex);
-                AutofillId autofillId = autofillField.getId();
-                int autofillType = autofillField.getAutofillType();
-                SavedAutofillValue savedAutofillValue = hintMap.get(hint);
-                switch (autofillType) {
-                    case View.AUTOFILL_TYPE_LIST:
-                        int listValue = autofillField.getAutofillOptionIndex(savedAutofillValue.getTextValue());
-                        if (listValue != -1) {
-                            datasetBuilder.setValue(autofillId, AutofillValue.forList(listValue));
-                            setValueAtLeastOnce = true;
-                        }
-                        break;
-                    case View.AUTOFILL_TYPE_DATE:
-                        long dateValue = savedAutofillValue.getDateValue();
-                        if (dateValue != -1) {
-                            datasetBuilder.setValue(autofillId, AutofillValue.forDate(dateValue));
-                            setValueAtLeastOnce = true;
-                        }
-                        break;
-                    case View.AUTOFILL_TYPE_TEXT:
-                        String textValue = savedAutofillValue.getTextValue();
-                        if (textValue != null) {
-                            datasetBuilder.setValue(autofillId, AutofillValue.forText(textValue));
-                            setValueAtLeastOnce = true;
-                        }
-                        break;
-                    case View.AUTOFILL_TYPE_TOGGLE:
-                        if (savedAutofillValue.hasToggleValue()) {
-                            boolean toggleValue = savedAutofillValue.getToggleValue();
-                            datasetBuilder.setValue(autofillId, AutofillValue.forToggle(toggleValue));
-                            setValueAtLeastOnce = true;
-                        }
-                        break;
-                    case View.AUTOFILL_TYPE_NONE:
-                    default:
-                        Log.w(TAG, "Invalid autofill type - " + autofillType);
-                        break;
-                }
-            }
-        }
-        return setValueAtLeastOnce;
-    }
-
-    public JSONObject toJson() {
-        JSONObject jsonObject = new JSONObject();
-        try {
-            jsonObject.put("datasetName", datasetName != null ? datasetName : JSONObject.NULL);
-            JSONObject jsonValues = new JSONObject();
-            Set<String> hints = hintMap.keySet();
-            for (String hint : hints) {
-                SavedAutofillValue value = hintMap.get(hint);
-                jsonValues.put(hint, value != null ? value.toJson() : JSONObject.NULL);
-            }
-            jsonObject.put("values", jsonValues);
-        } catch (JSONException e) {
-            Log.e(TAG, e.getMessage());
-        }
-        return jsonObject;
-    }
-
-    public boolean helpsWithHints(List<String> autofillHints) {
-        for (int i = 0; i < autofillHints.size(); i++) {
-            String autofillHint = autofillHints.get(i);
-            if (hintMap.get(autofillHint) != null && !hintMap.get(autofillHint).isNull()) {
-                return true;
-            }
-        }
-        return false;
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/ClientFormData.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/ClientFormData.kt
new file mode 100644
index 00000000..78980aaa
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/ClientFormData.kt
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.model
+
+import android.service.autofill.Dataset
+import android.util.Log
+import android.view.View
+import android.view.autofill.AutofillId
+import android.view.autofill.AutofillValue
+import java.util.HashMap
+
+
+/**
+ * ClientFormData is the model that represents all of the form data on a client app's page, plus the
+ * dataset name associated with it.
+ */
+class ClientFormData constructor(var datasetName: String? = null,
+        private val hintMap: HashMap<String, MutableAutofillValue> = HashMap<String, MutableAutofillValue>()) {
+
+    private val TAG = "ClientFormData"
+
+    /**
+     * Sets values for a list of autofillHints.
+     */
+    fun setAutofillValuesForHints(autofillHints: Array<String>, autofillValue: MutableAutofillValue) {
+        autofillHints.forEach { hint ->
+            hintMap[hint] = autofillValue
+        }
+    }
+
+    /**
+     * Populates a [Dataset.Builder] with appropriate values for each [AutofillId]
+     * in a `AutofillFieldsCollection`.
