WebView
public
class
WebView
extends AbsoluteLayout
implements
ViewTreeObserver.OnGlobalFocusChangeListener,
ViewGroup.OnHierarchyChangeListener
java.lang.Object | ||||
↳ | android.view.View | |||
↳ | android.view.ViewGroup | |||
↳ | android.widget.AbsoluteLayout | |||
↳ | android.webkit.WebView |
A View that displays web pages. This class is the basis upon which you can roll your own web browser or simply display some online content within your Activity. It uses the WebKit rendering engine to display web pages and includes methods to navigate forward and backward through a history, zoom in and out, perform text searches and more.
Note that, in order for your Activity to access the Internet and load web pages
in a WebView, you must add the INTERNET
permissions to your
Android Manifest file:
<uses-permission android:name="android.permission.INTERNET" />
This must be a child of the <manifest>
element.
For more information, read Building Web Apps in WebView.
Basic usage
By default, a WebView provides no browser-like widgets, does not enable JavaScript and web page errors are ignored. If your goal is only to display some HTML as a part of your UI, this is probably fine; the user won't need to interact with the web page beyond reading it, and the web page won't need to interact with the user. If you actually want a full-blown web browser, then you probably want to invoke the Browser application with a URL Intent rather than show it with a WebView. For example:
Uri uri = Uri.parse("https://www.example.com"); Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent);
See Intent
for more information.
To provide a WebView in your own Activity, include a <WebView>
in your layout,
or set the entire Activity window as a WebView during onCreate()
:
WebView webview = new WebView(this); setContentView(webview);
Then load the desired web page:
// Simplest usage: note that an exception will NOT be thrown // if there is an error loading this page (see below). webview.loadUrl("https://example.com/"); // OR, you can also load from an HTML string: String summary = "<html><body>You scored <b>192</b> points.</body></html>"; webview.loadData(summary, "text/html", null); // ... although note that there are restrictions on what this HTML can do. // SeeloadData(String, String, String)
andloadDataWithBaseURL(String, String, String, String, String)
for more info. // Also seeloadData(String, String, String)
for information on encoding special // characters.
A WebView has several customization points where you can add your own behavior. These are:
- Creating and setting a
WebChromeClient
subclass. This class is called when something that might impact a browser UI happens, for instance, progress updates and JavaScript alerts are sent here (see Debugging Tasks). - Creating and setting a
WebViewClient
subclass. It will be called when things happen that impact the rendering of the content, eg, errors or form submissions. You can also intercept URL loading here (viashouldOverrideUrlLoading()
). - Modifying the
WebSettings
, such as enabling JavaScript withsetJavaScriptEnabled()
. - Injecting Java objects into the WebView using the
addJavascriptInterface(Object, String)
method. This method allows you to inject Java objects into a page's JavaScript context, so that they can be accessed by JavaScript in the page.
Here's a more complicated example, showing error handling, settings, and progress notification:
// Let's display the progress in the activity title bar, like the // browser app does. getWindow().requestFeature(Window.FEATURE_PROGRESS); webview.getSettings().setJavaScriptEnabled(true); final Activity activity = this; webview.setWebChromeClient(new WebChromeClient() { public void onProgressChanged(WebView view, int progress) { // Activities and WebViews measure progress with different scales. // The progress meter will automatically disappear when we reach 100% activity.setProgress(progress * 1000); } }); webview.setWebViewClient(new WebViewClient() { public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) { Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show(); } }); webview.loadUrl("https://developer.android.com/");
Zoom
To enable the built-in zoom, set
WebSettings
.setBuiltInZoomControls(boolean)
(introduced in API level CUPCAKE
).
Note: Using zoom if either the height or width is set to
WRAP_CONTENT
may lead to undefined behavior
and should be avoided.
Cookie and window management
For obvious security reasons, your application has its own cache, cookie store etc.—it does not share the Browser application's data.
By default, requests by the HTML to open new windows are
ignored. This is true
whether they be opened by JavaScript or by
the target attribute on a link. You can customize your
WebChromeClient
to provide your own behavior for opening multiple windows,
and render them in whatever manner you want.
The standard behavior for an Activity is to be destroyed and
recreated when the device orientation or any other configuration changes. This will cause
the WebView to reload the current page. If you don't want that, you
can set your Activity to handle the orientation
and keyboardHidden
changes, and then just leave the WebView alone. It'll automatically
re-orient itself as appropriate. Read Handling Runtime Changes for
more information about how to handle configuration changes during runtime.
Building web pages to support different screen densities
The screen density of a device is based on the screen resolution. A screen with low density has fewer available pixels per inch, where a screen with high density has more — sometimes significantly more — pixels per inch. The density of a screen is important because, other things being equal, a UI element (such as a button) whose height and width are defined in terms of screen pixels will appear larger on the lower density screen and smaller on the higher density screen. For simplicity, Android collapses all actual screen densities into three generalized densities: high, medium, and low.
By default, WebView scales a web page so that it is drawn at a size that matches the default
appearance on a medium density screen. So, it applies 1.5x scaling on a high density screen
(because its pixels are smaller) and 0.75x scaling on a low density screen (because its pixels
are bigger).
Starting with API level ECLAIR
, WebView supports DOM, CSS,
and meta tag features to help you (as a web developer) target screens with different screen
densities.
Here's a summary of the features you can use to handle different screen densities:
- The
window.devicePixelRatio
DOM property. The value of this property specifies the default scaling factor used for the current device. For example, if the value ofwindow.devicePixelRatio
is "1.0", then the device is considered a medium density (mdpi) device and default scaling is not applied to the web page; if the value is "1.5", then the device is considered a high density device (hdpi) and the page content is scaled 1.5x; if the value is "0.75", then the device is considered a low density device (ldpi) and the content is scaled 0.75x. - The
-webkit-device-pixel-ratio
CSS media query. Use this to specify the screen densities for which this style sheet is to be used. The corresponding value should be either "0.75", "1", or "1.5", to indicate that the styles are for devices with low density, medium density, or high density screens, respectively. For example:<link rel="stylesheet" media="screen and (-webkit-device-pixel-ratio:1.5)" href="hdpi.css" />
The
hdpi.css
stylesheet is only used for devices with a screen pixel ratio of 1.5, which is the high density pixel ratio.
HTML5 Video support
In order to support inline HTML5 video in your application you need to have hardware acceleration turned on.
Full screen support
In order to support full screen — for video or other HTML content — you need to set a
WebChromeClient
and implement both
onShowCustomView(View, WebChromeClient.CustomViewCallback)
and onHideCustomView()
. If the implementation of either of these two methods is
missing then the web contents will not be allowed to enter full screen. Optionally you can implement
getVideoLoadingProgressView()
to customize the View displayed whilst a video
is loading.
HTML5 Geolocation API support
For applications targeting Android N and later releases
(API level > M
) the geolocation api is only supported on
secure origins such as https. For such applications requests to geolocation api on non-secure
origins are automatically denied without invoking the corresponding
onGeolocationPermissionsShowPrompt(String, GeolocationPermissions.Callback)
method.
Layout size
It is recommended to set the WebView layout height to a fixed value or to
MATCH_PARENT
instead of using
WRAP_CONTENT
.
When using MATCH_PARENT
for the height none of the WebView's parents should use a
WRAP_CONTENT
layout height since that could result in
incorrect sizing of the views.
Setting the WebView's height to WRAP_CONTENT
enables the following behaviors:
- The HTML body layout height is set to a fixed value. This means that elements with a height relative to the HTML body may not be sized correctly.
- For applications targeting
KITKAT
and earlier SDKs the HTML viewport meta tag will be ignored in order to preserve backwards compatibility.
Using a layout width of WRAP_CONTENT
is not
supported. If such a width is used the WebView will attempt to use the width of the parent
instead.
Metrics
WebView may upload anonymous diagnostic data to Google when the user has consented. This data
helps Google improve WebView. Data is collected on a per-app basis for each app which has
instantiated a WebView. An individual app can opt out of this feature by putting the following
tag in its manifest's <application>
element:
<manifest> <application> ... <meta-data android:name="android.webkit.WebView.MetricsOptOut" android:value="true" /> </application> </manifest>
Data will only be uploaded for a given app if the user has consented AND the app has not opted out.
Safe Browsing
With Safe Browsing, WebView will block malicious URLs and present a warning UI to the user to allow them to navigate back safely or proceed to the malicious page.
Safe Browsing is enabled by default on devices which support it. If your app needs to disable
Safe Browsing for all WebViews, it can do so in the manifest's <application>
element:
<manifest> <application> ... <meta-data android:name="android.webkit.WebView.EnableSafeBrowsing" android:value="false" /> </application> </manifest>
Otherwise, see setSafeBrowsingEnabled(boolean)
.
Summary
Nested classes | ||
---|---|---|
interface |
WebView.FindListener
Interface to listen for find results. |
|
class |
WebView.HitTestResult
|
|
interface |
WebView.PictureListener
This interface was deprecated in API level 12. This interface is now obsolete. |
|
class |
WebView.VisualStateCallback
Callback interface supplied to |
|
class |
WebView.WebViewTransport
Transportation object for returning WebView across thread boundaries. |
Inherited XML attributes | |
---|---|
Constants | |
---|---|
int |
RENDERER_PRIORITY_BOUND
The renderer associated with this WebView is bound with the default priority for services. |
int |
RENDERER_PRIORITY_IMPORTANT
The renderer associated with this WebView is bound with
|
int |
RENDERER_PRIORITY_WAIVED
The renderer associated with this WebView is bound with
|
String |
SCHEME_GEO
URI scheme for map address. |
String |
SCHEME_MAILTO
URI scheme for email address. |
String |
SCHEME_TEL
URI scheme for telephone number. |
Inherited constants |
---|
Inherited fields |
---|
Public constructors | |
---|---|
WebView(Context context)
Constructs a new WebView with an Activity Context object. |
|
WebView(Context context, AttributeSet attrs)
Constructs a new WebView with layout parameters. |
|
WebView(Context context, AttributeSet attrs, int defStyleAttr)
Constructs a new WebView with layout parameters and a default style. |
|
WebView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)
Constructs a new WebView with layout parameters and a default style. |
|
WebView(Context context, AttributeSet attrs, int defStyleAttr, boolean privateBrowsing)
This constructor was deprecated
in API level 17.
Private browsing is no longer supported directly via
WebView and will be removed in a future release. Prefer using
|
Public methods | |
---|---|
void
|
addJavascriptInterface(Object object, String name)
Injects the supplied Java object into this WebView. |
void
|
autofill(SparseArray<AutofillValue> values)
Automatically fills the content of the virtual children within this view. |
boolean
|
canGoBack()
Gets whether this WebView has a back history item. |
boolean
|
canGoBackOrForward(int steps)
Gets whether the page can go back or forward the given number of steps. |
boolean
|
canGoForward()
Gets whether this WebView has a forward history item. |
boolean
|
canZoomIn()
This method was deprecated
in API level 17.
This method is prone to inaccuracy due to race conditions
between the web rendering and UI threads; prefer
|
boolean
|
canZoomOut()
This method was deprecated
in API level 17.
This method is prone to inaccuracy due to race conditions
between the web rendering and UI threads; prefer
|
Picture
|
capturePicture()
This method was deprecated
in API level 19.
