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      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 
     17 package android.databinding;
     18 
     19 import android.os.Parcel;
     20 import android.os.Parcelable;
     21 
     22 import java.io.Serializable;
     23 
     24 /**
     25  * An observable class that holds a parcelable object.
     26  * <p>
     27  * Observable field classes may be used instead of creating an Observable object:
     28  * <pre><code>public class MyDataObject {
     29  *     public final ObservableParcelable&lt;String&gt; name = new ObservableParcelable&lt;String&gt;();
     30  *     public final ObservableInt age = new ObservableInt();
     31  * }</code></pre>
     32  * Fields of this type should be declared final because bindings only detect changes in the
     33  * field's value, not of the field itself.
     34  * <p>
     35  * This class is parcelable but you should keep in mind that listeners are ignored when the object
     36  * is parcelled. Unless you add custom observers, this should not be an issue because data binding
     37  * framework always re-registers observers when the view is bound.
     38  */
     39 public class ObservableParcelable<T extends Parcelable> extends ObservableField<T>
     40         implements Parcelable, Serializable {
     41     static final long serialVersionUID = 1L;
     42     /**
     43      * Wraps the given object and creates an observable object
     44      *
     45      * @param value The value to be wrapped as an observable.
     46      */
     47     public ObservableParcelable(T value) {
     48         super(value);
     49     }
     50 
     51     /**
     52      * Creates an empty observable object
     53      */
     54     public ObservableParcelable() {
     55         super();
     56     }
     57 
     58     @Override
     59     public int describeContents() {
     60         return 0;
     61     }
     62 
     63     @Override
     64     public void writeToParcel(Parcel dest, int flags) {
     65         dest.writeParcelable(get(), 0);
     66     }
     67 
     68     public static final Parcelable.Creator<ObservableParcelable> CREATOR
     69             = new Parcelable.Creator<ObservableParcelable>() {
     70 
     71         @Override
     72         public ObservableParcelable createFromParcel(Parcel source) {
     73             //noinspection unchecked
     74             return new ObservableParcelable(source.readParcelable(getClass().getClassLoader()));
     75         }
     76 
     77         @Override
     78         public ObservableParcelable[] newArray(int size) {
     79             return new ObservableParcelable[size];
     80         }
     81     };
     82 }
     83