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.documentsui;
18 
19 import static com.android.documentsui.base.SharedMinimal.DEBUG;
20 
21 import android.content.ContentProviderClient;
22 import android.content.ContentResolver;
23 import android.content.Context;
24 import android.net.Uri;
25 import android.os.CancellationSignal;
26 import android.os.FileUtils;
27 import android.util.Log;
28 
29 import androidx.annotation.Nullable;
30 
31 import com.android.documentsui.base.ApplicationScope;
32 import com.android.documentsui.base.BooleanConsumer;
33 import com.android.documentsui.base.CheckedTask;
34 import com.android.documentsui.base.DocumentInfo;
35 import com.android.documentsui.base.Features;
36 import com.android.documentsui.base.State;
37 
38 /**
39  * A {@link CheckedTask} that calls
40  * {@link ContentResolver#refresh(Uri, android.os.Bundle, android.os.CancellationSignal)} on the
41  * current directory, and then calls the supplied callback with the refresh return value.
42  */
43 public class RefreshTask extends TimeoutTask<Void, Boolean> {
44 
45     private final static String TAG = "RefreshTask";
46 
47     private final @ApplicationScope Context mContext;
48     private final Features mFeatures;
49     private final State mState;
50     private final DocumentInfo mDoc;
51     private final BooleanConsumer mCallback;
52     private final CancellationSignal mSignal;
53 
54 
RefreshTask(Features features, State state, DocumentInfo doc, long timeout, @ApplicationScope Context context, Check check, BooleanConsumer callback)55     public RefreshTask(Features features, State state, DocumentInfo doc, long timeout,
56             @ApplicationScope Context context, Check check, BooleanConsumer callback) {
57         super(check, timeout);
58         mFeatures = features;
59         mState = state;
60         mDoc = doc;
61         mContext = context;
62         mCallback = callback;
63         mSignal = new CancellationSignal();
64     }
65 
66     @Override
run(Void... params)67     public @Nullable Boolean run(Void... params) {
68         if (mDoc == null) {
69             Log.w(TAG, "Ignoring attempt to refresh due to null DocumentInfo.");
70             return false;
71         }
72 
73         if (mState.stack.isEmpty()) {
74             Log.w(TAG, "Ignoring attempt to refresh due to empty stack.");
75             return false;
76         }
77 
78         if (mDoc.derivedUri == null) {
79             Log.w(TAG, "Ignoring attempt to refresh due to null derived uri in DocumentInfo.");
80             return false;
81         }
82 
83         if (!mDoc.derivedUri.equals(mState.stack.peek().derivedUri)) {
84             Log.w(TAG, "Ignoring attempt to refresh on a non-top-level uri.");
85             return false;
86         }
87 
88         // API O introduces ContentResolver#refresh, and if available and the ContentProvider
89         // supports it, the ContentProvider will automatically send a content updated notification
90         // and we will update accordingly. Else, we just tell the callback that Refresh is not
91         // supported.
92         if (!mFeatures.isContentRefreshEnabled()) {
93             Log.w(TAG, "Ignoring attempt to call Refresh on an older Android platform.");
94             return false;
95         }
96 
97         final ContentResolver resolver = mContext.getContentResolver();
98         final String authority = mDoc.authority;
99         boolean refreshSupported = false;
100         ContentProviderClient client = null;
101         try {
102             client = DocumentsApplication.acquireUnstableProviderOrThrow(resolver, authority);
103             refreshSupported = client.refresh(mDoc.derivedUri, null, mSignal);
104         } catch (Exception e) {
105             Log.w(TAG, "Failed to refresh", e);
106         } finally {
107             FileUtils.closeQuietly(client);
108         }
109         return refreshSupported;
110     }
111 
112     @Override
onTimeout()113     protected void onTimeout() {
114         mSignal.cancel();
115         Log.w(TAG, "Provider taking too long to respond. Cancelling.");
116     }
117 
118     @Override
finish(Boolean refreshSupported)119     public void finish(Boolean refreshSupported) {
120         if (DEBUG) {
121             // In case of timeout, refreshSupported is null.
122             if (Boolean.TRUE.equals(refreshSupported)) {
123                 Log.v(TAG, "Provider supports refresh and has refreshed");
124             } else {
125                 Log.v(TAG, "Provider does not support refresh and did not refresh");
126             }
127         }
128         mCallback.accept(refreshSupported != null ? refreshSupported : Boolean.FALSE);
129     }
130 }
131