Use |
void
|
clearCache(boolean includeDiskFiles)
Clears the resource cache. |
static
void
|
clearClientCertPreferences(Runnable onCleared)
Clears the client certificate preferences stored in response to proceeding/cancelling client cert requests. |
void
|
clearFormData()
Removes the autocomplete popup from the currently focused form field, if present. |
void
|
clearHistory()
Tells this WebView to clear its internal back/forward list. |
void
|
clearMatches()
Clears the highlighting surrounding text matches created by
|
void
|
clearSslPreferences()
Clears the SSL preferences table stored in response to proceeding with SSL certificate errors. |
void
|
clearView()
This method was deprecated in API level 18. Use WebView.loadUrl("about:blank") to reliably reset the view state and release page resources (including any running JavaScript). |
void
|
computeScroll()
Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary. |
WebBackForwardList
|
copyBackForwardList()
Gets the WebBackForwardList for this WebView. |
PrintDocumentAdapter
|
createPrintDocumentAdapter(String documentName)
Creates a PrintDocumentAdapter that provides the content of this WebView for printing. |
PrintDocumentAdapter
|
createPrintDocumentAdapter()
This method was deprecated
in API level 21.
Use |
WebMessagePort[]
|
createWebMessageChannel()
Creates a message channel to communicate with JS and returns the message ports that represent the endpoints of this message channel. |
void
|
destroy()
Destroys the internal state of this WebView. |
static
void
|
disableWebView()
Indicate that the current process does not intend to use WebView, and that an exception should be thrown if a WebView is created or any other methods in the android.webkit package are used. |
boolean
|
dispatchKeyEvent(KeyEvent event)
Dispatch a key event to the next view on the focus path. |
void
|
documentHasImages(Message response)
Queries the document to see if it contains any image references. |
static
void
|
enableSlowWholeDocumentDraw()
For apps targeting the L release, WebView has a new default behavior that reduces memory footprint and increases performance by intelligently choosing the portion of the HTML document that needs to be drawn. |
void
|
evaluateJavascript(String script, ValueCallback<String> resultCallback)
Asynchronously evaluates JavaScript in the context of the currently displayed page. |
static
String
|
findAddress(String addr)
Gets the first substring consisting of the address of a physical location. |
int
|
findAll(String find)
This method was deprecated
in API level 16.
|
void
|
findAllAsync(String find)
Finds all instances of find on the page and highlights them, asynchronously. |
View
|
findFocus()
Find the view in the hierarchy rooted at this view that currently has focus. |
void
|
findNext(boolean forward)
Highlights and scrolls to the next match found by
|
void
|
flingScroll(int vx, int vy)
|
void
|
freeMemory()
This method was deprecated in API level 19. Memory caches are automatically dropped when no longer needed, and in response to system memory pressure. |
CharSequence
|
getAccessibilityClassName()
Return the class name of this object to be used for accessibility purposes. |
AccessibilityNodeProvider
|
getAccessibilityNodeProvider()
Gets the provider for managing a virtual view hierarchy rooted at this View
and reported to |
SslCertificate
|
getCertificate()
Gets the SSL certificate for the main top-level page or |
int
|
getContentHeight()
Gets the height of the HTML content. |
static
PackageInfo
|
getCurrentWebViewPackage()
If WebView has already been loaded into the current process this method will return the package that was used to load it. |
Bitmap
|
getFavicon()
Gets the favicon for the current page. |
Handler
|
getHandler()
|
WebView.HitTestResult
|
getHitTestResult()
Gets a HitTestResult based on the current cursor node. |
String[]
|
getHttpAuthUsernamePassword(String host, String realm)
This method was deprecated
in API level 26.
Use |
Looper
|
getLooper()
Returns the |
String
|
getOriginalUrl()
Gets the original URL for the current page. |
int
|
getProgress()
Gets the progress for the current page. |
boolean
|
getRendererPriorityWaivedWhenNotVisible()
Return whether this WebView requests a priority of
|
int
|
getRendererRequestedPriority()
Get the requested renderer priority for this WebView. |
static
Uri
|
getSafeBrowsingPrivacyPolicyUrl()
Returns a URL pointing to the privacy policy for Safe Browsing reporting. |
float
|
getScale()
This method was deprecated
in API level 17.
This method is prone to inaccuracy due to race conditions
between the web rendering and UI threads; prefer
|
WebSettings
|
getSettings()
Gets the WebSettings object used to control the settings for this WebView. |
TextClassifier
|
getTextClassifier()
Returns the |
String
|
getTitle()
Gets the title for the current page. |
String
|
getUrl()
Gets the URL for the current page. |
WebChromeClient
|
getWebChromeClient()
Gets the chrome handler. |
static
ClassLoader
|
getWebViewClassLoader()
Returns the |
WebViewClient
|
getWebViewClient()
Gets the WebViewClient. |
void
|
goBack()
Goes back in the history of this WebView. |
void
|
goBackOrForward(int steps)
Goes to the history item that is the number of steps away from the current item. |
void
|
goForward()
Goes forward in the history of this WebView. |
void
|
invokeZoomPicker()
Invokes the graphical zoom picker widget for this WebView. |
boolean
|
isPrivateBrowsingEnabled()
Gets whether private browsing is enabled in this WebView. |
void
|
loadData(String data, String mimeType, String encoding)
Loads the given data into this WebView using a 'data' scheme URL. |
void
|
loadDataWithBaseURL(String baseUrl, String data, String mimeType, String encoding, String historyUrl)
Loads the given data into this WebView, using baseUrl as the base URL for the content. |
void
|
loadUrl(String url)
Loads the given URL. |
void
|
loadUrl(String url, Map<String, String> additionalHttpHeaders)
Loads the given URL with the specified additional HTTP headers. |
void
|
onChildViewAdded(View parent, View child)
This method was deprecated in API level 8. WebView no longer needs to implement ViewGroup.OnHierarchyChangeListener. This method does nothing now. |
void
|
onChildViewRemoved(View p, View child)
This method was deprecated in API level 8. WebView no longer needs to implement ViewGroup.OnHierarchyChangeListener. This method does nothing now. |
InputConnection
|
onCreateInputConnection(EditorInfo outAttrs)
Creates a new InputConnection for an InputMethod to interact with the WebView. |
boolean
|
onDragEvent(DragEvent event)
Handles drag events sent by the system following a call to
|
void
|
onFinishTemporaryDetach()
Called after |
boolean
|
onGenericMotionEvent(MotionEvent event)
Implement this method to handle generic motion events. |
void
|
onGlobalFocusChanged(View oldFocus, View newFocus)
This method was deprecated in API level 3. WebView should not have implemented ViewTreeObserver.OnGlobalFocusChangeListener. This method does nothing now. |
boolean
|
onHoverEvent(MotionEvent event)
Implement this method to handle hover events. |
boolean
|
onKeyDown(int keyCode, KeyEvent event)
Default implementation of |
boolean
|
onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
Default implementation of |
boolean
|
onKeyUp(int keyCode, KeyEvent event)
Default implementation of |
void
|
onPause()
Does a best-effort attempt to pause any processing that can be paused safely, such as animations and geolocation. |
void
|
onProvideAutofillVirtualStructure(ViewStructure structure, int flags)
Populates a The |
void
|
onProvideVirtualStructure(ViewStructure structure)
Called when assist structure is being retrieved from a view as part of
|
void
|
onResume()
Resumes a WebView after a previous call to |
void
|
onStartTemporaryDetach()
This is called when a container is going to temporarily detach a child, with
|
boolean
|
onTouchEvent(MotionEvent event)
Implement this method to handle touch screen motion events. |
boolean
|
onTrackballEvent(MotionEvent event)
Implement this method to handle trackball motion events. |
void
|
onWindowFocusChanged(boolean hasWindowFocus)
Called when the window containing this view gains or loses focus. |
boolean
|
overlayHorizontalScrollbar()
This method was deprecated in API level 23. This method is now obsolete. |
boolean
|
overlayVerticalScrollbar()
This method was deprecated in API level 23. This method is now obsolete. |
boolean
|
pageDown(boolean bottom)
Scrolls the contents of this WebView down by half the page size. |
boolean
|
pageUp(boolean top)
Scrolls the contents of this WebView up by half the view size. |
void
|
pauseTimers()
Pauses all layout, parsing, and JavaScript timers for all WebViews. |
boolean
|
performLongClick()
Calls this view's OnLongClickListener, if it is defined. |
void
|
postUrl(String url, byte[] postData)
Loads the URL with postData using "POST" method into this WebView. |
void
|
postVisualStateCallback(long requestId, WebView.VisualStateCallback callback)
Posts a |
void
|
postWebMessage(WebMessage message, Uri targetOrigin)
Post a message to main frame. |
void
|
reload()
Reloads the current URL. |
void
|
removeJavascriptInterface(String name)
Removes a previously injected Java object from this WebView. |
boolean
|
requestChildRectangleOnScreen(View child, Rect rect, boolean immediate)
Called when a child of this group wants a particular rectangle to be positioned onto the screen. |
boolean
|
requestFocus(int direction, Rect previouslyFocusedRect)
Call this to try to give focus to a specific view or to one of its descendants
and give it hints about the direction and a specific rectangle that the focus
is coming from.
Looks for a view to give focus to respecting the setting specified by
|
void
|
requestFocusNodeHref(Message hrefMsg)
Requests the anchor or image element URL at the last tapped point. |
void
|
requestImageRef(Message msg)
Requests the URL of the image last touched by the user. |
WebBackForwardList
|
restoreState(Bundle inState)
Restores the state of this WebView from the given Bundle. |
void
|
resumeTimers()
Resumes all layout, parsing, and JavaScript timers for all WebViews. |
void
|
savePassword(String host, String username, String password)
This method was deprecated in API level 18. Saving passwords in WebView will not be supported in future versions. |
WebBackForwardList
|
saveState(Bundle outState)
Saves the state of this WebView used in
|
void
|
saveWebArchive(String filename)
Saves the current view as a web archive. |
void
|
saveWebArchive(String basename, boolean autoname, ValueCallback<String> callback)
Saves the current view as a web archive. |
void
|
setBackgroundColor(int color)
Sets the background color for this view. |
void
|
setCertificate(SslCertificate certificate)
This method was deprecated in API level 17. Calling this function has no useful effect, and will be ignored in future releases. |
static
void
|
setDataDirectorySuffix(String suffix)
Define the directory used to store WebView data for the current process. |
void
|
setDownloadListener(DownloadListener listener)
Registers the interface to be used when content can not be handled by the rendering engine, and should be downloaded instead. |
void
|
setFindListener(WebView.FindListener listener)
Registers the listener to be notified as find-on-page operations progress. |
void
|
setHorizontalScrollbarOverlay(boolean overlay)
This method was deprecated in API level 23. This method has no effect. |
void
|
setHttpAuthUsernamePassword(String host, String realm, String username, String password)
This method was deprecated
in API level 26.
Use |
void
|
setInitialScale(int scaleInPercent)
Sets the initial scale for this WebView. |
void
|
setLayerType(int layerType, Paint paint)
Specifies the type of layer backing this view. |
void
|
setLayoutParams(ViewGroup.LayoutParams params)
Set the layout parameters associated with this view. |
void
|
setMapTrackballToArrowKeys(boolean setMap)
This method was deprecated
in API level 17.