+     */
+    fun applyToFields(autofillFieldsCollection: AutofillFieldsCollection,
+            datasetBuilder: Dataset.Builder): Boolean {
+        var setValueAtLeastOnce = false
+        for (hint in autofillFieldsCollection.allAutofillHints) {
+            val autofillFields = autofillFieldsCollection.getFieldsForHint(hint) ?: continue
+            for (autofillField in autofillFields) {
+                val autofillId = autofillField.autofillId
+                val autofillType = autofillField.autofillType
+                val savedAutofillValue = hintMap[hint]
+                when (autofillType) {
+                    View.AUTOFILL_TYPE_LIST -> {
+                        savedAutofillValue?.textValue?.let(autofillField::getAutofillOptionIndex)?.let { index ->
+                            datasetBuilder.setValue(autofillId, AutofillValue.forList(index))
+                            setValueAtLeastOnce = true
+                        }
+                    }
+                    View.AUTOFILL_TYPE_DATE -> {
+                        savedAutofillValue?.dateValue?.let { date ->
+                            datasetBuilder.setValue(autofillId, AutofillValue.forDate(date))
+                            setValueAtLeastOnce = true
+                        }
+                    }
+                    View.AUTOFILL_TYPE_TEXT -> {
+                        savedAutofillValue?.textValue?.let { text ->
+                            datasetBuilder.setValue(autofillId, AutofillValue.forText(text))
+                            setValueAtLeastOnce = true
+                        }
+                    }
+                    View.AUTOFILL_TYPE_TOGGLE -> {
+                        savedAutofillValue?.toggleValue?.let { toggle ->
+                            datasetBuilder.setValue(autofillId, AutofillValue.forToggle(toggle))
+                            setValueAtLeastOnce = true
+                        }
+                    }
+                    else -> Log.w(TAG, "Invalid autofill type - " + autofillType)
+                }
+            }
+        }
+        return setValueAtLeastOnce
+    }
+
+    fun helpsWithHints(autofillHints: List<String>): Boolean {
+        for (autofillHint in autofillHints) {
+            hintMap[autofillHint]?.let { savedAutofillValue ->
+                if (!savedAutofillValue.isNull()) {
+                    return true
+                }
+            }
+        }
+        return false
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/MutableAutofillValue.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/MutableAutofillValue.kt
new file mode 100644
index 00000000..702a1358
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/MutableAutofillValue.kt
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.model
+
+import android.app.assist.AssistStructure
+import android.view.autofill.AutofillValue
+
+/**
+ * Mutable, JSON serializable data class containing the same data as an [AutofillValue].
+ */
+class MutableAutofillValue(viewNode: AssistStructure.ViewNode) {
+    var textValue: String? = null
+    var dateValue: Long? = null
+    var toggleValue: Boolean? = null
+
+    init {
+        viewNode.autofillValue?.let { autofillValue ->
+            if (autofillValue.isList) {
+                val index = autofillValue.listValue
+                viewNode.autofillOptions?.let { autofillOptions ->
+                    if (autofillOptions.size > index) {
+                        textValue = autofillOptions[index]
+                    }
+                }
+            } else if (autofillValue.isDate) {
+                dateValue = autofillValue.dateValue
+            } else if (autofillValue.isText) {
+                // Using toString of AutofillValue.getTextValue in order to save it to
+                // SharedPreferences.
