Summary: Nested Classes | Methods | Inherited Methods

WebViewCompat

Kotlin |Java

public class WebViewCompat
extends Object

java.lang.Object
↳	androidx.webkit.WebViewCompat

Compatibility version of WebView

Summary

Nested classes
`interface`	`WebViewCompat.VisualStateCallback` Callback interface supplied to `WebViewCompat.postVisualStateCallback(WebView, long, WebViewCompat.VisualStateCallback)` for receiving notifications about the visual state.
`interface`	`WebViewCompat.WebMessageListener` This listener receives messages sent on the JavaScript object which was injected by `WebViewCompat.addWebMessageListener(WebView, String, Set, WebViewCompat.WebMessageListener)`.

Public methods
`static void`	`addWebMessageListener(WebView webView, String jsObjectName, Set<String> allowedOriginRules, WebViewCompat.WebMessageListener listener)` Adds a `WebViewCompat.WebMessageListener` to the `WebView` and injects a JavaScript object into each frame that the `WebViewCompat.WebMessageListener` will listen on.
`static WebMessagePortCompat[]`	`createWebMessageChannel(WebView webview)` Creates a message channel to communicate with JS and returns the message ports that represent the endpoints of this message channel.
`static PackageInfo`	`getCurrentWebViewPackage(Context context)` If WebView has already been loaded into the current process this method will return the package that was used to load it.
`static Uri`	`getSafeBrowsingPrivacyPolicyUrl()` Returns a URL pointing to the privacy policy for Safe Browsing reporting.
`static WebChromeClient`	`getWebChromeClient(WebView webview)` Gets the WebChromeClient.
`static WebViewClient`	`getWebViewClient(WebView webview)` Gets the WebViewClient for the WebView argument.
`static WebViewRenderProcess`	`getWebViewRenderProcess(WebView webview)` Gets the WebView renderer associated with this WebView.
`static WebViewRenderProcessClient`	`getWebViewRenderProcessClient(WebView webview)` Gets the renderer client object associated with this WebView.
`static boolean`	`isMultiProcessEnabled()` Returns true if `WebView` is running in multi process mode.
`static void`	`postVisualStateCallback(WebView webview, long requestId, WebViewCompat.VisualStateCallback callback)` Posts a `WebViewCompat.VisualStateCallback`, which will be called when the current state of the WebView is ready to be drawn.
`static void`	`postWebMessage(WebView webview, WebMessageCompat message, Uri targetOrigin)` Post a message to main frame.
`static void`	`removeWebMessageListener(WebView webview, String jsObjectName)` Removes the `WebMessageListener` associated with `jsObjectName`.
`static void`	`setSafeBrowsingWhitelist(List<String> hosts, ValueCallback<Boolean> callback)` Sets the list of hosts (domain names/IP addresses) that are exempt from SafeBrowsing checks.
`static void`	`setWebViewRenderProcessClient(WebView webview, Executor executor, WebViewRenderProcessClient webViewRenderProcessClient)` Sets the renderer client object associated with this WebView.
`static void`	`setWebViewRenderProcessClient(WebView webview, WebViewRenderProcessClient webViewRenderProcessClient)` Sets the renderer client object associated with this WebView.
`static void`	`startSafeBrowsing(Context context, ValueCallback<Boolean> callback)` Starts Safe Browsing initialization.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()`
`boolean`	`equals(Object arg0)`
`void`	`finalize()`
`final Class<?>`	`getClass()`
`int`	`hashCode()`
`final void`	`notify()`
`final void`	`notifyAll()`
`String`	`toString()`
`final void`	`wait(long arg0, int arg1)`
`final void`	`wait(long arg0)`
`final void`	`wait()`

Public methods

addWebMessageListener

public static void addWebMessageListener (WebView webView, 
                String jsObjectName, 
                Set<String> allowedOriginRules, 
                WebViewCompat.WebMessageListener listener)

Adds a WebViewCompat.WebMessageListener to the WebView and injects a JavaScript object into each frame that the WebViewCompat.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:

