import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class ColorControls extends Panel {
    TextField tfield1, tfield2, tfield3;
    Scrollbar sb1, sb2, sb3;
    private int max1, max2, max3;
    private int curVal1, curVal2, curVal3;
    
    private Vector colorListeners = new Vector();

    public ColorControls(Object listener, String label1, String label2,
	String label3) {

	this(listener, label1, 255, label2, 255, label3, 255);
    }
    
    public ColorControls(Object listener, String label1, int lmax1,
	String label2, int lmax2, String label3, int lmax3) {
	max1 = lmax1;
	max2 = lmax2;
	max3 = lmax3;
	curVal1 = 0;
	curVal2 = 0;
	curVal3 = 0;
	
	setLayout(new GridLayout(3, 3, 10, 10));
	tfield1 = new TextField("0", 3);
	sb1 = new Scrollbar(Scrollbar.HORIZONTAL, 0, 1, 0, max1);
	tfield2 = new TextField("0", 3);
	sb2 = new Scrollbar(Scrollbar.HORIZONTAL, 0, 1, 0, max2);
	tfield3 = new TextField("0", 3);
	sb3 = new Scrollbar(Scrollbar.HORIZONTAL, 0, 1, 0, max3);
    
	add(new Label(label1, Label.RIGHT));
	add(tfield1);
	add(sb1);
    
	add(new Label(label2, Label.RIGHT));
	add(tfield2);
	add(sb2);
    
	add(new Label(label3, Label.RIGHT));
	add(tfield3);
	add(sb3);
    
	// create event handlers
	ColorTextHandler handler1 = new ColorTextHandler();
	ColorFocusHandler handler2 = new ColorFocusHandler();
	ColorAdjustmentHandler handler3 = new ColorAdjustmentHandler();

	// add event handlers to widgets
	tfield1.addActionListener(handler1);
	tfield2.addActionListener(handler1);
	tfield3.addActionListener(handler1);
	tfield1.addFocusListener(handler2);
	tfield2.addFocusListener(handler2);
	tfield3.addFocusListener(handler2);
	sb1.addAdjustmentListener(handler3);
	sb2.addAdjustmentListener(handler3);
	sb3.addAdjustmentListener(handler3);

	addColorChangeListener((ColorChangeListener)listener);
    }

    public synchronized void addColorChangeListener(
	ColorChangeListener listener) {
	if (!colorListeners.contains(listener)) {
	    colorListeners.addElement(listener);
	}
    }
    public synchronized void removeColorChangeListener(
	ColorChangeListener listener) {
	if (colorListeners.contains(listener)) {
	    colorListeners.removeElement(listener);
	}
    }
    public void notifyColorChange(int val1, int val2, int val3, int changer)
	throws ColorControlsException {
	ColorChangeEvent evt = new ColorChangeEvent(this, val1, val2, val3,
	    changer);
	Vector v;
	ColorChangeListener client;

	if (areValidArgs(val1, val2, val3)) {
	    synchronized (this) {
		curVal1 = val1;
		curVal2 = val2;
		curVal3 = val3;
		
		v = (Vector) colorListeners.clone();
		for (int i=0; i< v.size(); i++) {
		    client = (ColorChangeListener)v.elementAt(i);
		    client.colorChanged(evt);
		}
	    }
	}
	else {
	    // Throw an exception
	    throw (new ColorControlsException());
	}
	
    }

    private boolean areValidArgs(int val1, int val2, int val3)
    {
	boolean fValid = (val1 <= max1) && (val2 <= max2) && (val3 <= max3) &&
	    (val1 >= 0) && (val2 >= 0) && (val3 >= 0);
//	System.out.println("Valid Args?  " + val1 + " " + val2 + " " +
//	    val3 + " " + max1 + " " + max2 + " " + max3 + " " + fValid);
	return (fValid);
    }
        
    class ColorTextHandler implements ActionListener {
	public void actionPerformed(ActionEvent e) {
	    int val1 = Integer.parseInt(tfield1.getText());
	    int val2 = Integer.parseInt(tfield2.getText());
	    int val3 = Integer.parseInt(tfield3.getText());
//	    System.out.println("notifying Color Change(action): " + val1 +
//		", " + val2 + ", " + val3);
	    try {
		notifyColorChange(val1, val2, val3,
		    ColorChangeEvent.TEXTFIELD);
	    }
	    catch (ColorControlsException exc) {
		System.out.println("Exception!");
		tfield1.setText(String.valueOf(curVal1));
		tfield2.setText(String.valueOf(curVal2));
		tfield3.setText(String.valueOf(curVal3));
	    }
	}
    }

    class ColorFocusHandler extends FocusAdapter {
	public void focusLost(FocusEvent e) {
	    int val1 = Integer.parseInt(tfield1.getText());
	    int val2 = Integer.parseInt(tfield2.getText());
	    int val3 = Integer.parseInt(tfield3.getText());
//	    System.out.println("notifying Color Change(focus): " + val1 +
//		", " + val2 + ", " + val3);
	    try {
		notifyColorChange(val1, val2, val3,
		    ColorChangeEvent.TEXTFIELD);
	    }
	    catch (ColorControlsException exc) {
		System.out.println("Exception!");
		tfield1.setText(String.valueOf(curVal1));
		tfield2.setText(String.valueOf(curVal2));
		tfield3.setText(String.valueOf(curVal3));
	    }
	}
    }

    class ColorAdjustmentHandler implements AdjustmentListener {
	public void adjustmentValueChanged(AdjustmentEvent e) {

	    int val1 = sb1.getValue();
	    int val2 = sb2.getValue();
	    int val3 = sb3.getValue();
//	    System.out.println("notifying Color Change(adjust): " + val1 +
//		", " + val2 + ", " + val3);
	    try	{
		notifyColorChange(val1, val2, val3,
		    ColorChangeEvent.SCROLLBAR);
	    }
	    catch (ColorControlsException exc) {
		// This should never happen as the scrollbar component should
		// never allow us to go out of a valid range.
		System.out.println("Scrollbar exception");
		exc.toString();
	    }
	}
    }
}