public class WebView extends android.widget.AbsoluteLayout implements ViewDebug.HierarchyHandler, ViewTreeObserver.OnGlobalFocusChangeListener, ViewGroup.OnHierarchyChangeListener
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 {@code INTERNET} permissions to your
Android Manifest file:
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("http://www.example.com");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
See {@link android.content.Intent} for more information.
To provide a WebView in your own Activity, include a {@code <WebView>} in your layout,
or set the entire Activity window as a WebView during {@link
android.app.Activity#onCreate(Bundle) 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("http://slashdot.org/");
// 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.
// See the JavaDocs for {@link #loadData(String,String,String) loadData()} and {@link
#loadDataWithBaseURL(String,String,String,String,String) loadDataWithBaseURL()} for more info.
A WebView has several customization points where you can add your
own behavior. These are:
Creating and setting a {@link android.webkit.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 {@link android.webkit.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 (via {@link
android.webkit.WebViewClient#shouldOverrideUrlLoading(WebView,String)
shouldOverrideUrlLoading()}).
Modifying the {@link android.webkit.WebSettings}, such as
enabling JavaScript with {@link android.webkit.WebSettings#setJavaScriptEnabled(boolean)
setJavaScriptEnabled()}.
Injecting Java objects into the WebView using the
{@link android.webkit.WebView#addJavascriptInterface} 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("http://developer.android.com/");
Zoom
To enable the built-in zoom, set
{@link #getSettings() WebSettings}.{@link WebSettings#setBuiltInZoomControls(boolean)}
(introduced in API level {@link android.os.Build.VERSION_CODES#CUPCAKE}).
NOTE: Using zoom if either the height or width is set to
{@link android.view.ViewGroup.LayoutParams#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
{@link WebChromeClient} to provide your own behaviour 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 {@code orientation} and {@code 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 {@link android.os.Build.VERSION_CODES#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 {@code window.devicePixelRatio} DOM property. The value of this property specifies the
default scaling factor used for the current device. For example, if the value of {@code
window.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 {@code -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 {@code hdpi.css} stylesheet is only used for devices with a screen pixel ration 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, and set a {@link android.webkit.WebChromeClient}. For full screen support,
implementations of {@link WebChromeClient#onShowCustomView(View, WebChromeClient.CustomViewCallback)}
and {@link WebChromeClient#onHideCustomView()} are required,
{@link WebChromeClient#getVideoLoadingProgressView()} is optional.
Fields Summary
public static final String
DATA_REDUCTION_PROXY_SETTING_CHANGED
Broadcast Action: Indicates the data reduction proxy setting changed.
Sent by the settings app when user changes the data reduction proxy value. This intent will
always stay as a hidden API.
Constructs a new WebView with layout parameters and a default style.
param
context a Context object used to access application assets
param
attrs an AttributeSet passed to our parent
param
defStyleAttr 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.
Constructs a new WebView with layout parameters and a default style.
param
context a Context object used to access application assets
param
attrs an AttributeSet passed to our parent
param
defStyleAttr 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.
param
defStyleRes 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.
Constructs a new WebView with layout parameters and a default style.
param
context a Context object used to access application assets
param
attrs an AttributeSet passed to our parent
param
defStyleAttr 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.
param
privateBrowsing whether this WebView will be initialized in
private mode
deprecated
Private browsing is no longer supported directly via
WebView and will be removed in a future release. Prefer using
{@link WebSettings}, {@link WebViewDatabase}, {@link CookieManager}
and {@link WebStorage} for fine-grained control of privacy data.
Constructs a new WebView with layout parameters, a default style and a set
of custom Javscript interfaces to be added to this WebView at initialization
time. This guarantees that these interfaces will be available when the JS
context is initialized.
param
context a Context object used to access application assets
param
attrs an AttributeSet passed to our parent
param
defStyleAttr 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.
param
javaScriptInterfaces a Map of interface names, as keys, and
object implementing those interfaces, as
values
param
privateBrowsing whether this WebView will be initialized in
private mode
hide
This is used internally by dumprendertree, as it requires the javaScript interfaces to
be added synchronously, before a subsequent loadUrl call takes effect.
super(context, attrs, defStyleAttr, defStyleRes);
if (context == null) {
throw new IllegalArgumentException("Invalid context argument");
}
sEnforceThreadChecking = context.getApplicationInfo().targetSdkVersion >=
Build.VERSION_CODES.JELLY_BEAN_MR2;
checkThread();
if (TRACE) Log.d(LOGTAG, "WebView<init>");
ensureProviderCreated();
mProvider.init(javaScriptInterfaces, privateBrowsing);
// Post condition of creating a webview is the CookieSyncManager.getInstance() is allowed.
