Build a new FooterPreference UI.

- Create a new layout for footer prefs.
- Create a new FooterPreference type to use the layout
- Create a Mixin to create and add the pref to screen
- Create a new lifecycle observer type to invoke mixin at right time
- Switch SettingsPreferenceFragment to use footer mixin.
- Switch FingerprintSettings to use the new footer pref.

Bug: 33579394
Test: RunSettingsRoboTests
Change-Id: I548ac39a0d120196a7ffed09b4f98bd9a80bae90

res/drawable/ic_info_outline_24dp.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2016 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0"
+        android:tint="?android:attr/textColorSecondary">
+    <path
+        android:fillColor="#000000"
+        android:pathData="M11,17h2v-6h-2v6zM12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zM12,20c-4.41,0 -8,-3.59 -8,-8s3.59,-8 8,-8 8,3.59 8,8 -3.59,8 -8,8zM11,9h2L13,7h-2v2z"/>
+</vector>

res/layout/fingerprint_settings_footer.xml

@@ -1,26 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-  ~ Copyright (C) 2015 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
-  -->
-<com.android.settings.widget.LinkTextView
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    style="@android:style/TextAppearance.Material.Body1"
-    android:layout_width="wrap_content"
-    android:layout_height="wrap_content"
-    android:textColor="?android:attr/textColorSecondary"
-    android:paddingTop="32dp"
-    android:paddingStart="16dp"
-    android:paddingEnd="16dp"
-    android:selectable="false" />

res/layout/preference_footer.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2016 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.
+  -->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:minHeight="?android:attr/listPreferredItemHeight"
+    android:gravity="center_vertical"
+    android:paddingStart="?android:attr/listPreferredItemPaddingStart"
+    android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
+    android:background="?android:attr/selectableItemBackground"
+    android:clipToPadding="false">
+
+    <LinearLayout
+        android:id="@+id/icon_container"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:minWidth="60dp"
+        android:gravity="start|center_vertical"
+        android:orientation="horizontal"
+        android:paddingEnd="12dp"
+        android:paddingTop="4dp"
+        android:paddingBottom="4dp">
+        <com.android.internal.widget.PreferenceImageView
+            android:id="@android:id/icon"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"/>
+    </LinearLayout>
+
+    <com.android.settings.widget.LinkTextView
+        android:id="@android:id/title"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:paddingBottom="16dp"
+        android:paddingTop="16dp"
+        android:maxLines="10"
+        android:textColor="?android:attr/textColorSecondary"
+        android:ellipsize="marquee"/>
+
+</LinearLayout>

src/com/android/settings/SettingsPreferenceFragment.java

@@ -48,6 +48,7 @@ import com.android.settings.applications.LayoutPreference;
 import com.android.settings.core.InstrumentedPreferenceFragment;
 import com.android.settings.core.instrumentation.Instrumentable;
 import com.android.settings.core.instrumentation.InstrumentedDialogFragment;
+import com.android.settings.widget.FooterPreferenceMixin;
 import com.android.settingslib.HelpUtils;
 
 import java.util.UUID;
@@ -70,6 +71,9 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
 
     private static final String SAVE_HIGHLIGHTED_KEY = "android:preference_highlighted";
 
+    protected final FooterPreferenceMixin mFooterPreferenceMixin =
+            new FooterPreferenceMixin(this, getLifecycle());
+
     private SettingsDialogFragment mDialogFragment;
 
     private String mHelpUri;
@@ -123,7 +127,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
 
     private LayoutPreference mHeader;
 
-    private LayoutPreference mFooter;
     private View mEmptyView;
     private LinearLayoutManager mLayoutManager;
     private HighlightablePreferenceGroupAdapter mAdapter;
@@ -277,10 +280,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
         return mHeader;
     }
 
-    public LayoutPreference getFooterView() {
-        return mFooter;
-    }
-
     protected void setHeaderView(int resource) {
         mHeader = new LayoutPreference(getPrefContext(), resource);
         addPreferenceToTop(mHeader);
@@ -298,29 +297,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
         }
     }
 
