Worker.java revision b9701e2752b53221501cfaeb247256f1ae12baec 
1/*
2 * Copyright 2018 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
17package androidx.work;
18
19import android.content.Context;
20import android.net.Uri;
21import android.support.annotation.Keep;
22import android.support.annotation.NonNull;
23import android.support.annotation.Nullable;
24import android.support.annotation.RequiresApi;
25import android.support.annotation.RestrictTo;
26import android.support.annotation.WorkerThread;
27
28import androidx.work.impl.RuntimeExtras;
29
30/**
31 * The basic unit of work.
32 */
33public abstract class Worker {
34
35    public enum WorkerResult {
36        SUCCESS,
37        FAILURE,
38        RETRY
39    }
40
41    private @NonNull Context mAppContext;
42    private @NonNull String mId;
43    private @NonNull Data mInputData;
44    private @NonNull Data mOutputData = Data.EMPTY;
45    private @Nullable RuntimeExtras mRuntimeExtras;
46
47    public final @NonNull Context getAppContext() {
48        return mAppContext;
49    }
50
51    public final @NonNull String getId() {
52        return mId;
53    }
54
55    public final @NonNull Data getInputData() {
56        return mInputData;
57    }
58
59    @RequiresApi(24)
60    public final @Nullable Uri[] getTriggeredContentUris() {
61        return (mRuntimeExtras == null) ? null : mRuntimeExtras.triggeredContentUris;
62    }
63
64    @RequiresApi(24)
65    public final @Nullable String[] getTriggeredContentAuthorities() {
66        return (mRuntimeExtras == null)
67                ? null
68                : mRuntimeExtras.triggeredContentAuthorities;
69    }
70
71    /**
72     * Override this method to do your actual background processing.
73     *
74     * @return The result of the work, corresponding to a {@link WorkerResult} value.  If a
75     * different value is returned, the result shall be defaulted to
76     * {@link Worker.WorkerResult#FAILURE}.
77     */
78    @WorkerThread
79    public abstract @NonNull WorkerResult doWork();
80
81    /**
82     * Call this method to pass an {@link Data} object to {@link WorkRequest} that is dependent on
83     * this one.  Note that if there are multiple {@link Worker}s that contribute to the target, the
84     * Data will be merged together, so it is up to the developer to make sure that keys are
85     * unique.  New values and types will clobber old values and types, and if there are multiple
86     * parent Workers of a child Worker, the order of clobbering may not be deterministic.
87     *
88     * This method is invoked after {@link #doWork()} returns {@link Worker.WorkerResult#SUCCESS}
89     * and there are chained jobs available.
90     *
91     * For example, if you had this structure:
92     *
93     * {@code WorkManager.getInstance(context)
94     *            .enqueueWithDefaults(WorkerA.class, WorkerB.class)
95     *            .then(WorkerC.class)
96     *            .enqueue()}
97     *
98     * This method would be called for both WorkerA and WorkerB after their successful completion,
99     * modifying the input Data for WorkerC.
100     *
101     * @param outputData An {@link Data} object that will be merged into the input Data of any
102     *               WorkRequest that is dependent on this one, or {@code null} if there is nothing
103     *               to contribute
104     */
105    public final void setOutputData(@NonNull Data outputData) {
106        mOutputData = outputData;
107    }
108
109    public final @NonNull Data getOutputData() {
110        return mOutputData;
111    }
112
113    @Keep
114    private void internalInit(
115            @NonNull Context appContext,
116            @NonNull String id,
117            @NonNull Data inputData,
118            @Nullable RuntimeExtras runtimeExtras) {
119        mAppContext = appContext;
120        mId = id;
121        mInputData = inputData;
122        mRuntimeExtras = runtimeExtras;
123    }
124
125    /**
126     * Determines if the {@link Worker} was interrupted and should stop executing.
127     * The {@link Worker} can be interrupted for the following reasons:
128     * 1. The {@link WorkRequest} or {@link PeriodicWorkRequest} was explicitly cancelled.
129     *    {@link WorkManager#cancelAllWorkByTag(String)}
130     * 2. Constraints set in {@link WorkRequest} or {@link PeriodicWorkRequest} are no longer valid.
131     * @return {@code true} if {@link Worker} is instructed to stop executing.
132     */
133    protected final boolean isInterrupted() {
134        return Thread.currentThread().isInterrupted();
135    }
136
137    /**
138     * @hide
139     */
140    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
141    public @Nullable RuntimeExtras getRuntimeExtras() {
142        return mRuntimeExtras;
143    }
144}
145