Merge "Add pref for notification swipe direction"
diff --git a/res/layout-land/wifi_dpp_qrcode_scanner_fragment.xml b/res/layout-land/wifi_dpp_qrcode_scanner_fragment.xml
index 4eed0f6..0069e93 100644
--- a/res/layout-land/wifi_dpp_qrcode_scanner_fragment.xml
+++ b/res/layout-land/wifi_dpp_qrcode_scanner_fragment.xml
@@ -46,9 +46,14 @@
                     android:layout_height="match_parent"/>
             </com.android.settings.wifi.qrcode.QrPreviewLayout>
 
-            <TextView android:id="@+id/error_message"
+            <TextView
+                android:id="@+id/error_message"
                 android:layout_width="wrap_content"
-                android:layout_height="wrap_content"/>
+                android:layout_height="wrap_content"
+                android:textAlignment="center"
+                android:layout_marginTop="8dp"
+                android:visibility="invisible"
+                android:textColor="?android:attr/colorError"/>
 
         </LinearLayout>
 
diff --git a/res/layout/wifi_dpp_qrcode_scanner_fragment.xml b/res/layout/wifi_dpp_qrcode_scanner_fragment.xml
index c5e416b..9bd066b 100644
--- a/res/layout/wifi_dpp_qrcode_scanner_fragment.xml
+++ b/res/layout/wifi_dpp_qrcode_scanner_fragment.xml
@@ -50,8 +50,8 @@
                 android:id="@+id/error_message"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
+                android:textAlignment="center"
                 android:layout_marginTop="8dp"
-                android:text="@string/wifi_dpp_could_not_detect_valid_qr_code"
                 android:visibility="invisible"
                 android:textColor="?android:attr/colorError"/>
 
diff --git a/res/values/strings.xml b/res/values/strings.xml
index c76057a..10fc7d3 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -1859,6 +1859,11 @@
     <!-- This string asks the user whether or not to allow an app to disable WiFi. [CHAR LIMIT=NONE] -->
     <string name="wifi_ask_disable"><xliff:g id="requester" example="FancyApp">%s</xliff:g> wants to turn off Wi-Fi</string>
 
+    <!-- Debugging developer settings: Enable ART verifier for Debuggable Apps [CHAR LIMIT=40] -->
+    <string name="art_verifier_for_debuggable_title">Verify bytecode of debuggable apps</string>
+    <!-- Debugging developer settings: Enable ART verifier for Debuggable Apps [CHAR LIMIT=NONE] -->
+    <string name="art_verifier_for_debuggable_summary">Allow ART to verify bytecode for debuggable apps</string>
+
     <!-- NFC settings -->
     <!-- Used in the 1st-level settings screen to turn on NFC -->
     <string name="nfc_quick_toggle_title">NFC</string>
@@ -2119,7 +2124,19 @@
     <!-- Hint for the user to use another device to scan QR code on screen to join Wi-Fi [CHAR LIMIT=NONE] -->
     <string name="wifi_dpp_scan_qr_code_with_another_device">Scan this QR code with another device to join \u201c<xliff:g id="ssid" example="OfficeWifi">%1$s</xliff:g>\u201d</string>
     <!-- Hint for QR code detection [CHAR LIMIT=NONE]  -->
-    <string name="wifi_dpp_could_not_detect_valid_qr_code">Couldn\u2019t read QR code</string>
+    <string name="wifi_dpp_could_not_detect_valid_qr_code">Couldn\u2019t read QR code. Re-center code and try again</string>
+    <!-- Hint for Wi-Fi DPP handshake failure [CHAR LIMIT=NONE]  -->
+    <string name="wifi_dpp_failure_authentication_or_configuration">Try again. If the issue continues, contact the device manufacturer</string>
+    <!-- Hint for Wi-Fi DPP handshake failure [CHAR LIMIT=NONE]  -->
+    <string name="wifi_dpp_failure_not_compatible">Something went wrong</string>
+    <!-- Hint for Wi-Fi DPP handshake failure [CHAR LIMIT=NONE]  -->
+    <string name="wifi_dpp_failure_timeout">Make sure the device has been plugged in, charged, and turned on</string>
+    <!-- Hint for Wi-Fi DPP handshake failure [CHAR LIMIT=NONE]  -->
+    <string name="wifi_dpp_failure_generic">Make sure the device has been plugged in, charged, and turned on. If the issue continues, contact the device manufacturer</string>
+    <!-- Hint for Wi-Fi DPP handshake failure [CHAR LIMIT=NONE]  -->
+    <string name="wifi_dpp_failure_not_supported">Adding \u201c<xliff:g id="ssid" example="OfficeWifi">%1$s</xliff:g>\u201d isn\u2019t supported by this device</string>
+    <!-- Hint for Wi-Fi connection fail [CHAR LIMIT=NONE]  -->
+    <string name="wifi_dpp_check_connection_try_again">Check connection and try again</string>
     <!-- Title for the fragment choose network [CHAR LIMIT=50]  -->
     <string name="wifi_dpp_choose_network">Choose network</string>
     <!-- Hint for the user to center another device's QR code in the below camera window [CHAR LIMIT=NONE] -->
@@ -9180,7 +9197,7 @@
     <!-- Title of condition that do not disturb is on [CHAR LIMIT=36] -->
     <string name="condition_zen_title">Do Not Disturb is on</string>
 
-    <!-- Summary of condition that do not disturb is on and all exceptions set to off [CHAR LIMIT=36] -->
+    <!-- Summary of condition that do not disturb is on and all exceptions set to off [CHAR LIMIT=38] -->
     <string name="condition_zen_summary_phone_muted">Phone muted</string>
 
     <!-- Summary of condition that do not disturb is on and some exceptions are allowed [CHAR LIMIT=36] -->
diff --git a/res/xml/development_settings.xml b/res/xml/development_settings.xml
index d9b592c..032f622 100644
--- a/res/xml/development_settings.xml
+++ b/res/xml/development_settings.xml
@@ -175,6 +175,11 @@
             android:title="@string/verify_apps_over_usb_title"
             android:summary="@string/verify_apps_over_usb_summary" />
 