Only the default case, |
void
|
setNetworkAvailable(boolean networkUp)
Informs WebView of the network state. |
void
|
setOverScrollMode(int mode)
Set the over-scroll mode for this view. |
void
|
setPictureListener(WebView.PictureListener listener)
This method was deprecated in API level 12. This method is now obsolete. |
void
|
setRendererPriorityPolicy(int rendererRequestedPriority, boolean waivedWhenNotVisible)
Set the renderer priority policy for this |
static
void
|
setSafeBrowsingWhitelist(List<String> urls, ValueCallback<Boolean> callback)
Sets the list of domains that are exempt from SafeBrowsing checks. |
void
|
setScrollBarStyle(int style)
Specify the style of the scrollbars. |
void
|
setTextClassifier(TextClassifier textClassifier)
Sets the |
void
|
setVerticalScrollbarOverlay(boolean overlay)
This method was deprecated in API level 23. This method has no effect. |
void
|
setWebChromeClient(WebChromeClient client)
Sets the chrome handler. |
static
void
|
setWebContentsDebuggingEnabled(boolean enabled)
Enables debugging of web contents (HTML / CSS / JavaScript) loaded into any WebViews of this application. |
void
|
setWebViewClient(WebViewClient client)
Sets the WebViewClient that will receive various notifications and requests. |
boolean
|
shouldDelayChildPressedState()
Return true if the pressed state should be delayed for children or descendants of this ViewGroup. |
boolean
|
showFindDialog(String text, boolean showIme)
This method was deprecated in API level 18. This method does not work reliably on all Android versions; implementing a custom find dialog using WebView.findAllAsync() provides a more robust solution. |
static
void
|
startSafeBrowsing(Context context, ValueCallback<Boolean> callback)
Starts Safe Browsing initialization. |
void
|
stopLoading()
Stops the current load. |
void
|
zoomBy(float zoomFactor)
Performs a zoom operation in this WebView. |
boolean
|
zoomIn()
Performs zoom in in this WebView. |
boolean
|
zoomOut()
Performs zoom out in this WebView. |
Protected methods | |
---|---|
int
|
computeHorizontalScrollOffset()
Compute the horizontal offset of the horizontal scrollbar's thumb within the horizontal range. |
int
|
computeHorizontalScrollRange()
Compute the horizontal range that the horizontal scrollbar represents. |
int
|
computeVerticalScrollExtent()
Compute the vertical extent of the vertical scrollbar's thumb within the vertical range. |
int
|
computeVerticalScrollOffset()
Compute the vertical offset of the vertical scrollbar's thumb within the horizontal range. |
int
|
computeVerticalScrollRange()
Compute the vertical range that the vertical scrollbar represents. |
void
|
dispatchDraw(Canvas canvas)
Called by draw to draw the child views. |
void
|
onAttachedToWindow()
This is called when the view is attached to a window. |
void
|
onConfigurationChanged(Configuration newConfig)
Called when the current configuration of the resources being used by the application have changed. |
void
|
onDraw(Canvas canvas)
Implement this to do your drawing. |
void
|
onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect)
Called by the view system when the focus state of this view changes. |
void
|
onMeasure(int widthMeasureSpec, int heightMeasureSpec)
Measure the view and its content to determine the measured width and the measured height. |
void
|
onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY)
Called by |
void
|
onScrollChanged(int l, int t, int oldl, int oldt)
This is called in response to an internal scroll in this view (i.e., the view scrolled its own contents). |
void
|
onSizeChanged(int w, int h, int ow, int oh)
This is called during layout when the size of this view has changed. |
void
|
onVisibilityChanged(View changedView, int visibility)
Called when the visibility of the view or an ancestor of the view has changed. |
void
|
onWindowVisibilityChanged(int visibility)
Called when the window containing has change its visibility
(between |
Inherited methods | |
---|---|
Constants
RENDERER_PRIORITY_BOUND
int RENDERER_PRIORITY_BOUND
The renderer associated with this WebView is bound with
the default priority for services.
Use with setRendererPriorityPolicy(int, boolean)
.
Constant Value: 1 (0x00000001)
RENDERER_PRIORITY_IMPORTANT
int RENDERER_PRIORITY_IMPORTANT
The renderer associated with this WebView is bound with
BIND_IMPORTANT
.
Use with setRendererPriorityPolicy(int, boolean)
.
Constant Value: 2 (0x00000002)
RENDERER_PRIORITY_WAIVED
int RENDERER_PRIORITY_WAIVED
The renderer associated with this WebView is bound with
BIND_WAIVE_PRIORITY
. At this priority level
WebView
renderers will be strong targets for out of memory
killing.
Use with setRendererPriorityPolicy(int, boolean)
.
Constant Value: 0 (0x00000000)
SCHEME_GEO
String SCHEME_GEO
URI scheme for map address.
Constant Value: "geo:0,0?q="
SCHEME_MAILTO
String SCHEME_MAILTO
URI scheme for email address.
Constant Value: "mailto:"
SCHEME_TEL
String SCHEME_TEL
URI scheme for telephone number.
Constant Value: "tel:"
Public constructors
WebView
WebView (Context context)
Constructs a new WebView with an Activity Context object.
Note: WebView should always be instantiated with an Activity Context. If instantiated with an Application Context, WebView will be unable to provide several features, such as JavaScript dialogs and autofill.
Parameters | |
---|---|
context |
Context : an Activity Context to access application assets
|
WebView
WebView (Context context, AttributeSet attrs)
Constructs a new WebView with layout parameters.
Parameters | |
---|---|
context |
Context : an Activity Context to access application assets |
attrs |
AttributeSet : an AttributeSet passed to our parent
|
WebView
WebView (Context context, AttributeSet attrs, int defStyleAttr)
Constructs a new WebView with layout parameters and a default style.
Parameters | |
---|---|
context |
Context : an Activity Context to access application assets |
attrs |
AttributeSet : an AttributeSet passed to our parent |
defStyleAttr |
int : an attribute in the current theme that contains a
reference to a style resource that supplies default values for
the view. Can be 0 to not look for defaults.
|
WebView
WebView (Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)
Constructs a new WebView with layout parameters and a default style.
Parameters | |
---|---|
context |
Context : an Activity Context to access application assets |
attrs |
AttributeSet : an AttributeSet passed to our parent |
defStyleAttr |
int : an attribute in the current theme that contains a
reference to a style resource that supplies default values for
the view. Can be 0 to not look for defaults. |
defStyleRes |
int : a resource identifier of a style resource that
supplies default values for the view, used only if
defStyleAttr is 0 or can not be found in the theme. Can be 0
to not look for defaults.
|
WebView
WebView (Context context, AttributeSet attrs, int defStyleAttr, boolean privateBrowsing)
This constructor was deprecated
in API level 17.
Private browsing is no longer supported directly via
WebView and will be removed in a future release. Prefer using
WebSettings
, WebViewDatabase
, CookieManager
and WebStorage
for fine-grained control of privacy data.
Constructs a new WebView with layout parameters and a default style.
Parameters | |
---|---|
context |
Context : an Activity Context to access application assets |
attrs |
AttributeSet : an AttributeSet passed to our parent |
defStyleAttr |
int : an attribute in the current theme that contains a
reference to a style resource that supplies default values for
the view. Can be 0 to not look for defaults. |
privateBrowsing |
boolean : whether this WebView will be initialized in
private mode |
Public methods
addJavascriptInterface
void addJavascriptInterface (Object object, String name)
Injects the supplied Java object into this WebView. The object is
injected into the JavaScript context of the main frame, using the
supplied name. This allows the Java object's methods to be
accessed from JavaScript. For applications targeted to API
level JELLY_BEAN_MR1
and above, only public methods that are annotated with
JavascriptInterface
can be accessed from JavaScript.
For applications targeted to API level JELLY_BEAN
or below,
all public methods (including the inherited ones) can be accessed, see the
important security note below for implications.
Note that injected objects will not appear in JavaScript until the page is next (re)loaded. JavaScript should be enabled before injecting the object. For example:
class JsObject { @JavascriptInterface public String toString() { return "injectedObject"; } } webview.getSettings().setJavaScriptEnabled(true); webView.addJavascriptInterface(new JsObject(), "injectedObject"); webView.loadData("", "text/html", null); webView.loadUrl("javascript:alert(injectedObject.toString())");
IMPORTANT:
- This method can be used to allow JavaScript to control the host
application. This is a powerful feature, but also presents a security
risk for apps targeting
JELLY_BEAN
or earlier. Apps that target a version later thanJELLY_BEAN
are still vulnerable if the app runs on a device running Android earlier than 4.2. The most secure way to use this method is to targetJELLY_BEAN_MR1
and to ensure the method is called only when running on Android 4.2 or later. With these older versions, JavaScript could use reflection to access an injected object's public fields. Use of this method in a WebView containing untrusted content could allow an attacker to manipulate the host application in unintended ways, executing Java code with the permissions of the host application. Use extreme care when using this method in a WebView which could contain untrusted content. - JavaScript interacts with Java object on a private, background thread of this WebView. Care is therefore required to maintain thread safety.
- The Java object's fields are not accessible.
- For applications targeted to API level
LOLLIPOP
and above, methods of injected Java objects are enumerable from JavaScript.
Parameters | |
---|---|
object |
Object : the Java object to inject into this WebView's JavaScript
context. null values are ignored. |
name |
String : the name used to expose the object in JavaScript
|
autofill
void autofill (SparseArray<AutofillValue> values)
Automatically fills the content of the virtual children within this view.
Views with virtual children support the Autofill Framework mainly by:
- Providing the metadata defining what the virtual children mean and how they can be autofilled.
- Implementing the methods that autofill the virtual children.
onProvideAutofillVirtualStructure(ViewStructure, int)
is responsible for the
former, this method is responsible for the latter - see autofill(AutofillValue)
and
onProvideAutofillVirtualStructure(ViewStructure, int)
for more info about autofill.
If a child value is updated asynchronously, the next call to
notifyValueChanged(View, int, AutofillValue)
must happen
after the value was changed to the autofilled value. If not, the child will not be
considered autofilled.
Note: To indicate that a virtual view was autofilled,
?android:attr/autofilledHighlight
should be drawn over it until the data
changes.
Parameters | |
---|---|
values |
SparseArray : map of values to be autofilled, keyed by virtual child id. |
canGoBack
boolean canGoBack ()
Gets whether this WebView has a back history item.
Returns | |
---|---|
boolean |
true if this WebView has a back history item
|
canGoBackOrForward
boolean canGoBackOrForward (int steps)
Gets whether the page can go back or forward the given number of steps.
Parameters | |
---|---|
steps |
int : the negative or positive number of steps to move the
history
|
Returns | |
---|---|
boolean |
canGoForward
boolean canGoForward ()
Gets whether this WebView has a forward history item.
Returns | |
---|---|
boolean |
true if this WebView has a forward history item
|
canZoomIn
boolean canZoomIn ()
This method was deprecated
in API level 17.
This method is prone to inaccuracy due to race conditions
between the web rendering and UI threads; prefer
onScaleChanged(WebView, float, float)
.
Gets whether this WebView can be zoomed in.
Returns | |
---|---|
boolean |
true if this WebView can be zoomed in |
canZoomOut
boolean canZoomOut ()
This method was deprecated
in API level 17.
