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 
17 package androidx.webkit;
18 
19 import android.webkit.WebView;
20 
21 import org.jspecify.annotations.NonNull;
22 import org.jspecify.annotations.Nullable;
23 
24 /**
25  * Used to receive callbacks on {@link WebView} renderer events.
26  * <p>
27  * WebViewRenderProcessClient instances may be set or retrieved via {@link
28  * WebViewCompat#setWebViewRenderProcessClient(WebView, java.util.concurrent.Executor,
29  * WebViewRenderProcessClient)}
30  * and {@link WebViewCompat#getWebViewRenderProcessClient(WebView)}.
31  * <p>
32  * Instances may be attached to multiple WebViews, and thus a single renderer event may cause
33  * a callback to be called multiple times with different WebView parameters.
34  */
35 public abstract class WebViewRenderProcessClient {
36     /**
37      * Called when the renderer currently associated with {@code view} becomes unresponsive as a
38      * result of a long running blocking task such as the execution of JavaScript.
39      *
40      * <p>If a WebView fails to process an input event, or successfully navigate to a new URL within
41      * a reasonable time frame, the renderer is considered to be unresponsive, and this callback
42      * will be called.
43      *
44      * <p>This callback will continue to be called at regular intervals as long as the renderer
45      * remains unresponsive. If the renderer becomes responsive again, {@link
46      * WebViewRenderProcessClient#onRenderProcessResponsive} will be called once, and this method
47      * will not subsequently be called unless another period of unresponsiveness is detected.
48      *
49      * <p>The minimum interval between successive calls to {@code onRenderProcessUnresponsive} is 5
50      * seconds.
51      *
52      * <p>No action is taken by WebView as a result of this method call. Applications may
53      * choose to terminate the associated renderer via the object that is passed to this callback,
54      * if in multi-process mode, however this must be accompanied by correctly handling
55      * {@link android.webkit.WebViewClient#onRenderProcessGone} for this WebView, and all other
56      * WebViews associated with the same renderer. Failure to do so will result in application
57      * termination.
58      *
59      * @param view The {@link android.webkit.WebView} for which unresponsiveness was detected.
60      * @param renderer The {@link WebViewRenderProcess} that has become unresponsive, or
61      * {@code null} if WebView is running in single process mode.
62      */
onRenderProcessUnresponsive( @onNull WebView view, @Nullable WebViewRenderProcess renderer)63     public abstract void onRenderProcessUnresponsive(
64             @NonNull WebView view, @Nullable WebViewRenderProcess renderer);
65 
66     /**
67      * Called once when an unresponsive renderer currently associated with {@code view} becomes
68      * responsive.
69      *
70      * <p>After a WebView renderer becomes unresponsive, which is notified to the application by
71      * {@link WebViewRenderProcessClient#onRenderProcessUnresponsive}, it is possible for the
72      * blocking renderer task to complete, returning the renderer to a responsive state. In that
73      * case, this method is called once to indicate responsiveness.
74      *
75      * <p>No action is taken by WebView as a result of this method call.
76      *
77      * @param view The {@link android.webkit.WebView} for which responsiveness was detected.
78      *
79      * @param renderer The {@link WebViewRenderProcess} that has become responsive, or {@code null}
80      * if WebView is running in single process mode.
81      */
onRenderProcessResponsive( @onNull WebView view, @Nullable WebViewRenderProcess renderer)82     public abstract void onRenderProcessResponsive(
83             @NonNull WebView view, @Nullable WebViewRenderProcess renderer);
84 }
85