CookieSyncManager.setGetInstanceIsAllowed();
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 {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
and above, only public methods that are annotated with
{@link android.webkit.JavascriptInterface} can be accessed from JavaScript.
For applications targeted to API level {@link android.os.Build.VERSION_CODES#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. For example:
class JsObject {
{@literal @}JavascriptInterface
public String toString() { return "injectedObject"; }
}
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 {@link android.os.Build.VERSION_CODES#JELLY_BEAN} or earlier.
Apps that target a version later than {@link android.os.Build.VERSION_CODES#JELLY_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 target {@link android.os.Build.VERSION_CODES#JELLY_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 {@link android.os.Build.VERSION_CODES#LOLLIPOP}
and above, methods of injected Java objects are enumerable from
JavaScript.
param
object the Java object to inject into this WebView's JavaScript
context. Null values are ignored.
param
name the name used to expose the object in JavaScript
checkThread();
if (TRACE) Log.d(LOGTAG, "addJavascriptInterface=" + name);
mProvider.addJavascriptInterface(object, name);
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
{@link android.os.Build.VERSION_CODES#HONEYCOMB} and
{@link android.os.Build.VERSION_CODES#ICE_CREAM_SANDWICH} inclusive, the
picture does not include fixed position elements or scrollable divs.
Note that from {@link android.os.Build.VERSION_CODES#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
{@link android.graphics.Picture#createFromStream} and
{@link android.graphics.Picture#writeToStream} methods are not supported on the
returned object.
deprecated
Use {@link #onDraw} to obtain a bitmap snapshot of the WebView, or
{@link #saveWebArchive} to save the content to a file.
return
a picture that captures the current contents of this WebView
checkThread();
if (TRACE) Log.d(LOGTAG, "capturePicture");
return mProvider.capturePicture();
private void
checkThread()
// Ignore mWebViewThread == null because this can be called during in the super class
// constructor, before this class's own constructor has even started.
if (mWebViewThread != null && Looper.myLooper() != mWebViewThread) {
Throwable throwable = new Throwable(
"A WebView method was called on thread '" +
Thread.currentThread().getName() + "'. " +
"All WebView methods must be called on the same thread. " +
"(Expected Looper " + mWebViewThread + " called on " + Looper.myLooper() +
", FYI main Looper is " + Looper.getMainLooper() + ")");
Log.w(LOGTAG, Log.getStackTraceString(throwable));
StrictMode.onWebViewMethodCalledOnWrongThread(throwable);
if (sEnforceThreadChecking) {
throw new RuntimeException(throwable);
}
}
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
{@link KeyChain#ACTION_STORAGE_CHANGED} intent. The preferences are
shared by all the webviews that are created by the embedder application.
param
onCleared A runnable to be invoked when client certs are cleared.
The embedder can pass null if not interested in the
callback. The runnable will be called in UI thread.
if (TRACE) Log.d(LOGTAG, "clearClientCertPreferences");
getFactory().getStatics().clearClientCertPreferences(onCleared);
public 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 {@link WebViewDatabase#clearFormData}.
checkThread();
if (TRACE) Log.d(LOGTAG, "clearFormData");
mProvider.clearFormData();
public void
clearHistory()
Tells this WebView to clear its internal back/forward list.
checkThread();
if (TRACE) Log.d(LOGTAG, "clearHistory");
mProvider.clearHistory();
public void
clearMatches()
Clears the highlighting surrounding text matches created by
{@link #findAllAsync}.
checkThread();
if (TRACE) Log.d(LOGTAG, "clearMatches");
mProvider.clearMatches();
public void
clearSslPreferences()
Clears the SSL preferences table stored in response to proceeding with
SSL certificate errors.
checkThread();
if (TRACE) Log.d(LOGTAG, "clearSslPreferences");
mProvider.clearSslPreferences();
public void
clearView()
Clears this WebView so that onDraw() will draw nothing but white background,
and onMeasure() will return 0 if MeasureSpec is not MeasureSpec.EXACTLY.
deprecated
Use WebView.loadUrl("about:blank") to reliably reset the view state
and release page resources (including any running JavaScript).
checkThread();
if (TRACE) Log.d(LOGTAG, "clearView");
mProvider.clearView();
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.
