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      1 /*
      2  * Copyright (C) 2017 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.graphics;
     18 
     19 import com.android.internal.annotations.GuardedBy;
     20 
     21 import android.annotation.NonNull;
     22 import android.annotation.Nullable;
     23 import android.os.Parcel;
     24 import android.os.Process;
     25 import android.util.ArrayMap;
     26 
     27 import java.util.ArrayList;
     28 
     29 /**
     30  * This class is used for Parceling Typeface object.
     31  * Note: Typeface object can not be passed over the process boundary.
     32  *
     33  * @hide
     34  */
     35 public class LeakyTypefaceStorage {
     36     private static final Object sLock = new Object();
     37 
     38     @GuardedBy("sLock")
     39     private static final ArrayList<Typeface> sStorage = new ArrayList<>();
     40     @GuardedBy("sLock")
     41     private static final ArrayMap<Typeface, Integer> sTypefaceMap = new ArrayMap<>();
     42 
     43     /**
     44      * Write typeface to parcel.
     45      *
     46      * You can't transfer Typeface to a different process. {@link readTypefaceFromParcel} will
     47      * return {@code null} if the {@link readTypefaceFromParcel} is called in a different process.
     48      *
     49      * @param typeface A {@link Typeface} to be written.
     50      * @param parcel A {@link Parcel} object.
     51      */
     52     public static void writeTypefaceToParcel(@Nullable Typeface typeface, @NonNull Parcel parcel) {
     53         parcel.writeInt(Process.myPid());
     54         synchronized (sLock) {
     55             final int id;
     56             final Integer i = sTypefaceMap.get(typeface);
     57             if (i != null) {
     58                 id = i.intValue();
     59             } else {
     60                 id = sStorage.size();
     61                 sStorage.add(typeface);
     62                 sTypefaceMap.put(typeface, id);
     63             }
     64             parcel.writeInt(id);
     65         }
     66     }
     67 
     68     /**
     69      * Read typeface from parcel.
     70      *
     71      * If the {@link Typeface} was created in another process, this method returns null.
     72      *
     73      * @param parcel A {@link Parcel} object
     74      * @return A {@link Typeface} object.
     75      */
     76     public static @Nullable Typeface readTypefaceFromParcel(@NonNull Parcel parcel) {
     77         final int pid = parcel.readInt();
     78         final int typefaceId = parcel.readInt();
     79         if (pid != Process.myPid()) {
     80             return null;  // The Typeface was created and written in another process.
     81         }
     82         synchronized (sLock) {
     83             return sStorage.get(typefaceId);
     84         }
     85     }
     86 }
     87