--- /dev/null
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.core;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+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.OnResume;
+
+public abstract class DynamicAvailabilityPreferenceController extends PreferenceController
+ implements LifecycleObserver, OnResume {
+
+ private Preference mPreference;
+ private PreferenceScreen mScreen;
+
+ public DynamicAvailabilityPreferenceController(Context context, Lifecycle lifecycle) {
+ super(context);
+ if (lifecycle != null) {
+ lifecycle.addObserver(this);
+ }
+ }
+
+ @Override
+ public void displayPreference(PreferenceScreen screen) {
+ mScreen = screen;
+ mPreference = screen.findPreference(getPreferenceKey());
+ super.displayPreference(screen);
+ }
+
+ @Override
+ public void onResume() {
+ if (!isAvailable()) {
+ removePreference(mScreen, getPreferenceKey());
+ return;
+ }
+
+ updateState(mPreference);
+ if (mScreen.findPreference(getPreferenceKey()) == null) {
+ mScreen.addPreference(mPreference);
+ }
+ }
+}
--- /dev/null
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.core;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+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 static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests for {@link DynamicAvailabilityPreferenceController}.
+ */
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public final class DynamicAvailabilityPreferenceControllerTest {
+
+ private final String PREFERENCE_KEY = "preference_key";
+
+ private @Mock Context mContext;
+ private @Mock Preference mPreference;
+ private @Mock PreferenceScreen mScreen;
+ private @Mock Lifecycle mLifecycle;
+
+ private boolean mIsAvailable;
+ private Preference mUpdatedPreference = null;
+
+ @Before
+ public void setUp() {
+ MockitoAnnotations.initMocks(this);
+ when(mPreference.getKey()).thenReturn(PREFERENCE_KEY);
+ when(mScreen.findPreference(PREFERENCE_KEY)).thenReturn(mPreference);
+ when(mScreen.getPreferenceCount()).thenReturn(1);
+ when(mScreen.getPreference(0)).thenReturn(mPreference);
+ }
+
+ @Test
+ public void testAvailableToUnavailable() {
+ mIsAvailable = true;
+
+ final DynamicAvailabilityPreferenceController controller
+ = new DynamicAvailabilityPreferenceControllerTestable(mLifecycle);
+ verify(mLifecycle).addObserver(controller);
+
+ controller.displayPreference(mScreen);
+ verify(mScreen, never()).removePreference(mPreference);
+ verify(mScreen, never()).addPreference(mPreference);
+ assertThat(mUpdatedPreference).isNull();
+
+ controller.onResume();
+ verify(mScreen, never()).removePreference(mPreference);
+ verify(mScreen, never()).addPreference(mPreference);
+ assertThat(mUpdatedPreference).isEqualTo(mPreference);
+
+ mUpdatedPreference = null;
+ mIsAvailable = false;
+ controller.onResume();
+ verify(mScreen).removePreference(mPreference);
+ verify(mScreen, never()).addPreference(mPreference);
+ assertThat(mUpdatedPreference).isNull();
+ }
+
+ @Test
+ public void testUnavailableToAvailable() {
+ mIsAvailable = false;
+
+ final DynamicAvailabilityPreferenceController controller
+ = new DynamicAvailabilityPreferenceControllerTestable(mLifecycle);
+ verify(mLifecycle).addObserver(controller);
+
+ controller.displayPreference(mScreen);
+ verify(mScreen).removePreference(mPreference);
+ verify(mScreen, never()).addPreference(mPreference);
+ assertThat(mUpdatedPreference).isNull();
+
+ reset(mScreen);
+ controller.onResume();
+ verify(mScreen, never()).removePreference(mPreference);
+ verify(mScreen, never()).addPreference(mPreference);
+ assertThat(mUpdatedPreference).isNull();
+
+ mIsAvailable = true;
+ controller.onResume();
+ verify(mScreen, never()).removePreference(mPreference);
+ verify(mScreen).addPreference(mPreference);
+ assertThat(mUpdatedPreference).isEqualTo(mPreference);
+ }
+
+
+ private class DynamicAvailabilityPreferenceControllerTestable
+ extends DynamicAvailabilityPreferenceController {
+ public DynamicAvailabilityPreferenceControllerTestable(Lifecycle lifecycle) {
+ super(DynamicAvailabilityPreferenceControllerTest.this.mContext, lifecycle);
+ }
+
+ @Override
+ public boolean isAvailable() {
+ return mIsAvailable;
+ }
+
+ @Override
+ public void updateState(Preference preference) {
+ mUpdatedPreference = preference;
+ }
+
+ @Override
+ public String getPreferenceKey() {
+ return PREFERENCE_KEY;
+ }
+ }
+}