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/*
* VRwavePlugin.java
* Netscape Plugin wrapper around VRwave
*
* created: mpichler, 19970812
*
* changed: mpichler, 19970924
*
* $Id: VRwavePlugin.java,v 1.8 1997/09/24 15:26:26 mpichler Exp $
*/
import netscape.plugin.Plugin; // moz3_0.zip
import java.net.URL;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import iicm.vrml.vrwave.*; // VRwave core classes
import vrml.external.Browser; // Java-EAI
/**
* depending on whether Browser already extends Plugin or not,
* VRwavePlugin has to extend Browser or Plugin. In the first case,
* Browser location via JavaScript code will work too, otherwise only
* the clean interface of Browser.getBrowser will do so.
*/
public class VRwavePlugin extends Browser /*Plugin*/
{
Scene scene_; // my scene
SceneFrame sceneframe_;
PipedInputStream pin_; // to read data out of the pipe
PipedOutputStream pout_; // to write data into the pipe
Thread rthread_; // reader thread (parsing)
VRwaveReader vrreader_;
static final boolean DEBUG = true;
/**
* initialize plug-in instance: start VRwave
*/
public void init ()
{
System.out.println (VRwave.STARTUP);
if (DEBUG)
System.err.println ("Plugin.init was called");
try
{
scene_ = new Scene (null);
// TODO: where to load properties from?
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
}
} // init
/**
* create scene frame
* @param home VRWAVE_HOME to load icons.gif (later also font files etc.)
*/
void createSceneFrame (String home)
{
try
{
VRwave.setHome ("file:" + home); // must read from URL instead of file
sceneframe_ = new SceneFrame ("VRwave", scene_, true); // shows itself
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
}
} // createSceneFrame
/**
* plug-in gets unloaded: quit VRwave
*/
public void destroy ()
{
if (DEBUG)
System.err.println ("Plugin.destroy was called");
if (rthread_ != null && rthread_.isAlive ())
{
if (DEBUG)
System.err.println ("stopping reader thread");
rthread_.stop ();
}
if (scene_ != null)
{
try
{
if (DEBUG)
System.err.println ("clearScene");
Browser.stopVRwave (scene_);
scene_.clearScene (); // stop all scene activity
if (sceneframe_ != null)
{
if (sceneframe_.isVisible ())
sceneframe_.hide ();
sceneframe_.dispose (); // free frame resources
}
if (DEBUG)
System.err.println ("Frame closed");
scene_ = null;
sceneframe_ = null;
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
}
}
} // destroy
/**
* start a thread to read streamed data.
*/
public void startReading (String baseurl)
{
try
{
pin_ = new PipedInputStream ();
pout_ = new PipedOutputStream (pin_);
rthread_ = new Thread (vrreader_ = new VRwaveReader (scene_, pin_, baseurl));
rthread_.start ();
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
}
}
/**
* called when input is complete or to abort reading.
*/
public void dataComplete ()
{
try
{
pout_.close ();
// data are complete sent in pipe, parsing of buffered data has not yet finished
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
}
// reader thread is not stopped here - give parser time to complete,
// will complain about premature EOF itself when data is incomplete
}
/**
* tell how many bytes can be read by readData without blocking.
* only valid between startReading and dataComplete calls.
*/
public int readableData ()
{
// PipedIOStreams have no method to get this information.
// following code assumes a buffer size of at least 1024
// which the PipedInputStream can fill without blocking.
// method currently not unused.
try
{
int inbuf = pin_.available (); // >= 0
if (inbuf > 1024) // oops
return 0;
return (1024 - inbuf);
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
return 0;
}
} // readableData
/**
* read some chunk of data (by writing it into the pipe).
* only valid between startReading and dataComplete calls.
* be very careful not to lock netscape in this method.
*/
public void readData (byte[] data, int len)
{
try
{
if (scene_ != null && vrreader_ != null && vrreader_.acceptdata_)
pout_.write (data, 0, len);
}
catch (Throwable t)
{
System.err.println ("Error: " + t);
}
}
} // VRwavePlugin
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