Rule	Description	Example
http/https with hostname	`SCHEME` is http or https; `HOSTNAME_PATTERN` is a regular hostname; `PORT` is optional, when not present, the rule will match port `80` for http and port `443` for https.	`https://foobar.com:8080` - Matches https:// URL on port 8080, whose normalized host is foobar.com. `https://www.example.com` - Matches https:// URL on port 443, whose normalized host is www.example.com.
http/https with pattern matching	`SCHEME` is http or https; `HOSTNAME_PATTERN` is a sub-domain matching pattern with a leading `*.`; `PORT` is optional, when not present, the rule will match port `80` for http and port `443` for https.	`https://.example.com` - Matches https://calendar.example.com and https://foo.bar.example.com but not https://example.com. `https://.example.com:8080` - Matches https://calendar.example.com:8080
http/https with IP literal	`SCHEME` is https or https; `HOSTNAME_PATTERN` is IP literal; `PORT` is optional, when not present, the rule will match port `80` for http and port `443` for https.	`https://127.0.0.1` - Matches https:// URL on port 443, whose IPv4 address is 127.0.0.1 `https://[::1]` or `https://[0:0::1]`- Matches any URL to the IPv6 loopback address with port 443. `https://[::1]:99` - Matches any https:// URL to the IPv6 loopback on port 99.
Custom scheme	`SCHEME` is a custom scheme; `HOSTNAME_PATTERN` and `PORT` must not be present.	`my-app-scheme://` - Matches any my-app-scheme:// URL.
`*`	Wildcard rule, matches any origin.	`*`

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:

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

 // To receive the message posted from the app side. event has a "data" property, which is the
 // message string from the app side.
 myObject.onmessage(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 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!");
   }
 };
 WebViewCompat.addWebMessageListener(webView, "myObject", rules, myListener);

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.WEB_MESSAGE_LISTENER.

Parameters
`webView`	`WebView`: The `WebView` instance that we are interacting with.
`jsObjectName`	`String`: The name for the injected JavaScript object for this `WebViewCompat.WebMessageListener`.
`allowedOriginRules`	`Set`: A set of matching rules for the allowed origins.
`listener`	`WebViewCompat.WebMessageListener`: The `WebMessageListener` to handle postMessage() calls on the JavaScript object.

Throws
`IllegalArgumentException`	If one of the `allowedOriginRules` is invalid.

See also:

createWebMessageChannel

public static WebMessagePortCompat[] createWebMessageChannel (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 WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.CREATE_WEB_MESSAGE_CHANNEL.

Parameters
`webview`	`WebView`

Returns
`WebMessagePortCompat[]`	an array of size two, containing the two message ports that form the message channel.

getCurrentWebViewPackage

public static PackageInfo getCurrentWebViewPackage (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.

Parameters
`context`	`Context`

Returns
`PackageInfo`	the current WebView package, or `null` if there is none.

getSafeBrowsingPrivacyPolicyUrl

public static Uri getSafeBrowsingPrivacyPolicyUrl ()

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

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.SAFE_BROWSING_PRIVACY_POLICY_URL.

Returns
`Uri`	the url pointing to a privacy policy document which can be displayed to users.

getWebChromeClient

public static WebChromeClient getWebChromeClient (WebView webview)

Gets the WebChromeClient.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.GET_WEB_CHROME_CLIENT.

Parameters
`webview`	`WebView`

Returns
`WebChromeClient`	the WebChromeClient, or `null` if not yet set

getWebViewClient

public static WebViewClient getWebViewClient (WebView webview)

Gets the WebViewClient for the WebView argument.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.GET_WEB_VIEW_CLIENT.

Parameters
`webview`	`WebView`

Returns
`WebViewClient`	the WebViewClient, or a default client if not yet set

getWebViewRenderProcess

public static WebViewRenderProcess getWebViewRenderProcess (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 WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.GET_WEB_VIEW_RENDERER.

