Java/Swing JFC/Accessible

A GUI to show accessible information coming from the components in an

 
/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O"Reilly 
*/
// AssistiveExample.java
//A GUI to show accessible information coming from the components in an
//application. See BigExample.java for example of how to use this class.
//
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.accessibility.*;
import javax.accessibility.util.*;
public class BigExample extends JFrame {
  public BigExample() {
    super("Big Accessibility Example");
    setSize(700,500);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    JMenuBar jmb = new JMenuBar();
    JMenu fileMenu = new JMenu("File");
    JMenuItem openItem = new JMenuItem("Open");
    JMenuItem saveItem = new JMenuItem("Save");
    JMenuItem exitItem = new JMenuItem("Exit");
    exitItem.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        System.exit(0);
      }
    });
    fileMenu.add(openItem);
    fileMenu.add(saveItem);
    fileMenu.add(new JSeparator());
    fileMenu.add(exitItem);
    jmb.add(fileMenu);
    setJMenuBar(jmb);
    JTextArea jta = new JTextArea("[Notes]\n");
    JScrollPane sp1 = new JScrollPane(jta);
    sp1.setMinimumSize(new Dimension(200,200));
    sp1.setPreferredSize(new Dimension(200,200));
    String[] titles = { "Name", "Start Date", "Job Title" };
    String[][] data = {
      {"Jordan", "2001", "Director"},
      {"Naveen", "1999", "Programmer"},
      {"Jia", "2000", "Analyst"},
      {"Brooks", "1998", "Evangelist"}
    };
    JTable table = new JTable(data, titles);
    table.getAccessibleContext().setAccessibleDescription("Employee Statistics");
    JPanel rightPane = new JPanel(new BorderLayout());
    rightPane.add(new JScrollPane(table), BorderLayout.CENTER);
    rightPane.add(new JLabel(new ImageIcon("logo.gif")), BorderLayout.SOUTH);
    JSplitPane jsp = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, sp1, rightPane);
    getContentPane().add(jsp, BorderLayout.CENTER);
    JPanel bPane = new JPanel();
    JButton okButton = new JButton("Ok");
    JButton applyButton = new JButton("Apply");
    JButton clearButton = new JButton("Clear");
    bPane.add(okButton);
    bPane.add(applyButton);
    bPane.add(clearButton);
    getContentPane().add(bPane, BorderLayout.SOUTH);
    setVisible(true);
  }
  public static void main(String args[]) {
    new BigExample();
    new AssistiveExample();
  }
}