+                textValue = autofillValue.textValue.toString()
+            } else {
+            }
+        }
+    }
+
+    fun isNull(): Boolean {
+        return textValue == null && dateValue == null && toggleValue == null
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/SavedAutofillValue.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/SavedAutofillValue.java
deleted file mode 100644
index 73e0c81e..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/model/SavedAutofillValue.java
+++ /dev/null
@@ -1,135 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.model;
-
-import android.app.assist.AssistStructure;
-import android.util.Log;
-import android.view.autofill.AutofillValue;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-
-public class SavedAutofillValue {
-    private static final String TAG = "SavedAutofillValue";
-    private String textValue = null;
-    private Long dateValue = -1L;
-    private Boolean toggleValue = false;
-    private boolean hasToggleValue = false;
-
-    public static SavedAutofillValue fromJson(JSONObject jsonObject) {
-        if (jsonObject == null) {
-            return null;
-        }
-        try {
-            SavedAutofillValue savedAutofillValue = new SavedAutofillValue();
-
-            savedAutofillValue.textValue =
-                    !jsonObject.isNull("textValue") ? jsonObject.getString("textValue") : null;
-            savedAutofillValue.dateValue =
-                    !jsonObject.isNull("dateValue") ? jsonObject.getLong("dateValue") : null;
-            savedAutofillValue.setToggleValue
-                    (!jsonObject.isNull("toggleValue") ? jsonObject.getBoolean("toggleValue") : null);
-            return savedAutofillValue;
-        } catch (JSONException e) {
-            Log.e(TAG, e.getMessage());
-            return null;
-        }
-    }
-
-    public static SavedAutofillValue fromViewNode(AssistStructure.ViewNode viewNode) {
-        SavedAutofillValue savedAutofillValue = new SavedAutofillValue();
-        AutofillValue autofillValue = viewNode.getAutofillValue();
-        if (autofillValue != null) {
-            if (autofillValue.isList()) {
-                String[] autofillOptions = viewNode.getAutofillOptions();
-                int index = autofillValue.getListValue();
-                if (autofillOptions != null && autofillOptions.length > 0) {
-                    savedAutofillValue.textValue = autofillOptions[index];
-                }
-            } else if (autofillValue.isDate()) {
-                savedAutofillValue.dateValue = autofillValue.getDateValue();
-            } else if (autofillValue.isText()) {
-                // Using toString of AutofillValue.getTextValue in order to save it to
-                // SharedPreferences.
-                savedAutofillValue.textValue = autofillValue.getTextValue().toString();
-            }
-        }
-        return savedAutofillValue;
-    }
-
-    public JSONObject toJson() {
-        JSONObject jsonObject = new JSONObject();
-        try {
-            jsonObject.put("textValue", textValue != null ? textValue : JSONObject.NULL);
-            jsonObject.put("dateValue", dateValue != null ? dateValue : JSONObject.NULL);
-            jsonObject.put("toggleValue", toggleValue != null ? toggleValue : JSONObject.NULL);
-            return jsonObject;
-        } catch (JSONException e) {
-            Log.e(TAG, e.getMessage());
-            return null;
-        }
-    }
-
-    public String getTextValue() {
-        return textValue;
-    }
-
-    public long getDateValue() {
-        return dateValue;
-    }
-
-
-    public boolean getToggleValue() {
-        return toggleValue;
-    }
-
-    public void setToggleValue(Boolean toggleValue) {
-        this.toggleValue = toggleValue;
-        hasToggleValue = toggleValue != null;
-    }
-
-
-    public boolean isNull() {
-        return textValue == null && dateValue == -1L && !hasToggleValue;
-    }
-
-    public boolean hasToggleValue() {
-        return hasToggleValue;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        SavedAutofillValue that = (SavedAutofillValue) o;
-
-        if (textValue != null ? !textValue.equals(that.textValue) : that.textValue != null)
-            return false;
-        if (dateValue != null ? !dateValue.equals(that.dateValue) : that.dateValue != null)
-            return false;
-        return toggleValue != null ? toggleValue.equals(that.toggleValue) : that.toggleValue == null;
-
-    }
-
-    @Override
-    public int hashCode() {
-        int result = textValue != null ? textValue.hashCode() : 0;
-        result = 31 * result + (dateValue != null ? dateValue.hashCode() : 0);
-        result = 31 * result + (toggleValue != null ? toggleValue.hashCode() : 0);
-        return result;
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/MyPreferences.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/MyPreferences.java
deleted file mode 100644
index 3926530e..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/MyPreferences.java
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.settings;
-
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.service.autofill.Dataset;
-import android.service.autofill.FillResponse;
-import android.support.annotation.NonNull;
-
-public class MyPreferences {
-    private static final String TAG = "MyPreferences";
-
-    private static final String RESPONSE_AUTH_KEY = "response_auth";
-    private static final String DATASET_AUTH_KEY = "dataset_auth";
-    private static final String MASTER_PASSWORD_KEY = "master_password";
-
-    private static MyPreferences sInstance;
-    private final SharedPreferences mPrefs;
-
-    private MyPreferences(Context context) {
-        mPrefs = context.getApplicationContext().getSharedPreferences("my-settings",
-                Context.MODE_PRIVATE);
-    }
-
-    public static MyPreferences getInstance(Context context) {
-        if (sInstance == null) {
-            sInstance = new MyPreferences(context);
-        }
-        return sInstance;
-    }
-
-    /**
-     * Gets whether {@link FillResponse}s should require authentication.
