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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.android.contacts.list;
     17 
     18 import android.content.ContentResolver;
     19 import android.content.ContentValues;
     20 import android.content.Context;
     21 import android.database.ContentObserver;
     22 import android.database.Cursor;
     23 import android.os.Handler;
     24 import android.provider.ContactsContract.ProviderStatus;
     25 
     26 /**
     27  * Checks provider status and configures a list adapter accordingly.
     28  */
     29 public class ProviderStatusLoader extends ContentObserver {
     30 
     31     /**
     32      * Callback interface invoked when the provider status changes.
     33      */
     34     public interface ProviderStatusListener {
     35         public void onProviderStatusChange();
     36     }
     37 
     38     private static final String[] PROJECTION = new String[] {
     39         ProviderStatus.STATUS,
     40         ProviderStatus.DATA1
     41     };
     42 
     43     private static final int UNKNOWN = -1;
     44 
     45     private final Context mContext;
     46     private int mProviderStatus = UNKNOWN;
     47     private String mProviderData;
     48     private ProviderStatusListener mListener;
     49     private Handler mHandler = new Handler();
     50 
     51     public ProviderStatusLoader(Context context) {
     52         super(null);
     53         this.mContext = context;
     54     }
     55 
     56     public int getProviderStatus() {
     57         if (mProviderStatus == UNKNOWN) {
     58             loadProviderStatus();
     59         }
     60 
     61         return mProviderStatus;
     62     }
     63 
     64     public String getProviderStatusData() {
     65         if (mProviderStatus == UNKNOWN) {
     66             loadProviderStatus();
     67         }
     68 
     69         return mProviderData;
     70     }
     71 
     72     protected void loadProviderStatus() {
     73 
     74         // Default to normal status
     75         mProviderStatus = ProviderStatus.STATUS_NORMAL;
     76 
     77         // This query can be performed on the UI thread because
     78         // the API explicitly allows such use.
     79         Cursor cursor = mContext.getContentResolver().query(ProviderStatus.CONTENT_URI,
     80                 PROJECTION, null, null, null);
     81         if (cursor != null) {
     82             try {
     83                 if (cursor.moveToFirst()) {
     84                     mProviderStatus = cursor.getInt(0);
     85                     mProviderData = cursor.getString(1);
     86                 }
     87             } finally {
     88                 cursor.close();
     89             }
     90         }
     91     }
     92 
     93     public void setProviderStatusListener(ProviderStatusListener listener) {
     94         mListener = listener;
     95 
     96         ContentResolver resolver = mContext.getContentResolver();
     97         if (listener != null) {
     98             mProviderStatus = UNKNOWN;
     99             resolver.registerContentObserver(ProviderStatus.CONTENT_URI, false, this);
    100         } else {
    101             resolver.unregisterContentObserver(this);
    102         }
    103     }
    104 
    105     @Override
    106     public void onChange(boolean selfChange) {
    107         // Deliver a notification on the UI thread
    108         mHandler.post(new Runnable() {
    109             @Override
    110             public void run() {
    111                 if (mListener != null) {
    112                     mProviderStatus = UNKNOWN;
    113                     mListener.onProviderStatusChange();
    114                 }
    115             }
    116         });
    117     }
    118 
    119     /**
    120      * Sends a provider status update, which will trigger a retry of database upgrade
    121      */
    122     public void retryUpgrade() {
    123         ContentValues values = new ContentValues();
    124         values.put(ProviderStatus.STATUS, ProviderStatus.STATUS_UPGRADING);
    125         mContext.getContentResolver().update(ProviderStatus.CONTENT_URI, values, null, null);
    126     }
    127 }
    128