Show current setting for Tap & Pay

In Settings > Apps & notifications > Advanced > Default apps > Tap & pay
the setting labeled "Use default" is a drop down preference but wasn't
showing the current value it's set to in its summary. This CL fixes
that.

Change-Id: I891289abad781c3eeafa2d7979373f0d53faafc6
Fixes: 67754372
Test: make -j64 RunSettingsRoboTests

src/com/android/settings/nfc/NfcForegroundPreference.java

@@ -17,18 +17,27 @@ package com.android.settings.nfc;
 
 import android.content.Context;
 import android.support.v7.preference.DropDownPreference;
+import android.support.v7.preference.Preference;
 
 import com.android.settings.R;
 
 public class NfcForegroundPreference extends DropDownPreference implements
-        PaymentBackend.Callback {
+        PaymentBackend.Callback, Preference.OnPreferenceChangeListener {
 
     private final PaymentBackend mPaymentBackend;
     public NfcForegroundPreference(Context context, PaymentBackend backend) {
         super(context);
         mPaymentBackend = backend;
         mPaymentBackend.registerCallback(this);
+
+        setTitle(getContext().getString(R.string.nfc_payment_use_default));
+        setEntries(new CharSequence[] {
+                getContext().getString(R.string.nfc_payment_favor_open),
+                getContext().getString(R.string.nfc_payment_favor_default)
+        });
+        setEntryValues(new CharSequence[] { "1", "0" });
         refresh();
+        setOnPreferenceChangeListener(this);
     }
 
     @Override
@@ -37,27 +46,20 @@ public class NfcForegroundPreference extends DropDownPreference implements
     }
 
     void refresh() {
-        PaymentBackend.PaymentAppInfo defaultApp = mPaymentBackend.getDefaultApp();
         boolean foregroundMode = mPaymentBackend.isForegroundMode();
-        setPersistent(false);
-        setTitle(getContext().getString(R.string.nfc_payment_use_default));
-        CharSequence favorOpen;
-        CharSequence favorDefault;
-        setEntries(new CharSequence[] {
-                getContext().getString(R.string.nfc_payment_favor_open),
-                getContext().getString(R.string.nfc_payment_favor_default)
-        });
-        setEntryValues(new CharSequence[] { "1", "0" });
         if (foregroundMode) {
             setValue("1");
         } else {
             setValue("0");
         }
+        setSummary(getEntry());
     }
 
     @Override
-    protected boolean persistString(String value) {
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
-        mPaymentBackend.setForegroundMode(Integer.parseInt(value) != 0);
+        String newValueString = (String) newValue;
+        setSummary(getEntries()[findIndexOfValue(newValueString)]);
+        mPaymentBackend.setForegroundMode(Integer.parseInt(newValueString) != 0);
         return true;
     }
 }

tests/robotests/src/com/android/settings/nfc/NfcForegroundPreferenceTest.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2018 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.nfc;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.support.v7.preference.PreferenceManager;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class NfcForegroundPreferenceTest {
+    @Mock
+    private PaymentBackend mPaymentBackend;
+
+    private Context mContext;
+    private PreferenceScreen mScreen;
+    private NfcForegroundPreference mPreference;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application;
+        mScreen = spy(new PreferenceScreen(mContext, null));
+        when(mScreen.getPreferenceManager()).thenReturn(mock(PreferenceManager.class));
+        when(mPaymentBackend.isForegroundMode()).thenReturn(false);
+        mPreference = new NfcForegroundPreference(mContext, mPaymentBackend);
+        mScreen.addPreference(mPreference);
+    }
+
+    @Test
+    public void testTogglingMode() {
+        String nfc_payment_favor_default = mContext.getString(R.string.nfc_payment_favor_default);
+        String nfc_payment_favor_open = mContext.getString(R.string.nfc_payment_favor_open);
+
+        assertThat(mPreference.getEntry()).isEqualTo(nfc_payment_favor_default);
+        assertThat(mPreference.getSummary()).isEqualTo(nfc_payment_favor_default);
+
+        mPreference.setValueIndex(0);
+        mPreference.callChangeListener(mPreference.getEntryValues()[0]);
+        verify(mPaymentBackend).setForegroundMode(true);
+        assertThat(mPreference.getEntry()).isEqualTo(nfc_payment_favor_open);
+        assertThat(mPreference.getSummary()).isEqualTo(nfc_payment_favor_open);
+
+        mPreference.setValueIndex(1);
+        mPreference.callChangeListener(mPreference.getEntryValues()[1]);
+        verify(mPaymentBackend).setForegroundMode(false);
+        assertThat(mPreference.getEntry()).isEqualTo(nfc_payment_favor_default);
+        assertThat(mPreference.getSummary()).isEqualTo(nfc_payment_favor_default);
+    }
+}