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