protected override void BeforeClientNotification(RetrieverDoneArgs rda)
{
// A WMS server object is created here because doing so causes the
// returned WMS capabilities description to be parsed. During that
// parsing, schema or DTD URIs might be invoked by the parser, which
// will cause additional http requests to be sent to the net. We
// want all that to go on in the worker thread, so that the client
// thread won't have to block waiting for them to occur in the UI
// thread.
rda.destinationObject = new Server(rda.DestinationFile);
}
private void onContentReady(System.Object sender, RetrieverDoneArgs ea)
{
// This function is called on the UI thread when a message is sent
// from the worker thread. It merely invokes any listeners and then
// terminates the retrieval request.
if (this.monitor.Enabled)
{
this.monitor.Stop();
}
if (this.done != null)
{
this.done(this, ea);
}
this.endRequest();
}
private void monitorTick(System.Object sender, System.EventArgs ea)
{
if (this.state != RetrieverState.Retrieving)
{
return;
}
if (this.canceled)
{
this.endRequest();
return;
}
System.TimeSpan span = System.DateTime.Now - this.startTime;
if (span > this.timeoutInterval)
{
this.endRequest();
if (this.done != null)
{
RetrieverDoneArgs pda = new RetrieverDoneArgs(this);
pda.reason = RetrieverDoneArgs.CompletionReason.TimedOut;
this.done(this, pda);
}
return;
}
span = System.DateTime.Now - this.previousProgressTime;
if (span > this.progressInterval)
{
if (this.progress != null)
{
RetrieverProgressArgs pea = new RetrieverProgressArgs(this);
this.progress(this, pea);
}
this.previousProgressTime = System.DateTime.Now;
}
}
private void sendMessageToUiThread(RetrieverDoneArgs rda)
{
this.owner.Invoke(
new RetrieverDoneEventHandler(this.onContentReady),
new object[] { System.Threading.Thread.CurrentThread, rda });
}
protected virtual void BeforeClientNotification(RetrieverDoneArgs rda)
{
return; // default implementation returns w/o doing anything.
}
private void onRetrieval(System.IAsyncResult ar)
{
// This function is called by the System.Net.WebRequest class
// on the *worker* thread, not the UI thread.
System.Diagnostics.Debug.Assert(ar.IsCompleted);
System.Net.WebResponse webResponse = null;
try
{
webResponse = this.webRequest.EndGetResponse(ar);
}
catch (System.Net.WebException e)
{
if (e.Status == System.Net.WebExceptionStatus.RequestCanceled)
{
return; // the request was previously cancelled, a normal condition
}
else if (e.Status == System.Net.WebExceptionStatus.Success)
{
// ' Don't really understand this one. Why would an exception be thrown
// if the request worked? Anyway, allow for it.
System.Diagnostics.Debug.Assert(webResponse != null);
}
else
{
// Send the UI thread a message saying an error occurred.
RetrieverDoneArgs erda = new RetrieverDoneArgs(this);
erda.reason = RetrieverDoneArgs.CompletionReason.Error;
erda.Message = e.Message;
this.sendMessageToUiThread(erda);
return;
}
}
string suffixedDestination =
Wms.Client.ExtensionMap.AddSuffixToPath(this.destination, webResponse.ContentType);
try
{
System.IO.Stream rs = webResponse.GetResponseStream();
copyStreamToFile(webResponse.GetResponseStream(), suffixedDestination);
}
catch (System.Exception e)
{
// Send the UI thread a message saying an error occurred.
RetrieverDoneArgs erda = new RetrieverDoneArgs(this);
erda.reason = RetrieverDoneArgs.CompletionReason.Error;
erda.Message = e.Message;
this.sendMessageToUiThread(erda);
return;
}
finally
{
webResponse.Close(); // closes the response stream
}
// Send the UI thread a message saying the file is ready.
RetrieverDoneArgs rda = new RetrieverDoneArgs(this);
rda.destinationFile = suffixedDestination;
rda.contentLength = webResponse.ContentLength;
rda.contentType = webResponse.ContentType;
this.BeforeClientNotification(rda);
this.sendMessageToUiThread(rda);
}