-    protected void setFooterView(int resource) {
-        setFooterView(resource != 0 ? new LayoutPreference(getPrefContext(), resource) : null);
-    }
-
-    protected void setFooterView(View v) {
-        setFooterView(v != null ? new LayoutPreference(getPrefContext(), v) : null);
-    }
-
-    private void setFooterView(LayoutPreference footer) {
-        if (getPreferenceScreen() != null && mFooter != null) {
-            getPreferenceScreen().removePreference(mFooter);
-        }
-        if (footer != null) {
-            mFooter = footer;
-            mFooter.setOrder(ORDER_LAST);
-            if (getPreferenceScreen() != null) {
-                getPreferenceScreen().addPreference(mFooter);
-            }
-        } else {
-            mFooter = null;
-        }
-    }
-
     @Override
     public void setPreferenceScreen(PreferenceScreen preferenceScreen) {
         if (preferenceScreen != null && !preferenceScreen.isAttached()) {
@@ -332,9 +308,6 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
             if (mHeader != null) {
                 preferenceScreen.addPreference(mHeader);
             }
-            if (mFooter != null) {
-                preferenceScreen.addPreference(mFooter);
-            }
         }
     }
 
@@ -343,7 +316,7 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
         if (getPreferenceScreen() != null) {
             boolean show = (getPreferenceScreen().getPreferenceCount()
                     - (mHeader != null ? 1 : 0)
-                    - (mFooter != null ? 1 : 0)) <= 0;
+                    - (mFooterPreferenceMixin.hasFooter() ? 1 : 0)) <= 0;
             mEmptyView.setVisibility(show ? View.VISIBLE : View.GONE);
         } else {
             mEmptyView.setVisibility(View.VISIBLE);

src/com/android/settings/applications/ApplicationFeatureProvider.java

@@ -35,7 +35,7 @@ public interface ApplicationFeatureProvider {
     /**
      * Callback that receives the total number of packages installed on the device.
      */
-    public interface NumberOfInstalledAppsCallback {
+    interface NumberOfInstalledAppsCallback {
         void onNumberOfInstalledAppsResult(int num);
     }
 }

src/com/android/settings/bluetooth/BluetoothSettings.java

@@ -50,6 +50,7 @@ import com.android.settings.location.ScanningSettings;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settings.search.Indexable;
 import com.android.settings.search.SearchIndexableRaw;
+import com.android.settings.widget.FooterPreference;
 import com.android.settings.widget.SwitchBar;
 import com.android.settingslib.bluetooth.BluetoothCallback;
 import com.android.settingslib.bluetooth.BluetoothDeviceFilter;
@@ -97,7 +98,7 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment implem
 
 
     // accessed from inner class (not private to avoid thunks)
-    Preference mMyDevicePreference;
+    FooterPreference mMyDevicePreference;
 
     private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override
@@ -120,7 +121,7 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment implem
                 final Resources res = context.getResources();
                 final Locale locale = res.getConfiguration().getLocales().get(0);
                 final BidiFormatter bidiFormatter = BidiFormatter.getInstance(locale);
-                mMyDevicePreference.setSummary(res.getString(
+                mMyDevicePreference.setTitle(res.getString(
                             R.string.bluetooth_is_visible_message,
                             bidiFormatter.unicodeWrap(mLocalAdapter.getName())));
             }
@@ -171,10 +172,8 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment implem
         mAvailableDevicesCategory.setOrder(2);
         getPreferenceScreen().addPreference(mAvailableDevicesCategory);
 
-        mMyDevicePreference = new Preference(getPrefContext());
+        mMyDevicePreference = mFooterPreferenceMixin.createFooterPreference();
         mMyDevicePreference.setSelectable(false);
-        mMyDevicePreference.setOrder(3);
-        getPreferenceScreen().addPreference(mMyDevicePreference);
 
         setHasOptionsMenu(true);
     }
@@ -356,7 +355,7 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment implem
                 final Resources res = getResources();
                 final Locale locale = res.getConfiguration().getLocales().get(0);
                 final BidiFormatter bidiFormatter = BidiFormatter.getInstance(locale);
-                mMyDevicePreference.setSummary(res.getString(
+                mMyDevicePreference.setTitle(res.getString(
                             R.string.bluetooth_is_visible_message,
                             bidiFormatter.unicodeWrap(mLocalAdapter.getName())));
 

src/com/android/settings/core/lifecycle/Lifecycle.java

@@ -18,6 +18,7 @@ package com.android.settings.core.lifecycle;
 import android.annotation.UiThread;
 import android.content.Context;
 import android.os.Bundle;
+import android.support.v7.preference.PreferenceScreen;
 
 import com.android.settings.core.lifecycle.events.OnAttach;
 import com.android.settings.core.lifecycle.events.OnCreate;
@@ -27,6 +28,7 @@ import com.android.settings.core.lifecycle.events.OnResume;
 import com.android.settings.core.lifecycle.events.OnSaveInstanceState;
 import com.android.settings.core.lifecycle.events.OnStart;
 import com.android.settings.core.lifecycle.events.OnStop;
+import com.android.settings.core.lifecycle.events.SetPreferenceScreen;
 import com.android.settings.utils.ThreadUtils;
 
 import java.util.ArrayList;
@@ -73,6 +75,14 @@ public class Lifecycle {
         }
     }
 
