1/*
2 * Copyright (C) 2015 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 android.support.customtabs;
18
19import android.app.Service;
20import android.content.Intent;
21import android.net.Uri;
22import android.os.Bundle;
23import android.os.IBinder;
24import android.os.IBinder.DeathRecipient;
25import android.os.RemoteException;
26import android.support.v4.util.ArrayMap;
27
28import java.util.List;
29import java.util.Map;
30import java.util.NoSuchElementException;
31
32/**
33 * Abstract service class for implementing Custom Tabs related functionality. The service should
34 * be responding to the action ACTION_CUSTOM_TABS_CONNECTION. This class should be used by
35 * implementers that want to provide Custom Tabs functionality, not by clients that want to launch
36 * Custom Tabs.
37 */
38 public abstract class CustomTabsService extends Service {
39     /**
40      * The Intent action that a CustomTabsService must respond to.
41      */
42     public static final String ACTION_CUSTOM_TABS_CONNECTION =
43             "android.support.customtabs.action.CustomTabsService";
44
45     /**
46      * For {@link CustomTabsService#mayLaunchUrl} calls that wants to specify more than one url,
47      * this key can be used with {@link Bundle#putParcelable(String, android.os.Parcelable)}
48      * to insert a new url to each bundle inside list of bundles.
49      */
50     public static final String KEY_URL =
51             "android.support.customtabs.otherurls.URL";
52
53     private Map<IBinder, DeathRecipient> mDeathRecipientMap = new ArrayMap<>();
54
55     private ICustomTabsService.Stub mBinder = new ICustomTabsService.Stub() {
56
57         @Override
58         public boolean warmup(long flags) {
59             return CustomTabsService.this.warmup(flags);
60         }
61
62         @Override
63         public boolean newSession(ICustomTabsCallback callback) {
64             final CustomTabsSessionToken sessionToken = new CustomTabsSessionToken(callback);
65             try {
66                 DeathRecipient deathRecipient = new IBinder.DeathRecipient() {
67                     @Override
68                     public void binderDied() {
69                         cleanUpSession(sessionToken);
70                     }
71                 };
72                 synchronized (mDeathRecipientMap) {
73                     callback.asBinder().linkToDeath(deathRecipient, 0);
74                     mDeathRecipientMap.put(callback.asBinder(), deathRecipient);
75                 }
76                 return CustomTabsService.this.newSession(sessionToken);
77             } catch (RemoteException e) {
78                 return false;
79             }
80         }
81
82         @Override
83         public boolean mayLaunchUrl(ICustomTabsCallback callback, Uri url,
84                         Bundle extras, List<Bundle> otherLikelyBundles) {
85             return CustomTabsService.this.mayLaunchUrl(
86                     new CustomTabsSessionToken(callback), url, extras, otherLikelyBundles);
87         }
88
89         @Override
90         public Bundle extraCommand(String commandName, Bundle args) {
91             return CustomTabsService.this.extraCommand(commandName, args);
92         }
93     };
94
95     @Override
96     public IBinder onBind(Intent intent) {
97         return mBinder;
98     }
99
100     /**
101      * Called when the client side {@link IBinder} for this {@link CustomTabsSessionToken} is dead.
102      * Can also be used to clean up {@link DeathRecipient} instances allocated for the given token.
103      * @param sessionToken The session token for which the {@link DeathRecipient} call has been
104      *                     received.
105      * @return Whether the clean up was successful. Multiple calls with two tokens holdings the
106      *         same binder will return false.
107      */
108     protected boolean cleanUpSession(CustomTabsSessionToken sessionToken) {
109         try {
110             synchronized (mDeathRecipientMap) {
111                IBinder binder = sessionToken.getCallbackBinder();
112                DeathRecipient deathRecipient =
113                        mDeathRecipientMap.get(binder);
114                binder.unlinkToDeath(deathRecipient, 0);
115                mDeathRecipientMap.remove(binder);
116            }
117         } catch (NoSuchElementException e) {
118             return false;
119         }
120         return true;
121     }
122
123     /**
124      * Warms up the browser process asynchronously.
125      *
126      * @param flags Reserved for future use.
127      * @return      Whether warmup was/had been completed successfully. Multiple successful
128      *              calls will return true.
129      */
130     protected abstract boolean warmup(long flags);
131
132     /**
133      * Creates a new session through an ICustomTabsService with the optional callback. This session
134      * can be used to associate any related communication through the service with an intent and
135      * then later with a Custom Tab. The client can then send later service calls or intents to
136      * through same session-intent-Custom Tab association.
137      * @param sessionToken Session token to be used as a unique identifier. This also has access
138      *                     to the {@link CustomTabsCallback} passed from the client side through
139      *                     {@link CustomTabsSessionToken#getCallback()}.
140      * @return             Whether a new session was successfully created.
141      */
142     protected abstract boolean newSession(CustomTabsSessionToken sessionToken);
143
144     /**
145      * Tells the browser of a likely future navigation to a URL.
146      *
147      * The method {@link CustomTabsService#warmup(long)} has to be called beforehand.
148      * The most likely URL has to be specified explicitly. Optionally, a list of
149      * other likely URLs can be provided. They are treated as less likely than
150      * the first one, and have to be sorted in decreasing priority order. These
151      * additional URLs may be ignored.
152      * All previous calls to this method will be deprioritized.
153      *
154      * @param sessionToken       The unique identifier for the session. Can not be null.
155      * @param url                Most likely URL.
156      * @param extras             Reserved for future use.
157      * @param otherLikelyBundles Other likely destinations, sorted in decreasing
158      *                           likelihood order. Each Bundle has to provide a url.
159      * @return                   Whether the call was successful.
160      */
161     protected abstract boolean mayLaunchUrl(CustomTabsSessionToken sessionToken, Uri url,
162             Bundle extras, List<Bundle> otherLikelyBundles);
163
164     /**
165      * Unsupported commands that may be provided by the implementation.
166      *
167      * <p>
168      * <strong>Note:</strong>Clients should <strong>never</strong> rely on this method to have a
169      * defined behavior, as it is entirely implementation-defined and not supported.
170      *
171      * <p> This call can be used by implementations to add extra commands, for testing or
172      * experimental purposes.
173      *
174      * @param commandName Name of the extra command to execute.
175      * @param args Arguments for the command
176      * @return The result {@link Bundle}, or null.
177      */
178     protected abstract Bundle extraCommand(String commandName, Bundle args);
179 }
180