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
{@link android.print.PrintDocumentAdapter} for more information.
param
documentName The user-facing name of the printed document. See
{@link android.print.PrintDocumentInfo}
checkThread();
if (TRACE) Log.d(LOGTAG, "createPrintDocumentAdapter");
return mProvider.createPrintDocumentAdapter(documentName);
public void
debugDump()
deprecated
This method is now obsolete.
hide
Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
checkThread();
public 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.
checkThread();
if (TRACE) Log.d(LOGTAG, "destroy");
mProvider.destroy();
public static void
disablePlatformNotifications()
Disables platform notifications of data state and proxy changes.
Notifications are enabled by default.
deprecated
This method is now obsolete.
hide
Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
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.
param
response the message that will be dispatched with the result
Puts this WebView into text selection mode. Do not rely on this
functionality; it will be deprecated in the future.
deprecated
This method is now obsolete.
hide
Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
checkThread();
public static void
enablePlatformNotifications()
Enables platform notifications of data state and proxy changes.
Notifications are enabled by default.
deprecated
This method is now obsolete.
hide
Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
// noop
public 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. These
optimizations are transparent to the developers. However, under certain
circumstances, an App developer may want to disable them:
When an app uses {@link #onDraw} to do own drawing and accesses portions
of the page that is way outside the visible portion of the page.
When an app uses {@link #capturePicture} to capture a very large HTML document.
Note that capturePicture is a deprecated API.
Enabling drawing the entire HTML document has a significant performance
cost. This method should be called before any WebViews are created.
checkThread();
if (mProvider == null) {
// As this can get called during the base class constructor chain, pass the minimum
// number of dependencies here; the rest are deferred to init().
mProvider = getFactory().createWebView(this, new PrivateAccess());
}
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.
param
script the JavaScript to execute.
param
resultCallback A callback to be invoked when the script execution
completes with the result of the execution (if any).
May be null if no notificaion of the result is required.
checkThread();
if (TRACE) Log.d(LOGTAG, "evaluateJavascript=" + script);
mProvider.evaluateJavaScript(script, resultCallback);
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
All names must be correctly capitalized, and the zip code, if present,
must be valid for the state. The street type must be a standard USPS
spelling or abbreviation. The state or territory must also be spelled
or abbreviated using USPS standards. The house number may not exceed
five digits.
param
addr the string to search for addresses
return
the address, or if no address is found, null
// TODO: Rewrite this in Java so it is not needed to start up chromium
// Could also be deprecated
return getFactory().getStatics().findAddress(addr);
Finds all instances of find on the page and highlights them,
asynchronously. Notifies any registered {@link FindListener}.
Successive calls to this will cancel any pending searches.
param
find the string to find.
see
#setFindListener
checkThread();
if (TRACE) Log.d(LOGTAG, "findAllAsync");
mProvider.findAllAsync(find);
Highlights and scrolls to the next match found by
{@link #findAllAsync}, wrapping around page boundaries as necessary.
Notifies any registered {@link FindListener}. If {@link #findAllAsync(String)}
has not been called yet, or if {@link #clearMatches} has been called since the
last find operation, this function does nothing.
param
forward the direction to search
see
#setFindListener
checkThread();
if (TRACE) Log.d(LOGTAG, "findNext");
mProvider.findNext(forward);
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
{@link #requestFocusNodeHref} 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.
checkThread();
if (TRACE) Log.d(LOGTAG, "getHitTestResult");
return mProvider.getHitTestResult();
Retrieves HTTP authentication credentials for a given host and realm.
This method is intended to be used with
{@link WebViewClient#onReceivedHttpAuthRequest}.
param
host the host to which the credentials apply
param
realm the realm to which the credentials apply
return
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.
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.
return
the URL that was originally requested for the current page
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.
Gets the WebViewProvider. Used by providers to obtain the underlying
implementation, e.g. when the appliction responds to
WebViewClient.onCreateWindow() request.