+        <SwitchPreference
+            android:key="art_verifier_for_debuggable"
+            android:title="@string/art_verifier_for_debuggable_title"
+            android:summary="@string/art_verifier_for_debuggable_summary" />
+
         <ListPreference
             android:key="select_logd_size"
             android:title="@string/select_logd_size_title"
diff --git a/src/com/android/settings/development/ArtVerifierPreferenceController.java b/src/com/android/settings/development/ArtVerifierPreferenceController.java
new file mode 100644
index 0000000..4b2f030
--- /dev/null
+++ b/src/com/android/settings/development/ArtVerifierPreferenceController.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2019 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.android.settings.development;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.Preference;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.development.DeveloperOptionsPreferenceController;
+
+public class ArtVerifierPreferenceController extends DeveloperOptionsPreferenceController
+        implements Preference.OnPreferenceChangeListener, PreferenceControllerMixin {
+
+    private static final String ART_VERIFIER_FOR_DEBUGGABLE = "art_verifier_for_debuggable";
+
+    @VisibleForTesting
+    static final int SETTING_VALUE_ON = 1;
+    @VisibleForTesting
+    static final int SETTING_VALUE_OFF = 0;
+
+    public ArtVerifierPreferenceController(Context context) {
+        super(context);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return ART_VERIFIER_FOR_DEBUGGABLE;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        final boolean isEnabled = (Boolean) newValue;
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE,
+                isEnabled ? SETTING_VALUE_ON : SETTING_VALUE_OFF);
+        return true;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        final int verifyDebuggable = Settings.Global.getInt(
+                mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE, SETTING_VALUE_ON);
+        ((SwitchPreference) mPreference).setChecked(verifyDebuggable != SETTING_VALUE_OFF);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        super.onDeveloperOptionsSwitchDisabled();
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE, SETTING_VALUE_ON);
+        ((SwitchPreference) mPreference).setChecked(true);
+    }
+}
diff --git a/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java b/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
index 78520c6..adc23a8 100644
--- a/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
+++ b/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
@@ -424,6 +424,7 @@
         controllers.add(new WaitForDebuggerPreferenceController(context));
         controllers.add(new EnableGpuDebugLayersPreferenceController(context));
         controllers.add(new VerifyAppsOverUsbPreferenceController(context));
+        controllers.add(new ArtVerifierPreferenceController(context));
         controllers.add(new LogdSizePreferenceController(context));
         controllers.add(new LogPersistPreferenceController(context, fragment, lifecycle));
         controllers.add(new CameraLaserSensorPreferenceController(context));
diff --git a/src/com/android/settings/network/telephony/MobileDataPreferenceController.java b/src/com/android/settings/network/telephony/MobileDataPreferenceController.java
index f678e08..de54879 100644
--- a/src/com/android/settings/network/telephony/MobileDataPreferenceController.java
+++ b/src/com/android/settings/network/telephony/MobileDataPreferenceController.java
@@ -22,21 +22,21 @@
 import android.os.Handler;
 import android.os.Looper;
 import android.provider.Settings;
+import android.telephony.SubscriptionInfo;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+
 import androidx.annotation.VisibleForTesting;
 import androidx.fragment.app.FragmentManager;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceScreen;
 import androidx.preference.SwitchPreference;
 
-import com.android.settings.core.TogglePreferenceController;
-import com.android.settingslib.core.lifecycle.LifecycleObserver;
-import com.android.settingslib.core.lifecycle.events.OnStart;
-import com.android.settingslib.core.lifecycle.events.OnStop;
-
 /**
  * Preference controller for "Mobile data"
  */
@@ -115,8 +115,18 @@
 
     @Override
     public boolean isChecked() {
-        return mTelephonyManager.isDataEnabled()
-                && mSubId == SubscriptionManager.getDefaultDataSubscriptionId();
+        return mTelephonyManager.isDataEnabled();
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        super.updateState(preference);
+        preference.setEnabled(!isOpportunistic());
+    }
+
+    private boolean isOpportunistic() {
+        SubscriptionInfo info = mSubscriptionManager.getActiveSubscriptionInfo(mSubId);
+        return info != null && info.isOpportunistic();
     }
 
     public static Uri getObservableUri(int subId) {
diff --git a/src/com/android/settings/wifi/dpp/WifiDppAddDeviceFragment.java b/src/com/android/settings/wifi/dpp/WifiDppAddDeviceFragment.java
index 4523def..536924d 100644
--- a/src/com/android/settings/wifi/dpp/WifiDppAddDeviceFragment.java
+++ b/src/com/android/settings/wifi/dpp/WifiDppAddDeviceFragment.java
@@ -20,6 +20,8 @@
 import android.app.Activity;
 import android.app.settings.SettingsEnums;
 import android.content.Context;
+import android.content.pm.ActivityInfo;
+import android.net.wifi.EasyConnectStatusCallback;
 import android.net.wifi.WifiManager;
 import android.os.Bundle;
 import android.text.TextUtils;
@@ -30,6 +32,8 @@
 import android.widget.Button;
 import android.widget.ImageView;
 
+import androidx.lifecycle.ViewModelProviders;
+
 import com.android.settings.R;
 
 import java.util.concurrent.Executor;
@@ -46,7 +50,12 @@
     private Button mButtonLeft;
     private Button mButtonRight;
 
-    private class EasyConnectStatusCallback extends android.net.wifi.EasyConnectStatusCallback {
+    private int mLatestStatusCode = WifiDppUtils.EASY_CONNECT_EVENT_FAILURE_NONE;
+
+    // Key for Bundle usage
+    private static final String KEY_LATEST_ERROR_CODE = "key_latest_error_code";
+
+    private class EasyConnectConfiguratorStatusCallback extends EasyConnectStatusCallback {
         @Override
         public void onEnrolleeSuccess(int newNetworkId) {
             // Do nothing
@@ -54,32 +63,14 @@
 
         @Override
         public void onConfiguratorSuccess(int code) {
-            // Update success UI.
-            setHeaderIconImageResource(R.drawable.ic_devices_check_circle_green);
-            mTitle.setText(R.string.wifi_dpp_wifi_shared_with_device);
-            mSummary.setVisibility(View.INVISIBLE);
-            mWifiApPictureView.setImageResource(R.drawable.wifi_dpp_success);
-            mChooseDifferentNetwork.setVisibility(View.INVISIBLE);
-            mButtonLeft.setText(R.string.wifi_dpp_add_another_device);
-            mButtonLeft.setOnClickListener(v -> getFragmentManager().popBackStack());
-            mButtonRight.setText(R.string.done);
-            mButtonRight.setOnClickListener(v -> {
-                final Activity activity = getActivity();
-                activity.setResult(Activity.RESULT_OK);
-                activity.finish();
-            });
+            showSuccessUi(/* isConfigurationChange */ false);
         }
 
         @Override
         public void onFailure(int code) {
-            Log.d(TAG, "EasyConnectStatusCallback.onFailure " + code);
+            Log.d(TAG, "EasyConnectConfiguratorStatusCallback.onFailure " + code);
 
-            // Update fail UI.
-            mTitle.setText(R.string.wifi_dpp_could_not_add_device);
-            mSummary.setVisibility(View.INVISIBLE);
-            mWifiApPictureView.setImageResource(R.drawable.wifi_dpp_error);
-            mChooseDifferentNetwork.setVisibility(View.INVISIBLE);
-            mButtonRight.setText(R.string.retry);
+            showErrorUi(code, /* isConfigurationChange */ false);
         }
 
