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      1 /*
      2  * Copyright (C) 2016 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.storagemanager.deletionhelper;
     18 
     19 import android.content.Context;
     20 import android.support.v7.preference.Preference;
     21 import android.support.v7.preference.Preference.OnPreferenceChangeListener;
     22 import android.support.v7.preference.CheckBoxPreference;
     23 import android.util.AttributeSet;
     24 
     25 import com.android.storagemanager.deletionhelper.DeletionType;
     26 import com.android.storagemanager.R;
     27 
     28 /**
     29  * Preference to handle the deletion of various data types in the Deletion Helper.
     30  */
     31 public abstract class DeletionPreference extends CheckBoxPreference implements
     32         DeletionType.FreeableChangedListener, OnPreferenceChangeListener {
     33     private DeletionType.FreeableChangedListener mListener;
     34     private long mFreeableBytes;
     35     private int mFreeableItems;
     36     private DeletionType mDeletionService;
     37 
     38     public DeletionPreference(Context context, AttributeSet attrs) {
     39         super(context, attrs);
     40         setLayoutResource(R.layout.deletion_preference);
     41         setOnPreferenceChangeListener(this);
     42         setPersistent(false);
     43     }
     44 
     45     /**
     46      * Returns the number of bytes which can be cleared by the deletion service.
     47      * @return The number of bytes.
     48      */
     49     public long getFreeableBytes() {
     50         return isChecked() ? mFreeableBytes : 0;
     51     }
     52 
     53     /**
     54      * Register a listener to be called back on when the freeable bytes have changed.
     55      * @param listener The callback listener.
     56      */
     57     public void registerFreeableChangedListener(DeletionType.FreeableChangedListener listener) {
     58         mListener = listener;
     59     }
     60 
     61     /**
     62      * Registers a deletion service to update the preference's information.
     63      * @param deletionService A photo/video deletion service.
     64      */
     65     public void registerDeletionService(DeletionType deletionService) {
     66         mDeletionService = deletionService;
     67         if (mDeletionService != null) {
     68             mDeletionService.registerFreeableChangedListener(this);
     69         }
     70     }
     71 
     72     /**
     73      * Returns the deletion service powering the preference.
     74      * @return The deletion service.
     75      */
     76     public DeletionType getDeletionService() {
     77         return mDeletionService;
     78     }
     79 
     80     @Override
     81     public void onFreeableChanged(int numItems, long freeableBytes) {
     82         mFreeableItems = numItems;
     83         mFreeableBytes = freeableBytes;
     84         maybeUpdateListener();
     85     }
     86 
     87     @Override
     88     public boolean onPreferenceChange(Preference preference, Object newValue) {
     89         setChecked((boolean) newValue);
     90         maybeUpdateListener();
     91         return true;
     92     }
     93 
     94     private void maybeUpdateListener() {
     95         if (mListener != null) {
     96             mListener.onFreeableChanged(mFreeableItems, getFreeableBytes());
     97         }
     98     }
     99 }
    100