-     */
-    public boolean isResponseAuth() {
-        return mPrefs.getBoolean(RESPONSE_AUTH_KEY, false);
-    }
-
-    /**
-     * Enables/disables authentication for the entire autofill {@link FillResponse}.
-     */
-    public void setResponseAuth(boolean responseAuth) {
-        mPrefs.edit().putBoolean(RESPONSE_AUTH_KEY, responseAuth).apply();
-    }
-
-    /**
-     * Gets whether {@link Dataset}s should require authentication.
-     */
-    public boolean isDatasetAuth() {
-        return mPrefs.getBoolean(DATASET_AUTH_KEY, false);
-    }
-
-    /**
-     * Enables/disables authentication for individual autofill {@link Dataset}s.
-     */
-    public void setDatasetAuth(boolean datasetAuth) {
-        mPrefs.edit().putBoolean(DATASET_AUTH_KEY, datasetAuth).apply();
-    }
-
-    /**
-     * Gets autofill master username.
-     */
-    public String getMasterPassword() {
-        return mPrefs.getString(MASTER_PASSWORD_KEY, null);
-    }
-
-    /**
-     * Sets autofill master password.
-     */
-    public void setMasterPassword(@NonNull String masterPassword) {
-        mPrefs.edit().putString(MASTER_PASSWORD_KEY, masterPassword).apply();
-    }
-
-    public void clearCredentials() {
-        mPrefs.edit().remove(MASTER_PASSWORD_KEY).apply();
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/MyPreferences.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/MyPreferences.kt
new file mode 100644
index 00000000..096813f6
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/MyPreferences.kt
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.settings
+
+import android.content.Context
+import android.content.SharedPreferences
+import android.service.autofill.Dataset
+import android.service.autofill.FillResponse
+
+object MyPreferences {
+    private val TAG = "MyPreferences"
+
+    private val SHARED_PREF_KEY = "com.example.android.autofillframework.service.settings.MyPreferences"
+    private val RESPONSE_AUTH_KEY = "response_auth"
+    private val DATASET_AUTH_KEY = "dataset_auth"
+    private val MASTER_PASSWORD_KEY = "master_password"
+
+    private fun getPrefs(context: Context): SharedPreferences {
+        return context.applicationContext.getSharedPreferences(SHARED_PREF_KEY, Context.MODE_PRIVATE)
+    }
+
+    /**
+     * Determines whether [FillResponse]s should require authentication.
+     */
+    fun isResponseAuth(context: Context): Boolean {
+        return getPrefs(context).getBoolean(RESPONSE_AUTH_KEY, false)
+    }
+
+    fun setResponseAuth(context: Context, responseAuth: Boolean) {
+        getPrefs(context).edit().putBoolean(RESPONSE_AUTH_KEY, responseAuth).apply()
+    }
+
+    /**
+     * Determines whether [Dataset]s should require authentication.
+     */
+    fun isDatasetAuth(context: Context): Boolean {
+        return getPrefs(context).getBoolean(DATASET_AUTH_KEY, false)
+    }
+
+    fun setDatasetAuth(context: Context, datasetAuth: Boolean) {
+        getPrefs(context).edit().putBoolean(DATASET_AUTH_KEY, datasetAuth).apply()
+    }
+
+    /**
+     * Gets autofill master password.