         @Override
@@ -88,12 +79,145 @@
         }
     }
 
+    private void showSuccessUi(boolean isConfigurationChange) {
+        setHeaderIconImageResource(R.drawable.ic_devices_check_circle_green);
+        mTitle.setText(R.string.wifi_dpp_wifi_shared_with_device);
+        mSummary.setVisibility(View.INVISIBLE);
+        mWifiApPictureView.setImageResource(R.drawable.wifi_dpp_success);
+        mChooseDifferentNetwork.setVisibility(View.INVISIBLE);
+        mButtonLeft.setText(R.string.wifi_dpp_add_another_device);
+        mButtonLeft.setOnClickListener(v -> getFragmentManager().popBackStack());
+        mButtonRight.setText(R.string.done);
+        mButtonRight.setOnClickListener(v -> {
+            final Activity activity = getActivity();
+            activity.setResult(Activity.RESULT_OK);
+            activity.finish();
+        });
+
+        if (!isConfigurationChange) {
+            mLatestStatusCode = WifiDppUtils.EASY_CONNECT_EVENT_SUCCESS;
+        }
+    }
+
+    private void showErrorUi(int code, boolean isConfigurationChange) {
+        switch (code) {
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_INVALID_URI:
+                mSummary.setText(R.string.wifi_dpp_could_not_detect_valid_qr_code);
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_AUTHENTICATION:
+                mSummary.setText(R.string.wifi_dpp_failure_authentication_or_configuration);
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_NOT_COMPATIBLE:
+                mSummary.setText(R.string.wifi_dpp_failure_not_compatible);
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_CONFIGURATION:
+                mSummary.setText(R.string.wifi_dpp_failure_authentication_or_configuration);
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_BUSY:
+                if (isConfigurationChange) {
+                    return;
+                }
+
+                if (code == mLatestStatusCode) {
+                    throw(new IllegalStateException("Tried restarting EasyConnectSession but still"
+                            + "receiving EASY_CONNECT_EVENT_FAILURE_BUSY"));
+                }
+
+                mLatestStatusCode = code;
+                final WifiManager wifiManager =
+                        getContext().getSystemService(WifiManager.class);
+                wifiManager.stopEasyConnectSession();
+                startWifiDppConfiguratorInitiator();
+                return;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_TIMEOUT:
+                mSummary.setText(R.string.wifi_dpp_failure_timeout);
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_GENERIC:
+                mSummary.setText(R.string.wifi_dpp_failure_generic);
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_NOT_SUPPORTED:
+                mSummary.setText(getString(R.string.wifi_dpp_failure_not_supported, getSsid()));
+                break;
+
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_INVALID_NETWORK:
+                throw(new IllegalStateException("Wi-Fi DPP configurator used a non-PSK/non-SAE"
+                        + "network to handshake"));
+
+            default:
+                throw(new IllegalStateException("Unexpected Wi-Fi DPP error"));
+        }
+
+        mTitle.setText(R.string.wifi_dpp_could_not_add_device);
+        mWifiApPictureView.setImageResource(R.drawable.wifi_dpp_error);
+        mChooseDifferentNetwork.setVisibility(View.INVISIBLE);
+        if (hasRetryButton(code)) {
+            mButtonRight.setText(R.string.retry);
+        } else {
+            mButtonRight.setText(R.string.done);
+            mButtonRight.setOnClickListener(v -> getActivity().finish());
+            mButtonLeft.setVisibility(View.INVISIBLE);
+        }
+
+        if (!isConfigurationChange) {
+            mLatestStatusCode = code;
+        }
+
+        mButtonRight.setVisibility(isGoingInitiator() ? View.INVISIBLE : View.VISIBLE);
+    }
+
+    private boolean hasRetryButton(int code) {
+        switch (code) {
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_INVALID_URI:
+            case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_NOT_COMPATIBLE:
+                return false;
+
+            default:
+                break;
+        }
+
+        return true;
+    }
+
     @Override
     public int getMetricsCategory() {
         return SettingsEnums.SETTINGS_WIFI_DPP_CONFIGURATOR;
     }
 
     @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        if (savedInstanceState != null) {
+            mLatestStatusCode = savedInstanceState.getInt(KEY_LATEST_ERROR_CODE);
+        }
+
+        final WifiDppInitiatorViewModel model =
+                ViewModelProviders.of(this).get(WifiDppInitiatorViewModel.class);
+
+        model.getStatusCode().observe(this, statusCode -> {
+            // After configuration change, observe callback will be triggered,
+            // do nothing for this case if a handshake does not end
+            if (model.isGoingInitiator()) {
+                return;
+            }
+
+            int code = statusCode.intValue();
+            if (code == WifiDppUtils.EASY_CONNECT_EVENT_SUCCESS) {
+                new EasyConnectConfiguratorStatusCallback().onConfiguratorSuccess(code);
+            } else {
+                new EasyConnectConfiguratorStatusCallback().onFailure(code);
+            }
+        });
+    }
+
+    @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
 
@@ -125,14 +249,7 @@
             mTitle.setText(information);
         }
 
-        final WifiNetworkConfig wifiNetworkConfig = ((WifiDppConfiguratorActivity) getActivity())
-                .getWifiNetworkConfig();
-        if (!WifiNetworkConfig.isValidConfig(wifiNetworkConfig)) {
-            throw new IllegalStateException("Invalid Wi-Fi network for configuring");
-        }
-        mSummary.setText(getString(R.string.wifi_dpp_add_device_to_wifi,
-                wifiNetworkConfig.getSsid()));
-
+        mSummary.setText(getString(R.string.wifi_dpp_add_device_to_wifi, getSsid()));
         mWifiApPictureView = view.findViewById(R.id.wifi_ap_picture_view);
 
         mChooseDifferentNetwork = view.findViewById(R.id.choose_different_network);
@@ -146,19 +263,48 @@
 
         mButtonRight = view.findViewById(R.id.button_right);
         mButtonRight.setText(R.string.wifi_dpp_share_wifi);
-        mButtonRight.setOnClickListener(v -> startWifiDppInitiator());
+        mButtonRight.setOnClickListener(v -> {
+            mButtonRight.setVisibility(View.INVISIBLE);
+            startWifiDppConfiguratorInitiator();
+        });
+
+        if (savedInstanceState != null) {
+            if (mLatestStatusCode == WifiDppUtils.EASY_CONNECT_EVENT_SUCCESS) {
+                showSuccessUi(/* isConfigurationChange */ true);
+            } else if (mLatestStatusCode == WifiDppUtils.EASY_CONNECT_EVENT_FAILURE_NONE) {
+                mButtonRight.setVisibility(isGoingInitiator() ? View.INVISIBLE : View.VISIBLE);
+            } else {
+                showErrorUi(mLatestStatusCode, /* isConfigurationChange */ true);
+            }
+        }
     }
 
