src/com/android/emergency/preferences/EmergencyListPreference.java

/*
 * 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.emergency.preferences;

import android.content.Context;
import android.preference.ListPreference;
import android.text.TextUtils;
import android.util.AttributeSet;

import com.android.emergency.ReloadablePreferenceInterface;

/**
 * Custom {@link ListPreference} that allows us to refresh and update the summary.
 */
public class EmergencyListPreference extends ListPreference
        implements ReloadablePreferenceInterface {

    public EmergencyListPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public void reloadFromPreference() {
        setValue(getPersistedString(""));
    }

    @Override
    public boolean isNotSet() {
        return TextUtils.isEmpty(getValue());
    }

    @Override
    public CharSequence getSummary() {
        final CharSequence value = getValue();
        if (TextUtils.isEmpty(value)) {
            return super.getSummary();
        } else {
            return value;
        }
    }
}