Worker.java revision 7b5c560e4098585f73564951621060de708e441f 
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.Extras;
29
30import java.util.Set;
31
32/**
33 * The basic unit of work.
34 */
35public abstract class Worker {
36
37    public enum WorkerResult {
38        SUCCESS,
39        FAILURE,
40        RETRY
41    }
42
43    private @NonNull Context mAppContext;
44    private @NonNull String mId;
45    private @NonNull Extras mExtras;
46    private @NonNull Data mOutputData = Data.EMPTY;
47
48    public final @NonNull Context getApplicationContext() {
49        return mAppContext;
50    }
51
52    public final @NonNull String getId() {
53        return mId;
54    }
55
56    public final @NonNull Data getInputData() {
57        return mExtras.getInputData();
58    }
59
60    public final @NonNull Set<String> getTags() {
61        return mExtras.getTags();
62    }
63
64    @RequiresApi(24)
65    public final @Nullable Uri[] getTriggeredContentUris() {
66        Extras.RuntimeExtras runtimeExtras = mExtras.getRuntimeExtras();
67        return (runtimeExtras == null) ? null : runtimeExtras.triggeredContentUris;
68    }
69
70    @RequiresApi(24)
71    public final @Nullable String[] getTriggeredContentAuthorities() {
72        Extras.RuntimeExtras runtimeExtras = mExtras.getRuntimeExtras();
73        return (runtimeExtras == null) ? null : runtimeExtras.triggeredContentAuthorities;
74    }
75
76    /**
77     * Override this method to do your actual background processing.
78     *
79     * @return The result of the work, corresponding to a {@link WorkerResult} value.  If a
80     * different value is returned, the result shall be defaulted to
81     * {@link Worker.WorkerResult#FAILURE}.
82     */
83    @WorkerThread
84    public abstract @NonNull WorkerResult doWork();
85
86    /**
87     * Call this method to pass an {@link Data} object to {@link Worker} that is
88     * dependent on this one.
89     *
90     * Note that if there are multiple {@link Worker}s that contribute to the target, the
91     * Data will be merged together, so it is up to the developer to make sure that keys are
92     * unique.  New values and types will clobber old values and types, and if there are multiple
93     * parent Workers of a child Worker, the order of clobbering may not be deterministic.
94     *
95     * This method is invoked after {@link #doWork()} returns {@link Worker.WorkerResult#SUCCESS}
96     * and there are chained jobs available.
97     *
98     * For example, if you had this structure:
99     *
100     * {@code WorkManager.getInstance(context)
101     *             .enqueueWithDefaults(WorkerA.class, WorkerB.class)
102     *             .then(WorkerC.class)
103     *             .enqueue()}
104     *
105     * This method would be called for both WorkerA and WorkerB after their successful completion,
106     * modifying the input Data for WorkerC.
107     *
108     * @param outputData An {@link Data} object that will be merged into the input Data of any
109     *                   OneTimeWorkRequest that is dependent on this one, or {@code null} if there
110     *                   is nothing to contribute
111     */
112    public final void setOutputData(@NonNull Data outputData) {
113        mOutputData = outputData;
114    }
115
116    public final @NonNull Data getOutputData() {
117        return mOutputData;
118    }
119
120    @Keep
121    private void internalInit(
122            @NonNull Context appContext,
123            @NonNull String id,
124            @NonNull Extras extras) {
125        mAppContext = appContext;
126        mId = id;
127        mExtras = extras;
128    }
129
130    /**
131     * @hide
132     */
133    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
134    public @NonNull Extras getExtras() {
135        return mExtras;
136    }
137}
138