hirondelle.stocks.quotes
Class FetchQuotesAction

Object
  AbstractAction
      FetchQuotesAction

All Implemented Interfaces:

ActionListener, Serializable, Cloneable, EventListener, Observer, Action

public final class FetchQuotesAction
extends AbstractAction
implements Observer

Fetch current quote data for the CurrentPortfolio from a data source on the web.

This action is performed at many different times :

• once upon startup
• periodically, at an interval which is configured by the user
• when the end user explicitly requests a refresh of quote info
• when the user makes a change to the current portfolio

This class performs most of its work in a background daemon thread, and uses EventQueue.invokeLater to update the user interface with the result. The user interface remains responsive, regardless of the time taken for its work to complete.

A daemon thread is used since daemon threads do not prevent an application from terminating.

See Also:

Serialized Form

Field Summary

Fields inherited from class AbstractAction

changeSupport, enabled

Fields inherited from interface Action

ACCELERATOR_KEY, ACTION_COMMAND_KEY, DEFAULT, LONG_DESCRIPTION, MNEMONIC_KEY, NAME, SHORT_DESCRIPTION, SMALL_ICON

Constructor Summary

FetchQuotesAction(CurrentPortfolio aCurrentPortfolio, QuoteTablePreferencesEditor aQuoteTablePrefEditor, QuoteTable aQuoteTable, SummaryView aSummaryView)
Constructor.

Method Summary

void	actionPerformed(ActionEvent e) Fetch quotes from the web for the CurrentPortfolio.
void	update(Observable aPublisher, Object aData) Listens for changes to the CurrentPortfolio or the user preference for update frequency, and calls actionPerformed(java.awt.event.ActionEvent).

Methods inherited from class AbstractAction

addPropertyChangeListener, clone, firePropertyChange, getKeys, getPropertyChangeListeners, getValue, isEnabled, putValue, removePropertyChangeListener, setEnabled

Methods inherited from class Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FetchQuotesAction

public FetchQuotesAction(CurrentPortfolio aCurrentPortfolio,
                         QuoteTablePreferencesEditor aQuoteTablePrefEditor,
                         QuoteTable aQuoteTable,
                         SummaryView aSummaryView)

Constructor.

Parameters:

aCurrentPortfolio - an Observable which notifies this object when the CurrentPortfolio is changed

aQuoteTablePrefEditor - allows this class to read the user preference for the frequency of periodic fetches

aQuoteTable - a GUI element which is updated when a fetch is performed

aSummaryView - a GUI element which is updated when a fetch is performed

Method Detail

actionPerformed

public void actionPerformed(ActionEvent e)

Fetch quotes from the web for the CurrentPortfolio.

Specified by:

actionPerformed in interface ActionListener

update

public void update(Observable aPublisher,
                   Object aData)

Listens for changes to the CurrentPortfolio or the user preference for update frequency, and calls actionPerformed(java.awt.event.ActionEvent).

In the case of changes to the update frequency, actionPerformed is called only if the udate frequency has been assigned a new value.

Specified by:

update in interface Observer