package awt;

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


  Button - a class that produces a lightweight Open Look button.
 
  Lightweight components can have "transparent" areas, meaning that
  you can see the background of the container behind them.
 
public class Button extends Component {

static final int capWidth = 20;	// The width of the Button's endcap
private String label;	// The Button's text
private boolean pressed = false;	// true if the button is detented.
private boolean mousePressed = false;	// true if user is still pressing button
private ActionListener actionListener;	// Post action events to listeners

 Constructs a Button with no label. 
public Button() {
	this("");
}


  Constructs a Button with the specified label.
  @param label the label of the button
 
public Button(String label) {
	this.label = label;
	enableEvents(AWTEvent.MOUSE_EVENT_MASK);
}


  gets the label
  @see setLabel
 
public String getLabel() {
	return label;
}
 
public void setBackground(Color c) {
	super.setBackground(c);
	repaint();
}
 
public void setForeground(Color c) {
	super.setForeground(c);
	repaint();
}

public void setEnabled(boolean b) {
	if (b != isEnabled()) {
		super.setEnabled(b);
		repaint();
	}
}


  sets the label
  @see getLabel
 
public void setLabel(String label) {
	this.label = label;
	invalidate();
	repaint();
}
  
 factor is e.g. 0.7 
private Color darker(Color col,float factor)
{
	return new Color((int)(col.getRed() * factor),
		(int)(col.getGreen() * factor),
		(int)(col.getBlue() * factor));
}

private Color brighter(Color col,float factor)
{
	return new Color(Math.min((int)(col.getRed() / factor),255),
		Math.min((int)(col.getGreen() / factor),255),
		Math.min((int)(col.getBlue() / factor),255));
}

public void paint(Graphics g) {
	int width = getSize().width - 1;
	int height = getSize().height - 1;

	Color interior = getBackground();
	Color highlight1;
	Color highlight2;

	int labelWidth;
	int capwidth;
	Font f = getFont();
	if (f != null) {
		FontMetrics fm = getFontMetrics(getFont());
		labelWidth = fm.stringWidth(label);
		capwidth = width - labelWidth;
		if (capwidth > height) capwidth = height;
		if (capwidth < capWidth) capwidth = capWidth;
		if (capwidth > (width*4)/5) capwidth = (width*4)/5;
	} else {
		capwidth = capWidth;
		labelWidth = 0;
	}

	// ***** determine what colors to use
	if(pressed) {
		highlight1 = darker(interior,0.7f);
		highlight2 = brighter(interior,0.7f);
	} else {
		highlight1 = brighter(interior,0.7f);
		highlight2 = darker(interior,0.7f);
	}

	// ***** paint the interior of the button
	g.setColor(pressed ? darker(interior,0.85f) : interior);
	// left cap
	g.fillArc(0,0, 			// start
		capwidth,height,	// size
		90,180);		// angle

	// right cap
	g.fillArc(width - capwidth,0,	// start
		capwidth,height,	// size
		270,180);	// angle

	// inner rectangle
	g.fillRect(capwidth/2, 0, width - capwidth + 1, height);
  
	// ***** highlight the perimeter of the button
	drawOpenlookOval(g,0,0,width,height,highlight1,highlight2,capwidth);

	// lower arc right cap
	g.setColor(highlight2);
	g.drawArc(width - capwidth,0,	// start
		capwidth,height,	// size
		270,180-40);	// angle

	// ***** draw the label centered in the button
	if (f != null) {
		FontMetrics fm = getFontMetrics(getFont());
		g.setColor(getForeground());
		g.drawString(label,
			(width-labelWidth) / 2,
			(height+fm.getHeight()) / 2 - fm.getMaxDescent()
		);
		// very strange bug in jdk1.2
		g.setColor(getBackground());
		g.drawLine(0,0,0,0);
	}
	if (!isEnabled()) {
		g.setColor(Color.white);
		for (int y = 0; y < height; y+=2) {
			for (int x = (y%4==0) ? 0 : 2; x < width; x+=4)
				g.drawLine(x,y,x,y);
		}
	}
}