-    private void startWifiDppInitiator() {
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        outState.putInt(KEY_LATEST_ERROR_CODE, mLatestStatusCode);
+
+        super.onSaveInstanceState(outState);
+    }
+
+    private String getSsid() {
+        final WifiNetworkConfig wifiNetworkConfig = ((WifiDppConfiguratorActivity) getActivity())
+                .getWifiNetworkConfig();
+        if (!WifiNetworkConfig.isValidConfig(wifiNetworkConfig)) {
+            throw new IllegalStateException("Invalid Wi-Fi network for configuring");
+        }
+        return wifiNetworkConfig.getSsid();
+    }
+
+    private void startWifiDppConfiguratorInitiator() {
         final WifiQrCode wifiQrCode = ((WifiDppConfiguratorActivity) getActivity())
                 .getWifiDppQrCode();
         final String qrCode = wifiQrCode.getQrCode();
         final int networkId =
                 ((WifiDppConfiguratorActivity) getActivity()).getWifiNetworkConfig().getNetworkId();
-        final WifiManager wifiManager = getContext().getSystemService(WifiManager.class);
-        wifiManager.startEasyConnectAsConfiguratorInitiator(qrCode, networkId,
-                WifiManager.EASY_CONNECT_NETWORK_ROLE_STA, getContext().getMainExecutor(),
-                new EasyConnectStatusCallback());
+        final WifiDppInitiatorViewModel model =
+                ViewModelProviders.of(this).get(WifiDppInitiatorViewModel.class);
+
+        model.startEasyConnectAsConfiguratorInitiator(qrCode, networkId);
     }
 
     // Container Activity must implement this interface
@@ -180,4 +326,12 @@
 
         super.onDetach();
     }
+
+    // Check is Easy Connect handshaking or not
+    private boolean isGoingInitiator() {
+        final WifiDppInitiatorViewModel model =
+                ViewModelProviders.of(this).get(WifiDppInitiatorViewModel.class);
+
+        return model.isGoingInitiator();
+    }
 }
diff --git a/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivity.java b/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivity.java
index 65be11c..1770a02 100644
--- a/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivity.java
+++ b/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivity.java
@@ -57,7 +57,6 @@
         WifiNetworkConfig.Retriever,
         WifiDppQrCodeGeneratorFragment.OnQrCodeGeneratorFragmentAddButtonClickedListener,
         WifiDppQrCodeScannerFragment.OnScanWifiDppSuccessListener,
-        WifiDppQrCodeScannerFragment.OnScanZxingWifiFormatSuccessListener,
         WifiDppAddDeviceFragment.OnClickChooseDifferentNetworkListener,
         WifiNetworkListFragment.OnChooseNetworkListener {
 
@@ -102,7 +101,7 @@
         if (savedInstanceState != null) {
             String qrCode = savedInstanceState.getString(KEY_QR_CODE);
 
-            mWifiDppQrCode = getValidWifiDppQrCodeOrNull(qrCode);
+            mWifiDppQrCode = WifiQrCode.getValidWifiDppQrCodeOrNull(qrCode);
 
             String security = savedInstanceState.getString(KEY_WIFI_SECURITY);
             String ssid = savedInstanceState.getString(KEY_WIFI_SSID);
@@ -148,7 +147,7 @@
             case Settings.ACTION_PROCESS_WIFI_EASY_CONNECT_QR_CODE:
                 String qrCode = intent.getStringExtra(Settings.EXTRA_QR_CODE);
                 mIsTest = intent.getBooleanExtra(WifiDppUtils.EXTRA_TEST, false);
-                mWifiDppQrCode = getValidWifiDppQrCodeOrNull(qrCode);
+                mWifiDppQrCode = WifiQrCode.getValidWifiDppQrCodeOrNull(qrCode);
                 final boolean isDppSupported = WifiDppUtils.isWifiDppEnabled(this);
                 if (!isDppSupported) {
                     Log.d(TAG, "Device doesn't support Wifi DPP");
@@ -285,21 +284,6 @@
         fragmentTransaction.commit();
     }
 
-    private WifiQrCode getValidWifiDppQrCodeOrNull(String qrCode) {
-        WifiQrCode wifiQrCode;
-        try {
-            wifiQrCode = new WifiQrCode(qrCode);
-        } catch(IllegalArgumentException e) {
-            return null;
-        }
-
-        if (WifiQrCode.SCHEME_DPP.equals(wifiQrCode.getScheme())) {
-            return wifiQrCode;
-        }
-
-        return null;
-    }
-
     @Override
     public WifiNetworkConfig getWifiNetworkConfig() {
         return mWifiNetworkConfig;
@@ -359,11 +343,6 @@
     }
 
     @Override
-    public void onScanZxingWifiFormatSuccess(WifiNetworkConfig wifiNetworkConfig) {
-        // Do nothing, it's impossible to be a configurator without a Wi-Fi DPP QR code
-    }
-
-    @Override
     public void onClickChooseDifferentNetwork() {
         showChooseSavedWifiNetworkFragment(/* addToBackStack */ true);
     }
diff --git a/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivity.java b/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivity.java
index 143f87f..392b27d 100644
--- a/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivity.java
+++ b/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivity.java
@@ -17,14 +17,10 @@
 package com.android.settings.wifi.dpp;
 
 import android.app.ActionBar;
-import android.app.Activity;
 import android.app.settings.SettingsEnums;
 import android.content.Context;
 import android.content.Intent;
-import android.net.wifi.WifiConfiguration;
-import android.net.wifi.WifiManager;
 import android.os.Bundle;
-import android.provider.Settings;
 import android.util.Log;
 
 import androidx.fragment.app.Fragment;
@@ -34,9 +30,6 @@
 import com.android.settings.R;
 import com.android.settings.core.InstrumentedActivity;
 
-import java.util.List;
-import java.util.concurrent.Executor;
-
 /**
  * To provision "this" device with specified Wi-Fi network.
  *
@@ -44,9 +37,7 @@
  * Wi-Fi network to be provisioned in {@code WifiDppUtils.EXTRA_WIFI_SSID}.
  */
 public class WifiDppEnrolleeActivity extends InstrumentedActivity implements
-        WifiManager.ActionListener,
-        WifiDppQrCodeScannerFragment.OnScanWifiDppSuccessListener,
-        WifiDppQrCodeScannerFragment.OnScanZxingWifiFormatSuccessListener {
+        WifiDppQrCodeScannerFragment.OnScanWifiDppSuccessListener {
     private static final String TAG = "WifiDppEnrolleeActivity";
 
     public static final String ACTION_ENROLLEE_QR_CODE_SCANNER =
@@ -54,40 +45,6 @@
 
     private FragmentManager mFragmentManager;
 