This method is prone to inaccuracy due to race conditions
between the web rendering and UI threads; prefer
onScaleChanged(WebView, float, float)
.
Gets whether this WebView can be zoomed out.
Returns | |
---|---|
boolean |
true if this WebView can be zoomed out |
capturePicture
Picture capturePicture ()
This method was deprecated
in API level 19.
Use onDraw(Canvas)
to obtain a bitmap snapshot of the WebView, or
saveWebArchive(String)
to save the content to a file.
Gets a new picture that captures the current contents of this WebView. The picture is of the entire document being displayed, and is not limited to the area currently displayed by this WebView. Also, the picture is a static copy and is unaffected by later changes to the content being displayed.
Note that due to internal changes, for API levels between
HONEYCOMB
and
ICE_CREAM_SANDWICH
inclusive, the
picture does not include fixed position elements or scrollable divs.
Note that from JELLY_BEAN_MR1
the returned picture
should only be drawn into bitmap-backed Canvas - using any other type of Canvas will involve
additional conversion at a cost in memory and performance. Also the
createFromStream(InputStream)
and
writeToStream(OutputStream)
methods are not supported on the
returned object.
Returns | |
---|---|
Picture |
a picture that captures the current contents of this WebView |
clearCache
void clearCache (boolean includeDiskFiles)
Clears the resource cache. Note that the cache is per-application, so this will clear the cache for all WebViews used.
Parameters | |
---|---|
includeDiskFiles |
boolean : if false , only the RAM cache is cleared
|
clearClientCertPreferences
void clearClientCertPreferences (Runnable onCleared)
Clears the client certificate preferences stored in response
to proceeding/cancelling client cert requests. Note that WebView
automatically clears these preferences when it receives a
ACTION_STORAGE_CHANGED
intent. The preferences are
shared by all the WebViews that are created by the embedder application.
Parameters | |
---|---|
onCleared |
Runnable : A runnable to be invoked when client certs are cleared.
The runnable will be called in UI thread.
This value may be |
clearFormData
void clearFormData ()
Removes the autocomplete popup from the currently focused form field, if
present. Note this only affects the display of the autocomplete popup,
it does not remove any saved form data from this WebView's store. To do
that, use clearFormData()
.
clearHistory
void clearHistory ()
Tells this WebView to clear its internal back/forward list.
clearMatches
void clearMatches ()
Clears the highlighting surrounding text matches created by
findAllAsync(String)
.
clearSslPreferences
void clearSslPreferences ()
Clears the SSL preferences table stored in response to proceeding with SSL certificate errors.
clearView
void clearView ()
This method was deprecated
in API level 18.
Use WebView.loadUrl("about:blank") to reliably reset the view state
and release page resources (including any running JavaScript).
Clears this WebView so that onDraw() will draw nothing but white background, and onMeasure() will return 0 if MeasureSpec is not MeasureSpec.EXACTLY.
computeScroll
void computeScroll ()
Called by a parent to request that a child update its values for mScrollX
and mScrollY if necessary. This will typically be done if the child is
animating a scroll using a Scroller
object.
copyBackForwardList
WebBackForwardList copyBackForwardList ()
Gets the WebBackForwardList for this WebView. This contains the back/forward list for use in querying each item in the history stack. This is a copy of the private WebBackForwardList so it contains only a snapshot of the current state. Multiple calls to this method may return different objects. The object returned from this method will not be updated to reflect any new state.
Returns | |
---|---|
WebBackForwardList |
createPrintDocumentAdapter
PrintDocumentAdapter createPrintDocumentAdapter (String documentName)
Creates a PrintDocumentAdapter that provides the content of this WebView for printing.
The adapter works by converting the WebView contents to a PDF stream. The WebView cannot
be drawn during the conversion process - any such draws are undefined. It is recommended
to use a dedicated off screen WebView for the printing. If necessary, an application may
temporarily hide a visible WebView by using a custom PrintDocumentAdapter instance
wrapped around the object returned and observing the onStart and onFinish methods. See
PrintDocumentAdapter
for more information.
Parameters | |
---|---|
documentName |
String : The user-facing name of the printed document. See
PrintDocumentInfo
|
Returns | |
---|---|
PrintDocumentAdapter |
createPrintDocumentAdapter
PrintDocumentAdapter createPrintDocumentAdapter ()
This method was deprecated
in API level 21.
Use createPrintDocumentAdapter(String)
which requires user
to provide a print document name.
Returns | |
---|---|
PrintDocumentAdapter |
createWebMessageChannel
WebMessagePort[] createWebMessageChannel ()
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.
Returns | |
---|---|
WebMessagePort[] |
the two message ports that form the message channel. |
destroy
void destroy ()
Destroys the internal state of this WebView. This method should be called after this WebView has been removed from the view system. No other methods may be called on this WebView after destroy.
disableWebView
void disableWebView ()
Indicate that the current process does not intend to use WebView, and that an exception should be thrown if a WebView is created or any other methods in the android.webkit package are used.
Applications with multiple processes may wish to call this in processes
that are not intended to use WebView to avoid accidentally incurring
the memory usage of initializing WebView in long-lived processes that
have no need for it, and to prevent potential data directory conflicts
(see setDataDirectorySuffix(String)
).
For example, an audio player application with one process for its
activities and another process for its playback service may wish to call
this method in the playback service's onCreate()
.
Throws | |
---|---|
IllegalStateException |
if WebView has already been initialized in the current process. |
dispatchKeyEvent
boolean dispatchKeyEvent (KeyEvent event)
Dispatch a key event to the next view on the focus path. This path runs from the top of the view tree down to the currently focused view. If this view has focus, it will dispatch to itself. Otherwise it will dispatch the next node down the focus path. This method also fires any key listeners.
Parameters | |
---|---|
event |
KeyEvent : The key event to be dispatched. |
Returns | |
---|---|
boolean |
True if the event was handled, false otherwise. |
documentHasImages
void documentHasImages (Message response)
Queries the document to see if it contains any image references. The message object will be dispatched with arg1 being set to 1 if images were found and 0 if the document does not reference any images.
Parameters | |
---|---|
response |
Message : the message that will be dispatched with the result
|
enableSlowWholeDocumentDraw
void enableSlowWholeDocumentDraw ()
For apps targeting the L release, WebView has a new default behavior that reduces memory footprint and increases performance by intelligently choosing the portion of the HTML document that needs to be drawn. These optimizations are transparent to the developers. However, under certain circumstances, an App developer may want to disable them:
- When an app uses
onDraw(Canvas)
to do own drawing and accesses portions of the page that is way outside the visible portion of the page. - When an app uses
capturePicture()
to capture a very large HTML document. Note that capturePicture is a deprecated API.
evaluateJavascript
void evaluateJavascript (String script, ValueCallback<String> resultCallback)
Asynchronously evaluates JavaScript in the context of the currently displayed page. If non-null, |resultCallback| will be invoked with any result returned from that execution. This method must be called on the UI thread and the callback will be made on the UI thread.
Compatibility note. Applications targeting N
or
later, JavaScript state from an empty WebView is no longer persisted across navigations like
loadUrl(String)
. For example, global variables and functions defined before calling
loadUrl(String)
will not exist in the loaded page. Applications should use
addJavascriptInterface(Object, String)
instead to persist JavaScript objects across navigations.
Parameters | |
---|---|
script |
String : the JavaScript to execute. |
resultCallback |
ValueCallback : A callback to be invoked when the script execution
completes with the result of the execution (if any).
May be null if no notification of the result is required.
|
findAddress
String findAddress (String addr)
Gets the first substring consisting of the address of a physical location. Currently, only addresses in the United States are detected, and consist of:
- a house number
- a street name
- a street type (Road, Circle, etc), either spelled out or abbreviated
- a city name
- a state or territory, either spelled out or two-letter abbr
- an optional 5 digit or 9 digit zip code
Parameters | |
---|---|
addr |
String : the string to search for addresses |
Returns | |
---|---|
String |
the address, or if no address is found, null
|
findAll
int findAll (String find)
This method was deprecated
in API level 16.
findAllAsync(String)
is preferred.
Finds all instances of find on the page and highlights them.
Notifies any registered WebView.FindListener
.
Parameters | |
---|---|
find |
String : the string to find |
Returns | |
---|---|
int |
the number of occurrences of the String "find" that were found |
See also:
findAllAsync
void findAllAsync (String find)
Finds all instances of find on the page and highlights them,
asynchronously. Notifies any registered WebView.FindListener
.
Successive calls to this will cancel any pending searches.
Parameters | |
---|---|
find |
String : the string to find. |
See also:
findFocus
View findFocus ()
Find the view in the hierarchy rooted at this view that currently has focus.
Returns | |
---|---|
View |
The view that currently has focus, or null if no focused view can be found. |
findNext
void findNext (boolean forward)
Highlights and scrolls to the next match found by
findAllAsync(String)
, wrapping around page boundaries as necessary.
Notifies any registered WebView.FindListener
. If findAllAsync(String)
has not been called yet, or if clearMatches()
has been called since the
last find operation, this function does nothing.
Parameters | |
---|---|
forward |
boolean : the direction to search |
See also:
freeMemory
void freeMemory ()
This method was deprecated
in API level 19.
Memory caches are automatically dropped when no longer needed, and in response
to system memory pressure.
Informs this WebView that memory is low so that it can free any available memory.
getAccessibilityClassName
CharSequence getAccessibilityClassName ()
Return the class name of this object to be used for accessibility purposes.
Subclasses should only override this if they are implementing something that
should be seen as a completely new class of view when used by accessibility,
unrelated to the class it is deriving from. This is used to fill in
AccessibilityNodeInfo.setClassName
.
Returns | |
---|---|
CharSequence |
getAccessibilityNodeProvider
AccessibilityNodeProvider getAccessibilityNodeProvider ()
Gets the provider for managing a virtual view hierarchy rooted at this View
and reported to AccessibilityService
s
that explore the window content.
If this method returns an instance, this instance is responsible for managing
AccessibilityNodeInfo
s describing the virtual sub-tree rooted at this
View including the one representing the View itself. Similarly the returned
instance is responsible for performing accessibility actions on any virtual
view or the root view itself.
If an View.AccessibilityDelegate
has been specified via calling
setAccessibilityDelegate(AccessibilityDelegate)
its
getAccessibilityNodeProvider(View)
is responsible for handling this call.
Returns | |
---|---|
AccessibilityNodeProvider |
The provider. |
getCertificate
SslCertificate getCertificate ()
Gets the SSL certificate for the main top-level page or null
if there is
no certificate (the site is not secure).
Returns | |
---|---|
SslCertificate |
the SSL certificate for the main top-level page
This value may be |
getContentHeight
int getContentHeight ()
Gets the height of the HTML content.
Returns | |
---|---|
int |
the height of the HTML content |
getCurrentWebViewPackage
PackageInfo getCurrentWebViewPackage ()
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.
Returns | |
---|---|
PackageInfo |
the current WebView package, or null if there is none.
|
getFavicon
Bitmap getFavicon ()
Gets the favicon for the current page. This is the favicon of the current page until WebViewClient.onReceivedIcon is called.