+     */
+    fun getMasterPassword(context: Context): String? {
+        return getPrefs(context).getString(MASTER_PASSWORD_KEY, null)
+    }
+
+    /**
+     * Sets autofill master password.
+     */
+    fun setMasterPassword(context: Context, masterPassword: String) {
+        getPrefs(context).edit().putString(MASTER_PASSWORD_KEY, masterPassword).apply()
+    }
+
+    /**
+     * Removes master password.
+     */
+    fun clearCredentials(context: Context) {
+        getPrefs(context).edit().remove(MASTER_PASSWORD_KEY).apply()
+    }
+}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/SettingsActivity.java b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/SettingsActivity.java
deleted file mode 100644
index 6387d36b..00000000
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/SettingsActivity.java
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.example.android.autofillframework.service.settings;
-
-import android.content.DialogInterface;
-import android.os.Bundle;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.app.AppCompatActivity;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.CompoundButton;
-import android.widget.EditText;
-import android.widget.ImageView;
-import android.widget.Switch;
-import android.widget.TextView;
-
-import com.example.android.autofillframework.R;
-import com.example.android.autofillframework.service.datasource.LocalAutofillRepository;
-
-public class SettingsActivity extends AppCompatActivity {
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        setContentView(R.layout.settings_activity);
-        final MyPreferences preferences = MyPreferences.getInstance(this);
-        setupSettingsSwitch(R.id.settings_auth_responses_container,
-                R.id.settings_auth_responses_label,
-                R.id.settings_auth_responses_switch,
-                preferences.isResponseAuth(),
-                new CompoundButton.OnCheckedChangeListener() {
-                    @Override
-                    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
-                        preferences.setResponseAuth(b);
-                    }
-                });
-        setupSettingsSwitch(R.id.settings_auth_datasets_container,
-                R.id.settings_auth_datasets_label,
-                R.id.settings_auth_datasets_switch,
-                preferences.isDatasetAuth(),
-                new CompoundButton.OnCheckedChangeListener() {
-                    @Override
-                    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
-                        preferences.setDatasetAuth(b);
-                    }
-                });
-        setupSettingsButton(R.id.settings_clear_data_container,
-                R.id.settings_clear_data_label,
-                R.id.settings_clear_data_icon,
-                new View.OnClickListener() {
-                    @Override
-                    public void onClick(View view) {
-                        buildClearDataDialog().show();
-                    }
-                });
-
-        setupSettingsButton(R.id.settings_auth_credentials_container,
-                R.id.settings_auth_credentials_label,
-                R.id.settings_auth_credentials_icon,
-                new View.OnClickListener() {
-                    @Override
-                    public void onClick(View view) {
-                        if (preferences.getMasterPassword() != null) {
-                            buildCurrentCredentialsDialog().show();
-                        } else {
-                            buildNewCredentialsDialog().show();
-                        }
-                    }
-                });
-    }
-
-    private AlertDialog buildClearDataDialog() {
-        return new AlertDialog.Builder(SettingsActivity.this)
-                .setMessage(R.string.settings_clear_data_confirmation)
-                .setTitle(R.string.settings_clear_data_confirmation_title)
-                .setNegativeButton(R.string.cancel, null)
-                .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialog, int which) {
-                        LocalAutofillRepository.getInstance
-                                (SettingsActivity.this).clear();
-                        MyPreferences.getInstance(SettingsActivity.this)
-                                .clearCredentials();
-                        dialog.dismiss();
-                    }
-                })
-                .create();
-    }
-
-    private AlertDialog.Builder prepareCredentialsDialog() {
-        return new AlertDialog.Builder(SettingsActivity.this)
-                .setTitle(R.string.settings_auth_change_credentials_title)
