Add DynamicAvailabilityPreferenceController

/*

 * 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);

        }

    }

}

/*

 * 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;

        }

    }

}