  The preferred size of the button. 
 
public Dimension getPreferredSize() {
	Font f = getFont();
	if (f != null) {
		FontMetrics fm = getFontMetrics(getFont());
		return new Dimension(fm.stringWidth(label) + capWidth/* *2 */,fm.getHeight() + 5);	// was +10 (gve)
	} else {
		return new Dimension(100, 50);
	}
}
  

  The minimum size of the button. 
 
public Dimension getMinimumSize() {
	return getPreferredSize();
}


  Adds the specified action listener to receive action events
  from this button.
  @param listener the action listener
 
public void addActionListener(ActionListener listener) {
	actionListener = AWTEventMulticaster.add(actionListener, listener);
	enableEvents(AWTEvent.MOUSE_EVENT_MASK);
}
 

  Removes the specified action listener so it no longer receives
  action events from this button.
  @param listener the action listener
 
public void removeActionListener(ActionListener listener) {
	actionListener = AWTEventMulticaster.remove(actionListener, listener);
}
 
 

  Paints the button and sends an action event to all listeners.
 
public void processMouseEvent(MouseEvent e) {
	if (isEnabled()) switch (e.getID()) {
	case MouseEvent.MOUSE_PRESSED:
		// render myself inverted....
		pressed = mousePressed = true;
		// Repaint might flicker a bit. To avoid this, you can use
		// double buffering (see the Gauge example).
		repaint();
		break;
	case MouseEvent.MOUSE_RELEASED:
		// render myself normal again
		mousePressed = false;
		if (pressed) {
			pressed = false;
			// Repaint might flicker a bit. To avoid this, you can use
			// double buffering (see the Gauge example).
			repaint();
			if (actionListener!=null) {
				actionListener.actionPerformed(new ActionEvent(
					this,ActionEvent.ACTION_PERFORMED,label));
			}
		}
		break;
	case MouseEvent.MOUSE_ENTERED:
		if (!pressed && mousePressed) {
			pressed = true;
			repaint();
		}
 		break;
 	case MouseEvent.MOUSE_EXITED:
		if (pressed && mousePressed) {
			// Cancel! Don't send action event.
			pressed = false;
			// Repaint might flicker a bit. To avoid this, you can use
			// double buffering (see the Gauge example).
			repaint();
		}
		break;
	}
	super.processMouseEvent(e);
}

 This method works out nice colors given the interior of the oval
  (e.g. getBackground() of a component) 
static public void drawOpenlookOval(Graphics g,int x,int y,int width,int height,Color interior,boolean pressed) {
	if (pressed) drawOpenlookOval(g,x,y,width,height,interior.darker(),interior.brighter());
	else drawOpenlookOval(g,x,y,width,height,interior.brighter(),interior.darker());
}

static public void drawOpenlookOval(Graphics g,int x,int y,int width,int height,Color highlight1,Color highlight2) {
	drawOpenlookOval(g,x,y,width,height,highlight1,highlight2,capWidth);
}

static public void drawOpenlookOval(Graphics g,int x,int y,int width,int height,Color highlight1,Color highlight2,int capwidth) {
	// draw upper and lower highlight lines
	g.setColor(highlight1);
	g.drawLine(x+capwidth/2,y,x+width-capwidth/2,y);
	g.setColor(highlight2);
	g.drawLine(x+capwidth/2,y+height,x+width-capwidth/2,y+height);

	// upper arc left cap
	g.setColor(highlight1);
		g.drawArc(x, y,	// start
		capwidth,height,	// size
		90, 180-40);	// angle
 
	// lower arc left cap
	g.setColor(highlight2);
		g.drawArc(x,y,   // start
		capwidth, height,   // size
		270-40, 40);	// angle

	// upper arc right cap
	g.setColor(highlight1);
	g.drawArc(x+width - capwidth,y,	// start
		capwidth, height,	// size
		90-40,40);	// angle
 
	// lower arc right cap
	g.setColor(highlight2);
	g.drawArc(x+width - capwidth,y,	// start
		capwidth,height,	// size
		270,180-40);	// angle
}

}