-                .setNegativeButton(R.string.cancel, null);
-    }
-
-    private AlertDialog buildCurrentCredentialsDialog() {
-        final EditText currentPasswordField = LayoutInflater
-                .from(SettingsActivity.this)
-                .inflate(R.layout.settings_authentication_dialog, null)
-                .findViewById(R.id.master_password_field);
-        return prepareCredentialsDialog()
-                .setMessage(R.string.settings_auth_enter_current_password)
-                .setView(currentPasswordField)
-                .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialog, int which) {
-                        String password = currentPasswordField.getText().toString();
-                        if (MyPreferences.getInstance(SettingsActivity.this).getMasterPassword()
-                                .equals(password)) {
-                            buildNewCredentialsDialog().show();
-                            dialog.dismiss();
-                        }
-                    }
-                })
-                .create();
-    }
-
-    private AlertDialog buildNewCredentialsDialog() {
-        final EditText newPasswordField = LayoutInflater
-                .from(SettingsActivity.this)
-                .inflate(R.layout.settings_authentication_dialog, null)
-                .findViewById(R.id.master_password_field);
-        return prepareCredentialsDialog()
-                .setMessage(R.string.settings_auth_enter_new_password)
-                .setView(newPasswordField)
-                .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialog, int which) {
-                        String password = newPasswordField.getText().toString();
-                        MyPreferences.getInstance(SettingsActivity.this).setMasterPassword(password);
-                        dialog.dismiss();
-                    }
-                })
-                .create();
-    }
-
-    private void setupSettingsSwitch(int containerId, int labelId, int switchId, boolean checked,
-            CompoundButton.OnCheckedChangeListener checkedChangeListener) {
-        ViewGroup container = (ViewGroup) findViewById(containerId);
-        String switchLabel = ((TextView) container.findViewById(labelId)).getText().toString();
-        final Switch switchView = container.findViewById(switchId);
-        switchView.setContentDescription(switchLabel);
-        switchView.setChecked(checked);
-        container.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                switchView.performClick();
-            }
-        });
-        switchView.setOnCheckedChangeListener(checkedChangeListener);
-    }
-
-    private void setupSettingsButton(int containerId, int labelId, int imageViewId,
-            final View.OnClickListener onClickListener) {
-        ViewGroup container = (ViewGroup) findViewById(containerId);
-        String buttonLabel = ((TextView) container.findViewById(labelId)).getText().toString();
-        final ImageView imageView = container.findViewById(imageViewId);
-        imageView.setContentDescription(buttonLabel);
-        container.setOnClickListener(onClickListener);
-    }
-}
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/SettingsActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/SettingsActivity.kt
new file mode 100644
index 00000000..cfa9d82f
--- /dev/null
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/service/settings/SettingsActivity.kt
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.autofillframework.service.settings
+
+import android.os.Bundle
+import android.support.v7.app.AlertDialog
+import android.support.v7.app.AppCompatActivity
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.CompoundButton
+import android.widget.EditText
+import android.widget.ImageView
+import android.widget.Switch
+import android.widget.TextView
+import com.example.android.autofillframework.R
+import com.example.android.autofillframework.service.datasource.SharedPrefsAutofillRepository
+
+class SettingsActivity : AppCompatActivity() {
+
+    public override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        setContentView(R.layout.settings_activity)
+        setupSettingsSwitch(R.id.settings_auth_responses_container,
+                R.id.settings_auth_responses_label,
+                R.id.settings_auth_responses_switch,
+                MyPreferences.isResponseAuth(this),
+                CompoundButton.OnCheckedChangeListener { compoundButton, b ->
+                    MyPreferences.setResponseAuth(this@SettingsActivity, b)
+                })
+        setupSettingsSwitch(R.id.settings_auth_datasets_container,
+                R.id.settings_auth_datasets_label,
