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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  * Copyright (C) 2016 Mopria Alliance, Inc.
      4  *
      5  * Licensed under the Apache License, Version 2.0 (the "License");
      6  * you may not use this file except in compliance with the License.
      7  * You may obtain a copy of the License at
      8  *
      9  *      http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  * Unless required by applicable law or agreed to in writing, software
     12  * distributed under the License is distributed on an "AS IS" BASIS,
     13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  * See the License for the specific language governing permissions and
     15  * limitations under the License.
     16  */
     17 
     18 package com.android.bips.discovery;
     19 
     20 import android.net.Uri;
     21 import android.util.Log;
     22 
     23 import java.util.ArrayList;
     24 import java.util.Arrays;
     25 import java.util.Collection;
     26 import java.util.List;
     27 
     28 /** Combines the behavior of multiple child {@link Discovery} objects to a single one */
     29 public class MultiDiscovery extends Discovery {
     30     private static final String TAG = MultiDiscovery.class.getSimpleName();
     31     private static final boolean DEBUG = false;
     32 
     33     private final List<Discovery> mDiscoveries = new ArrayList<>();
     34     private final List<Discovery> mStartedDiscoveries = new ArrayList<>();
     35     private final Listener mChildListener;
     36 
     37     /**
     38      * Construct an aggregate discovery mechanism, with preferred discovery mechanisms first
     39      */
     40     public MultiDiscovery(Discovery first, Discovery... rest) {
     41         super(first.getPrintService());
     42         mDiscoveries.add(first);
     43         mDiscoveries.addAll(Arrays.asList(rest));
     44         mChildListener = new Listener() {
     45             @Override
     46             public void onPrinterFound(DiscoveredPrinter printer) {
     47                 printerFound(first(printer.getUri()));
     48             }
     49 
     50             @Override
     51             public void onPrinterLost(DiscoveredPrinter printer) {
     52                 // Merge remaining printer records, if any
     53                 DiscoveredPrinter first = first(printer.getUri());
     54                 if (first == null) {
     55                     printerLost(printer.getUri());
     56                 } else {
     57                     printerFound(first);
     58                 }
     59             }
     60         };
     61     }
     62 
     63     /** For a given URI return the first matching record, based on discovery mechanism order */
     64     private DiscoveredPrinter first(Uri printerUri) {
     65         for (Discovery discovery : getChildren()) {
     66             DiscoveredPrinter found = discovery.getPrinter(printerUri);
     67             if (found != null) {
     68                 return found;
     69             }
     70         }
     71         return null;
     72     }
     73 
     74     @Override
     75     void onStart() {
     76         if (DEBUG) Log.d(TAG, "onStart()");
     77         for (Discovery discovery : mDiscoveries) {
     78             discovery.start(mChildListener);
     79             mStartedDiscoveries.add(discovery);
     80         }
     81     }
     82 
     83     private void stopAndClearAll() {
     84         for (Discovery discovery : mStartedDiscoveries) {
     85             discovery.stop(mChildListener);
     86         }
     87         mStartedDiscoveries.clear();
     88         allPrintersLost();
     89     }
     90 
     91     @Override
     92     void onStop() {
     93         if (DEBUG) Log.d(TAG, "onStop()");
     94         stopAndClearAll();
     95     }
     96 
     97     @Override
     98     Collection<Discovery> getChildren() {
     99         List<Discovery> children = new ArrayList<>();
    100         for (Discovery child : mDiscoveries) {
    101             children.addAll(child.getChildren());
    102         }
    103         return children;
    104     }
    105 }
    106