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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 com.android.camera.session;
     18 
     19 import java.io.File;
     20 import java.io.IOException;
     21 
     22 import javax.annotation.Nullable;
     23 
     24 /**
     25  * Used to create temporary session files to be used by e.g. Photo Sphere to
     26  * write into.
     27  * <p>
     28  * This file also handles the correct creation of the file and makes sure that
     29  * it is available for writing into from e.g. native code.
     30  */
     31 public class TemporarySessionFile {
     32 
     33     private final SessionStorageManager mSessionStorageManager;
     34     private final String mSessionDirectory;
     35     private final String mTitle;
     36 
     37     @Nullable
     38     private File mFile;
     39 
     40     public TemporarySessionFile(SessionStorageManager sessionStorageManager, String
     41             sessionDirectory, String title) {
     42         mSessionStorageManager = sessionStorageManager;
     43         mSessionDirectory = sessionDirectory;
     44         mTitle = title;
     45         mFile = null;
     46     }
     47 
     48     /**
     49      * Creates the file and all the directories it is in if necessary.
     50      * <p>
     51      * If file was prepared successfully, additional calls to this method will
     52      * be no-ops and 'true' will be returned.
     53      *
     54      * @return Whether the file could be created and is ready to be written to.
     55      */
     56     public synchronized boolean prepare() {
     57         if (mFile != null) {
     58             return true;
     59         }
     60 
     61         try {
     62             mFile = mSessionStorageManager.createTemporaryOutputPath(mSessionDirectory, mTitle);
     63         } catch (IOException e) {
     64             return false;
     65         }
     66         return true;
     67     }
     68 
     69     /**
     70      * @return Whether the file has been created and is usable.
     71      */
     72     public synchronized boolean isUsable() {
     73         return mFile != null;
     74     }
     75 
     76     /**
     77      * @return The file or null, if {@link #prepare} has not be called yet or
     78      *         preparation failed.
     79      */
     80     @Nullable
     81     public synchronized File getFile() {
     82         return mFile;
     83     }
     84 
     85 }
     86