/*
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
import java.applet.*;
import java.awt.*;
import java.util.Enumeration;

public class Sender extends Applet {
    private String myName;
    private TextField nameField;
    private TextArea status;

    public void init() {
	GridBagLayout gridBag = new GridBagLayout();
	GridBagConstraints c = new GridBagConstraints();

	setLayout(gridBag);

	Label receiverLabel = new Label("Receiver name:", Label.RIGHT);
	gridBag.setConstraints(receiverLabel, c);
	add(receiverLabel);

	nameField = new TextField(getParameter("RECEIVERNAME"), 10);
	c.fill = GridBagConstraints.HORIZONTAL;
	gridBag.setConstraints(nameField, c);
	add(nameField);

	Button button = new Button("Send message");
	c.gridwidth = GridBagConstraints.REMAINDER; //end row
	c.anchor = GridBagConstraints.WEST; //stick to the text field
	c.fill = GridBagConstraints.NONE; //keep the button small
	gridBag.setConstraints(button, c);
	add(button);

	status = new TextArea(5, 60);
	status.setEditable(false);
	c.anchor = GridBagConstraints.CENTER; //reset to the default
	c.fill = GridBagConstraints.BOTH; //make this big
	c.weightx = 1.0;
	c.weighty = 1.0;
	gridBag.setConstraints(status, c);
	add(status);

	myName = getParameter("NAME");
	Label senderLabel = new Label("(My name is " + myName + ".)", 
				Label.CENTER);
	c.weightx = 0.0;
	c.weighty = 0.0;
	gridBag.setConstraints(senderLabel, c);
	add(senderLabel);

	validate();
    }

    public boolean action(Event event, Object o) {
	Applet receiver = null;
	String receiverName = nameField.getText();
	receiver = getAppletContext().getApplet(receiverName);
	if (receiver != null) {
	    if (!(receiver instanceof Receiver)) {
	        status.appendText("Found applet named "
				  + receiverName + ", "
				  + "but it's not a Receiver object.\n");
	    } else {
	        status.appendText("Found applet named "
				  + receiverName + ".\n"
	        		  + "  Sending message to it.\n");
	        ((Receiver)receiver).processRequestFrom(myName);
	    }
	} else {
	    status.appendText("Couldn't find any applet named "
			      + receiverName + ".\n"
		       	      + "  Searching all applets on page "
			      + "for a Receiver.\n");
	    searchAllApplets();
	}
	status.selectAll();
	int n = status.getSelectionEnd();
	status.select(n,n);
	return false;

    }

    public Insets insets() {
	return new Insets(3,3,3,3);
    }

    public void paint(Graphics g) {
	g.drawRect(0, 0, size().width - 1, size().height - 1);
    }

    public String getAppletInfo() {
	return "Sender by Kathy Walrath";
    }

    public void searchAllApplets() {
        Enumeration appletList = getAppletContext().getApplets();
	boolean foundReceiver = false;

        while (appletList.hasMoreElements() && !foundReceiver) {
            Applet applet = (Applet)appletList.nextElement();
	    if (applet instanceof Receiver) {
	        status.appendText("  Found Receiver applet.\n"
				  + "  Sending message to it.\n");
	
	        ((Receiver)applet).processRequestFrom(myName);
	    }
        }
    }
}