WebViewCompat

@UiThread
@RequiresFeature(name = WebViewFeature.DOCUMENT_START_SCRIPT, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @NonNull ScriptHandler addDocumentStartJavaScript(
    @NonNull WebView webview,
    @NonNull String script,
    @NonNull Set<String> allowedOriginRules
)

Adds a JavaScript script to the WebView which will be executed in any frame whose origin matches allowedOriginRules when the document begins to load.

Note that the script will run before any of the page's JavaScript code and the DOM tree might not be ready at this moment. It will block the loading of the page until it's finished, so should be kept as short as possible.

The injected object from addWebMessageListener API will be injected first and the script can rely on the injected object to send messages to the app.

The script will only run in frames which begin loading after the call returns, therefore it should typically be called before making any loadUrl(), loadData() or loadDataWithBaseURL() call to load the page.

This method can be called multiple times to inject multiple scripts. If more than one script matches a frame's origin, they will be executed in the order they were added.

See addWebMessageListener for the rules of the allowedOriginRules parameter.

This method should only be called if isFeatureSupported returns true for DOCUMENT_START_SCRIPT.

@UiThread
@RequiresFeature(name = WebViewFeature.WEB_MESSAGE_LISTENER, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static void addWebMessageListener(
    @NonNull WebView webView,
    @NonNull String jsObjectName,
    @NonNull Set<String> allowedOriginRules,
    @NonNull WebViewCompat.WebMessageListener listener
)

Adds a WebMessageListener to the WebView and injects a JavaScript object into each frame that the WebMessageListener will listen on.

The injected JavaScript object will be named jsObjectName in the global scope. This will inject the JavaScript object in any frame whose origin matches allowedOriginRules for every navigation after this call, and the JavaScript object will be available immediately when the page begins to load.

Each allowedOriginRules entry must follow the format SCHEME "://" [ HOSTNAME_PATTERN [ ":" PORT ] ], each part is explained in the below table:

Note that this is a powerful API, as the JavaScript object will be injected when the frame's origin matches any one of the allowed origins. The HTTPS scheme is strongly recommended for security; allowing HTTP origins exposes the injected object to any potential network-based attackers. If a wildcard "*" is provided, it will inject the JavaScript object to all frames. A wildcard should only be used if the app wants any third party web page to be able to use the injected object. When using a wildcard, the app must treat received messages as untrustworthy and validate any data carefully.

This method can be called multiple times to inject multiple JavaScript objects.

Let's say the injected JavaScript object is named myObject. We will have following methods on that object once it is available to use:

// Web page (in JavaScript)
// message needs to be a JavaScript String or ArrayBuffer, MessagePorts is an optional
// parameter.
myObject.postMessage(message[, MessagePorts])

          

// To receive messages posted from the app side, assign a function to the "onmessage"
// property. This function should accept a single "event" argument. "event" has a "data"
// property, which is the message String or ArrayBuffer from the app side.
myObject.onmessage = function(event) { ... }

          

// To be compatible with DOM EventTarget's addEventListener, it accepts type and listener
// parameters, where type can be only "message" type and listener can only be a JavaScript
// function for myObject. An event object will be passed to listener with a "data" property,
// which is the message String or ArrayBuffer from the app side.
myObject.addEventListener(type, listener)

          

// To be compatible with DOM EventTarget's removeEventListener, it accepts type and listener
// parameters, where type can be only "message" type and listener can only be a JavaScript
// function for myObject.
myObject.removeEventListener(type, listener)

        

We start the communication between JavaScript and the app from the JavaScript side. In order to send message from the app to JavaScript, it needs to post a message from JavaScript first, so the app will have a JavaScriptReplyProxy object to respond. Example:

// Web page (in JavaScript)
myObject.onmessage = function(event) {
  // prints "Got it!" when we receive the app's response.
  console.log(event.data);
}
myObject.postMessage("I'm ready!");

// App (in Java)
WebMessageListener myListener = new WebMessageListener() {
  @Override
  public void onPostMessage(WebView view, WebMessageCompat message, Uri sourceOrigin,
           boolean isMainFrame, JavaScriptReplyProxy replyProxy) {
    // do something about view, message, sourceOrigin and isMainFrame.
    replyProxy.postMessage("Got it!");
  }
};
if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER)) {
  WebViewCompat.addWebMessageListener(webView, "myObject", rules, myListener);
}

Suppose the communication is already setup, to send ArrayBuffer from the app to web, it needs to check feature flag(WEB_MESSAGE_ARRAY_BUFFER). Here is a example to send file content from app to web:

// App (in Java)
WebMessageListener myListener = new WebMessageListener() {
  @Override
  public void onPostMessage(WebView view, WebMessageCompat message, Uri sourceOrigin,
           boolean isMainFrame, JavaScriptReplyProxy replyProxy) {
    // Communication is setup, send file data to web.
    if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_ARRAY_BUFFER)) {
      // Suppose readFileData method is to read content from file.
      byte[] fileData = readFileData("myFile.dat");
      replyProxy.postMessage(fileData);
    }
  }
}

// Web page (in JavaScript)
myObject.onmessage = function(event) {
  if (event.data instanceof ArrayBuffer) {
    const data = event.data;  // Received file content from app.
    const dataView = new DataView(data);
    // Consume file content by using JavaScript DataView to access ArrayBuffer.
  }
}
myObject.postMessage("Setup!");