+    public void setPreferenceScreen(PreferenceScreen preferenceScreen) {
+        for (LifecycleObserver observer : mObservers) {
+            if (observer instanceof SetPreferenceScreen) {
+                ((SetPreferenceScreen) observer).setPreferenceScreen(preferenceScreen);
+            }
+        }
+    }
+
     public void onResume() {
         for (LifecycleObserver observer : mObservers) {
             if (observer instanceof OnResume) {

src/com/android/settings/core/lifecycle/ObservablePreferenceFragment.java

@@ -20,6 +20,7 @@ import android.annotation.CallSuper;
 import android.content.Context;
 import android.os.Bundle;
 import android.support.v14.preference.PreferenceFragment;
+import android.support.v7.preference.PreferenceScreen;
 
 /**
  * {@link PreferenceFragment} that has hooks to observe fragment lifecycle events.
@@ -46,6 +47,12 @@ public abstract class ObservablePreferenceFragment extends PreferenceFragment {
         super.onCreate(savedInstanceState);
     }
 
+    @Override
+    public void setPreferenceScreen(PreferenceScreen preferenceScreen) {
+        mLifecycle.setPreferenceScreen(preferenceScreen);
+        super.setPreferenceScreen(preferenceScreen);
+    }
+
     @CallSuper
     @Override
     public void onSaveInstanceState(Bundle outState) {

src/com/android/settings/core/lifecycle/events/SetPreferenceScreen.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2016 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.core.lifecycle.events;
+
+import android.support.v7.preference.PreferenceScreen;
+
+public interface SetPreferenceScreen {
+
+    void setPreferenceScreen(PreferenceScreen preferenceScreen);
+}

src/com/android/settings/fingerprint/FingerprintSettings.java

@@ -17,7 +17,6 @@
 package com.android.settings.fingerprint;
 
 
-import android.annotation.Nullable;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Dialog;
@@ -26,7 +25,6 @@ import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
-import android.content.pm.PackageManager;
 import android.graphics.Typeface;
 import android.graphics.drawable.Drawable;
 import android.hardware.fingerprint.Fingerprint;
@@ -49,15 +47,12 @@ import android.text.Annotation;
 import android.text.SpannableString;
 import android.text.SpannableStringBuilder;
 import android.text.TextPaint;
-import android.text.method.LinkMovementMethod;
 import android.text.style.URLSpan;
 import android.util.AttributeSet;
 import android.util.Log;
-import android.view.LayoutInflater;
 import android.view.View;
 import android.view.WindowManager;
 import android.widget.EditText;
-import android.widget.TextView;
 import android.widget.Toast;
 
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
@@ -68,6 +63,8 @@ import com.android.settings.SettingsPreferenceFragment;
 import com.android.settings.SubSettings;
 import com.android.settings.Utils;
 import com.android.settings.core.instrumentation.InstrumentedDialogFragment;
+import com.android.settings.widget.FooterPreference;
+import com.android.settings.widget.FooterPreferenceMixin;
 import com.android.settingslib.HelpUtils;
 import com.android.settingslib.RestrictedLockUtils;
 
@@ -298,21 +295,14 @@ public class FingerprintSettings extends SubSettings {
                 mLaunchedConfirm = true;
                 launchChooseOrConfirmLock();
             }
-        }
 
