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// teched.java
// (C) Copyright 1998 by Robert S. Sutor. All rights reserved.
// We first import the classes we need from the standard Java
// distribution. This will work with Java 1.0 or higher.
import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import java.applet.Applet;
// The following brings in the Netscape LiveConnect classes
// that we will use.
import netscape.javascript.JSObject;
// These are the classes that we use that are exposed by
// techexplorer. The first is the basic interface to the
// plug-in. The others are the event and listener classes.
import ibm.techexplorer.plugin.techexplorerPlugin;
import ibm.techexplorer.awt.AWTEvent;
import ibm.techexplorer.awt.event.KeyListener;
import ibm.techexplorer.awt.event.KeyEvent;
public class teched
extends java.applet.Applet
implements KeyListener
{
// The JavaScript window object
JSObject Window = null;
// The JavaScript document object
JSObject Document = null;
// The techexplorer plug-in instance
techexplorerPlugin tePlugin = null;
// The editable text area for the markup source
TextArea markupInputArea = null;
// The 'Clear input' button
Button clearInputButton = null;
// A utility buffer for holding the markup.
StringBuffer markupString = new StringBuffer("");
public boolean action(Event evt, Object arg) {
// We only handle the 'Clear input' action.
boolean result = false;
if ( evt.target == clearInputButton ) {
// Empty the markup edit area.
markupInputArea.setText( "" );
// Reinitialize the techexplorer document. This
// needs to be a non-empty string to actually
// updated the document, so we give it some
// non-visible input.
tePlugin.reloadFromTeXString( "\\(\\)" );
result = true;
}
return result;
}
public void init() {
// Initialize the components we are displaying
// with this Java applet.
clearInputButton = new Button("Clear input");
markupInputArea = new TextArea( 5, 80 );
this.setLayout( new FlowLayout() );
this.add( markupInputArea );
this.add( clearInputButton );
}
public void keyPressed( ibm.techexplorer.awt.event.KeyEvent e ) {
// We don't do anything with this event given us by
// techexplorer. But see 'keyTyped'.
}
public void keyTyped( ibm.techexplorer.awt.event.KeyEvent e ) {
// This is a naive (but effective!) way of dealing with
// keys coming to us from techexplorer. We grab the key
// that was pressed and put it on the end of our markup.
// Then we update the techexplorer window.
if ( e.getSource() == tePlugin ) {
markupInputArea.appendText(
( new Character( e.getKeyChar() )).toString() );
// This replaces the document within the techexplorer
// window with that gotten by parsing the string
// passed to it.
tePlugin.reloadFromTeXString( markupInputArea.getText() );
}
}
public void keyReleased( ibm.techexplorer.awt.event.KeyEvent e ) {
// This is where we deal with key release events coming to
// us from the techexplorer window.
switch ( e.getKeyCode() ) {
case KeyEvent.VK_DELETE:
// When we see a 'delete' key, we remove the last character
// in the markup.
if ( e.getSource() == tePlugin ) {
markupString = new StringBuffer( markupInputArea.getText() );
int length = markupString.length();
if ( length > 0 )
--length;
markupString.setLength( length );
markupInputArea.setText( markupString.toString() );
tePlugin.reloadFromTeXString( markupInputArea.getText() );
}
break;
case KeyEvent.VK_ENTER:
// When we see that the 'enter' key has been pressed, we
// insert a newline in the markup. This improves readability.
if ( e.getSource() == tePlugin ) {
markupInputArea.appendText( "\n" );
tePlugin.reloadFromTeXString( markupInputArea.getText() );
}
break;
default:
break;
}
}
public boolean keyUp( Event evt, int key )
{
// This key is one from the markup input area.
// When a key is released, update the techexplorer
// document with the current markup.
boolean result = false;
if ( evt.target == markupInputArea ) {
if ( evt.id == Event.KEY_RELEASE ) {
int length = markupInputArea.getText().length();
if ( length > 0 )
tePlugin.reloadFromTeXString(
markupInputArea.getText() );
else
tePlugin.reloadFromTeXString( "\\(\\)" );
}
result = true;
}
return result;
}
public void start() {
// Initialize the Netscape JavaScript objects.
Window = (JSObject) JSObject.getWindow(this);
Document = (JSObject) Window.getMember("document");
// Try to get the techexplorer plug-in object.
tePlugin = (techexplorerPlugin) Document.getMember("teInput");
if ( tePlugin == null )
// If we didn't get it, print a debug message.
System.out.println("teched: start(): null teched");
else
// Otherwise add the listener for techexplorer keys.
tePlugin.addKeyListener( (KeyListener) this );
}
public void stop() {
if ( tePlugin == null )
// If we don't have the techexplorer plug-in object,
// print a debug message.
System.out.println("teched: stop(): null teched");
else
// Otherwise remove the listener for techexplorer keys.
tePlugin.removeKeyListener( (KeyListener) this );
}
}
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