Suppose the communication is already setup, and feature flag WEB_MESSAGE_ARRAY_BUFFER is check. Here is a example to download image in WebView, and send to app:

// Web page (in JavaScript)
const response = await fetch('example.jpg');
if (response.ok) {
    const imageData = await response.arrayBuffer();
    myObject.postMessage(imageData);
}

// App (in Java)
WebMessageListener myListener = new WebMessageListener() {
  @Override
  public void onPostMessage(WebView view, WebMessageCompat message, Uri sourceOrigin,
           boolean isMainFrame, JavaScriptReplyProxy replyProxy) {
    if (message.getType() == WebMessageCompat.TYPE_ARRAY_BUFFER) {
      byte[] imageData = message.getArrayBuffer();
      // do something like draw image on ImageView.
    }
  }
};

This method should only be called if isFeatureSupported returns true for WEB_MESSAGE_LISTENER.

@UiThread
@RequiresFeature(name = WebViewFeature.CREATE_WEB_MESSAGE_CHANNEL, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @NonNull WebMessagePortCompat[] createWebMessageChannel(@NonNull WebView webview)

Creates a message channel to communicate with JS and returns the message ports that represent the endpoints of this message channel. The HTML5 message channel functionality is described here

The returned message channels are entangled and already in started state.

This method should only be called if isFeatureSupported returns true for CREATE_WEB_MESSAGE_CHANNEL.

@AnyThread
public static @Nullable PackageInfo getCurrentWebViewPackage(@NonNull Context context)

If WebView has already been loaded into the current process this method will return the package that was used to load it. Otherwise, the package that would be used if the WebView was loaded right now will be returned; this does not cause WebView to be loaded, so this information may become outdated at any time. The WebView package changes either when the current WebView package is updated, disabled, or uninstalled. It can also be changed through a Developer Setting. If the WebView package changes, any app process that has loaded WebView will be killed. The next time the app starts and loads WebView it will use the new WebView package instead.

@UiThread
@RequiresFeature(name = WebViewFeature.MULTI_PROFILE, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @NonNull Profile getProfile(@NonNull WebView webView)

Gets the Profile associated with this WebView.

Gets the profile object set on this WebView using setProfile, or the default profile if it has not been changed.

@AnyThread
@RequiresFeature(name = WebViewFeature.SAFE_BROWSING_PRIVACY_POLICY_URL, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @NonNull Uri getSafeBrowsingPrivacyPolicyUrl()

Returns a URL pointing to the privacy policy for Safe Browsing reporting.

This method should only be called if isFeatureSupported returns true for SAFE_BROWSING_PRIVACY_POLICY_URL.

@AnyThread
@RequiresFeature(name = WebViewFeature.GET_VARIATIONS_HEADER, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @NonNull String getVariationsHeader()

Gets the WebView variations encoded to be used as the X-Client-Data HTTP header.

The app is responsible for adding the X-Client-Data header to any request that may use variations metadata, such as requests to Google web properties. The returned string will be a base64 encoded ClientVariations proto: https://source.chromium.org/chromium/chromium/src/+/main:components/variations/proto /client_variations.proto

@UiThread
@RequiresFeature(name = WebViewFeature.GET_WEB_CHROME_CLIENT, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @Nullable WebChromeClient getWebChromeClient(@NonNull WebView webview)

Gets the WebChromeClient.

This method should only be called if isFeatureSupported returns true for GET_WEB_CHROME_CLIENT.

@RequiresFeature(name = WebViewFeature.NAVIGATION_CALLBACK_BASIC, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
@UiThread
@WebNavigationClient.ExperimentalNavigationCallback
public static @NonNull WebNavigationClient getWebNavigationClient(@NonNull WebView webView)

Gets the WebNavigationClient currently set for the given WebView.

@UiThread
@RequiresFeature(name = WebViewFeature.GET_WEB_VIEW_CLIENT, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @NonNull WebViewClient getWebViewClient(@NonNull WebView webview)

Gets the WebViewClient for the WebView argument.

This method should only be called if isFeatureSupported returns true for GET_WEB_VIEW_CLIENT.

@UiThread
@RequiresFeature(name = WebViewFeature.GET_WEB_VIEW_RENDERER, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @Nullable WebViewRenderProcess getWebViewRenderProcess(@NonNull WebView webview)

Gets the WebView renderer associated with this WebView.

In Android O and above, WebView may run in "multiprocess" mode. In multiprocess mode, rendering of web content is performed by a sandboxed renderer process separate to the application process. This renderer process may be shared with other WebViews in the application, but is not shared with other application processes.

If WebView is running in multiprocess mode, this method returns a handle to the renderer process associated with the WebView, which can be used to control the renderer process.

This method should only be called if isFeatureSupported returns true for GET_WEB_VIEW_RENDERER.

@UiThread
@RequiresFeature(name = WebViewFeature.WEB_VIEW_RENDERER_CLIENT_BASIC_USAGE, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static @Nullable WebViewRenderProcessClient getWebViewRenderProcessClient(@NonNull WebView webview)

Gets the renderer client object associated with this WebView.

This method should only be called if isFeatureSupported returns true for WEB_VIEW_RENDERER_CLIENT_BASIC_USAGE.

@UiThread
@RequiresFeature(name = WebViewFeature.MUTE_AUDIO, enforcement = "androidx.webkit.WebViewFeature#isFeatureSupported")
public static boolean isAudioMuted(@NonNull WebView webView)

Returns whether this WebView is muted.