Gets the zoom controls for this WebView, as a separate View. The caller
is responsible for inserting this View into the layout hierarchy.
API level {@link android.os.Build.VERSION_CODES#CUPCAKE} introduced
built-in zoom mechanisms for the WebView, as opposed to these separate
zoom controls. The built-in mechanisms are preferred and can be enabled
using {@link WebSettings#setBuiltInZoomControls}.
deprecated
the built-in zoom mechanisms are preferred
hide
Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN}
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.
param
steps the number of steps to take back or forward in the back
forward list
checkThread();
if (TRACE) Log.d(LOGTAG, "goBackOrForwad=" + steps);
mProvider.goBackOrForward(steps);
public void
goForward()
Goes forward in the history of this WebView.
checkThread();
if (TRACE) Log.d(LOGTAG, "goForward");
mProvider.goForward();
public 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.
checkThread();
if (TRACE) Log.d(LOGTAG, "invokeZoomPicker");
mProvider.invokeZoomPicker();
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 {@link
#loadDataWithBaseURL(String,String,String,String,String)
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'. For all other values of the parameter,
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. For example, '#',
'%', '\', '?' should be replaced by %23, %25, %27, %3f respectively.
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 {@link #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.
param
data a String of data in the given encoding
param
mimeType the MIME type of the data, e.g. 'text/html'
param
encoding the encoding of the data
checkThread();
if (TRACE) Log.d(LOGTAG, "loadData");
mProvider.loadData(data, mimeType, encoding);
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.
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 {@link #loadData(String,String,String) 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.
param
baseUrl the URL to use as the page's base URL. If null defaults to
'about:blank'.
param
data a String of data in the given encoding
param
mimeType the MIMEType of the data, e.g. 'text/html'. If null,
defaults to 'text/html'.
param
encoding the encoding of the data
param
historyUrl the URL to use as the history entry. If null defaults
to 'about:blank'. If non-null, this must be a valid URL.
Loads the given URL with the specified additional HTTP headers.
param
url the URL of the resource to load
param
additionalHttpHeaders 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 overriden by this WebView's defaults.
Pauses any extra processing associated with this WebView and its
associated DOM, plugins, JavaScript etc. For example, if this WebView is
taken offscreen, this could be called to reduce unnecessary CPU or
network traffic. When this WebView is again "active", call onResume().
Note that this differs from pauseTimers(), which affects all WebViews.
checkThread();
if (TRACE) Log.d(LOGTAG, "onPause");
mProvider.onPause();
public void
onResume()
Resumes a WebView after a previous call to onPause().
checkThread();
if (TRACE) Log.d(LOGTAG, "onResume");
mProvider.onResume();
super.onVisibilityChanged(changedView, visibility);
// This method may be called in the constructor chain, before the WebView provider is
// created.
ensureProviderCreated();
mProvider.getViewDelegate().onVisibilityChanged(changedView, visibility);
Scrolls the contents of this WebView up by half the view size.
param
top true to jump to the top of the page
return
true if the page was scrolled
checkThread();
if (TRACE) Log.d(LOGTAG, "pageUp");
return mProvider.pageUp(top);
public 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.
checkThread();
if (TRACE) Log.d(LOGTAG, "pauseTimers");
mProvider.pauseTimers();
Loads the URL with postData using "POST" method into this WebView. If url
is not a network URL, it will be loaded with {@link #loadUrl(String)}
instead, ignoring the postData param.
param
url the URL of the resource to load
param
postData the data will be passed to "POST" request, which must be
be "application/x-www-form-urlencoded" encoded.
checkThread();
if (TRACE) Log.d(LOGTAG, "postUrl=" + url);
if (URLUtil.isNetworkUrl(url)) {
mProvider.postUrl(url, postData);
} else {
mProvider.loadUrl(url);
}
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 {@link #addJavascriptInterface}.
param
name the name used to expose the object in JavaScript
checkThread();
if (TRACE) Log.d(LOGTAG, "removeJavascriptInterface=" + name);
mProvider.removeJavascriptInterface(name);
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.
param
hrefMsg 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.
checkThread();
if (TRACE) Log.d(LOGTAG, "requestFocusNodeHref");
mProvider.requestFocusNodeHref(hrefMsg);
Restores the display data that was saved in {@link #savePicture}. Used in
conjunction with {@link #restoreState}. Note that this will not work if
this WebView is hardware accelerated.