Returns | |
---|---|
Bitmap |
the favicon for the current page |
getHandler
Handler getHandler ()
Returns | |
---|---|
Handler |
A handler associated with the thread running the View. This handler can be used to pump events in the UI events queue. |
getHitTestResult
WebView.HitTestResult getHitTestResult ()
Gets a HitTestResult based on the current cursor node. If a HTML::a
tag is found and the anchor has a non-JavaScript URL, the HitTestResult
type is set to SRC_ANCHOR_TYPE and the URL is set in the "extra" field.
If the anchor does not have a URL or if it is a JavaScript URL, the type
will be UNKNOWN_TYPE and the URL has to be retrieved through
requestFocusNodeHref(Message)
asynchronously. If a HTML::img tag is
found, the HitTestResult type is set to IMAGE_TYPE and the URL is set in
the "extra" field. A type of
SRC_IMAGE_ANCHOR_TYPE indicates an anchor with a URL that has an image as
a child node. If a phone number is found, the HitTestResult type is set
to PHONE_TYPE and the phone number is set in the "extra" field of
HitTestResult. If a map address is found, the HitTestResult type is set
to GEO_TYPE and the address is set in the "extra" field of HitTestResult.
If an email address is found, the HitTestResult type is set to EMAIL_TYPE
and the email is set in the "extra" field of HitTestResult. Otherwise,
HitTestResult type is set to UNKNOWN_TYPE.
Returns | |
---|---|
WebView.HitTestResult |
getHttpAuthUsernamePassword
String[] getHttpAuthUsernamePassword (String host, String realm)
This method was deprecated
in API level 26.
Use getHttpAuthUsernamePassword(String, String)
instead
Retrieves HTTP authentication credentials for a given host and realm from the WebViewDatabase
instance.
Parameters | |
---|---|
host |
String : the host to which the credentials apply |
realm |
String : the realm to which the credentials apply |
Returns | |
---|---|
String[] |
the credentials as a String array, if found. The first element
is the username and the second element is the password. null if
no credentials are found. |
getLooper
Looper getLooper ()
Returns the Looper
corresponding to the thread on which WebView calls must be made.
Returns | |
---|---|
Looper |
This value will never be |
getOriginalUrl
String getOriginalUrl ()
Gets the original URL for the current page. This is not always the same as the URL passed to WebViewClient.onPageStarted because although the load for that URL has begun, the current page may not have changed. Also, there may have been redirects resulting in a different URL to that originally requested.
Returns | |
---|---|
String |
the URL that was originally requested for the current page |
getProgress
int getProgress ()
Gets the progress for the current page.
Returns | |
---|---|
int |
the progress for the current page between 0 and 100 |
getRendererPriorityWaivedWhenNotVisible
boolean getRendererPriorityWaivedWhenNotVisible ()
Return whether this WebView requests a priority of
RENDERER_PRIORITY_WAIVED
when not visible.
Returns | |
---|---|
boolean |
whether this WebView requests a priority of
RENDERER_PRIORITY_WAIVED when not visible.
|
getRendererRequestedPriority
int getRendererRequestedPriority ()
Get the requested renderer priority for this WebView.
Returns | |
---|---|
int |
the requested renderer priority policy.
Value is |
getSafeBrowsingPrivacyPolicyUrl
Uri getSafeBrowsingPrivacyPolicyUrl ()
Returns a URL pointing to the privacy policy for Safe Browsing reporting.
Returns | |
---|---|
Uri |
the url pointing to a privacy policy document which can be displayed to users.
This value will never be |
getScale
float getScale ()
This method was deprecated
in API level 17.
This method is prone to inaccuracy due to race conditions
between the web rendering and UI threads; prefer
onScaleChanged(WebView, float, float)
.
Gets the current scale of this WebView.
Returns | |
---|---|
float |
the current scale |
getSettings
WebSettings getSettings ()
Gets the WebSettings object used to control the settings for this WebView.
Returns | |
---|---|
WebSettings |
a WebSettings object that can be used to control this WebView's settings |
getTextClassifier
TextClassifier getTextClassifier ()
Returns the TextClassifier
used by this WebView.
If no TextClassifier has been set, this WebView uses the default set by the system.
Returns | |
---|---|
TextClassifier |
This value will never be |
getTitle
String getTitle ()
Gets the title for the current page. This is the title of the current page until WebViewClient.onReceivedTitle is called.
Returns | |
---|---|
String |
the title for the current page |
getUrl
String getUrl ()
Gets the URL for the current page. This is not always the same as the URL passed to WebViewClient.onPageStarted because although the load for that URL has begun, the current page may not have changed.
Returns | |
---|---|
String |
the URL for the current page |
getWebChromeClient
WebChromeClient getWebChromeClient ()
Gets the chrome handler.
Returns | |
---|---|
WebChromeClient |
the WebChromeClient, or null if not yet set |
See also:
getWebViewClassLoader
ClassLoader getWebViewClassLoader ()
Returns the ClassLoader
used to load internal WebView classes.
This method is meant for use by the WebView Support Library, there is no reason to use this
method otherwise.
Returns | |
---|---|
ClassLoader |
This value will never be |
getWebViewClient
WebViewClient getWebViewClient ()
Gets the WebViewClient.
Returns | |
---|---|
WebViewClient |
the WebViewClient, or a default client if not yet set |
See also:
goBackOrForward
void goBackOrForward (int steps)
Goes to the history item that is the number of steps away from the current item. Steps is negative if backward and positive if forward.
Parameters | |
---|---|
steps |
int : the number of steps to take back or forward in the back
forward list
|
invokeZoomPicker
void invokeZoomPicker ()
Invokes the graphical zoom picker widget for this WebView. This will result in the zoom widget appearing on the screen to control the zoom level of this WebView.
isPrivateBrowsingEnabled
boolean isPrivateBrowsingEnabled ()
Gets whether private browsing is enabled in this WebView.
Returns | |
---|---|
boolean |
loadData
void loadData (String data, String mimeType, String encoding)
Loads the given data into this WebView using a 'data' scheme URL.
Note that JavaScript's same origin policy means that script running in a
page loaded using this method will be unable to access content loaded
using any scheme other than 'data', including 'http(s)'. To avoid this
restriction, use loadDataWithBaseURL()
with an appropriate base URL.
The encoding
parameter specifies whether the data is base64 or URL
encoded. If the data is base64 encoded, the value of the encoding
parameter must be 'base64'. HTML can be encoded with encodeToString(byte[], int)
like so:
String unencodedHtml = "<html><body>'%28' is the code for '('</body></html>"; String encodedHtml = Base64.encodeToString(unencodedHtml.getBytes(), Base64.NO_PADDING); webView.loadData(encodedHtml, "text/html", "base64");
For all other values of encoding
(including null
) it is assumed that the
data uses ASCII encoding for octets inside the range of safe URL characters and use the
standard %xx hex encoding of URLs for octets outside that range. See RFC 3986 for more information.
The mimeType
parameter specifies the format of the data.
If WebView can't handle the specified MIME type, it will download the data.
If null
, defaults to 'text/html'.
The 'data' scheme URL formed by this method uses the default US-ASCII
charset. If you need need to set a different charset, you should form a
'data' scheme URL which explicitly specifies a charset parameter in the
mediatype portion of the URL and call loadUrl(String)
instead.
Note that the charset obtained from the mediatype portion of a data URL
always overrides that specified in the HTML or XML document itself.
Parameters | |
---|---|
data |
String : a String of data in the given encoding |
mimeType |
String : the MIME type of the data, e.g. 'text/html'.This value may be |
encoding |
String : the encoding of the data
This value may be |
loadDataWithBaseURL
void loadDataWithBaseURL (String baseUrl, String data, String mimeType, String encoding, String historyUrl)
Loads the given data into this WebView, using baseUrl as the base URL for the content. The base URL is used both to resolve relative URLs and when applying JavaScript's same origin policy. The historyUrl is used for the history entry.
The mimeType
parameter specifies the format of the data.
If WebView can't handle the specified MIME type, it will download the data.
If null
, defaults to 'text/html'.
Note that content specified in this way can access local device files (via 'file' scheme URLs) only if baseUrl specifies a scheme other than 'http', 'https', 'ftp', 'ftps', 'about' or 'javascript'.
If the base URL uses the data scheme, this method is equivalent to
calling loadData()
and the
historyUrl is ignored, and the data will be treated as part of a data: URL.
If the base URL uses any other scheme, then the data will be loaded into
the WebView as a plain string (i.e. not part of a data URL) and any URL-encoded
entities in the string will not be decoded.
Note that the baseUrl is sent in the 'Referer' HTTP header when requesting subresources (images, etc.) of the page loaded using this method.
Parameters | |
---|---|
baseUrl |
String : the URL to use as the page's base URL. If null defaults to
'about:blank'. |
data |
String : a String of data in the given encoding |
mimeType |
String : the MIME type of the data, e.g. 'text/html'.This value may be |
encoding |
String : the encoding of the dataThis value may be |
historyUrl |
String : the URL to use as the history entry. If null defaults
to 'about:blank'. If non-null, this must be a valid URL.
|
loadUrl
void loadUrl (String url)
Loads the given URL.
Also see compatibility note on evaluateJavascript(String, ValueCallback
.
Parameters | |
---|---|
url |
String : the URL of the resource to load
|
loadUrl
void loadUrl (String url, Map<String, String> additionalHttpHeaders)
Loads the given URL with the specified additional HTTP headers.
Also see compatibility note on evaluateJavascript(String, ValueCallback
.
Parameters | |
---|---|
url |
String : the URL of the resource to load |
additionalHttpHeaders |
Map : the additional headers to be used in the
HTTP request for this URL, specified as a map from name to
value. Note that if this map contains any of the headers
that are set by default by this WebView, such as those
controlling caching, accept types or the User-Agent, their
values may be overridden by this WebView's defaults.
|
onChildViewAdded
void onChildViewAdded (View parent, View child)
This method was deprecated
in API level 8.
WebView no longer needs to implement
ViewGroup.OnHierarchyChangeListener. This method does nothing now.
Called when a new child is added to a parent view.
Parameters | |
---|---|
parent |
View : the view in which a child was added |
child |
View : the new child view added in the hierarchy
|
onChildViewRemoved
void onChildViewRemoved (View p, View child)
This method was deprecated
in API level 8.
WebView no longer needs to implement
ViewGroup.OnHierarchyChangeListener. This method does nothing now.
Called when a child is removed from a parent view.
Parameters | |
---|---|
p |
View : the view from which the child was removed |
child |
View : the child removed from the hierarchy
|
onCreateInputConnection
InputConnection onCreateInputConnection (EditorInfo outAttrs)
Creates a new InputConnection for an InputMethod to interact with the WebView.
This is similar to onCreateInputConnection(EditorInfo)
but note that WebView
calls InputConnection methods on a thread other than the UI thread.
If these methods are overridden, then the overriding methods should respect
thread restrictions when calling View methods or accessing data.
Parameters | |
---|---|
outAttrs |
EditorInfo : Fill in with attribute information about the connection.
|
Returns | |
---|---|
InputConnection |
onDragEvent
boolean onDragEvent (DragEvent event)
Handles drag events sent by the system following a call to
startDragAndDrop()
.
When the system calls this method, it passes a
DragEvent
object. A call to
getAction()
returns one of the action type constants defined
in DragEvent. The method uses these to determine what is happening in the drag and drop
operation.
Parameters | |
---|---|
event |
DragEvent : The DragEvent sent by the system.
