1 package com.android.mail.providers; 2 3 import android.os.Parcel; 4 import android.os.Parcelable; 5 6 import com.google.common.collect.ImmutableList; 7 8 import java.util.Collection; 9 import java.util.Collections; 10 import java.util.List; 11 12 /** 13 * Simple class to encapsulate an immutable list of {@link Folder} objects, and handle serialization 14 * and de-serialization. 15 */ 16 public class FolderList implements Parcelable { 17 18 private static final FolderList EMPTY = new FolderList(Collections.<Folder> emptyList()); 19 20 public final ImmutableList<Folder> folders; 21 22 // Private to reinforce the copyOf() API, which makes it more clear that creating a FolderList 23 // has copy overhead. 24 private FolderList(Collection<Folder> in) { 25 if (in == null) { 26 folders = ImmutableList.of(); 27 } else { 28 folders = ImmutableList.copyOf(in); 29 } 30 } 31 32 public FolderList(Parcel in) { 33 folders = ImmutableList.copyOf(in.createTypedArrayList(Folder.CREATOR)); 34 } 35 36 @Override 37 public int describeContents() { 38 return 0; 39 } 40 41 @Override 42 public void writeToParcel(Parcel dest, int flags) { 43 dest.writeTypedList(folders); 44 } 45 46 public byte[] toBlob() { 47 final Parcel p = Parcel.obtain(); 48 writeToParcel(p, 0); 49 final byte[] result = p.marshall(); 50 p.recycle(); 51 return result; 52 } 53 54 /** 55 * Directly turns a list of {@link Folder}s into a byte-array. Avoids the 56 * list-copy overhead of {@link #copyOf(Collection)} + {@link #toBlob()}. 57 * 58 * @param in a list of Folders 59 * @return the marshalled byte-array form of a {@link FolderList} 60 */ 61 public static byte[] listToBlob(List<Folder> in) { 62 final Parcel p = Parcel.obtain(); 63 p.writeTypedList(in); 64 final byte[] result = p.marshall(); 65 p.recycle(); 66 return result; 67 } 68 69 public static FolderList fromBlob(byte[] blob) { 70 if (blob == null) { 71 return EMPTY; 72 } 73 74 final Parcel p = Parcel.obtain(); 75 p.unmarshall(blob, 0, blob.length); 76 p.setDataPosition(0); 77 final FolderList result = CREATOR.createFromParcel(p); 78 p.recycle(); 79 return result; 80 } 81 82 public static FolderList copyOf(Collection<Folder> in) { 83 return new FolderList(in); 84 } 85 86 @Override 87 public boolean equals(Object o) { 88 return folders.equals(o); 89 } 90 91 @Override 92 public int hashCode() { 93 return folders.hashCode(); 94 } 95 96 public static final Creator<FolderList> CREATOR = new Creator<FolderList>() { 97 98 @Override 99 public FolderList createFromParcel(Parcel source) { 100 return new FolderList(source); 101 } 102 103 @Override 104 public FolderList[] newArray(int size) { 105 return new FolderList[size]; 106 } 107 }; 108 109 } 110