-    private class EasyConnectStatusCallback extends android.net.wifi.EasyConnectStatusCallback {
-        @Override
-        public void onEnrolleeSuccess(int newNetworkId) {
-            // Connect to the new network.
-            final WifiManager wifiManager = getSystemService(WifiManager.class);
-            final List<WifiConfiguration> wifiConfigs =
-                    wifiManager.getPrivilegedConfiguredNetworks();
-            for (WifiConfiguration wifiConfig : wifiConfigs) {
-                if (wifiConfig.networkId == newNetworkId) {
-                    wifiManager.connect(wifiConfig, WifiDppEnrolleeActivity.this);
-                    return;
-                }
-            }
-            Log.e(TAG, "Invalid networkId " + newNetworkId);
-            WifiDppEnrolleeActivity.this.onFailure(WifiManager.ERROR_AUTHENTICATING);
-        }
-
-        @Override
-        public void onConfiguratorSuccess(int code) {
-            // Do nothing
-        }
-
-        @Override
-        public void onFailure(int code) {
-            //TODO(b/122429170): Show DPP enrollee error state UI
-            Log.d(TAG, "EasyConnectStatusCallback.onFailure " + code);
-        }
-
-        @Override
-        public void onProgress(int code) {
-            // Do nothing
-        }
-    }
-
     @Override
     public int getMetricsCategory() {
         return SettingsEnums.SETTINGS_WIFI_DPP_ENROLLEE;
@@ -158,30 +115,6 @@
 
     @Override
     public void onScanWifiDppSuccess(WifiQrCode wifiQrCode) {
-        final WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
-        wifiManager.startEasyConnectAsEnrolleeInitiator(wifiQrCode.getQrCode(), getMainExecutor(),
-                new EasyConnectStatusCallback());
-    }
-
-    @Override
-    public void onScanZxingWifiFormatSuccess(WifiNetworkConfig wifiNetworkConfig) {
-        wifiNetworkConfig.connect(/* context */ this, /* listener */ this);
-    }
-
-    @Override
-    public void onSuccess() {
-        startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));
-        setResult(Activity.RESULT_OK);
-        finish();
-    }
-
-    @Override
-    public void onFailure(int reason) {
-        Log.d(TAG, "Wi-Fi connect onFailure reason - " + reason);
-
-        final Fragment fragment = mFragmentManager.findFragmentById(R.id.fragment_container);
-        if (fragment instanceof WifiDppQrCodeScannerFragment) {
-            ((WifiDppQrCodeScannerFragment)fragment).showErrorMessage(true);
-        }
+        // Do nothing
     }
 }
diff --git a/src/com/android/settings/wifi/dpp/WifiDppInitiatorViewModel.java b/src/com/android/settings/wifi/dpp/WifiDppInitiatorViewModel.java
new file mode 100644
index 0000000..24e5ebe
--- /dev/null
+++ b/src/com/android/settings/wifi/dpp/WifiDppInitiatorViewModel.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2019 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.android.settings.wifi.dpp;
+
+import android.app.Application;
+import android.net.wifi.EasyConnectStatusCallback;
+import android.net.wifi.WifiManager;
+
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.AndroidViewModel;
+
+public class WifiDppInitiatorViewModel extends AndroidViewModel {
+    private MutableLiveData<Integer> mEnrolleeSuccessNetworkId;
+    private MutableLiveData<Integer> mStatusCode;
+    private boolean mIsGoingInitiator;
+
+    public WifiDppInitiatorViewModel(Application application) {
+        super(application);
+    }
+
+    public MutableLiveData<Integer> getEnrolleeSuccessNetworkId() {
+        if (mEnrolleeSuccessNetworkId == null) {
+            mEnrolleeSuccessNetworkId = new MutableLiveData<>();
+        }
+
+        return mEnrolleeSuccessNetworkId;
+    }
+
+    public MutableLiveData<Integer> getStatusCode() {
+        if (mStatusCode == null) {
+            mStatusCode = new MutableLiveData<>();
+        }
+
+        return mStatusCode;
+    }
+
+    public boolean isGoingInitiator() {
+        return mIsGoingInitiator;
+    }
+
+    public void startEasyConnectAsConfiguratorInitiator(String qrCode, int networkId) {
+        mIsGoingInitiator = true;
+        final WifiManager wifiManager = getApplication().getSystemService(WifiManager.class);
+
+        wifiManager.startEasyConnectAsConfiguratorInitiator(qrCode, networkId,
+                WifiManager.EASY_CONNECT_NETWORK_ROLE_STA, getApplication().getMainExecutor(),
+                new EasyConnectDelegateCallback());
+    }
+
+    public void startEasyConnectAsEnrolleeInitiator(String qrCode) {
+        mIsGoingInitiator = true;
+        final WifiManager wifiManager = getApplication().getSystemService(WifiManager.class);
+
+        wifiManager.startEasyConnectAsEnrolleeInitiator(qrCode, getApplication().getMainExecutor(),
+                new EasyConnectDelegateCallback());
+    }
+
+    private class EasyConnectDelegateCallback extends EasyConnectStatusCallback {
+        @Override
+        public void onEnrolleeSuccess(int newNetworkId) {
+            mIsGoingInitiator = false;
+            mEnrolleeSuccessNetworkId.setValue(newNetworkId);
+        }
+
+        @Override
+        public void onConfiguratorSuccess(int code) {
+            mIsGoingInitiator = false;
+            mStatusCode.setValue(WifiDppUtils.EASY_CONNECT_EVENT_SUCCESS);
+        }
+
+        @Override
+        public void onFailure(int code) {
+            mIsGoingInitiator = false;
+            mStatusCode.setValue(code);
+        }
+
+        @Override
+        public void onProgress(int code) {
+            // Do nothing
+        }
+    }
+}
diff --git a/src/com/android/settings/wifi/dpp/WifiDppQrCodeScannerFragment.java b/src/com/android/settings/wifi/dpp/WifiDppQrCodeScannerFragment.java
index 9524fee..c88313b 100644
--- a/src/com/android/settings/wifi/dpp/WifiDppQrCodeScannerFragment.java
+++ b/src/com/android/settings/wifi/dpp/WifiDppQrCodeScannerFragment.java
@@ -17,15 +17,23 @@
 package com.android.settings.wifi.dpp;
 
 import android.app.ActionBar;
+import android.app.Activity;
 import android.app.settings.SettingsEnums;
 import android.content.Context;
+import android.content.pm.ActivityInfo;
+import android.content.Intent;
 import android.graphics.Matrix;
 import android.graphics.Rect;
 import android.graphics.SurfaceTexture;
+import android.net.wifi.EasyConnectStatusCallback;
+import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiManager;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
+import android.provider.Settings;
 import android.text.TextUtils;
+import android.util.Log;
 import android.util.Size;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -36,13 +44,18 @@
 import android.view.ViewGroup;
 import android.widget.TextView;
 
+import androidx.lifecycle.ViewModelProviders;
+
 import com.android.settings.R;
 import com.android.settings.wifi.qrcode.QrCamera;
 import com.android.settings.wifi.qrcode.QrDecorateView;
 
