/*
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* Copyright (C) 2017 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.android.settings.widget;
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import android.content.Context;
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import android.text.TextUtils;
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/**
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* Helper class that listens to settings changes and notifies client when there is update in
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* corresponding summary info.
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*/
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public abstract class SummaryUpdater {
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protected final Context mContext;
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private final OnSummaryChangeListener mListener;
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private String mSummary;
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/**
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* Interface definition for a callback to be invoked when the summary has been changed.
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*/
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public interface OnSummaryChangeListener {
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/**
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* Called when summary has changed.
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*
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* @param summary The new summary .
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*/
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void onSummaryChanged(String summary);
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}
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/**
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* Constructor
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*
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* @param context The Context the updater is running in, through which it can register broadcast
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* receiver etc.
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* @param listener The listener that would like to receive summary change notification.
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*
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*/
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public SummaryUpdater(Context context, OnSummaryChangeListener listener) {
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mContext = context;
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mListener = listener;
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}
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/**
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* Notifies the listener when there is update in summary
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*/
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protected void notifyChangeIfNeeded() {
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String summary = getSummary();
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if (!TextUtils.equals(mSummary, summary)) {
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mSummary = summary;
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if (mListener != null) {
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mListener.onSummaryChanged(summary);
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}
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}
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}
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/**
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* Starts/stops receiving updates on the summary.
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*
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* @param register true if we want to receive updates, false otherwise
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*/
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public abstract void register(boolean register);
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/**
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* Gets the summary. Subclass should checks latest conditions and update the summary
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* accordingly.
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*
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* @return the latest summary text
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*/
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protected abstract String getSummary();
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}
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