// implemented for ActionListener event handling
public void actionPerformed(ActionEvent e) {
String actionCmd = e.getActionCommand();
Stack locStack = parentBrowserFrame.locationStack;
Stack fwdStack = parentBrowserFrame.forwardStack;
if (actionCmd.equals(homeCmd)) // event from home button
{
fwdStack.removeAllElements();
parentBrowserFrame.setBrowserLocation(mainBrowserURL);
} else if (actionCmd.equals(backCmd)) // event from back button
{
if (!locStack.isEmpty()) {
String myLocale = (String) (locStack.pop());
// push current location on forward stack
fwdStack.push(location);
getForwardButton().setEnabled(true);
// do *not* cache the last location in the stack
parentBrowserFrame.setBrowserLocation(myLocale, false);
}
} else if (actionCmd.equals(forwardCmd)) // event from forward button
{
if (!fwdStack.isEmpty()) {
// remove location from forward stack
String newLoc = (String) (fwdStack.pop());
// DO add the current location to the back stack
parentBrowserFrame.setBrowserLocation(newLoc);
}
} else if (actionCmd.equals(comboCmd)) // event from URL combo box!
{
if (e.getSource() instanceof JComboBox) // just to be sure
{
JComboBox thisBox = (JComboBox) e.getSource();
String newLoc = thisBox.getSelectedItem().toString();
if (newLoc != null && !newLoc.equals("")) // ignore empty selections
{
if (thisBox.getSelectedIndex() == -1) {
thisBox.insertItemAt(newLoc, 0);
}
fwdStack.removeAllElements();
parentBrowserFrame.setBrowserLocation(newLoc);
}
}
}
// disable the back button if we find the location stack is empty
if (locStack.isEmpty()) {
getBackButton().setEnabled(false);
}
// disable forward button if forward stack is empty
if (fwdStack.isEmpty()) {
getForwardButton().setEnabled(false);
}
}
protected void addMyControls() {
// add browser-style control buttons
JButton home = new JButton(new ImageIcon("data/Home24.gif"));
JButton back = new JButton(new ImageIcon("data/Back24.gif"));
JButton fwd = new JButton(new ImageIcon("data/Forward24.gif"));
home.setToolTipText("Home");
home.addActionListener(this);
home.setActionCommand(homeCmd);
back.setToolTipText("Back");
back.addActionListener(this);
back.setActionCommand(backCmd);
back.setEnabled(false); // initially disabled
fwd.setToolTipText("Forward");
fwd.addActionListener(this);
fwd.setActionCommand(forwardCmd);
fwd.setEnabled(false); // initially disabled
add(home);
add(back);
add(fwd);
add(new JToolBar.Separator());
// set built-in index variables
homeIndex = getComponentIndex(home);
backIndex = getComponentIndex(back);
forwardIndex = getComponentIndex(fwd);
JComboBox comboBox = new JComboBox();
comboBox.setEditable(true);
comboBox.addActionListener(this);
comboBox.setActionCommand(comboCmd);
comboBox.setMaximumRowCount(3); // don't let it get too long
comboBox.insertItemAt(mainBrowserURL, 0); // don't start it out empty
add(comboBox);
comboBoxIndex = getComponentIndex(comboBox);
}
