Home | History | Annotate | Download | only in telecom 
      1 /*
      2  * Copyright (C) 2015 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.car.dialer.telecom;
     17 
     18 import android.content.ContentResolver;
     19 import android.graphics.Bitmap;
     20 import android.os.AsyncTask;
     21 import android.support.annotation.MainThread;
     22 import android.support.annotation.Nullable;
     23 import android.widget.ImageView;
     24 
     25 import java.lang.ref.WeakReference;
     26 
     27 /**
     28  * Helper task that retrieves a Contact photo from the local Contacts store. The loading task
     29  * is tied to an ImageView that allows a lightweight management of the task upon update of the view.
     30  *
     31  * TODO(mcrico): Using a View's TAG to store and manage Async task loading is pretty brittle.
     32  * Vanagon is not depending on this logic and projected shouldn't either.
     33  */
     34 public class ContactBitmapWorker extends AsyncTask<Void, Void, Bitmap> {
     35     private final WeakReference<ImageView> mImageViewReference;
     36     private final WeakReference<ContentResolver> mContentResolverReference;
     37     private final String mNumber;
     38     private final BitmapWorkerListener mListener;
     39 
     40     /** Interface to receive updates from this worker */
     41     public interface BitmapWorkerListener {
     42         /** Called in the main thread upon bitmap load finish */
     43         @MainThread
     44         void onBitmapLoaded(@Nullable Bitmap bitmap);
     45     }
     46 
     47     /**
     48      * @return A worker task if a new one was needed to load the bitmap.
     49      */
     50     @Nullable public static ContactBitmapWorker loadBitmap(
     51             ContentResolver contentResolver,
     52             ImageView imageView,
     53             String number,
     54             BitmapWorkerListener listener) {
     55 
     56         // This work may be underway already.
     57         if (!cancelPotentialWork(number, imageView)) {
     58             return null;
     59         }
     60 
     61         ContactBitmapWorker task =
     62                 new ContactBitmapWorker(contentResolver, imageView, number, listener);
     63         imageView.setTag(task);
     64         imageView.setImageResource(0);
     65         task.execute();
     66         return task;
     67     }
     68 
     69     /** Use {@link #loadBitmap} instead, as it guarantees de-duplication of work */
     70     private ContactBitmapWorker(
     71             ContentResolver contentResolver,
     72             ImageView imageView,
     73             String number,
     74             BitmapWorkerListener listener) {
     75         mImageViewReference = new WeakReference<>(imageView);
     76         mContentResolverReference = new WeakReference<>(contentResolver);
     77         mNumber = number;
     78         mListener = listener;
     79     }
     80 
     81     @Override
     82     protected Bitmap doInBackground(Void... voids) {
     83         final ContentResolver contentResolver = mContentResolverReference.get();
     84         if (contentResolver != null) {
     85             return TelecomUtils.getContactPhotoFromNumber(contentResolver, mNumber);
     86         }
     87         return null;
     88     }
     89 
     90     @Override
     91     protected void onPostExecute(Bitmap bitmap) {
     92         if (isCancelled()) {
     93             return;
     94         }
     95 
     96         if (mImageViewReference.get() != null) {
     97             mListener.onBitmapLoaded(bitmap);
     98         }
     99     }
    100 
    101     /**
    102      * @return Whether a new Bitmap loading should continue for this imageView.
    103      */
    104     private static boolean cancelPotentialWork(String number, ImageView imageView) {
    105         final ContactBitmapWorker bitmapWorkerTask = (ContactBitmapWorker) imageView.getTag();
    106         if (bitmapWorkerTask != null) {
    107             if (bitmapWorkerTask.mNumber != number) {
    108                 bitmapWorkerTask.cancel(true);
    109                 imageView.setTag(null);
    110             } else {
    111                 // The same work is already in progress
    112                 return false;
    113             }
    114         }
    115 
    116         return true;
    117     }
    118 }
    119