package com.gwt.sample.stockexchange.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.user.client.Window;
import java.util.ArrayList;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Random;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.i18n.client.DateTimeFormat;
import java.util.Date;
/**
* Entry point classes define onModuleLoad().
*/
public class StockExchange implements EntryPoint {
private VerticalPanel mainPanel = new VerticalPanel();
private FlexTable stocksFlexTable = new FlexTable();
private HorizontalPanel addPanel = new HorizontalPanel();
private TextBox newSymbolTextBox = new TextBox();
private Button addStockButton = new Button("Add");
private Label lastUpdatedLabel = new Label();
private ArrayList stocks = new ArrayList();
private static final int REFRESH_INTERVAL = 5000; // m
/**
* This is the entry point method.
*/
public void onModuleLoad() {
stocksFlexTable.setText(0, 0, "Symbol");
stocksFlexTable.setText(0, 1, "Price");
stocksFlexTable.setText(0, 2, "Change");
stocksFlexTable.setText(0, 3, "Remove");
// Assemble Add Stock panel.
addPanel.add(newSymbolTextBox);
addPanel.add(addStockButton);
// Assemble Main panel.
mainPanel.add(stocksFlexTable);
mainPanel.add(addPanel);
mainPanel.add(lastUpdatedLabel);
// Associate the Main panel with the HTML host page.
RootPanel.get("stockList").add(mainPanel);
// Move cursor focus to the input box.
newSymbolTextBox.setFocus(true);
// Setup timer to refresh list automatically.
Timer refreshTimer = new Timer() {
@Override
public void run() {
refreshWatchList();
}
};
refreshTimer.scheduleRepeating(REFRESH_INTERVAL)
// Listen for mouse events on the Add button.
addStockButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
addStock();
}
});
// Listen for keyboard events in the input box.
newSymbolTextBox.addKeyDownHandler(new KeyDownHandler() {
public void onKeyDown(KeyDownEvent event) {
if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
addStock();
}
}
});
}
/**
* Add stock to FlexTable. Executed when the user clicks the addStockButton or
* presses enter in the newSymbolTextBox.
*/
private void addStock() {
final String symbol = newSymbolTextBox.getText().toUpperCase().trim();
newSymbolTextBox.setFocus(true);
// Stock code must be between 1 and 10 chars that are numbers, letters, or dots.
if (!symbol.matches("^[0-9A-Z\\.]{1,10}$")) {
Window.alert("'" + symbol + "' is not a valid symbol.");
newSymbolTextBox.selectAll();
return;
}
newSymbolTextBox.setText("");
// Don't add the stock if it's already in the table.
if (stocks.contains(symbol))
return;
// Add the stock to the table.
int row = stocksFlexTable.getRowCount();
stocks.add(symbol);
stocksFlexTable.setText(row, 0, symbol);
// Add a button to remove this stock from the table.
Button removeStockButton = new Button("x");
removeStockButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
int removedIndex = stocks.indexOf(symbol);
stocks.remove(removedIndex);
stocksFlexTable.removeRow(removedIndex + 1);
}
});
stocksFlexTable.setWidget(row, 3, removeStockButton);
// Get the stock price.
refreshWatchList();
}
private void refreshWatchList() {
final double MAX_PRICE = 100.0; // $100.00
final double MAX_PRICE_CHANGE = 0.02; // +/- 2%
StockPrice[] prices = new StockPrice[stocks.size()];
for (int i = 0; i < stocks.size(); i++) {
double price = Random.nextDouble() * MAX_PRICE;
double change = price * MAX_PRICE_CHANGE
* (Random.nextDouble() * 2.0 - 1.0);
prices[i] = new StockPrice(stocks.get(i), price, change);
}
updateTable(prices);
}
private void updateTable(StockPrice[] prices) {
for (int i = 0; i < prices.length; i++) {
updateTable(prices[i]);
}
// Display timestamp showing last refresh.
DateTimeFormat dateFormat = DateTimeFormat.getFormat(
DateTimeFormat.PredefinedFormat.DATE_TIME_MEDIUM);
lastUpdatedLabel.setText("Last update : "
+ dateFormat.format(new Date()));
}
private void updateTable(StockPrice price) {
// Make sure the stock is still in the stock table.
if (!stocks.contains(price.getSymbol())) {
return;
}
int row = stocks.indexOf(price.getSymbol()) + 1;
// Format the data in the Price and Change fields.
String priceText = NumberFormat.getFormat("#,##0.00").format(
price.getPrice());
NumberFormat changeFormat = NumberFormat.getFormat("+#,##0.00;-#,##0.00");
String changeText = changeFormat.format(price.getChange());
String changePercentText = changeFormat.format(price.getChangePercent());
// Populate the Price and Change fields with new data.
stocksFlexTable.setText(row, 1, priceText);
stocksFlexTable.setText(row, 2, changeText + " (" + changePercentText
+ "%)");
}
}
StockPrice.java
package com.gwt.sample.stockexchange.client;
public class StockPrice {
private String symbol;
private double price;
private double change;
public StockPrice() {
}
public StockPrice(String symbol, double price, double change) {
this.symbol = symbol;
this.price = price;
this.change = change;
}
public String getSymbol() {
return this.symbol;
}
public double getPrice() {
return this.price;
}
public double getChange() {
return this.change;
}
public double getChangePercent() {
return 10.0 * this.change / this.price;
}
public void setSymbol(String symbol) {
this.symbol = symbol;
}
public void setPrice(double price) {
this.price = price;
}
public void setChange(double change) {
this.change = change;
}
}
