import java.lang.reflect.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import utilities.beans.*;

public class FindBeanProperties extends Frame
                             implements ItemListener, WindowListener {

protected Object bean;					// the bean we analyze
protected Class target;					// the Class of the bean's class

protected Vector properties;			// the list of bean properties

protected Hashtable rProperties = new Hashtable();
protected Hashtable wProperties = new Hashtable();

// AWT Components for the GUI
protected List propertiesList;
protected TextField propertyValueTF;

//-------------------------------------------------------------------
// main() entry point
//-------------------------------------------------------------------
public static void main (String[] args) {
String beanClassName;
Object sampleBeanObj = null;

	if ( args.length != 1 ) {
		System.out.println("Usage: FindBeanProperties <beanClassName>");
		System.exit(10);
	}

	beanClassName = args[0];

	// obtain bean instance
	sampleBeanObj = BeansKit.newBean(beanClassName);
	if ( sampleBeanObj == null ) {
		System.out.println("Could not instantiate bean!");
		System.exit(10);
	}

	// finally, pop open our window and let user play with props.
	new FindBeanProperties(sampleBeanObj);
}
//-------------------------------------------------------------------
// FindBeanProperties Constructor
//-------------------------------------------------------------------
public FindBeanProperties(Object beanObj) {
	super("Properties Lister");

	this.bean = beanObj;

	properties = findProperties(beanObj);
	propertiesList = buildList(properties);
	propertiesList.setMultipleMode(false);	// single selections only

	propertyValueTF = new TextField();
	propertyValueTF.setEditable(false);		// textfield is for output only

	add(propertiesList, "Center");
	add(propertyValueTF, "South");

	propertiesList.addItemListener(this);
	addWindowListener(this);				// listen to our own window close

	setSize(new Dimension(130,300));
	setVisible(true);
}
//-------------------------------------------------------------------
// Construct a List component from the elements contained in a Vector
//-------------------------------------------------------------------
protected List buildList(Vector listItems) {
List aList = new List();
String item;

	Enumeration vecIterator = listItems.elements();
	while ( vecIterator.hasMoreElements() ) {
		item = (String) vecIterator.nextElement();
		aList.add(item);
	}
	return aList;
}
//-------------------------------------------------------------------
// Analyze a bean's public methods and record all methods starting
// with getXXX and setXXX.
//-------------------------------------------------------------------
protected Vector findProperties(Object anObject) {

Vector properties = new Vector();
Method[] publicMethods;
String methodName;
String propertyName = null;

	// get Class for bean
	target = anObject.getClass();
	// get list of accessible public methods
	publicMethods = target.getMethods();

	// forall public methods
	for (int i=0; i < publicMethods.length; i++) {
		methodName = publicMethods[i].getName();

		if ( methodName.startsWith("set")) {
			// extract property name from method name
			propertyName = Character.toLowerCase(methodName.charAt(3)) +
												methodName.substring(4);
			// add property to set of WRITE properties
			wProperties.put(propertyName, methodName);

			// check if we've already encountered a matching getter
			// if so, don't add this property to list again !
			if ( rProperties.get(propertyName) != null ) {
				continue;
			}
		} else
		if ( methodName.startsWith("get")) {
			propertyName = Character.toLowerCase(methodName.charAt(3)) +
												methodName.substring(4);

			// add property to set of READ properties
			rProperties.put(propertyName, methodName);

			// check if we've already encountered a matching setter
			// if so, don't add this property to list again !
			if ( wProperties.get(propertyName) != null ) {
				continue;
			}
		} else {
			continue;
		}

		// add property to list of properties
		properties.addElement(propertyName);
	} // end forall public methods

	return properties;
}
//-------------------------------------------------------------------
// ItemListener method
//-------------------------------------------------------------------
public void itemStateChanged(ItemEvent itemEvent) {

String property, propertyValueText;
String methodName;
Method getter = null;
Object value = "! ERROR !";		// in case we trip over an exception
Class[] argsList = {};			// empty argument list for getters

	property = ((List)(itemEvent.getSource() )).getSelectedItem();

	if ( rProperties.get(property) == null ) {

		propertyValueText = "not a read property";

	} else {

		// recall getter method name for this property
		methodName = (String) ( rProperties.get(property) );
		try {
			getter = target.getMethod(methodName, argsList);
		} catch (NoSuchMethodException ouch) {
			System.out.println("");
			System.out.println("We don't support indexed getters" + ouch);
		}

		// invoke getter to obtain property value
		System.out.println("Invoking '" + methodName +
									"()' to obtain property value");
		try {
			value = getter.invoke(bean, argsList);
		} catch (IllegalArgumentException badArgs) {
			System.out.println(badArgs);
			System.exit(10);
		} catch (IllegalAccessException noAccess) {
			System.out.println(noAccess);
			System.exit(10);
		} catch (InvocationTargetException wrongTarget) {
			System.out.println(wrongTarget);
			System.exit(10);
		}

		// convert value to readable representation
		if ( value == null ) {
			value = "null";
		}
		propertyValueText = value.toString();
	}

	// display property value
	propertyValueTF.setText(propertyValueText);
}
//-------------------------------------------------------------------
// WindowListener methods, mostly no-ops, except for close request
//-------------------------------------------------------------------
public void windowOpened		(WindowEvent windowEvent) {}
public void windowClosing		(WindowEvent windowEvent) {
	System.exit(0);
}
public void windowClosed		(WindowEvent windowEvent) {}
public void windowIconified		(WindowEvent windowEvent) {}
public void windowDeiconified	(WindowEvent windowEvent) {}
public void windowActivated		(WindowEvent windowEvent) {}
public void windowDeactivated	(WindowEvent windowEvent) {}
} // End of Class FindBeanProperties