/*
* Copyright (c) 1996,1997,1998,1999
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
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* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
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*
* This software is not designed or intended for use in on-line control of
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*/
package examples.stock;
import java.applet.Applet;
import java.awt.*;
import java.net.URL;
import java.rmi.*;
import java.rmi.server.*;
import java.util.*;
/**
* The StockApplet exports a remote object, and contacts the StockWatch
* server to register interest in receiving stock updates. The applet
* displays the updates in a graph format.
*/
public class StockApplet extends Applet
implements StockNotify, java.io.Serializable
{
/** maximum number of updates displayed */
static final int MAX_UPDATES = 34;
/** maximum width of panel */
private static final int width = 500;
/** maximum height of panel */
private static final int height = 350;
/** vector containing time of each update */
private Vector time = null;
/** vector to hold references to checkboxes */
private Vector checkboxes = null;
/** table mapping stock names to stock data */
private Hashtable stockTable = null;
/** reference to StockWatch server */
private StockWatch stockWatch = null;
private static String name[] = { "Sun", "HP", "Microsoft", "Compaq", "Novell",
"IBM", "Apple", "AOL", "Inprise", "SGI"};
private Color color[]= { new Color(205,92,92),
Color.orange,
new Color(220,220,90),
new Color(85, 107, 47),
Color.blue,
new Color(160,32,240),
new Color(238, 130, 238),
Color.black,
new Color(205,120,92),
new Color(0,100,0) };
/**
* Notification of stock updates for a particular time.
* @param date the time of the stock update
* @param stocks an array containing the stocks for which the
* object has registered interest.
*/
public synchronized void update (Date date, Stock[] stock)
{
System.out.println("StockApplet.update: " + date);
// record date
if (time.size() == MAX_UPDATES) {
time.removeElementAt(0);
}
time.addElement(date);
// record individual stock updates
int numUpdates = time.size();
for (int i=0; i<stock.length; i++) {
StockData data = (StockData)stockTable.get(stock[i].symbol);
if (data != null) {
data.update(stock[i], numUpdates);
}
}
repaint();
}
/**
* Initialize applet: export the applet as a remote object that
* gets notified of stock updates.
*/
public void init()
{
// record export exception
Exception ee = null;
try {
// initialize applet fields here to properly handle a restart
synchronized (this) {
time = new Vector(MAX_UPDATES);
stockTable = new Hashtable();
stockWatch = null;
}
// export the applet as a remote object
System.out.println("StockApplet.init: exporting remote object");
try {
UnicastRemoteObject.exportObject(this);
ee = null;
} catch (java.rmi.server.ExportException e) {
// use already exported object; remember exception
ee = e;
}
// lookup StockWatch server
URL base = getDocumentBase();
String serverName = "//" + base.getHost() + ":" +
getParameter("registryPort") + "/example.stock.StockServer";
System.out.println("StockApplet.init: looking up server");
stockWatch = (StockWatch)Naming.lookup(serverName);
// register interest in receiving stock updates
for (int i=0; i<name.length; i++) {
System.out.println("StockApplet.init: watch stock " + name[i]);
stockWatch.watch(name[i], this);
stockTable.put(name[i], new StockData(name[i], color[i]));
}
System.out.println("StockApplet.init: done registering stocks");
} catch (Exception e) {
add(new Label("exception occurred during initialization; " +
"check the log"));
add(new Label(e.getClass().getName() + ": " + e.getMessage()));
// fatal error
System.out.println("got exception: " + e.getMessage());
e.printStackTrace();
return;
}
setLayout(null);
// clean up after previous run, remove old checkboxes
if ((ee != null) && (checkboxes != null)) {
Enumeration oldCheckboxes = checkboxes.elements();
while (oldCheckboxes.hasMoreElements()) {
SensitiveCheckbox cb = (SensitiveCheckbox)
oldCheckboxes.nextElement();
remove(cb);
}
}
// draw checkboxes
checkboxes = new Vector();
Enumeration enum = stockTable.elements();
int i=0;
while (enum.hasMoreElements()) {
StockData data = (StockData)enum.nextElement();
SensitiveCheckbox cb = new SensitiveCheckbox (data, this);
data.cb = cb;
checkboxes.add(cb);
add(cb);
cb.setState(data.displayed);
cb.reshape(10,i++*25+35,110,18);
}
}
/**
* Called when applet is destroyed; the applet cancels all
* requests for stock updates.
