package com.google.gwt.sample.stockwatcher.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
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.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import java.util.ArrayList;
import java.util.Date;
public class StockWatcher implements EntryPoint {
private static final int REFRESH_INTERVAL = 5000; // ms
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<String> stocks = new ArrayList<String>();
private StockPriceServiceAsync stockPriceSvc = GWT.create(StockPriceService.class);
private Label errorMsgLabel = new Label();
/**
* Entry point method.
*/
public void onModuleLoad() {
// Create table for stock data.
stocksFlexTable.setText(0, 0, "Symbol");
stocksFlexTable.setText(0, 1, "Price");
stocksFlexTable.setText(0, 2, "Change");
stocksFlexTable.setText(0, 3, "Remove");
// Add styles to elements in the stock list table.
stocksFlexTable.setCellPadding(6);
stocksFlexTable.getRowFormatter().addStyleName(0, "watchListHeader");
stocksFlexTable.addStyleName("watchList");
stocksFlexTable.getCellFormatter().addStyleName(0, 1, "watchListNumericColumn");
stocksFlexTable.getCellFormatter().addStyleName(0, 2, "watchListNumericColumn");
stocksFlexTable.getCellFormatter().addStyleName(0, 3, "watchListRemoveColumn");
// Assemble Add Stock panel.
addPanel.add(newSymbolTextBox);
addPanel.add(addStockButton);
addPanel.addStyleName("addPanel");
// Assemble Main panel.
errorMsgLabel.setStyleName("errorMessage");
errorMsgLabel.setVisible(false);
mainPanel.add(errorMsgLabel);
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.addKeyPressHandler(new KeyPressHandler() {
public void onKeyPress(KeyPressEvent event) {
if (event.getCharCode() == 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-zA-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);
stocksFlexTable.setWidget(row, 2, new Label());
stocksFlexTable.getCellFormatter().addStyleName(row, 1, "watchListNumericColumn");
stocksFlexTable.getCellFormatter().addStyleName(row, 2, "watchListNumericColumn");
stocksFlexTable.getCellFormatter().addStyleName(row, 3, "watchListRemoveColumn");
// Add a button to remove this stock from the table.
Button removeStockButton = new Button("x");
removeStockButton.addStyleDependentName("remove");
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();
}
/**
* Generate random stock prices.
*/
private void refreshWatchList() {
// Initialize the service proxy.
if (stockPriceSvc == null) {
stockPriceSvc = GWT.create(StockPriceService.class);
}
// Set up the callback object.
AsyncCallback<StockPrice[]> callback = new AsyncCallback<StockPrice[]>() {
public void onFailure(Throwable caught) {
// If the stock code is in the list of delisted codes, display an error message.
String details = caught.getMessage();
if (caught instanceof DelistedException) {
details = "Company '" + ((DelistedException)caught).getSymbol() + "' was delisted";
}
else if ( caught instanceof ServiceUnavailableException ) {
details = "Stock updates temporarily unavailable";
}
errorMsgLabel.setText("Error: " + details);
errorMsgLabel.setVisible(true);
}
public void onSuccess(StockPrice[] result) {
updateTable(result);
}
};
// Make the call to the stock price service.
stockPriceSvc.getPrices(stocks.toArray(new String[0]), callback);
}
/**
* Update the Price and Change fields all the rows in the stock table.
*
* @param prices Stock data for all rows.
*/
private void updateTable(StockPrice[] prices) {
for (int i = 0; i < prices.length; i++) {
updateTable(prices[i]);
}
// Display timestamp showing last refresh.
lastUpdatedLabel.setText("Last update : "
+ DateTimeFormat.getMediumDateTimeFormat().format(new Date()));
// Clear any errors.
errorMsgLabel.setVisible(false);
}
/**
* Update a single row in the stock table.
*
* @param price Stock data for a single row.
*/
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);
Label changeWidget = (Label)stocksFlexTable.getWidget(row, 2);
changeWidget.setText(changeText + " (" + changePercentText + "%)");
// Change the color of text in the Change field based on its value.
String changeStyleName = "noChange";
if (price.getChangePercent() < -0.1f) {
changeStyleName = "negativeChange";
}
else if (price.getChangePercent() > 0.1f) {
changeStyleName = "positiveChange";
}
changeWidget.setStyleName(changeStyleName);
}
}