+                R.id.settings_auth_datasets_switch,
+                MyPreferences.isDatasetAuth(this),
+                CompoundButton.OnCheckedChangeListener { compoundButton, b ->
+                    MyPreferences.setDatasetAuth(this@SettingsActivity, b)
+                })
+        setupSettingsButton(R.id.settings_clear_data_container,
+                R.id.settings_clear_data_label,
+                R.id.settings_clear_data_icon,
+                View.OnClickListener { buildClearDataDialog().show() })
+
+        setupSettingsButton(R.id.settings_auth_credentials_container,
+                R.id.settings_auth_credentials_label,
+                R.id.settings_auth_credentials_icon,
+                View.OnClickListener {
+                    MyPreferences.getMasterPassword(this@SettingsActivity)?.let {
+                        buildCurrentCredentialsDialog().show()
+                    } ?: buildNewCredentialsDialog().show()
+                })
+    }
+
+    private fun buildClearDataDialog(): AlertDialog {
+        return AlertDialog.Builder(this@SettingsActivity)
+                .setMessage(R.string.settings_clear_data_confirmation)
+                .setTitle(R.string.settings_clear_data_confirmation_title)
+                .setNegativeButton(R.string.cancel, null)
+                .setPositiveButton(R.string.ok) { dialog, which ->
+                    SharedPrefsAutofillRepository.clear(this@SettingsActivity)
+                    MyPreferences.clearCredentials(this@SettingsActivity)
+                    dialog.dismiss()
+                }
+                .create()
+    }
+
+    private fun prepareCredentialsDialog(): AlertDialog.Builder {
+        return AlertDialog.Builder(this@SettingsActivity)
+                .setTitle(R.string.settings_auth_change_credentials_title)
+                .setNegativeButton(R.string.cancel, null)
+    }
+
+    private fun buildCurrentCredentialsDialog(): AlertDialog {
+        val currentPasswordField = LayoutInflater
+                .from(this@SettingsActivity)
+                .inflate(R.layout.settings_authentication_dialog, null)
+                .findViewById<EditText>(R.id.master_password_field)
+        return prepareCredentialsDialog()
+                .setMessage(R.string.settings_auth_enter_current_password)
+                .setView(currentPasswordField)
+                .setPositiveButton(R.string.ok) { dialog, which ->
+                    val password = currentPasswordField.text.toString()
+                    if (MyPreferences.getMasterPassword(this@SettingsActivity) == password) {
+                        buildNewCredentialsDialog().show()
+                        dialog.dismiss()
+                    }
+                }
+                .create()
+    }
+
+    private fun buildNewCredentialsDialog(): AlertDialog {
+        val newPasswordField = LayoutInflater
+                .from(this@SettingsActivity)
+                .inflate(R.layout.settings_authentication_dialog, null)
+                .findViewById<EditText>(R.id.master_password_field)
+        return prepareCredentialsDialog()
+                .setMessage(R.string.settings_auth_enter_new_password)
+                .setView(newPasswordField)
+                .setPositiveButton(R.string.ok) { dialog, which ->
+                    val password = newPasswordField.text.toString()
+                    MyPreferences.setMasterPassword(this@SettingsActivity, password)
+                    dialog.dismiss()
+                }
+                .create()
+    }
+
+    private fun setupSettingsSwitch(containerId: Int, labelId: Int, switchId: Int, checked: Boolean,
+            checkedChangeListener: CompoundButton.OnCheckedChangeListener) {
+        val container = findViewById(containerId) as ViewGroup
+        val switchLabel = (container.findViewById<View>(labelId) as TextView).text.toString()
+        val switchView = container.findViewById<Switch>(switchId)
+        switchView.contentDescription = switchLabel
+        switchView.isChecked = checked
+        container.setOnClickListener { switchView.performClick() }
+        switchView.setOnCheckedChangeListener(checkedChangeListener)
+    }
+
+    private fun setupSettingsButton(containerId: Int, labelId: Int, imageViewId: Int,
+            onClickListener: View.OnClickListener) {
+        val container = findViewById(containerId) as ViewGroup
+        val buttonLabel = (container.findViewById<View>(labelId) as TextView).text.toString()
+        val imageView = container.findViewById<ImageView>(imageViewId)
+        imageView.contentDescription = buttonLabel
+        container.setOnClickListener(onClickListener)
+    }
+}