The getAction() method returns an action type constant defined
in DragEvent, indicating the type of drag event represented by this object. |
Returns | |
---|---|
boolean |
true if the method was successful, otherwise false .
The method should return
The method should also return For all other events, the return value is ignored. |
onFinishTemporaryDetach
void onFinishTemporaryDetach ()
Called after onStartTemporaryDetach()
when the container is done
changing the view.
onGenericMotionEvent
boolean onGenericMotionEvent (MotionEvent event)
Implement this method to handle generic motion events.
Generic motion events describe joystick movements, mouse hovers, track pad
touches, scroll wheel movements and other input events. The
source
of the motion event specifies
the class of input that was received. Implementations of this method
must examine the bits in the source before processing the event.
The following code example shows how this is done.
Generic motion events with source class SOURCE_CLASS_POINTER
are delivered to the view under the pointer. All other generic motion events are
delivered to the focused view.
public boolean onGenericMotionEvent(MotionEvent event) { if (event.isFromSource(InputDevice.SOURCE_CLASS_JOYSTICK)) { if (event.getAction() == MotionEvent.ACTION_MOVE) { // process the joystick movement... return true; } } if (event.isFromSource(InputDevice.SOURCE_CLASS_POINTER)) { switch (event.getAction()) { case MotionEvent.ACTION_HOVER_MOVE: // process the mouse hover movement... return true; case MotionEvent.ACTION_SCROLL: // process the scroll wheel movement... return true; } } return super.onGenericMotionEvent(event); }
Parameters | |
---|---|
event |
MotionEvent : The generic motion event being processed. |
Returns | |
---|---|
boolean |
True if the event was handled, false otherwise. |
onGlobalFocusChanged
void onGlobalFocusChanged (View oldFocus, View newFocus)
This method was deprecated
in API level 3.
WebView should not have implemented
ViewTreeObserver.OnGlobalFocusChangeListener. This method does nothing now.
Callback method to be invoked when the focus changes in the view tree. When the view tree transitions from touch mode to non-touch mode, oldFocus is null. When the view tree transitions from non-touch mode to touch mode, newFocus is null. When focus changes in non-touch mode (without transition from or to touch mode) either oldFocus or newFocus can be null.
Parameters | |
---|---|
oldFocus |
View : The previously focused view, if any. |
newFocus |
View : The newly focused View, if any.
|
onHoverEvent
boolean onHoverEvent (MotionEvent event)
Implement this method to handle hover events.
This method is called whenever a pointer is hovering into, over, or out of the
bounds of a view and the view is not currently being touched.
Hover events are represented as pointer events with action
ACTION_HOVER_ENTER
, ACTION_HOVER_MOVE
,
or ACTION_HOVER_EXIT
.
- The view receives a hover event with action
ACTION_HOVER_ENTER
when the pointer enters the bounds of the view. - The view receives a hover event with action
ACTION_HOVER_MOVE
when the pointer has already entered the bounds of the view and has moved. - The view receives a hover event with action
ACTION_HOVER_EXIT
when the pointer has exited the bounds of the view or when the pointer is about to go down due to a button click, tap, or similar user action that causes the view to be touched.
The view should implement this method to return true to indicate that it is handling the hover event, such as by changing its drawable state.
The default implementation calls setHovered(boolean)
to update the hovered state
of the view when a hover enter or hover exit event is received, if the view
is enabled and is clickable. The default implementation also sends hover
accessibility events.
Parameters | |
---|---|
event |
MotionEvent : The motion event that describes the hover. |
Returns | |
---|---|
boolean |
True if the view handled the hover event. |
onKeyDown
boolean onKeyDown (int keyCode, KeyEvent event)
Default implementation of KeyEvent.Callback.onKeyDown()
: perform press of the view
when KEYCODE_DPAD_CENTER
or KEYCODE_ENTER
is released, if the view is enabled and clickable.
Key presses in software keyboards will generally NOT trigger this listener, although some may elect to do so in some situations. Do not rely on this to catch software key presses.
Parameters | |
---|---|
keyCode |
int : a key code that represents the button pressed, from
KeyEvent |
event |
KeyEvent : the KeyEvent object that defines the button action
|
Returns | |
---|---|
boolean |
If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false. |
onKeyMultiple
boolean onKeyMultiple (int keyCode, int repeatCount, KeyEvent event)
Default implementation of KeyEvent.Callback.onKeyMultiple()
: always returns false (doesn't handle
the event).
Key presses in software keyboards will generally NOT trigger this listener, although some may elect to do so in some situations. Do not rely on this to catch software key presses.
Parameters | |
---|---|
keyCode |
int : A key code that represents the button pressed, from
KeyEvent . |
repeatCount |
int : The number of times the action was made. |
event |
KeyEvent : The KeyEvent object that defines the button action.
|
Returns | |
---|---|
boolean |
If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false. |
onKeyUp
boolean onKeyUp (int keyCode, KeyEvent event)
Default implementation of KeyEvent.Callback.onKeyUp()
: perform clicking of the view
when KEYCODE_DPAD_CENTER
, KEYCODE_ENTER
or KEYCODE_SPACE
is released.
Key presses in software keyboards will generally NOT trigger this listener, although some may elect to do so in some situations. Do not rely on this to catch software key presses.
Parameters | |
---|---|
keyCode |
int : A key code that represents the button pressed, from
KeyEvent . |
event |
KeyEvent : The KeyEvent object that defines the button action.
|
Returns | |
---|---|
boolean |
If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false. |
onPause
void onPause ()
Does a best-effort attempt to pause any processing that can be paused
safely, such as animations and geolocation. Note that this call
does not pause JavaScript. To pause JavaScript globally, use
pauseTimers()
.
To resume WebView, call onResume()
.
onProvideAutofillVirtualStructure
void onProvideAutofillVirtualStructure (ViewStructure structure, int flags)
Populates a ViewStructure
containing virtual children to fullfil an autofill
request.
This method should be used when the view manages a virtual structure under this view. For
example, a view that draws input fields using draw(Canvas)
.
When implementing this method, subclasses must follow the rules below:
- Add virtual children by calling the
newChild(int)
orasyncNewChild(int)
methods, where theid
is an unique id identifying the children in the virtual structure. - The children hierarchy can have multiple levels if necessary, but ideally it should exclude intermediate levels that are irrelevant for autofill; that would improve the autofill performance.
- Also implement
autofill(SparseArray)
to autofill the virtual children. - Set the autofill properties of the child structure as defined by
onProvideAutofillStructure(ViewStructure, int)
, usingsetAutofillId(AutofillId, int)
to set its autofill id. - Call
notifyViewEntered(View, int, Rect)
and/ornotifyViewExited(View, int)
when the focused virtual child changed. - Override
isVisibleToUserForAutofill(int)
to allow the platform to query whether a given virtual view is visible to the user in order to support triggering save when all views of interest go away. - Call
notifyValueChanged(View, int, AutofillValue)
when the value of a virtual child changed. - Call
notifyViewVisibilityChanged(View, int, boolean)
when the visibility of a virtual child changed. - Call
commit()
when the autofill context of the view structure changed and the current context should be committed (for example, when the user tapped aSUBMIT
button in an HTML page). - Call
cancel()
when the autofill context of the view structure changed and the current context should be canceled (for example, when the user tapped aCANCEL
button in an HTML page). - Provide ways for users to manually request autofill by calling
requestAutofill(View, int, Rect)
. - The
left
andtop
values set insetDimens(int, int, int, int, int, int)
must be relative to the nextisImportantForAutofill()
predecessor view included in the structure.
Views with virtual children support the Autofill Framework mainly by:
- Providing the metadata defining what the virtual children mean and how they can be autofilled.
- Implementing the methods that autofill the virtual children.
This method is responsible for the former; autofill(SparseArray)
is responsible
for the latter.
The ViewStructure
traditionally represents a View
, while for web pages
it represent HTML nodes. Hence, it's necessary to "map" the HTML properties in a way that is
understood by the AutofillService
implementations:
- Only the HTML nodes inside a
FORM
are generated. - The source of the HTML is set using
setWebDomain(String)
in the node representing the WebView. - If a web page has multiple
FORM
s, only the data for the current form is represented—if the user taps a field from another form, then the current autofill context is canceled (by callingcancel()
and a new context is created for thatFORM
. - Similarly, if the page has
IFRAME
nodes, they are not initially represented in the view structure until the user taps a field from aFORM
inside theIFRAME
, in which case it would be treated the same way as multiple forms described above, except that theweb domain
of theFORM
contains thesrc
attribute from theIFRAME
node. - The W3C autofill field (
autocomplete
tag attribute) maps tosetAutofillHints(String[])
. - If the view is editable, the
setAutofillType(int)
andsetAutofillValue(AutofillValue)
must be set. - The
placeholder
attribute maps tosetHint(CharSequence)
. - Other HTML attributes can be represented through
setHtmlInfo(android.view.ViewStructure.HtmlInfo)
.
If the WebView implementation can determine that the value of a field was set statically
(for example, not through Javascript), it should also call
structure.setDataIsSensitive(false)
.
For example, an HTML form with 2 fields for username and password:
<label>Username:</label> <input type="text" name="username" id="user" value="Type your username" autocomplete="username" placeholder="Email or username"> <label>Password:</label> <input type="password" name="password" id="pass" autocomplete="current-password" placeholder="Password">
Would map to:
int index = structure.addChildCount(2); ViewStructure username = structure.newChild(index); username.setAutofillId(structure.getAutofillId(), 1); // id 1 - first child username.setAutofillHints("username"); username.setHtmlInfo(username.newHtmlInfoBuilder("input") .addAttribute("type", "text") .addAttribute("name", "username") .addAttribute("label", "Username:") .build()); username.setHint("Email or username"); username.setAutofillType(View.AUTOFILL_TYPE_TEXT); username.setAutofillValue(AutofillValue.forText("Type your username")); // Value of the field is not sensitive because it was created statically and not changed. username.setDataIsSensitive(false); ViewStructure password = structure.newChild(index + 1); username.setAutofillId(structure, 2); // id 2 - second child password.setAutofillHints("current-password"); password.setHtmlInfo(password.newHtmlInfoBuilder("input") .addAttribute("type", "password") .addAttribute("name", "password") .addAttribute("label", "Password:") .build()); password.setHint("Password"); password.setAutofillType(View.AUTOFILL_TYPE_TEXT);
Parameters | |
---|---|
structure |
ViewStructure : fill in with virtual children data for autofill purposes. |
flags |
int : optional flags. |
onProvideVirtualStructure
void onProvideVirtualStructure (ViewStructure structure)
Called when assist structure is being retrieved from a view as part of
Activity.onProvideAssistData
to
generate additional virtual structure under this view. The defaullt implementation
uses getAccessibilityNodeProvider()
to try to generate this from the
view's virtual accessibility nodes, if any. You can override this for a more
optimal implementation providing this data.
Parameters | |
---|---|
structure |
ViewStructure |
onResume
void onResume ()
Resumes a WebView after a previous call to onPause()
.
onStartTemporaryDetach
void onStartTemporaryDetach ()
This is called when a container is going to temporarily detach a child, with
ViewGroup.detachViewFromParent
.
It will either be followed by onFinishTemporaryDetach()
or
onDetachedFromWindow()
when the container is done.
onTouchEvent
boolean onTouchEvent (MotionEvent event)
Implement this method to handle touch screen motion events.