param
b a Bundle containing the saved display data
param
src the file where the picture data was stored
return
true if the picture was successfully restored
deprecated
This method is now obsolete.
hide
Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
checkThread();
if (TRACE) Log.d(LOGTAG, "restorePicture=" + src.getName());
return mProvider.restorePicture(b, src);
Restores the state of this WebView from the given Bundle. This method is
intended for use in {@link android.app.Activity#onRestoreInstanceState}
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.
param
inState the incoming Bundle of state
return
the restored back/forward list or null if restoreState failed
checkThread();
if (TRACE) Log.d(LOGTAG, "restoreState");
return mProvider.restoreState(inState);
public void
resumeTimers()
Resumes all layout, parsing, and JavaScript timers for all WebViews.
This will resume dispatching all timers.
checkThread();
if (TRACE) Log.d(LOGTAG, "resumeTimers");
mProvider.resumeTimers();
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.
param
host the host that required the credentials
param
username the username for the given host
param
password the password for the given host
see
WebViewDatabase#clearUsernamePassword
see
WebViewDatabase#hasUsernamePassword
deprecated
Saving passwords in WebView will not be supported in future versions.
checkThread();
if (TRACE) Log.d(LOGTAG, "savePassword=" + host);
mProvider.savePassword(host, username, password);
Saves the state of this WebView used in
{@link android.app.Activity#onSaveInstanceState}. Please note that this
method no longer stores the display data for this WebView. The previous
behavior could potentially leak files if {@link #restoreState} was never
called.
param
outState the Bundle to store this WebView's state
return
the same copy of the back/forward list used to save the state. If
saveState fails, the returned list will be null.
checkThread();
if (TRACE) Log.d(LOGTAG, "saveState");
return mProvider.saveState(outState);
basename the filename where the archive should be placed
param
autoname 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.
param
callback 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.
checkThread();
if (TRACE) Log.d(LOGTAG, "saveWebArchive(auto)=" + basename);
mProvider.saveWebArchive(basename, autoname, callback);
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.
Stores HTTP authentication credentials for a given host and realm. This
method is intended to be used with
{@link WebViewClient#onReceivedHttpAuthRequest}.
Sets the initial scale for this WebView. 0 means default.
The behavior for the default scale depends on the state of
{@link WebSettings#getUseWideViewPort()} and
{@link WebSettings#getLoadWithOverviewMode()}.
If the content fits into the WebView control by width, then
the zoom is set to 100%. For wide content, the behavor
depends on the state of {@link WebSettings#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.
param
scaleInPercent the initial scale in percent
checkThread();
if (TRACE) Log.d(LOGTAG, "setInitialScale=" + scaleInPercent);
mProvider.setInitialScale(scaleInPercent);
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
param
networkUp a boolean indicating if network is available
checkThread();
if (TRACE) Log.d(LOGTAG, "setNetworkAvailable=" + networkUp);
mProvider.setNetworkAvailable(networkUp);
super.setOverScrollMode(mode);
// This method may be called in the constructor chain, before the WebView provider is
// created.
ensureProviderCreated();
mProvider.getViewDelegate().setOverScrollMode(mode);
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.
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.
Starts an ActionMode for finding text in this WebView. Only works if this
WebView is attached to the view system.
param
text 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.
param
showIme if true, show the IME, assuming the user will begin typing.
If false and text is non-null, perform a find all.
return
true if the find dialog is shown, false otherwise
deprecated
This method does not work reliably on all Android versions;
implementing a custom find dialog using WebView.findAllAsync()
provides a more robust solution.
checkThread();
if (TRACE) Log.d(LOGTAG, "showFindDialog");
return mProvider.showFindDialog(text, showIme);
public void
stopLoading()
Stops the current load.
checkThread();
if (TRACE) Log.d(LOGTAG, "stopLoading");
mProvider.stopLoading();
zoomFactor 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.
checkThread();
if (zoomFactor < 0.01)
throw new IllegalArgumentException("zoomFactor must be greater than 0.01.");
if (zoomFactor > 100.0)
throw new IllegalArgumentException("zoomFactor must be less than 100.");
mProvider.zoomBy(zoomFactor);