class AssistiveExample extends JPanel implements MouseMotionListener,
    ActionListener, GUIInitializedListener {
  Timer timer;
  static JFrame frame;
  JLabel nameLabel = new JLabel();
  JLabel descriptionLabel = new JLabel();
  JLabel tableLabel = new JLabel();
  JCheckBox selectionCheckBox = new JCheckBox("Selection", false);
  JCheckBox textCheckBox = new JCheckBox("Text", false);
  JCheckBox valueCheckBox = new JCheckBox("Value", false);
  JCheckBox componentCheckBox = new JCheckBox("Component", false);
  JCheckBox actionCheckBox = new JCheckBox("Action", false);
  JCheckBox hypertextCheckBox = new JCheckBox("Hypertext", false);
  JCheckBox iconCheckBox = new JCheckBox("Icon", false);
  JCheckBox tableCheckBox = new JCheckBox("Table", false);
  JCheckBox editableTextCheckBox = new JCheckBox("EditableText", false);
  JLabel classLabel = new JLabel();
  JLabel parentLabel = new JLabel();
  JLabel relationLabel = new JLabel();
  JButton performAction = new JButton("Perform Action");
  public AssistiveExample() {
    frame = new JFrame("Assistive Example");
    // Insert the appropriate labels and check boxes
    setLayout(new GridLayout(0, 1)); // just make as many rows as we need
    add(nameLabel);
    add(descriptionLabel);
    add(tableLabel);
    add(new JSeparator());
    add(actionCheckBox);
    add(componentCheckBox);
    add(editableTextCheckBox);
    add(hypertextCheckBox);
    add(iconCheckBox);
    add(selectionCheckBox);
    add(tableCheckBox);
    add(textCheckBox);
    add(valueCheckBox);
    add(classLabel);
    add(parentLabel);
    add(relationLabel);
    add(performAction);
    setBorder(new TitledBorder("Accessible Component"));
    performAction.addActionListener(this);
    frame.getContentPane().add(this, BorderLayout.CENTER);
    frame.setBounds(100, 100, 500, 600);
    frame.setVisible(true);
    //  Check to see if the GUI subsystem is initialized
    //  correctly. (This is needed in JDK 1.2 and higher).
    //  If it isn"t ready, then we have to wait.
    if (EventQueueMonitor.isGUIInitialized()) {
      createGUI();
    } else {
      EventQueueMonitor.addGUIInitializedListener(this);
    }
    performAction.grabFocus();
  }
  public void guiInitialized() {
    createGUI();
  }
  public void createGUI() {
    //  We want to track the mouse motions, so notify the
    //  Swing event monitor of this.
    SwingEventMonitor.addMouseMotionListener(this);
    //  Start a Timer object to measure how long the mouse stays
    //  over a particular area.
    timer = new Timer(500, this);
  }
  public void mouseMoved(MouseEvent e) {
    //  If the mouse moves, restart the timer.
    timer.restart();
  }
  public void mouseDragged(MouseEvent e) {
    //  If the mouse is dragged, restart the timer.
    timer.restart();
  }
  public void actionPerformed(ActionEvent e) {
    //Find the component currently under the mouse.
    Point currentPosition = EventQueueMonitor.getCurrentMousePosition();
    Accessible comp = EventQueueMonitor.getAccessibleAt(currentPosition);
    //If the user pressed the button, and the component
    //has an accessible action, then execute it.
    if (e.getActionCommand() == "Perform Action") {
      AccessibleContext context = comp.getAccessibleContext();
      AccessibleAction action = context.getAccessibleAction();
      if (action != null)
        action.doAccessibleAction(0);
      else
        System.out.println("No accessible action present!");
      return;
    }
    //  Otherwise, the timer has fired. Stop it and update the window.
    timer.stop();
    updateWindow(comp);
  }
  private void updateWindow(Accessible component) {
    if (component == null) {
      return;
    }
    // Reset the check boxes
    actionCheckBox.setSelected(false);
    selectionCheckBox.setSelected(false);
    textCheckBox.setSelected(false);
    componentCheckBox.setSelected(false);
    valueCheckBox.setSelected(false);
    hypertextCheckBox.setSelected(false);
    iconCheckBox.setSelected(false);
    tableCheckBox.setSelected(false);
    editableTextCheckBox.setSelected(false);
    // Get the accessibile context of the component in question
    AccessibleContext context = component.getAccessibleContext();
    AccessibleRelationSet ars = context.getAccessibleRelationSet();
    nameLabel.setText("Name: " + context.getAccessibleName());
    descriptionLabel.setText("Desc: " + context.getAccessibleDescription());
    relationLabel.setText("Relation: " + ars);
    // Check the context for each of the accessibility types
    if (context.getAccessibleAction() != null)
      actionCheckBox.setSelected(true);
    if (context.getAccessibleSelection() != null)
      selectionCheckBox.setSelected(true);
    if (context.getAccessibleText() != null) {
      textCheckBox.setSelected(true);
      if (context.getAccessibleText() instanceof AccessibleHypertext)
        hypertextCheckBox.setSelected(true);
    }
    if (context.getAccessibleComponent() != null) {
      componentCheckBox.setSelected(true);
      classLabel.setText("Class: " + context.getAccessibleComponent());
      parentLabel.setText("Parent: " + context.getAccessibleParent());
    }
    if (context.getAccessibleValue() != null)
      valueCheckBox.setSelected(true);
    if (context.getAccessibleIcon() != null)
      iconCheckBox.setSelected(true);
    if ((context.getAccessibleTable() != null)
        || (context.getAccessibleParent() instanceof JTable)) {
      tableCheckBox.setSelected(true);
      tableLabel.setText("Table Desc: "
          + context.getAccessibleParent().getAccessibleContext()
              .getAccessibleDescription());
    } else {
      tableLabel.setText("");
    }
    // On 1.4+ systems, you can check for editable text with these two
    // lines.
    // Note that because of the 1.4 restriction, these lines will not
    // compile
    // on a Mac system as of the time of this writing. You can comment out
    // these lines and still compile/run the example, though.
    //if (context.getAccessibleEditableText() != null)
    //  editableTextCheckBox.setSelected(true);
    repaint();
  }
}