-        @Override
+            final FooterPreference pref = mFooterPreferenceMixin.createFooterPreference();
-        public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+            final EnforcedAdmin admin = RestrictedLockUtils.checkIfKeyguardFeaturesDisabled(
-            super.onViewCreated(view, savedInstanceState);
+                    activity, DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT, mUserId);
-            TextView v = (TextView) LayoutInflater.from(view.getContext()).inflate(
+            pref.setTitle(LearnMoreSpan.linkify(getText(admin != null
-                    R.layout.fingerprint_settings_footer, null);
-            EnforcedAdmin admin = RestrictedLockUtils.checkIfKeyguardFeaturesDisabled(
-                    getActivity(), DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT, mUserId);
-            v.setText(LearnMoreSpan.linkify(getText(admin != null
                             ? R.string.security_settings_fingerprint_enroll_disclaimer_lockscreen_disabled
                             : R.string.security_settings_fingerprint_enroll_disclaimer),
                     getString(getHelpResource()), admin));
-            v.setMovementMethod(new LinkMovementMethod());
-            setFooterView(v);
         }
 
         protected void removeFingerprintPreference(int fingerprintId) {

src/com/android/settings/widget/FooterPreference.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2016 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.widget;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceViewHolder;
+import android.text.method.LinkMovementMethod;
+import android.util.AttributeSet;
+import android.widget.TextView;
+
+import com.android.settings.R;
+
+/**
+ * A custom preference acting as "footer" of a page. It has a field for icon and text. It is added
+ * to screen as the last preference.
+ */
+public class FooterPreference extends Preference {
+
+    static final int ORDER_FOOTER = Integer.MAX_VALUE - 1;
+    static final String KEY_FOOTER = "footer_preference";
+
+    public FooterPreference(Context context, AttributeSet attrs,
+            int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init();
+    }
+
+    public FooterPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init();
+    }
+
+    public FooterPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init();
+    }
+
+    public FooterPreference(Context context) {
+        super(context);
+        init();
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+        TextView title = (TextView) holder.itemView.findViewById(android.R.id.title);
+        title.setMovementMethod(new LinkMovementMethod());
+    }
+
+    private void init() {
+        setLayoutResource(R.layout.preference_footer);
+        setIcon(R.drawable.ic_info_outline_24dp);
+        setKey(KEY_FOOTER);
+        setOrder(ORDER_FOOTER);
+    }
+}

src/com/android/settings/widget/FooterPreferenceMixin.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2016 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.widget;
+
+import android.content.Context;
+import android.support.v14.preference.PreferenceFragment;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.core.lifecycle.Lifecycle;
+import com.android.settings.core.lifecycle.LifecycleObserver;
+import com.android.settings.core.lifecycle.events.SetPreferenceScreen;
+
+public class FooterPreferenceMixin implements LifecycleObserver, SetPreferenceScreen {
+
+    private final PreferenceFragment mFragment;
+    private FooterPreference mFooterPreference;
+
+    public FooterPreferenceMixin(PreferenceFragment fragment, Lifecycle lifecycle) {
+        mFragment = fragment;
+        lifecycle.addObserver(this);
+    }
+
+    @Override
+    public void setPreferenceScreen(PreferenceScreen preferenceScreen) {
+        if (mFooterPreference != null) {
+            preferenceScreen.addPreference(mFooterPreference);
+        }
+    }
+
+    /**
+     * Creates a new {@link FooterPreference}.
+     */
+    public FooterPreference createFooterPreference() {
+        final PreferenceScreen screen = mFragment.getPreferenceScreen();
+        if (mFooterPreference != null && screen != null) {
+            screen.removePreference(mFooterPreference);
+        }
+        mFooterPreference = new FooterPreference(getPrefContext());
+
+        if (screen != null) {
+            screen.addPreference(mFooterPreference);
+        }
+        return mFooterPreference;
+    }
+
+    /**
+     * Returns an UI context with theme properly set for new Preference objects.
+     */
+    private Context getPrefContext() {
+        return mFragment.getPreferenceManager().getContext();
+    }
+
+    public boolean hasFooter() {
+        return mFooterPreference != null;
+    }
+}
+

tests/robotests/src/com/android/settings/search/SearchResultBuilderTest.java

@@ -100,24 +100,18 @@ public class SearchResultBuilderTest {
     }
 
     @Test
-    public void testNoRank_BuildSearchResultException() {
+    public void testNoRank_BuildSearchResult_pass() {
         mBuilder.addTitle(mTitle)
                 .addSummary(mSummary)
                 .addBreadcrumbs(mBreadcrumbs)
                 .addIcon(mIcon)
                 .addPayload(mResultPayload);
 
-        SearchResult result = null;
+        assertThat(mBuilder.build()).isNotNull();
-        try {
-            result = mBuilder.build();
-        } catch (IllegalArgumentException e) {
-            // passes.
-        }
-        assertThat(result).isNull();
     }
 
