Package org.eclipse.swt.browser

Class BrowserFunction

java.lang.Object

org.eclipse.swt.browser.BrowserFunction

public class BrowserFunction
extends Object

Instances of this class represent java-side "functions" that are invokable from javascript. Browser clients define these functions by subclassing BrowserFunction and overriding its function(Object[]) method. This method will be invoked whenever javascript running in the Browser makes a call with the function's name.

Application code must explicitly invoke the BrowserFunction.dispose() method to release the resources managed by each instance when those instances are no longer required. Since there is usually a correlation between the registering of BrowserFunction(s) in a Browser and the loading of a page in the Browser that is aware of these functions, the LocationListener.changed() listener is often a good place to do this.

Note that disposing a Browser automatically disposes all BrowserFunctions associated with it.

Since:

3.5

See Also:

• dispose()
• function(Object[])
• LocationListener.changed(LocationEvent)

Constructor Summary

Constructors

Constructor	Description
BrowserFunction(Browser browser, String name)	Constructs a new instance of this class, which will be invokable by javascript running in the specified Browser.
BrowserFunction(Browser browser, String name, boolean top, String[] frameNames)	Constructs a new instance of this class, which will be invokable by javascript running in the specified Browser.

Method Summary

Modifier and Type	Method	Description
void	dispose()	Disposes of the resources associated with this BrowserFunction.
Object	function(Object[] arguments)	Subclasses should override this method.
Browser	getBrowser()	Returns the Browser whose pages can invoke this BrowserFunction.
String	getName()	Returns the name that javascript can use to invoke this BrowserFunction.
boolean	isDisposed()	Returns true if this BrowserFunction has been disposed and false otherwise.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

BrowserFunction

public BrowserFunction(Browser browser,
 String name)

Constructs a new instance of this class, which will be invokable by javascript running in the specified Browser. The function will be accessible in the top-level window and all child frames. To create a function with a reduced scope of accessibility use the BrowserFunction constructor that accepts frame names instead.

You must dispose the BrowserFunction when it is no longer required. A common place to do this is in a LocationListener.changed() listener.

Parameters:

browser - the browser whose javascript can invoke this function

name - the name that javascript will use to invoke this function

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the browser is null
• ERROR_NULL_ARGUMENT - if the name is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the browser has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

• dispose()
• BrowserFunction(Browser, String, boolean, String[])
• LocationListener.changed(LocationEvent)

BrowserFunction

public BrowserFunction(Browser browser,
 String name,
 boolean top,
 String[] frameNames)

Constructs a new instance of this class, which will be invokable by javascript running in the specified Browser. The accessibility of the function to the top-level window and its child frames is determined by the top and frameNames arguments. To create a function that is globally accessible to the top-level window and all child frames use the BrowserFunction constructor that does not accept frame names instead.

You must dispose the BrowserFunction when it is no longer required. A common place to do this is in a LocationListener.changed() listener.

Parameters:

browser - the browser whose javascript can invoke this function

name - the name that javascript will use to invoke this function

top - true if the function should be accessible to the top-level window and false otherwise

frameNames - the names of the child frames that the function should be accessible in

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the browser is null
• ERROR_NULL_ARGUMENT - if the name is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the browser has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

Since:

3.8

See Also:

• dispose()
• BrowserFunction(Browser, String)
• LocationListener.changed(LocationEvent)

Method Details

dispose

public void dispose()

Disposes of the resources associated with this BrowserFunction. Applications must dispose of all BrowserFunctions that they create.

Note that disposing a Browser automatically disposes all BrowserFunctions associated with it.

function

public Object function(Object[] arguments)

Subclasses should override this method. This method is invoked when the receiver's function is called from javascript. If all of the arguments that are passed to the javascript function call are of supported types then this method is invoked with the argument values converted as follows: javascript null or undefined -> null javascript number -> java.lang.Double javascript string -> java.lang.String javascript boolean -> java.lang.Boolean javascript array whose elements are all of supported types -> java.lang.Object[] If any of the javascript arguments are of unsupported types then the function invocation will fail and this method will not be called. This method must return a value with one of these supported java types to the javascript caller. Note that null values are converted to javascript's null value (not undefined), and instances of any java.lang.Number subclass will be converted to a javascript number.

Parameters:

arguments - the javascript arguments converted to java equivalents

Returns:

the value to return to the javascript caller

Throws:

SWTException -

• ERROR_THREAD_INVALID_ACCESS when called from the wrong thread
• ERROR_FUNCTION_DISPOSED when the BrowserFunction has been disposed

getBrowser

public Browser getBrowser()

Returns the Browser whose pages can invoke this BrowserFunction.

Returns:

the Browser associated with this BrowserFunction

Throws:

SWTException -

• ERROR_THREAD_INVALID_ACCESS when called from the wrong thread
• ERROR_FUNCTION_DISPOSED when the BrowserFunction has been disposed

getName

public String getName()

Returns the name that javascript can use to invoke this BrowserFunction.

Returns:

the BrowserFunction's name

Throws:

SWTException -

• ERROR_THREAD_INVALID_ACCESS when called from the wrong thread
• ERROR_FUNCTION_DISPOSED when the BrowserFunction has been disposed

isDisposed

public boolean isDisposed()

Returns true if this BrowserFunction has been disposed and false otherwise.

This method gets the dispose state for the BrowserFunction. When a BrowserFunction has been disposed it is an error to invoke any of its methods.

Note that disposing a Browser automatically disposes all BrowserFunctions associated with it.

Returns:

true if this BrowserFunction has been disposed and false otherwise