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      1 /*
      2  * Copyright (C) 2009 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 
     17 package com.example.android.businesscard;
     18 
     19 import android.content.ContentResolver;
     20 import android.content.Intent;
     21 import android.net.Uri;
     22 import android.os.Build;
     23 
     24 /**
     25  * This abstract class defines SDK-independent API for communication with
     26  * Contacts Provider. The actual implementation used by the application depends
     27  * on the level of API available on the device. If the API level is Cupcake or
     28  * Donut, we want to use the {@link ContactAccessorSdk3_4} class. If it is
     29  * Eclair or higher, we want to use {@link ContactAccessorSdk5}.
     30  */
     31 public abstract class ContactAccessor {
     32 
     33     /**
     34      * Static singleton instance of {@link ContactAccessor} holding the
     35      * SDK-specific implementation of the class.
     36      */
     37     private static ContactAccessor sInstance;
     38 
     39     public static ContactAccessor getInstance() {
     40         if (sInstance == null) {
     41             String className;
     42 
     43             /*
     44              * Check the version of the SDK we are running on. Choose an
     45              * implementation class designed for that version of the SDK.
     46              *
     47              * Unfortunately we have to use strings to represent the class
     48              * names. If we used the conventional ContactAccessorSdk5.class.getName()
     49              * syntax, we would get a ClassNotFoundException at runtime on pre-Eclair SDKs.
     50              * Using the above syntax would force Dalvik to load the class and try to
     51              * resolve references to all other classes it uses. Since the pre-Eclair
     52              * does not have those classes, the loading of ContactAccessorSdk5 would fail.
     53              */
     54             @SuppressWarnings("deprecation")
     55             int sdkVersion = Integer.parseInt(Build.VERSION.SDK);       // Cupcake style
     56             if (sdkVersion < Build.VERSION_CODES.ECLAIR) {
     57                 className = "com.example.android.businesscard.ContactAccessorSdk3_4";
     58             } else {
     59                 className = "com.example.android.businesscard.ContactAccessorSdk5";
     60             }
     61 
     62             /*
     63              * Find the required class by name and instantiate it.
     64              */
     65             try {
     66                 Class<? extends ContactAccessor> clazz =
     67                         Class.forName(className).asSubclass(ContactAccessor.class);
     68                 sInstance = clazz.newInstance();
     69             } catch (Exception e) {
     70                 throw new IllegalStateException(e);
     71             }
     72         }
     73 
     74         return sInstance;
     75     }
     76 
     77     /**
     78      * Returns the {@link Intent#ACTION_PICK} intent configured for the right authority: legacy
     79      * or current.
     80      */
     81     public abstract Intent getPickContactIntent();
     82 
     83     /**
     84      * Loads contact data for the supplied URI. The actual queries will differ for different APIs
     85      * used, but the result is the same: the {@link #mDisplayName} and {@link #mPhoneNumber}
     86      * fields are populated with correct data.
     87      */
     88     public abstract ContactInfo loadContact(ContentResolver contentResolver, Uri contactUri);
     89 }
     90