Parameters
`webview`	`WebView`

Returns
`WebViewRenderProcess`	the `WebViewRenderProcess` renderer handle associated with this `WebView`, or `null` if WebView is not runing in multiprocess mode.

getWebViewRenderProcessClient

public static WebViewRenderProcessClient getWebViewRenderProcessClient (WebView webview)

Gets the renderer client object associated with this WebView.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.WEB_VIEW_RENDERER_CLIENT_BASIC_USAGE.

Parameters
`webview`	`WebView`

Returns
`WebViewRenderProcessClient`	the `WebViewRenderProcessClient` object associated with this WebView, if one has been set via `setWebViewRenderProcessClient(WebView, WebViewRenderProcessClient)` or `null` otherwise.

isMultiProcessEnabled

public static boolean isMultiProcessEnabled ()

Returns true if WebView is running in multi process mode.

Returns
`boolean`

postVisualStateCallback

public static void postVisualStateCallback (WebView webview, 
                long requestId, 
                WebViewCompat.VisualStateCallback callback)

Posts a WebViewCompat.VisualStateCallback, which will be called when the current state of the WebView is ready to be drawn.

Because updates to the DOM are processed asynchronously, updates to the DOM may not immediately be reflected visually by subsequent WebView.onDraw(Canvas) invocations. The WebViewCompat.VisualStateCallback provides a mechanism to notify the caller when the contents of the DOM at the current time are ready to be drawn the next time the WebView draws.

The next draw after the callback completes is guaranteed to reflect all the updates to the DOM up to the point at which the WebViewCompat.VisualStateCallback was posted, but it may also contain updates applied after the callback was posted.

The state of the DOM covered by this API includes the following:

primitive HTML elements (div, img, span, etc..)
images
CSS animations
WebGL
canvas

It does not include the state of:

the video tag

To guarantee that the WebView will successfully render the first frame after the WebViewCompat.VisualStateCallback.onComplete(long) method has been called a set of conditions must be met:

If the WebView's visibility is set to VISIBLE then * the WebView must be attached to the view hierarchy.
If the WebView's visibility is set to INVISIBLE then the WebView must be attached to the view hierarchy and must be made VISIBLE from the WebViewCompat.VisualStateCallback.onComplete(long) method.
If the WebView's visibility is set to GONE then the WebView must be attached to the view hierarchy and its LayoutParams's width and height need to be set to fixed values and must be made VISIBLE from the WebViewCompat.VisualStateCallback.onComplete(long) method.

When using this API it is also recommended to enable pre-rasterization if the WebView is off screen to avoid flickering. See WebSettings.setOffscreenPreRaster(boolean) for more details and do consider its caveats.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.VISUAL_STATE_CALLBACK.

Parameters
`webview`	`WebView`
`requestId`	`long`: An id that will be returned in the callback to allow callers to match requests with callbacks.
`callback`	`WebViewCompat.VisualStateCallback`: The callback to be invoked.

postWebMessage

public static void postWebMessage (WebView webview, 
                WebMessageCompat message, 
                Uri targetOrigin)

Post a message to main frame. The embedded application can restrict the messages to a certain target origin. See HTML5 spec for how target origin can be used.

A target origin can be set as a wildcard ("*"). However this is not recommended. See the page above for security issues.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.POST_WEB_MESSAGE.

Parameters
`webview`	`WebView`
`message`	`WebMessageCompat`: the WebMessage
`targetOrigin`	`Uri`: the target origin.

removeWebMessageListener

public static void removeWebMessageListener (WebView webview, 
                String jsObjectName)

Removes the WebMessageListener associated with jsObjectName.

Note that after this call, the injected JavaScript object is still in the JavaScript context, however any message sent after this call won't reach the WebMessageListener.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.WEB_MESSAGE_LISTENER.

Parameters
`webview`	`WebView`
`jsObjectName`	`String`: The JavaScript object's name that was previously passed to `addWebMessageListener(WebView, String, Set, WebMessageListener)`.

See also:

addWebMessageListener(WebView, String, Set, WebMessageListener)

setSafeBrowsingWhitelist

public static void setSafeBrowsingWhitelist (List<String> hosts, 
                ValueCallback<Boolean> callback)

Sets the list of hosts (domain names/IP addresses) that are exempt from SafeBrowsing checks. The list is global for all the WebViews.

