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      1 /*
      2  * Copyright (C) 2008 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.android.calendar;
     18 
     19 import android.content.Context;
     20 import android.graphics.drawable.Drawable;
     21 import android.net.Uri;
     22 import android.os.Handler;
     23 import android.os.HandlerThread;
     24 import android.os.Looper;
     25 import android.os.Message;
     26 import android.provider.ContactsContract.Contacts;
     27 import android.util.Log;
     28 import android.view.View;
     29 import android.widget.ImageView;
     30 
     31 import java.io.InputStream;
     32 
     33 /**
     34  * Helper class for async access of images.
     35  */
     36 public class ContactsAsyncHelper extends Handler {
     37 
     38     private static final boolean DBG = false;
     39     private static final String LOG_TAG = "ContactsAsyncHelper";
     40 
     41     /**
     42      * Interface for a WorkerHandler result return.
     43      */
     44     public interface OnImageLoadCompleteListener {
     45         /**
     46          * Called when the image load is complete.
     47          *
     48          * @param imagePresent true if an image was found
     49          */
     50         public void onImageLoadComplete(int token, Object cookie, ImageView iView,
     51                 boolean imagePresent);
     52     }
     53 
     54     // constants
     55     private static final int EVENT_LOAD_IMAGE = 1;
     56     private static final int DEFAULT_TOKEN = -1;
     57 
     58     // static objects
     59     private static Handler sThreadHandler;
     60     private static ContactsAsyncHelper sInstance;
     61 
     62     static {
     63         sInstance = new ContactsAsyncHelper();
     64     }
     65 
     66     private static final class WorkerArgs {
     67         public Context context;
     68         public ImageView view;
     69         public Uri uri;
     70         public int defaultResource;
     71         public Object result;
     72     }
     73 
     74     /**
     75      * Thread worker class that handles the task of opening the stream and loading
     76      * the images.
     77      */
     78     private class WorkerHandler extends Handler {
     79         public WorkerHandler(Looper looper) {
     80             super(looper);
     81         }
     82 
     83         @Override
     84         public void handleMessage(Message msg) {
     85             WorkerArgs args = (WorkerArgs) msg.obj;
     86 
     87             switch (msg.arg1) {
     88                 case EVENT_LOAD_IMAGE:
     89                     InputStream inputStream = null;
     90                     try {
     91                         inputStream = Contacts.openContactPhotoInputStream(
     92                                 args.context.getContentResolver(), args.uri);
     93                     } catch (Exception e) {
     94                         Log.e(LOG_TAG, "Error opening photo input stream", e);
     95                     }
     96 
     97                     if (inputStream != null) {
     98                         args.result = Drawable.createFromStream(inputStream, args.uri.toString());
     99 
    100                         if (DBG) Log.d(LOG_TAG, "Loading image: " + msg.arg1 +
    101                                 " token: " + msg.what + " image URI: " + args.uri);
    102                     } else {
    103                         args.result = null;
    104                         if (DBG) Log.d(LOG_TAG, "Problem with image: " + msg.arg1 +
    105                                 " token: " + msg.what + " image URI: " + args.uri +
    106                                 ", using default image.");
    107                     }
    108                     break;
    109                 default:
    110             }
    111 
    112             // send the reply to the enclosing class.
    113             Message reply = ContactsAsyncHelper.this.obtainMessage(msg.what);
    114             reply.arg1 = msg.arg1;
    115             reply.obj = msg.obj;
    116             reply.sendToTarget();
    117         }
    118     }
    119 
    120     /**
    121      * Private constructor for static class
    122      */
    123     private ContactsAsyncHelper() {
    124         HandlerThread thread = new HandlerThread("ContactsAsyncWorker");
    125         thread.start();
    126         sThreadHandler = new WorkerHandler(thread.getLooper());
    127     }
    128 
    129     /**
    130      * Start an image load, attach the result to the specified CallerInfo object.
    131      * Note, when the query is started, we make the ImageView INVISIBLE if the
    132      * placeholderImageResource value is -1.  When we're given a valid (!= -1)
    133      * placeholderImageResource value, we make sure the image is visible.
    134      */
    135     public static final void updateImageViewWithContactPhotoAsync(Context context,
    136             ImageView imageView, Uri person, int placeholderImageResource) {
    137 
    138         // in case the source caller info is null, the URI will be null as well.
    139         // just update using the placeholder image in this case.
    140         if (person == null) {
    141             if (DBG) Log.d(LOG_TAG, "target image is null, just display placeholder.");
    142             imageView.setVisibility(View.VISIBLE);
    143             imageView.setImageResource(placeholderImageResource);
    144             return;
    145         }
    146 
    147         // Added additional Cookie field in the callee to handle arguments
    148         // sent to the callback function.
    149 
    150         // setup arguments
    151         WorkerArgs args = new WorkerArgs();
    152         args.context = context;
    153         args.view = imageView;
    154         args.uri = person;
    155         args.defaultResource = placeholderImageResource;
    156 
    157         // setup message arguments
    158         Message msg = sThreadHandler.obtainMessage(DEFAULT_TOKEN);
    159         msg.arg1 = EVENT_LOAD_IMAGE;
    160         msg.obj = args;
    161 
    162         if (DBG) Log.d(LOG_TAG, "Begin loading image: " + args.uri +
    163                 ", displaying default image for now.");
    164 
    165         // set the default image first, when the query is complete, we will
    166         // replace the image with the correct one.
    167         if (placeholderImageResource != -1) {
    168             imageView.setVisibility(View.VISIBLE);
    169             imageView.setImageResource(placeholderImageResource);
    170         } else {
    171             imageView.setVisibility(View.INVISIBLE);
    172         }
    173 
    174         // notify the thread to begin working
    175         sThreadHandler.sendMessage(msg);
    176     }
    177 
    178     /**
    179      * Called when loading is done.
    180      */
    181     @Override
    182     public void handleMessage(Message msg) {
    183         WorkerArgs args = (WorkerArgs) msg.obj;
    184         switch (msg.arg1) {
    185             case EVENT_LOAD_IMAGE:
    186                 boolean imagePresent = false;
    187 
    188                 // if the image has been loaded then display it, otherwise set default.
    189                 // in either case, make sure the image is visible.
    190                 if (args.result != null) {
    191                     args.view.setVisibility(View.VISIBLE);
    192                     args.view.setImageDrawable((Drawable) args.result);
    193                     imagePresent = true;
    194                 } else if (args.defaultResource != -1) {
    195                     args.view.setVisibility(View.VISIBLE);
    196                     args.view.setImageResource(args.defaultResource);
    197                 }
    198                 break;
    199             default:
    200         }
    201     }
    202 }
    203