+import java.util.List;
+
 public class WifiDppQrCodeScannerFragment extends WifiDppQrCodeBaseFragment implements
         SurfaceTextureListener,
-        QrCamera.ScannerCallback {
+        QrCamera.ScannerCallback,
+        WifiManager.ActionListener {
     private static final String TAG = "WifiDppQrCodeScannerFragment";
 
     /** Message sent to hide error message */
@@ -57,12 +70,12 @@
     /** Message sent to manipulate ZXing Wi-Fi QR code */
     private static final int MESSAGE_SCAN_ZXING_WIFI_FORMAT_SUCCESS = 4;
 
-    private static final long SHOW_ERROR_MESSAGE_INTERVAL = 2000;
+    private static final long SHOW_ERROR_MESSAGE_INTERVAL = 10000;
     private static final long SHOW_SUCCESS_SQUARE_INTERVAL = 1000;
 
     // Key for Bundle usage
-    private static final String KEY_PUBLIC_URI = "key_public_uri";
     private static final String KEY_IS_CONFIGURATOR_MODE = "key_is_configurator_mode";
+    private static final String KEY_LATEST_ERROR_CODE = "key_latest_error_code";
 
     private QrCamera mCamera;
     private TextureView mTextureView;
@@ -78,13 +91,41 @@
     /** QR code data scanned by camera */
     private WifiQrCode mWifiQrCode;
 
+    private int mLatestStatusCode = WifiDppUtils.EASY_CONNECT_EVENT_FAILURE_NONE;
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         if (savedInstanceState != null) {
             mIsConfiguratorMode = savedInstanceState.getBoolean(KEY_IS_CONFIGURATOR_MODE);
+            mLatestStatusCode = savedInstanceState.getInt(KEY_LATEST_ERROR_CODE);
         }
+
+        final WifiDppInitiatorViewModel model =
+                ViewModelProviders.of(this).get(WifiDppInitiatorViewModel.class);
+
+        model.getEnrolleeSuccessNetworkId().observe(this, networkId -> {
+            // After configuration change, observe callback will be triggered,
+            // do nothing for this case if a handshake does not end
+            if (model.isGoingInitiator()) {
+                return;
+            }
+
+            new EasyConnectEnrolleeStatusCallback().onEnrolleeSuccess(networkId.intValue());
+        });
+
+        model.getStatusCode().observe(this, statusCode -> {
+            // After configuration change, observe callback will be triggered,
+            // do nothing for this case if a handshake does not end
+            if (model.isGoingInitiator()) {
+                return;
+            }
+
+            int code = statusCode.intValue();
+            Log.d(TAG, "Easy connect enrollee callback onFailure " + code);
+            new EasyConnectEnrolleeStatusCallback().onFailure(code);
+        });
     }
 
     @Override
@@ -102,12 +143,6 @@
     }
     OnScanWifiDppSuccessListener mScanWifiDppSuccessListener;
 
-    // Container Activity must implement this interface
-    public interface OnScanZxingWifiFormatSuccessListener {
-        public void onScanZxingWifiFormatSuccess(WifiNetworkConfig wifiNetworkConfig);
-    }
-    OnScanZxingWifiFormatSuccessListener mScanZxingWifiFormatSuccessListener;
-
     /**
      * Configurator container activity of the fragment should create instance with this constructor.
      */
@@ -144,13 +179,11 @@
         super.onAttach(context);
 
         mScanWifiDppSuccessListener = (OnScanWifiDppSuccessListener) context;
-        mScanZxingWifiFormatSuccessListener = (OnScanZxingWifiFormatSuccessListener) context;
     }
 
     @Override
     public void onDetach() {
         mScanWifiDppSuccessListener = null;
-        mScanZxingWifiFormatSuccessListener = null;
 
         super.onDetach();
     }
@@ -289,7 +322,9 @@
     }
 
     private void handleWifiDpp() {
-        destroyCamera();
+        if (mCamera != null) {
+            mCamera.stop();
+        }
         mDecorateView.setFocused(true);
 
         Message message = mHandler.obtainMessage(MESSAGE_SCAN_WIFI_DPP_SUCCESS);
@@ -299,7 +334,9 @@
     }
 
     private void handleZxingWifiFormat() {
-        destroyCamera();
+        if (mCamera != null) {
+            mCamera.stop();
+        }
         mDecorateView.setFocused(true);
 
         Message message = mHandler.obtainMessage(MESSAGE_SCAN_ZXING_WIFI_FORMAT_SUCCESS);
@@ -317,7 +354,14 @@
         // Check if the camera has already created.
         if (mCamera == null) {
             mCamera = new QrCamera(getContext(), this);
-            mCamera.start(surface);
+
+            if (isGoingInitiator()) {
+                if (mDecorateView != null) {
+                    mDecorateView.setFocused(true);
+                }
+            } else {
+                mCamera.start(surface);
+            }
         }
     }
 
@@ -328,14 +372,13 @@
         }
     }
 
-    public void showErrorMessage(boolean show) {
-        mErrorMessage.setVisibility(show ? View.VISIBLE : View.INVISIBLE);
+    public void showErrorMessage(String message) {
+        mErrorMessage.setVisibility(View.VISIBLE);
+        mErrorMessage.setText(message);
 
-        if (show) {
-            mHandler.removeMessages(MESSAGE_HIDE_ERROR_MESSAGE);
-            mHandler.sendEmptyMessageDelayed(MESSAGE_HIDE_ERROR_MESSAGE,
-                    SHOW_ERROR_MESSAGE_INTERVAL);
-        }
+        mHandler.removeMessages(MESSAGE_HIDE_ERROR_MESSAGE);
+        mHandler.sendEmptyMessageDelayed(MESSAGE_HIDE_ERROR_MESSAGE,
+                SHOW_ERROR_MESSAGE_INTERVAL);
     }
 
     private final Handler mHandler = new Handler() {
@@ -343,26 +386,32 @@
         public void handleMessage(Message msg) {
             switch (msg.what) {
                 case MESSAGE_HIDE_ERROR_MESSAGE:
-                    showErrorMessage(false);
+                    mErrorMessage.setVisibility(View.INVISIBLE);
                     break;
 
                 case MESSAGE_SHOW_ERROR_MESSAGE:
-                    showErrorMessage(true);
+                    showErrorMessage(getString(R.string.wifi_dpp_could_not_detect_valid_qr_code));
                     break;
 
                 case MESSAGE_SCAN_WIFI_DPP_SUCCESS:
+                    mErrorMessage.setVisibility(View.INVISIBLE);
+
                     if (mScanWifiDppSuccessListener == null) {
                         return;
                     }
                     mScanWifiDppSuccessListener.onScanWifiDppSuccess((WifiQrCode)msg.obj);
+
+                    if (!mIsConfiguratorMode) {
+                        startWifiDppEnrolleeInitiator((WifiQrCode)msg.obj);
+                    }
                     break;
 