     @Test
-    public void testNoIcon_BuildSearchResultException() {
+    public void testNoIcon_BuildSearchResult_pass() {
         mBuilder.addTitle(mTitle)
                 .addSummary(mSummary)
                 .addRank(mRank)

tests/robotests/src/com/android/settings/widget/FooterPreferenceMixinTest.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2016 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.widget;
+
+import android.support.v14.preference.PreferenceFragment;
+import android.support.v7.preference.PreferenceManager;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+import com.android.settings.core.lifecycle.Lifecycle;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowApplication;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class FooterPreferenceMixinTest {
+
+    @Mock
+    private PreferenceFragment mFragment;
+    @Mock
+    private PreferenceScreen mScreen;
+
+    private Lifecycle mLifecycle;
+    private FooterPreferenceMixin mMixin;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mLifecycle = new Lifecycle();
+        when(mFragment.getPreferenceManager()).thenReturn(mock(PreferenceManager.class));
+        when(mFragment.getPreferenceManager().getContext())
+                .thenReturn(ShadowApplication.getInstance().getApplicationContext());
+        mMixin = new FooterPreferenceMixin(mFragment, mLifecycle);
+    }
+
+    @Test
+    public void createFooter_screenNotAvailable_noCrash() {
+        assertThat(mMixin.createFooterPreference()).isNotNull();
+    }
+
+    @Test
+    public void createFooter_screenAvailable_canAttachToScreen() {
+        when(mFragment.getPreferenceScreen()).thenReturn(mScreen);
+
+        final FooterPreference preference = mMixin.createFooterPreference();
+
+        assertThat(preference).isNotNull();
+        verify(mScreen).addPreference(preference);
+    }
+
+    @Test
+    public void createFooter_screenAvailableDelayed_canAttachToScreen() {
+        final FooterPreference preference = mMixin.createFooterPreference();
+
+        mLifecycle.setPreferenceScreen(mScreen);
+
+        assertThat(preference).isNotNull();
+        verify(mScreen).addPreference(preference);
+    }
+
+    @Test
+    public void createFooterTwice_screenAvailable_replaceOldFooter() {
+        when(mFragment.getPreferenceScreen()).thenReturn(mScreen);
+
+        mMixin.createFooterPreference();
+        mMixin.createFooterPreference();
+
+        verify(mScreen).removePreference(any(FooterPreference.class));
+        verify(mScreen, times(2)).addPreference(any(FooterPreference.class));
+    }
+
+}

tests/robotests/src/com/android/settings/widget/FooterPreferenceTest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2016 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.widget;
+
+import android.content.Context;
+import android.support.v7.preference.PreferenceViewHolder;
+import android.text.method.LinkMovementMethod;
+import android.view.LayoutInflater;
+import android.widget.TextView;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowApplication;
+
+import static com.google.common.truth.Truth.assertThat;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class FooterPreferenceTest {
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = ShadowApplication.getInstance().getApplicationContext();
+    }
+
+    @Test
+    public void createNewPreference_shouldSetKeyAndOrder() {
+        final FooterPreference preference = new FooterPreference(mContext);
+
+        assertThat(preference.getKey()).isEqualTo(FooterPreference.KEY_FOOTER);
+        assertThat(preference.getOrder()).isEqualTo(FooterPreference.ORDER_FOOTER);
+    }
+
+    @Test
+    public void bindPreference_shouldLinkifyContent() {
+        final FooterPreference preference = new FooterPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+                LayoutInflater.from(mContext).inflate(R.layout.preference_footer, null));
+
+        preference.onBindViewHolder(holder);
+        assertThat(((TextView) holder.findViewById(android.R.id.title)).getMovementMethod())
+                .isInstanceOf(LinkMovementMethod.class);
+    }
+}

tests/robotests/src/com/android/settings/widget/RingProgressBarTest.java

@@ -16,21 +16,21 @@
 
 package com.android.settings.widget;
 
-import static junit.framework.Assert.assertEquals;
-
 import android.content.Context;
 import android.view.View.MeasureSpec;
 
+import com.android.settings.SettingsRobolectricTestRunner;
 import com.android.settings.TestConfig;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
 
-@RunWith(RobolectricTestRunner.class)
+import static junit.framework.Assert.assertEquals;
+
+@RunWith(SettingsRobolectricTestRunner.class)
 @Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class RingProgressBarTest {