*/
public void destroy()
{
// cancel request for stock updates
if (stockWatch != null) {
try {
stockWatch.cancelAll(this);
} catch (Exception e) {
// eat exception
}
}
}
/**
* Called to repaint the panel.
*/
public void paint(Graphics g) {
// draw black boarder
g.setColor(Color.black);
g.drawRect(0,0,width-1,height-1);
float miny = 0.0f;
float maxy = 75.0f;
// draw all stock data
Enumeration enum = stockTable.elements();
while (enum.hasMoreElements()) {
StockData data = (StockData)enum.nextElement();
int size;
Stock[] updates;
synchronized (data.updates) {
size = data.updates.size();
updates = new Stock[size];
data.updates.copyInto(updates);
}
g.setColor(data.color);
if (data.displayed) {
// draw box around checkbox if mouse is over it
if (data.cb != null && data.cb.haveMouse()) {
Point p = data.cb.location();
Dimension d = data.cb.size();
g.drawRect(p.x-1, p.y-1, d.width+4, d.height+4);
g.drawRect(p.x-2, p.y-2, d.width+4, d.height+4);
// point to graph for stock
if (size > 0)
g.drawLine(p.x+d.width+2,p.y+10,150,
scale(updates[0].current));
}
// draw graph of updates for this stock
int x = 150, inc = 10;
for (int i = 0; i < size; i++) {
if (updates[i] != null) {
g.drawRect(x-1,scale(updates[i].current)-1,3,3);
if ((i < size - 1) && updates[i + 1] != null) {
int x2 = x + inc;
g.drawLine(x, scale(updates[i].current), x2,
scale(updates[i + 1].current));
}
}
x += inc;
}
}
}
}
/**
* Used to scale y-values.
*/
int scale(float y) {
return height - (int) (y*5+.5);
}
/**
* Make sure that mouseHere is set properly (fix for windows
* display problems).
*/
void setMouseHere(boolean display)
{
Enumeration enum = stockTable.elements();
while (enum.hasMoreElements()) {
StockData data = (StockData)enum.nextElement();
data.cb.mouseHere = display;
}
}
/**
* StockData contains stock updates and display information.
*/
static class StockData {
public String name;
public Vector updates;
public Color color;
public boolean displayed;
public SensitiveCheckbox cb;
public StockData(String name, Color cl) {
this.name = name;
this.color = cl;
this.updates = new Vector(StockApplet.MAX_UPDATES);
displayed = true;
}
/**
* Update stock.
*/
void update(Stock stock, int numUpdates) {
synchronized (updates) {
if (updates.size() == StockApplet.MAX_UPDATES) {
updates.removeElementAt(0);
}
// If this stock has not received updates for previous timeslices,
// fill them in with the current update value as well.
if (updates.size() < numUpdates) {
for (int i=updates.size(); i<numUpdates-1; i++) {
updates.addElement(stock);
}
}
updates.addElement(stock);
}
}
}
/**
* A mouse-sensitive checkbox that records whether the mouse is over
* the checkbox.
*/
static class SensitiveCheckbox extends Canvas {
StockData data;
boolean state = true;
StockApplet panel;
boolean mouseHere = false;
public boolean haveMouse() {
return mouseHere;
}
public SensitiveCheckbox(StockData data, StockApplet p) {
this.data = data;
panel = p;
}
public boolean mouseEnter(Event evt, int x, int y) {
if (state) {
panel.setMouseHere(false); // for windows
mouseHere = true;
panel.repaint();
}
return false;
}
public boolean mouseExit(Event evt, int x, int y) {
if (state) {
mouseHere = false;
panel.repaint();
}
return false;
}
public boolean mouseDown(Event evt, int x, int y) {
if (state)
state = false;
else
state = true;
mouseHere=state;
data.displayed = state;
repaint();
panel.repaint();
return true;
}
public void paint(Graphics g) {
g.setColor(Color.black);
g.drawLine(4,4,14,4);
g.drawLine(4,4,4,14);
g.setColor(Color.gray);
g.drawLine(5,14,14,14);
g.drawLine(14,5,14,14);
g.setColor(data.color);
g.fillRect(5,5,8,8);
g.setColor(data.color);
g.drawString(data.name, 17,15);
g.setColor(Color.black);
if (state) {
if (data.color == Color.black)
g.setColor(Color.gray);
if (data.color == Color.blue)
g.setColor(Color.gray);
g.drawLine(5,5,13,13);
g.drawLine(5,6,12,13);
g.drawLine(13,5,5,13);
g.drawLine(13,6,6,13);
}
}
public void setState(boolean s) {
state = s;
repaint();
}
}
}
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