If this method is used to detect click actions, it is recommended that
the actions be performed by implementing and calling
performClick()
. This will ensure consistent system behavior,
including:
- obeying click sound preferences
- dispatching OnClickListener calls
- handling
ACTION_CLICK
when accessibility features are enabled
Parameters | |
---|---|
event |
MotionEvent : The motion event. |
Returns | |
---|---|
boolean |
True if the event was handled, false otherwise. |
onTrackballEvent
boolean onTrackballEvent (MotionEvent event)
Implement this method to handle trackball motion events. The
relative movement of the trackball since the last event
can be retrieve with MotionEvent.getX()
and
MotionEvent.getY()
. These are normalized so
that a movement of 1 corresponds to the user pressing one DPAD key (so
they will often be fractional values, representing the more fine-grained
movement information available from a trackball).
Parameters | |
---|---|
event |
MotionEvent : The motion event. |
Returns | |
---|---|
boolean |
True if the event was handled, false otherwise. |
onWindowFocusChanged
void onWindowFocusChanged (boolean hasWindowFocus)
Called when the window containing this view gains or loses focus. Note that this is separate from view focus: to receive key events, both your view and its window must have focus. If a window is displayed on top of yours that takes input focus, then your own window will lose focus but the view focus will remain unchanged.
Parameters | |
---|---|
hasWindowFocus |
boolean : True if the window containing this view now has
focus, false otherwise.
|
overlayHorizontalScrollbar
boolean overlayHorizontalScrollbar ()
This method was deprecated
in API level 23.
This method is now obsolete.
Gets whether horizontal scrollbar has overlay style.
Returns | |
---|---|
boolean |
true
|
overlayVerticalScrollbar
boolean overlayVerticalScrollbar ()
This method was deprecated
in API level 23.
This method is now obsolete.
Gets whether vertical scrollbar has overlay style.
Returns | |
---|---|
boolean |
false
|
pageDown
boolean pageDown (boolean bottom)
Scrolls the contents of this WebView down by half the page size.
Parameters | |
---|---|
bottom |
boolean : true to jump to bottom of page |
Returns | |
---|---|
boolean |
true if the page was scrolled
|
pageUp
boolean pageUp (boolean top)
Scrolls the contents of this WebView up by half the view size.
Parameters | |
---|---|
top |
boolean : true to jump to the top of the page |
Returns | |
---|---|
boolean |
true if the page was scrolled
|
pauseTimers
void pauseTimers ()
Pauses all layout, parsing, and JavaScript timers for all WebViews. This is a global requests, not restricted to just this WebView. This can be useful if the application has been paused.
performLongClick
boolean performLongClick ()
Calls this view's OnLongClickListener, if it is defined. Invokes the context menu if the OnLongClickListener did not consume the event.
Returns | |
---|---|
boolean |
true if one of the above receivers consumed the event,
false otherwise
|
postUrl
void postUrl (String url, byte[] postData)
Loads the URL with postData using "POST" method into this WebView. If url
is not a network URL, it will be loaded with loadUrl(String)
instead, ignoring the postData param.
Parameters | |
---|---|
url |
String : the URL of the resource to load |
postData |
byte : the data will be passed to "POST" request, which must be
be "application/x-www-form-urlencoded" encoded.
|
postVisualStateCallback
void postVisualStateCallback (long requestId, WebView.VisualStateCallback callback)
Posts a WebView.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 onDraw(Canvas)
invocations. The
WebView.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 WebView.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
- the video tag
To guarantee that the WebView
will successfully render the first frame
after the onComplete(long)
method has been called a set of conditions
must be met:
- If the
WebView
's visibility is set toVISIBLE
then theWebView
must be attached to the view hierarchy. - If the
WebView
's visibility is set toINVISIBLE
then theWebView
must be attached to the view hierarchy and must be madeVISIBLE
from theonComplete(long)
method. - If the
WebView
's visibility is set toGONE
then theWebView
must be attached to the view hierarchy and itsLayoutParams
's width and height need to be set to fixed values and must be madeVISIBLE
from theonComplete(long)
method.
When using this API it is also recommended to enable pre-rasterization if the WebView
is off screen to avoid flickering. See setOffscreenPreRaster(boolean)
for
more details and do consider its caveats.
Parameters | |
---|---|
requestId |
long : An id that will be returned in the callback to allow callers to match
requests with callbacks. |
callback |
WebView.VisualStateCallback : The callback to be invoked.
|
postWebMessage
void postWebMessage (WebMessage 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.
Parameters | |
---|---|
message |
WebMessage : the WebMessage |
targetOrigin |
Uri : the target origin.
|
removeJavascriptInterface
void removeJavascriptInterface (String name)
Removes a previously injected Java object from this WebView. Note that
the removal will not be reflected in JavaScript until the page is next
(re)loaded. See addJavascriptInterface(Object, String)
.
Parameters | |
---|---|
name |
String : the name used to expose the object in JavaScript
This value must never be |
requestChildRectangleOnScreen
boolean requestChildRectangleOnScreen (View child, Rect rect, boolean immediate)
Called when a child of this group wants a particular rectangle to be
positioned onto the screen. ViewGroup
s overriding this can trust
that:
- child will be a direct child of this group
- rectangle will be in the child's content coordinates
ViewGroup
s overriding this should uphold the contract:
- nothing will change if the rectangle is already visible
- the view port will be scrolled only just enough to make the rectangle visible
Parameters | |
---|---|
child |
View : The direct child making the request. |
rect |
Rect : The rectangle in the child's coordinates the child
wishes to be on the screen. |
immediate |
boolean : True to forbid animated or delayed scrolling,
false otherwise |
Returns | |
---|---|
boolean |
Whether the group scrolled to handle the operation |
requestFocus
boolean requestFocus (int direction, Rect previouslyFocusedRect)
Call this to try to give focus to a specific view or to one of its descendants
and give it hints about the direction and a specific rectangle that the focus
is coming from. The rectangle can help give larger views a finer grained hint
about where focus is coming from, and therefore, where to show selection, or
forward focus change internally.
A view will not actually take focus if it is not focusable (isFocusable()
returns
false), or if it is focusable and it is not focusable in touch mode
(isFocusableInTouchMode()
) while the device is in touch mode.
A View will not take focus if it is not visible.
A View will not take focus if one of its parents has
getDescendantFocusability()
equal to
FOCUS_BLOCK_DESCENDANTS
.
See also focusSearch(int)
, which is what you call to say that you
have focus, and you want your parent to look for the next one.
You may wish to override this method if your custom View
has an internal
View
that it wishes to forward the request to.
Looks for a view to give focus to respecting the setting specified by
getDescendantFocusability()
.
Uses onRequestFocusInDescendants(int, android.graphics.Rect)
to
find focus within the children of this group when appropriate.
Parameters | |
---|---|
direction |
int : One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT |
previouslyFocusedRect |
Rect : The rectangle (in this View's coordinate system)
to give a finer grained hint about where focus is coming from. May be null
if there is no hint. |
Returns | |
---|---|
boolean |
Whether this view or one of its descendants actually took focus. |
requestFocusNodeHref
void requestFocusNodeHref (Message hrefMsg)
Requests the anchor or image element URL at the last tapped point.
If hrefMsg is null
, this method returns immediately and does not
dispatch hrefMsg to its target. If the tapped point hits an image,
an anchor, or an image in an anchor, the message associates
strings in named keys in its data. The value paired with the key
may be an empty string.
Parameters | |
---|---|
hrefMsg |
Message : the message to be dispatched with the result of the
request. The message data contains three keys. "url"
returns the anchor's href attribute. "title" returns the
anchor's text. "src" returns the image's src attribute.
This value may be |
requestImageRef
void requestImageRef (Message msg)
Requests the URL of the image last touched by the user. msg will be sent to its target with a String representing the URL as its object.
Parameters | |
---|---|
msg |
Message : the message to be dispatched with the result of the request
as the data member with "url" as key. The result can be null .
|
restoreState
WebBackForwardList restoreState (Bundle inState)
Restores the state of this WebView from the given Bundle. This method is
intended for use in onRestoreInstanceState(Bundle)
and should be called to restore the state of this WebView. If
it is called after this WebView has had a chance to build state (load
pages, create a back/forward list, etc.) there may be undesirable
side-effects. Please note that this method no longer restores the
display data for this WebView.
Parameters | |
---|---|
inState |
Bundle : the incoming Bundle of state |
Returns | |
---|---|
WebBackForwardList |
the restored back/forward list or null if restoreState failed
|
resumeTimers
void resumeTimers ()
Resumes all layout, parsing, and JavaScript timers for all WebViews. This will resume dispatching all timers.
savePassword
void savePassword (String host, String username, String password)
This method was deprecated
in API level 18.
Saving passwords in WebView will not be supported in future versions.
Sets a username and password pair for the specified host. This data is used by the WebView to autocomplete username and password fields in web forms. Note that this is unrelated to the credentials used for HTTP authentication.
Parameters | |
---|---|
host |
String : the host that required the credentials |
username |
String : the username for the given host |
password |
String : the password for the given host |
saveState
WebBackForwardList saveState (Bundle outState)
Saves the state of this WebView used in
onSaveInstanceState(Bundle)
. Please note that this
method no longer stores the display data for this WebView. The previous
behavior could potentially leak files if restoreState(Bundle)
was never
called.
Parameters | |
---|---|
outState |
Bundle : the Bundle to store this WebView's state |
Returns | |
---|---|
WebBackForwardList |
the same copy of the back/forward list used to save the state, null if the
method fails.
|
saveWebArchive
void saveWebArchive (String filename)
Saves the current view as a web archive.
Parameters | |
---|---|
filename |
String : the filename where the archive should be placed
|
saveWebArchive
void saveWebArchive (String basename, boolean autoname, ValueCallback<String> callback)
Saves the current view as a web archive.
Parameters | |
---|---|
basename |
String : the filename where the archive should be placed |
autoname |
boolean : if false , takes basename to be a file. If true , basename
is assumed to be a directory in which a filename will be
chosen according to the URL of the current page. |
callback |
ValueCallback : called after the web archive has been saved. The
parameter for onReceiveValue will either be the filename
under which the file was saved, or null if saving the
file failed.
|
setBackgroundColor
void setBackgroundColor (int color)
Sets the background color for this view.
Parameters | |
---|---|
color |
int : the color of the background
|
setCertificate
void setCertificate (SslCertificate certificate)
This method was deprecated
in API level 17.
Calling this function has no useful effect, and will be
ignored in future releases.
Sets the SSL certificate for the main top-level page.
Parameters | |
---|---|
certificate |
SslCertificate |
setDataDirectorySuffix
void setDataDirectorySuffix (String suffix)
Define the directory used to store WebView data for the current process. The provided suffix will be used when constructing data and cache directory paths. If this API is not called, no suffix will be used. Each directory can be used by only one process in the application. If more than one process in an app wishes to use WebView, only one process can use the default directory, and other processes must call this API to define a unique suffix.
This means that different processes in the same application cannot directly
share WebView-related data, since the data directories must be distinct.
Applications that use this API may have to explicitly pass data between
processes. For example, login cookies may have to be copied from one
process's cookie jar to the other using CookieManager
if both
processes' WebViews are intended to be logged in.