                 case MESSAGE_SCAN_ZXING_WIFI_FORMAT_SUCCESS:
-                    if (mScanZxingWifiFormatSuccessListener == null) {
-                        return;
-                    }
-                    mScanZxingWifiFormatSuccessListener.onScanZxingWifiFormatSuccess(
-                            (WifiNetworkConfig)msg.obj);
+                    mErrorMessage.setVisibility(View.INVISIBLE);
+
+                    final WifiNetworkConfig wifiNetworkConfig = (WifiNetworkConfig)msg.obj;
+                    wifiNetworkConfig.connect(getContext(),
+                            /* listener */ WifiDppQrCodeScannerFragment.this);
                     break;
 
                 default:
@@ -374,7 +423,149 @@
     @Override
     public void onSaveInstanceState(Bundle outState) {
         outState.putBoolean(KEY_IS_CONFIGURATOR_MODE, mIsConfiguratorMode);
+        outState.putInt(KEY_LATEST_ERROR_CODE, mLatestStatusCode);
 
         super.onSaveInstanceState(outState);
     }
+
+    private class EasyConnectEnrolleeStatusCallback extends EasyConnectStatusCallback {
+        @Override
+        public void onEnrolleeSuccess(int newNetworkId) {
+
+            // Connect to the new network.
+            final WifiManager wifiManager = getContext().getSystemService(WifiManager.class);
+            final List<WifiConfiguration> wifiConfigs =
+                    wifiManager.getPrivilegedConfiguredNetworks();
+            for (WifiConfiguration wifiConfig : wifiConfigs) {
+                if (wifiConfig.networkId == newNetworkId) {
+                    mLatestStatusCode = WifiDppUtils.EASY_CONNECT_EVENT_SUCCESS;
+                    wifiManager.connect(wifiConfig, WifiDppQrCodeScannerFragment.this);
+                    return;
+                }
+            }
+
+            Log.e(TAG, "Invalid networkId " + newNetworkId);
+            mLatestStatusCode = EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_GENERIC;
+            showErrorMessage(getString(R.string.wifi_dpp_check_connection_try_again));
+            restartCamera();
+        }
+
+        @Override
+        public void onConfiguratorSuccess(int code) {
+            // Do nothing
+        }
+
+        @Override
+        public void onFailure(int code) {
+            Log.d(TAG, "EasyConnectEnrolleeStatusCallback.onFailure " + code);
+
+            switch (code) {
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_INVALID_URI:
+                    showErrorMessage(getString(R.string.wifi_dpp_could_not_detect_valid_qr_code));
+                    break;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_AUTHENTICATION:
+                    showErrorMessage(
+                            getString(R.string.wifi_dpp_failure_authentication_or_configuration));
+                    break;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_NOT_COMPATIBLE:
+                    showErrorMessage(getString(R.string.wifi_dpp_failure_not_compatible));
+                    break;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_CONFIGURATION:
+                    showErrorMessage(
+                            getString(R.string.wifi_dpp_failure_authentication_or_configuration));
+                    break;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_BUSY:
+                    if (code == mLatestStatusCode) {
+                        throw(new IllegalStateException("stopEasyConnectSession and try again for"
+                                + "EASY_CONNECT_EVENT_FAILURE_BUSY but still failed"));
+                    }
+
+                    mLatestStatusCode = code;
+                    final WifiManager wifiManager =
+                        getContext().getSystemService(WifiManager.class);
+                    wifiManager.stopEasyConnectSession();
+                    startWifiDppEnrolleeInitiator(mWifiQrCode);
+                    return;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_TIMEOUT:
+                    showErrorMessage(getString(R.string.wifi_dpp_failure_timeout));
+                    break;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_GENERIC:
+                    showErrorMessage(getString(R.string.wifi_dpp_failure_generic));
+                    break;
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_NOT_SUPPORTED:
+                    throw(new IllegalStateException("EASY_CONNECT_EVENT_FAILURE_NOT_SUPPORTED" +
+                            " should be a configurator only error"));
+
+                case EasyConnectStatusCallback.EASY_CONNECT_EVENT_FAILURE_INVALID_NETWORK:
+                    throw(new IllegalStateException("EASY_CONNECT_EVENT_FAILURE_INVALID_NETWORK" +
+                            " should be a configurator only error"));
+
+                default:
+                    throw(new IllegalStateException("Unexpected Wi-Fi DPP error"));
+            }
+
+            mLatestStatusCode = code;
+            restartCamera();
+        }
+
+        @Override
+        public void onProgress(int code) {
+            // Do nothing
+        }
+    }
+
+    private void startWifiDppEnrolleeInitiator(WifiQrCode wifiQrCode) {
+        final WifiDppInitiatorViewModel model =
+                ViewModelProviders.of(this).get(WifiDppInitiatorViewModel.class);
+
+        model.startEasyConnectAsEnrolleeInitiator(wifiQrCode.getQrCode());
+    }
+
+    @Override
+    public void onSuccess() {
+        startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));
+        final Activity hostActivity = getActivity();
+        hostActivity.setResult(Activity.RESULT_OK);
+        hostActivity.finish();
+    }
+
+    @Override
+    public void onFailure(int reason) {
+        Log.d(TAG, "Wi-Fi connect onFailure reason - " + reason);
+
+        showErrorMessage(getString(R.string.wifi_dpp_check_connection_try_again));
+        restartCamera();
+    }
+
+    // Check is Easy Connect handshaking or not
+    private boolean isGoingInitiator() {
+        final WifiDppInitiatorViewModel model =
+                ViewModelProviders.of(this).get(WifiDppInitiatorViewModel.class);
+
+        return model.isGoingInitiator();
+    }
+
+    /**
+     * To resume camera decoding task after handshake fail or Wi-Fi connection fail.
+     */
+    private void restartCamera() {
+        if (mCamera == null) {
+            Log.d(TAG, "mCamera is not available for restarting camera");
+            return;
+        }
+
+        final SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture();
+        if (surfaceTexture == null) {
+            throw new IllegalStateException("SurfaceTexture is not ready for restarting camera");
+        }
+
+        mCamera.start(surfaceTexture);
+    }
 }
diff --git a/src/com/android/settings/wifi/dpp/WifiDppUtils.java b/src/com/android/settings/wifi/dpp/WifiDppUtils.java
index 8b333e2..24cd1d7 100644
--- a/src/com/android/settings/wifi/dpp/WifiDppUtils.java
+++ b/src/com/android/settings/wifi/dpp/WifiDppUtils.java
@@ -75,6 +75,16 @@
     public static final String EXTRA_TEST = "test";
 