An example of getting the Accessible information from a Button object

 
/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O"Reilly 
*/
// ActionExampleButton.java
//An example of getting the Accessible information from a Button object.
//(You could see this information by attaching an AssistiveExample object
//to the button. See BigExample.java for an example of that attachment.)
//
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Locale;
import javax.accessibility.Accessible;
import javax.accessibility.AccessibleAction;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRole;
import javax.accessibility.AccessibleStateSet;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class ActionExample extends Button implements ActionListener, Accessible {
  public ActionExample() {
    super("Press this Button");
    addActionListener(this);
  }
  public AccessibleContext getAccessibleContext() {
    return (new ActionAccessibleContext());
  }
  public void actionPerformed(ActionEvent e) {
    System.out.println("The button was pressed!");
  }
  public void processActionEvent(ActionEvent e) {
    super.processActionEvent(e);
  }
  // This class contains the accessible context for the component. Many
  // abstract methods simply call the SwingUtilities class to get the job
  // done; this is advised if you can get away with it. Otherwise, see the
  // source code for SwingUtilities.
  class ActionAccessibleContext extends AccessibleContext {
    public ActionAccessibleContext() {
      super();
      setAccessibleName("Button");
      setAccessibleDescription("Press the Button");
    }
    public AccessibleRole getAccessibleRole() {
      // Fill in whatever role you want here
      return (AccessibleRole.AWT_COMPONENT);
    }
    public AccessibleStateSet getAccessibleStateSet() {
      return SwingUtilities.getAccessibleStateSet(ActionExample.this);
    }
    public int getAccessibleIndexInParent() {
      return SwingUtilities
          .getAccessibleIndexInParent(ActionExample.this);
    }
    public int getAccessibleChildrenCount() {
      return SwingUtilities
          .getAccessibleChildrenCount(ActionExample.this);
    }
    public Accessible getAccessibleChild(int i) {
      return SwingUtilities.getAccessibleChild(ActionExample.this, i);
    }
    public Locale getLocale() {
      //  Ask the component what its locale is
      return ActionExample.this.getLocale();
    }
    public AccessibleAction getAccessibleAction() {
      return new AccessAction();
    }
  }
  // This class implements the AccessibleAction interface. Essentially, there
  // is only one action that is the equivalent of pushing the button.
  class AccessAction implements AccessibleAction {
    final int NUMBER_OF_ACTIONS = 1;
    final String DESCRIPTION = "Presses the button";
    public int getAccessibleActionCount() {
      return NUMBER_OF_ACTIONS;
    }
    public String getAccessibleActionDescription(int i) {
      if (i == 0)
        return (DESCRIPTION);
      else
        return null;
    }
    public boolean doAccessibleAction(int i) {
      if (i == 0) {
        // Simulate pressing a button
        ActionExample.this.processActionEvent(new ActionEvent(this,
            ActionEvent.ACTION_PERFORMED, ActionExample.this
                .getActionCommand()));
        return true;
      } else
        return false;
    }
  }
  public static void main(String s[]) {
    ActionExample example = new ActionExample();
    JFrame frame = new JFrame("AccessibleAction Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(example, BorderLayout.CENTER);
    frame.setSize(100, 100);
    frame.setVisible(true);
  }
}

Associating a Label with a Component

 
import javax.swing.JLabel;
import javax.swing.JTextField;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTextField component = new JTextField();
    JLabel label = new JLabel("Name:");
    label.setDisplayedMnemonic("N");
    label.setLabelFor(component);
  }
}

Has Displayed Name

   
import javax.swing.AbstractButton;
import javax.swing.JLabel;
import javax.swing.text.JTextComponent;

public class Util {
  public static boolean hasDisplayedName(Class componentClass) {
    return ((AbstractButton.class.isAssignableFrom(componentClass))
            || (JLabel.class.isAssignableFrom(componentClass))
            || (JTextComponent.class.isAssignableFrom(componentClass))
    );
  }
}

implement Accessible to make your object accessible

 
import java.awt.IllegalComponentStateException;
import java.util.Locale;
import javax.accessibility.Accessible;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRole;
import javax.accessibility.AccessibleStateSet;
public class Main implements Accessible {
  public AccessibleContext getAccessibleContext() {
    return new AccessibleContext() {
      @Override
      public AccessibleRole getAccessibleRole() {
        return null;
      }
      @Override
      public AccessibleStateSet getAccessibleStateSet() {
        return null;
      }
      @Override
      public int getAccessibleIndexInParent() {
        return 0;
      }
      @Override
      public int getAccessibleChildrenCount() {
        return 0;
      }
      @Override
      public Accessible getAccessibleChild(int i) {
        return null;
      }
      @Override
      public Locale getLocale() throws IllegalComponentStateException {
        return null;
      }
    };
  }
}

Setting a Description for Image Icons

 
import javax.swing.ImageIcon;
public class Main {
  public static void main(String[] argv) throws Exception {
    ImageIcon icon = new ImageIcon("image.gif");
    icon.setDescription("Description of Image");
  }
}

Setting a Keyboard Accelerator for a Menu Item

 
import java.awt.event.KeyEvent;
import javax.swing.JMenuItem;
import javax.swing.KeyStroke;
public class Main {
  public static void main(String[] argv) throws Exception {
    JMenuItem item = new JMenuItem("Item");
    item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_I, KeyEvent.SHIFT_MASK));
  }
}

Setting a Mnemonic for a Menu for Accessible

 
import javax.swing.JMenu;
public class Main {
  public static void main(String[] argv) throws Exception {
    JMenu menu = new JMenu("Menu");
    menu.setMnemonic("M");
  }
}

Setting a Mnemonic for Buttons for Accessible

 
import javax.swing.JButton;
import javax.swing.JCheckBox;
public class Main {
  public static void main(String[] argv) throws Exception {
    JButton button = new JButton("Button");
    button.setMnemonic("B");
    JCheckBox checkBox = new JCheckBox("CheckBox");
    checkBox.setMnemonic("C");
  }
}

Setting an Accessible Name for an Image Button

 
import javax.swing.ImageIcon;
import javax.swing.JButton;
public class Main {
  public static void main(String[] argv) throws Exception {
  JButton button = new JButton(new ImageIcon("image.gif"));
    button.setToolTipText("Button Name");
    button.getAccessibleContext().setAccessibleName("Button Name");
  }
}