Most applications should simply ensure that all components of the app
that rely on WebView are in the same process, to avoid needing multiple
data directories. The disableWebView()
method can be used to ensure
that the other processes do not use WebView by accident in this case.
This API must be called before any instances of WebView are created in this process and before any other methods in the android.webkit package are called by this process.
Parameters | |
---|---|
suffix |
String : The directory name suffix to be used for the current
process. Must not contain a path separator. |
Throws | |
---|---|
IllegalStateException |
if WebView has already been initialized in the current process. |
IllegalArgumentException |
if the suffix contains a path separator. |
setDownloadListener
void setDownloadListener (DownloadListener listener)
Registers the interface to be used when content can not be handled by the rendering engine, and should be downloaded instead. This will replace the current handler.
Parameters | |
---|---|
listener |
DownloadListener : an implementation of DownloadListener
|
setFindListener
void setFindListener (WebView.FindListener listener)
Registers the listener to be notified as find-on-page operations progress. This will replace the current listener.
Parameters | |
---|---|
listener |
WebView.FindListener : an implementation of WebView.FindListener
|
setHorizontalScrollbarOverlay
void setHorizontalScrollbarOverlay (boolean overlay)
This method was deprecated
in API level 23.
This method has no effect.
Specifies whether the horizontal scrollbar has overlay style.
Parameters | |
---|---|
overlay |
boolean : true if horizontal scrollbar should have overlay style
|
setHttpAuthUsernamePassword
void setHttpAuthUsernamePassword (String host, String realm, String username, String password)
This method was deprecated
in API level 26.
Use setHttpAuthUsernamePassword(String, String, String, String)
instead
Stores HTTP authentication credentials for a given host and realm to the WebViewDatabase
instance.
Parameters | |
---|---|
host |
String : the host to which the credentials apply |
realm |
String : the realm to which the credentials apply |
username |
String : the username |
password |
String : the password |
setInitialScale
void setInitialScale (int scaleInPercent)
Sets the initial scale for this WebView. 0 means default.
The behavior for the default scale depends on the state of
getUseWideViewPort()
and
getLoadWithOverviewMode()
.
If the content fits into the WebView control by width, then
the zoom is set to 100%. For wide content, the behavior
depends on the state of getLoadWithOverviewMode()
.
If its value is true
, the content will be zoomed out to be fit
by width into the WebView control, otherwise not.
If initial scale is greater than 0, WebView starts with this value
as initial scale.
Please note that unlike the scale properties in the viewport meta tag,
this method doesn't take the screen density into account.
Parameters | |
---|---|
scaleInPercent |
int : the initial scale in percent
|
setLayerType
void setLayerType (int layerType, Paint paint)
Specifies the type of layer backing this view. The layer can be
LAYER_TYPE_NONE
, LAYER_TYPE_SOFTWARE
or
LAYER_TYPE_HARDWARE
.
A layer is associated with an optional Paint
instance that controls how the layer is composed on screen. The following
properties of the paint are taken into account when composing the layer:
If this view has an alpha value set to < 1.0 by calling
setAlpha(float)
, the alpha value of the layer's paint is superseded
by this view's alpha value.
Refer to the documentation of LAYER_TYPE_NONE
,
LAYER_TYPE_SOFTWARE
and LAYER_TYPE_HARDWARE
for more information on when and how to use layers.
Parameters | |
---|---|
layerType |
int : The type of layer to use with this view, must be one of
LAYER_TYPE_NONE , LAYER_TYPE_SOFTWARE or
LAYER_TYPE_HARDWARE |
paint |
Paint : The paint used to compose the layer. This argument is optional
and can be null. It is ignored when the layer type is
LAYER_TYPE_NONE |
setLayoutParams
void setLayoutParams (ViewGroup.LayoutParams params)
Set the layout parameters associated with this view. These supply parameters to the parent of this view specifying how it should be arranged. There are many subclasses of ViewGroup.LayoutParams, and these correspond to the different subclasses of ViewGroup that are responsible for arranging their children.
Parameters | |
---|---|
params |
ViewGroup.LayoutParams : The layout parameters for this view, cannot be null
|
setMapTrackballToArrowKeys
void setMapTrackballToArrowKeys (boolean setMap)
This method was deprecated
in API level 17.
Only the default case, true
, will be supported in a future version.
Parameters | |
---|---|
setMap |
boolean |
setNetworkAvailable
void setNetworkAvailable (boolean networkUp)
Informs WebView of the network state. This is used to set the JavaScript property window.navigator.isOnline and generates the online/offline event as specified in HTML5, sec. 5.7.7
Parameters | |
---|---|
networkUp |
boolean : a boolean indicating if network is available
|
setOverScrollMode
void setOverScrollMode (int mode)
Set the over-scroll mode for this view. Valid over-scroll modes are
OVER_SCROLL_ALWAYS
(default), OVER_SCROLL_IF_CONTENT_SCROLLS
(allow over-scrolling only if the view content is larger than the container),
or OVER_SCROLL_NEVER
.
Setting the over-scroll mode of a view will have an effect only if the
view is capable of scrolling.
Parameters | |
---|---|
mode |
int : The new over-scroll mode for this view.
|
setPictureListener
void setPictureListener (WebView.PictureListener listener)
This method was deprecated
in API level 12.
This method is now obsolete.
Sets the Picture listener. This is an interface used to receive notifications of a new Picture.
Parameters | |
---|---|
listener |
WebView.PictureListener : an implementation of WebView.PictureListener |
setRendererPriorityPolicy
void setRendererPriorityPolicy (int rendererRequestedPriority, boolean waivedWhenNotVisible)
Set the renderer priority policy for this WebView
. The
priority policy will be used to determine whether an out of
process renderer should be considered to be a target for OOM
killing.
Because a renderer can be associated with more than one
WebView, the final priority it is computed as the maximum of
any attached WebViews. When a WebView is destroyed it will
cease to be considerered when calculating the renderer
priority. Once no WebViews remain associated with the renderer,
the priority of the renderer will be reduced to
RENDERER_PRIORITY_WAIVED
.
The default policy is to set the priority to
RENDERER_PRIORITY_IMPORTANT
regardless of visibility,
and this should not be changed unless the caller also handles
renderer crashes with
onRenderProcessGone(WebView, RenderProcessGoneDetail)
. Any other setting
will result in WebView renderers being killed by the system
more aggressively than the application.
Parameters | |
---|---|
rendererRequestedPriority |
int : the minimum priority at which
this WebView desires the renderer process to be bound.Value is |
waivedWhenNotVisible |
boolean : if true , this flag specifies that
when this WebView is not visible, it will be treated as
if it had requested a priority of
RENDERER_PRIORITY_WAIVED .
|
setSafeBrowsingWhitelist
void setSafeBrowsingWhitelist (List<String> urls, ValueCallback<Boolean> callback)
Sets the list of domains 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.
Parameters | |
---|---|
urls |
List : the list of URLsThis value must never be |
callback |
ValueCallback : will be called with true if URLs are successfully added to the
whitelist. It will be called with false if any URLs are malformed. The callback will
be run on the UI thread
This value may be |
setScrollBarStyle
void setScrollBarStyle (int style)
Specify the style of the scrollbars. The scrollbars can be overlaid or inset. When inset, they add to the padding of the view. And the scrollbars can be drawn inside the padding area or on the edge of the view. For example, if a view has a background drawable and you want to draw the scrollbars inside the padding specified by the drawable, you can use SCROLLBARS_INSIDE_OVERLAY or SCROLLBARS_INSIDE_INSET. If you want them to appear at the edge of the view, ignoring the padding, then you can use SCROLLBARS_OUTSIDE_OVERLAY or SCROLLBARS_OUTSIDE_INSET.
Parameters | |
---|---|
style |
int : the style of the scrollbars. Should be one of
SCROLLBARS_INSIDE_OVERLAY, SCROLLBARS_INSIDE_INSET,
SCROLLBARS_OUTSIDE_OVERLAY or SCROLLBARS_OUTSIDE_INSET. |
setTextClassifier
void setTextClassifier (TextClassifier textClassifier)
Sets the TextClassifier
for this WebView.
Parameters | |
---|---|
textClassifier |
TextClassifier This value may be |
setVerticalScrollbarOverlay
void setVerticalScrollbarOverlay (boolean overlay)
This method was deprecated
in API level 23.
This method has no effect.
Specifies whether the vertical scrollbar has overlay style.
Parameters | |
---|---|
overlay |
boolean : true if vertical scrollbar should have overlay style
|
setWebChromeClient
void setWebChromeClient (WebChromeClient client)
Sets the chrome handler. This is an implementation of WebChromeClient for use in handling JavaScript dialogs, favicons, titles, and the progress. This will replace the current handler.
Parameters | |
---|---|
client |
WebChromeClient : an implementation of WebChromeClient |
See also:
setWebContentsDebuggingEnabled
void setWebContentsDebuggingEnabled (boolean enabled)
Enables debugging of web contents (HTML / CSS / JavaScript)
loaded into any WebViews of this application. This flag can be enabled
in order to facilitate debugging of web layouts and JavaScript
code running inside WebViews. Please refer to WebView documentation
for the debugging guide.
The default is false
.
Parameters | |
---|---|
enabled |
boolean : whether to enable web contents debugging
|
setWebViewClient
void setWebViewClient (WebViewClient client)
Sets the WebViewClient that will receive various notifications and requests. This will replace the current handler.
Parameters | |
---|---|
client |
WebViewClient : an implementation of WebViewClient |
See also:
shouldDelayChildPressedState
boolean shouldDelayChildPressedState ()
Return true if the pressed state should be delayed for children or descendants of this ViewGroup. Generally, this should be done for containers that can scroll, such as a List. This prevents the pressed state from appearing when the user is actually trying to scroll the content. The default implementation returns true for compatibility reasons. Subclasses that do not scroll should generally override this method and return false.
Returns | |
---|---|
boolean |
showFindDialog
boolean showFindDialog (String text, boolean showIme)
This method was deprecated
in API level 18.
This method does not work reliably on all Android versions;
implementing a custom find dialog using WebView.findAllAsync()
provides a more robust solution.
Starts an ActionMode for finding text in this WebView. Only works if this WebView is attached to the view system.
Parameters | |
---|---|
text |
String : if non-null, will be the initial text to search for.
Otherwise, the last String searched for in this WebView will
be used to start. |
showIme |
boolean : if true , show the IME, assuming the user will begin typing.
If false and text is non-null, perform a find all. |
Returns | |
---|---|
boolean |
true if the find dialog is shown, false otherwise |
startSafeBrowsing
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 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).
Parameters | |
---|---|
context |
Context : Application Context. |
callback |
ValueCallback : will be called on the UI thread with true if initialization is
successful, false otherwise.
This value may be |
zoomBy
void zoomBy (float zoomFactor)
Performs a zoom operation in this WebView.
Parameters | |
---|---|
zoomFactor |
float : the zoom factor to apply. The zoom factor will be clamped to the WebView's
zoom limits. This value must be in the range 0.01 to 100.0 inclusive.
|
zoomIn
boolean zoomIn ()
Performs zoom in in this WebView.
Returns | |
---|---|
boolean |
true if zoom in succeeds, false if no zoom changes
|
zoomOut
boolean zoomOut ()
Performs zoom out in this WebView.
Returns | |
---|---|
boolean |
true if zoom out succeeds, false if no zoom changes
|