org.gwtwidgets.client.stream
Class HtmlStreamReader

java.lang.Object
  org.gwtwidgets.client.stream.HtmlStreamReader

public class HtmlStreamReader
extends java.lang.Object

Decodes SL stream protocol messages sent via the HtmlSLStreamWriterImpl. This implementation creates an invisible IFrame which is appended to the current document and polled in intervals. Decoded messages are then removed from the DOM in order to reduce resource consumption.

Author:

George Georgovassilis, g.georgovassilis[at]gmail.com

Field Summary

protected java.util.Date	dateOfCreation
protected com.google.gwt.dom.client.IFrameElement	frame
protected int	lastMessageId
protected long	maxAge
protected long	pollingInterval
protected com.google.gwt.user.client.Timer	timer

Constructor Summary

HtmlStreamReader()

Method Summary

void	close() Should be called if the client wants to close the stream communication with the server.
protected com.google.gwt.dom.client.Element	getFrame()
protected com.google.gwt.dom.client.Document	getFrameContents(com.google.gwt.dom.client.IFrameElement frame)
long	getPollingInterval()
void	readAsync(java.lang.String url, StreamCallback callback) Connects to a URL an starts streaming messages from there.
protected Message	readNextMessage()
protected void	reconnect(java.lang.String url, StreamCallback callback)
void	setInnerFrameVisibility(boolean status) For debugging purposes, can be used to show the IFrame used to receive server messages.
void	setMaxAge(long maxAge) Determines the age (in ms) of a connection to a server before closing and refreshing it
void	setPollingInterval(long pollingInterval) Sets a polling interval - messages arriving from the server will be decoded every such interval.

Methods inherited from class java.lang.Object

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

Field Detail

frame

protected com.google.gwt.dom.client.IFrameElement frame

pollingInterval

protected long pollingInterval

maxAge

protected long maxAge

timer

protected com.google.gwt.user.client.Timer timer

dateOfCreation

protected java.util.Date dateOfCreation

lastMessageId

protected int lastMessageId

Constructor Detail

HtmlStreamReader

public HtmlStreamReader()

Method Detail

getFrameContents

protected com.google.gwt.dom.client.Document getFrameContents(com.google.gwt.dom.client.IFrameElement frame)

readNextMessage

protected Message readNextMessage()

getPollingInterval

public long getPollingInterval()

setPollingInterval

public void setPollingInterval(long pollingInterval)

Sets a polling interval - messages arriving from the server will be decoded every such interval. Please note that this parameter is passed to Timer.schedule(int) which receives an integer argument; hence large values for pollingInterval will not yield the desired behavior.

Parameters:

pollingInterval - Polling interval in milliseconds

getFrame

protected com.google.gwt.dom.client.Element getFrame()

setInnerFrameVisibility

public void setInnerFrameVisibility(boolean status)

For debugging purposes, can be used to show the IFrame used to receive server messages.

Parameters:

status -

readAsync

public void readAsync(java.lang.String url,
                      StreamCallback callback)

Connects to a URL an starts streaming messages from there. Note that despite this being an asynchronous message, the HtmlStreamReader is a stateful object which cannot be used to simultaneously access more resources.

Parameters:

url -

callback -

reconnect

protected void reconnect(java.lang.String url,
                         StreamCallback callback)

close

public void close()

Should be called if the client wants to close the stream communication with the server.

setMaxAge

public void setMaxAge(long maxAge)

Determines the age (in ms) of a connection to a server before closing and refreshing it

Parameters:

maxAge -