     /**
+     * Default status code for Easy Connect
+     */
+    public static final int EASY_CONNECT_EVENT_FAILURE_NONE = 0;
+
+    /**
+     * Success status code for Easy Connect.
+     */
+    public static final int EASY_CONNECT_EVENT_SUCCESS = 1;
+
+    /**
      * Returns whether the device support WiFi DPP.
      */
     public static boolean isWifiDppEnabled(Context context) {
diff --git a/src/com/android/settings/wifi/dpp/WifiQrCode.java b/src/com/android/settings/wifi/dpp/WifiQrCode.java
index a08fb44..10971cf 100644
--- a/src/com/android/settings/wifi/dpp/WifiQrCode.java
+++ b/src/com/android/settings/wifi/dpp/WifiQrCode.java
@@ -228,4 +228,19 @@
 
         return new WifiNetworkConfig(mWifiNetworkConfig);
     }
+
+    public static WifiQrCode getValidWifiDppQrCodeOrNull(String qrCode) {
+        WifiQrCode wifiQrCode;
+        try {
+            wifiQrCode = new WifiQrCode(qrCode);
+        } catch(IllegalArgumentException e) {
+            return null;
+        }
+
+        if (SCHEME_DPP.equals(wifiQrCode.getScheme())) {
+            return wifiQrCode;
+        }
+
+        return null;
+    }
 }
diff --git a/tests/robotests/src/com/android/settings/development/ArtVerifierPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/development/ArtVerifierPreferenceControllerTest.java
new file mode 100644
index 0000000..e5dade4
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/development/ArtVerifierPreferenceControllerTest.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2019 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.android.settings.development;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import androidx.preference.PreferenceScreen;
+import androidx.preference.SwitchPreference;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public class ArtVerifierPreferenceControllerTest {
+
+    @Mock
+    private SwitchPreference mPreference;
+    @Mock
+    private PreferenceScreen mPreferenceScreen;
+
+    private Context mContext;
+    private ArtVerifierPreferenceController mController;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application;
+        mController = new ArtVerifierPreferenceController(mContext);
+        when(mPreferenceScreen.findPreference(mController.getPreferenceKey()))
+            .thenReturn(mPreference);
+        mController.displayPreference(mPreferenceScreen);
+    }
+
+    @Test
+    public void onPreferenceChanged_settingEnabled_turnOnArtVerifier() {
+        mController.onPreferenceChange(mPreference, true /* new value */);
+
+        final int mode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE, -1 /* default */);
+
+        assertThat(mode).isEqualTo(ArtVerifierPreferenceController.SETTING_VALUE_ON);
+    }
+
+    @Test
+    public void onPreferenceChanged_settingDisabled_turnOffArtVerifier() {
+        mController.onPreferenceChange(mPreference, false /* new value */);
+
+        final int mode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE, -1 /* default */);
+
+        assertThat(mode).isEqualTo(ArtVerifierPreferenceController.SETTING_VALUE_OFF);
+    }
+
+    @Test
+    public void updateState_settingEnabled_preferenceShouldBeChecked() {
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE,
+                ArtVerifierPreferenceController.SETTING_VALUE_ON);
+        mController.updateState(mPreference);
+
+        verify(mPreference).setChecked(true);
+    }
+
+    @Test
+    public void updateState_settingDisabled_preferenceShouldBeChecked() {
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE,
+                ArtVerifierPreferenceController.SETTING_VALUE_OFF);
+        mController.updateState(mPreference);
+
+        verify(mPreference).setChecked(false);
+    }
+
+    @Test
+    public void onDeveloperOptionsSwitchDisabled_shouldDisablePreference() {
+        mController.onDeveloperOptionsSwitchDisabled();
+        final int mode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.ART_VERIFIER_VERIFY_DEBUGGABLE, -1 /* default */);
+
+        assertThat(mode).isEqualTo(ArtVerifierPreferenceController.SETTING_VALUE_ON);
+        verify(mPreference).setEnabled(false);
+        verify(mPreference).setChecked(true);
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/network/telephony/MobileDataPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/network/telephony/MobileDataPreferenceControllerTest.java
index 4c242c1..1b7b4b4 100644
--- a/tests/robotests/src/com/android/settings/network/telephony/MobileDataPreferenceControllerTest.java
+++ b/tests/robotests/src/com/android/settings/network/telephony/MobileDataPreferenceControllerTest.java
@@ -149,4 +149,23 @@
 
         verify(mTelephonyManager).setDataEnabled(true);
     }
+
+    @Test
+    public void isChecked_returnUserDataEnabled() {
+        mController.init(mFragmentManager, SUB_ID);
+        assertThat(mController.isChecked()).isFalse();
+
+        doReturn(true).when(mTelephonyManager).isDataEnabled();
+        assertThat(mController.isChecked()).isTrue();
+    }
+
+    @Test
+    public void updateState_opportunistic_disabled() {
+        doReturn(mSubscriptionInfo).when(mSubscriptionManager).getActiveSubscriptionInfo(SUB_ID);
+        mController.init(mFragmentManager, SUB_ID);
+        doReturn(true).when(mSubscriptionInfo).isOpportunistic();
+        mController.updateState(mPreference);
+
+        assertThat(mPreference.isEnabled()).isFalse();
+    }
 }
diff --git a/tests/unit/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivityTest.java b/tests/unit/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivityTest.java
index 76df764..a425177 100644
--- a/tests/unit/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivityTest.java
+++ b/tests/unit/src/com/android/settings/wifi/dpp/WifiDppConfiguratorActivityTest.java
@@ -110,14 +110,6 @@
     }
 
     @Test
-    public void testActivity_shouldImplementsOnScanZxingWifiFormatSuccessCallback() {
-        WifiDppConfiguratorActivity activity = mActivityRule.getActivity();
-
-        assertThat(activity instanceof WifiDppQrCodeScannerFragment
-                .OnScanZxingWifiFormatSuccessListener).isEqualTo(true);
-    }
-
-    @Test
     public void testActivity_shouldImplementsOnClickChooseDifferentNetworkCallback() {
         WifiDppConfiguratorActivity activity = mActivityRule.getActivity();
 
diff --git a/tests/unit/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivityTest.java b/tests/unit/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivityTest.java
index 283da13..aef4767 100644
--- a/tests/unit/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivityTest.java
+++ b/tests/unit/src/com/android/settings/wifi/dpp/WifiDppEnrolleeActivityTest.java
@@ -38,12 +38,4 @@
         assertThat(activity instanceof WifiDppQrCodeScannerFragment
                 .OnScanWifiDppSuccessListener).isEqualTo(true);
     }
-
-    @Test
-    public void testActivity_shouldImplementsOnScanZxingWifiFormatSuccessCallback() {
-        WifiDppEnrolleeActivity activity = mActivityRule.getActivity();
-
-        assertThat(activity instanceof WifiDppQrCodeScannerFragment
-                .OnScanZxingWifiFormatSuccessListener).isEqualTo(true);
-    }
 }