Each rule should take one of these:

Rule	Example	Matches Subdomain
HOSTNAME	example.com	Yes
.HOSTNAME	.example.com	No
IPV4_LITERAL	192.168.1.1	No
IPV6_LITERAL_WITH_BRACKETS	[10:20:30:40:50:60:70:80]	No

All other rules, including wildcards, are invalid.

The correct syntax for hosts is defined by RFC 3986.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.SAFE_BROWSING_WHITELIST.

Parameters
`hosts`	`List`: the list of hosts
`callback`	`ValueCallback`: will be called with `true` if hosts are successfully added to the whitelist. It will be called with `false` if any hosts are malformed. The callback will be run on the UI thread

setWebViewRenderProcessClient

public static void setWebViewRenderProcessClient (WebView webview, 
                Executor executor, 
                WebViewRenderProcessClient webViewRenderProcessClient)

Sets the renderer client object associated with this WebView.

The renderer client encapsulates callbacks relevant to WebView renderer state. See WebViewRenderProcessClient for details.

Although many WebView instances may share a single underlying renderer, and renderers may live either in the application process, or in a sandboxed process that is isolated from the application process, instances of WebViewRenderProcessClient are set per-WebView. Callbacks represent renderer events from the perspective of this WebView, and may or may not be correlated with renderer events affecting other WebViews.

The renderer client encapsulates callbacks relevant to WebView renderer state. See WebViewRenderProcessClient for details.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.WEB_VIEW_RENDERER_CLIENT_BASIC_USAGE.

Parameters
`webview`	`WebView`: the `WebView` on which to monitor responsiveness.
`executor`	`Executor`: the `Executor` that will be used to execute callbacks.
`webViewRenderProcessClient`	`WebViewRenderProcessClient`: the `WebViewRenderProcessClient` to set for callbacks.

setWebViewRenderProcessClient

public static void setWebViewRenderProcessClient (WebView webview, 
                WebViewRenderProcessClient webViewRenderProcessClient)

Sets the renderer client object associated with this WebView.

See setWebViewRenderProcessClient(WebView, Executor, WebViewRenderProcessClient) for details, with the following differences:

Callbacks will execute directly on the thread on which this WebView was instantiated.

Passing null for webViewRenderProcessClient will clear the renderer client object for this WebView.

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.WEB_VIEW_RENDERER_CLIENT_BASIC_USAGE.

Parameters
`webview`	`WebView`: the `WebView` on which to monitor responsiveness.
`webViewRenderProcessClient`	`WebViewRenderProcessClient`: the `WebViewRenderProcessClient` to set for callbacks.

startSafeBrowsing

public static void startSafeBrowsing (Context context, 
                ValueCallback<Boolean> callback)

Starts Safe Browsing initialization.

URL loads are not guaranteed to be protected by Safe Browsing until after callback is invoked with true. Safe Browsing is not fully supported on all devices. For those devices callback will receive false.

This should not be called if Safe Browsing has been disabled by manifest tag or WebSettings.setSafeBrowsingEnabled(boolean). This prepares resources used for Safe Browsing.

This should be called with the Application Context (and will always use the Application context to do its work regardless).

This method should only be called if WebViewFeature.isFeatureSupported(String) returns true for WebViewFeature.START_SAFE_BROWSING.

Parameters
`context`	`Context`: Application Context.
`callback`	`ValueCallback`: will be called on the UI thread with `true` if initialization is successful, `false` otherwise.

WebViewCompat

Summary

Nested classes

Public methods

Inherited methods

Public methods

addWebMessageListener

createWebMessageChannel

getCurrentWebViewPackage

getSafeBrowsingPrivacyPolicyUrl

getWebChromeClient

getWebViewClient

getWebViewRenderProcess

getWebViewRenderProcessClient

isMultiProcessEnabled

postVisualStateCallback

postWebMessage

removeWebMessageListener

setSafeBrowsingWhitelist

setWebViewRenderProcessClient

setWebViewRenderProcessClient

startSafeBrowsing