com.google.gwt.sample.stockwatcher.client.StockWatcher1.java Source code

Introduction

Here is the source code for com.google.gwt.sample.stockwatcher.client.StockWatcher1.java

Source

package com.google.gwt.sample.stockwatcher.client;

import java.util.ArrayList;
import java.util.Date;

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.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.event.dom.client.StockPrice;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.Random;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
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;

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class StockWatcher1 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<String> stocks = new ArrayList<String>();
    private static final int REFRESH_INTERVAL = 5000;

    /**
     * Entry point method.
     */
    public void onModuleLoad() {
        // TODO 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");
        // 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);

        addStockButton.addClickHandler(new ClickHandler() {

            @Override
            public void onClick(ClickEvent event) {
                addStocks();

            }

        });

        newSymbolTextBox.addKeyPressHandler(new KeyPressHandler() {
            public void onKeyPress(KeyPressEvent event) {
                if (event.getCharCode() == KeyCodes.KEY_ENTER) {
                    addStocks();
                }
            }
        });

    }

    protected 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.
        lastUpdatedLabel.setText("Last update : " + DateTimeFormat.getMediumDateTimeFormat().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 + "%)");

    }

    private void addStocks() {
        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;
        }

        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);

    }
}