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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 
     17 
     18 package com.replica.replicaisland;
     19 
     20 import java.util.Comparator;
     21 
     22 /**
     23  * A derivation of ObjectManager that sorts its children if they are of type PhasedObject.
     24  * Sorting is performed on add.
     25  */
     26 public class PhasedObjectManager extends ObjectManager {
     27     private final static PhasedObjectComparator sPhasedObjectComparator
     28         = new PhasedObjectComparator();
     29     private boolean mDirty;
     30     private PhasedObject mSearchDummy;  // A dummy object allocated up-front for searching by phase.
     31 
     32     public PhasedObjectManager() {
     33         super();
     34         mDirty = false;
     35         getObjects().setComparator(sPhasedObjectComparator);
     36         getPendingObjects().setComparator(sPhasedObjectComparator);
     37         mSearchDummy = new PhasedObject();
     38     }
     39 
     40     public PhasedObjectManager(int arraySize) {
     41         super(arraySize);
     42         mDirty = false;
     43         getObjects().setComparator(sPhasedObjectComparator);
     44         getPendingObjects().setComparator(sPhasedObjectComparator);
     45         mSearchDummy = new PhasedObject();
     46     }
     47 
     48     @Override
     49     public void commitUpdates() {
     50         super.commitUpdates();
     51         if (mDirty) {
     52             getObjects().sort(true);
     53             mDirty = false;
     54         }
     55     }
     56 
     57     @Override
     58     public void add(BaseObject object) {
     59 
     60         if (object instanceof PhasedObject) {
     61             super.add(object);
     62             mDirty = true;
     63         } else {
     64             // The only reason to restrict PhasedObjectManager to PhasedObjects is so that
     65             // the PhasedObjectComparator can assume all of its contents are PhasedObjects and
     66             // avoid calling instanceof every time.
     67             assert false : "Can't add a non-PhasedObject to a PhasedObjectManager!";
     68         }
     69     }
     70 
     71     public BaseObject find(int phase) {
     72         mSearchDummy.setPhase(phase);
     73         int index = getObjects().find(mSearchDummy, false);
     74         BaseObject result = null;
     75         if (index != -1) {
     76             result = getObjects().get(index);
     77         } else {
     78             index = getPendingObjects().find(mSearchDummy, false);
     79             if (index != -1) {
     80                 result = getPendingObjects().get(index);
     81             }
     82         }
     83         return result;
     84     }
     85 
     86     /** Comparator for phased objects. */
     87     private static class PhasedObjectComparator implements Comparator<BaseObject>  {
     88         public int compare(BaseObject object1, BaseObject object2) {
     89             int result = 0;
     90             if (object1 != null && object2 != null) {
     91                 result = ((PhasedObject) object1).phase - ((PhasedObject) object2).phase;
     92             } else if (object1 == null && object2 != null) {
     93                 result = 1;
     94             } else if (object2 == null && object1 != null) {
     95                 result = -1;
     96             }
     97             return result;
     98         }
     99     }
    100 
    101 }
    102