/**
 * @file       JSlider.java
 * @author     R Daniel Bergeron
 * @version    2.0
 * @see        Draw3d.java
 * <P>
 * description Build a class that supports a Scrollbar with a label (and 
 *             maybe someday a label that shows the current value) and an 
 * arbitrary range of floating point values and some other conveniences.
 * This class also provides a simple version of an Adjustment Listener
 * for float values.
 * The user of the slider can create an instance of a FloatListener and
 * ask that object to be called (through it's valueChanged method)
 * whenever the slider value is changed. This is done by passing the
 * Float Listener to the addFloatListener method of Slider.
 *
 * <P>
 * modified by         Robert S Laramee
 * modification date   Thursday 10 Dec 98
 *                     Sliders were replaced with JSliders (Swing Components)
 *                     Slider    --> JSlider
 *                     Panel     --> JPanel
 *                     Scrollbar --> JScrollBar
 *                     Label     --> JLabel
 *                     List      --> JList
 */

import java.awt.*;
import java.awt.event.*;
//import list.List;
import javax.swing.*;           

public class JSlider extends JPanel {

    protected final int	MAXVAL = 500;   // max scrollbar value
    protected JPanel    	spanel;
    protected JScrollBar 	sbar;
    protected JLabel		titleLabel;
    protected JLabel		valueLabel;
    protected List		listenerList;

    protected float		minValue;
    protected float		maxValue;
    protected float		curValue;
    protected boolean		curValueSet = false; //hack for mouse problem


    //---------- Slider( title, orient ) ------------------
    public JSlider( String title, int   orient ) 
    {
        this( title, orient, 0, 1, (float) 0.5 );
    }
    //---------- Slider( title, orient, min, max, init ) ------------------
    public JSlider( String title, int   orient, 
    			     float min, float max, float init )
    {
	GridBagLayout	   gbl      = new GridBagLayout();
	GridBagConstraints gbcLabel = new GridBagConstraints();
	GridBagConstraints gbcSbar  = new GridBagConstraints();
	JLabel		   label    = new JLabel( title );

        setLayout ( gbl );
	gbcLabel.fill       = GridBagConstraints.NONE;
	gbcLabel.gridx      = 0;
	gbcLabel.gridy      = 0;
	gbcLabel.gridwidth  = 1;
	gbcLabel.gridheight = 1;
	curValue            = init;
	minValue            = min;
	maxValue            = max;
	int initval         = toIntValue( init );
        listenerList        = new List();

	if ( orient == JScrollBar.HORIZONTAL )	{
	   gbcLabel.anchor    = GridBagConstraints.EAST;
	   gbcSbar.fill       = GridBagConstraints.HORIZONTAL;
	   gbcSbar.gridx      = 1 ;
	   gbcSbar.gridy      = 0 ;
	   gbcSbar.weightx    = 1000 ;
	   gbcSbar.gridwidth  = 100 ;
	   gbcSbar.gridheight = 1 ;

	} else {

	   gbcLabel.anchor    = GridBagConstraints.WEST;
	   gbcSbar.fill       = GridBagConstraints.VERTICAL;
	   gbcSbar.fill       = GridBagConstraints.BOTH;
	   gbcSbar.gridx      = 0 ;
	   gbcSbar.gridy      = 1 ;
	   gbcSbar.weighty    = 1000 ;
	   gbcSbar.gridwidth  = 1 ;
	   gbcSbar.gridheight = 100 ;
	}
	gbl.setConstraints( label, gbcLabel );
        add( label );

        sbar = new JScrollBar( orient );
        sbar.setValues( initval, 5 /* visible */, 0, MAXVAL+5 );
        sbar.setUnitIncrement( 10 );
        sbar.setBlockIncrement( 50 );
	sbar.addMouseListener( 
	    new MouseAdapter( )
	        // some peers don't seem to generated button up events??
	        { public void mouseReleased( MouseEvent e)
		    { resetSlider( e ); }
	          public void mouseExited( MouseEvent e)
	            { resetSlider( e ); } 
	        } );

	gbl.setConstraints( sbar, gbcSbar );
        add ( sbar );

        sbar.addAdjustmentListener( new FloatAL( 0, MAXVAL, min, max ) );
    }
    //---------- toIntValue( float ) ------------------
    public int toIntValue( float val )
    {
       return (int)( (val-minValue)/(maxValue-minValue) * (float)MAXVAL);
    }
    //---------- setValue( float ) ------------------
    public void setValue( float newValue )
    {
       if ( minValue < maxValue )
       {
           newValue = Math.max( newValue, minValue );
           newValue = Math.min( newValue, maxValue );
       }
       else
       {
           newValue = Math.min( newValue, minValue );
           newValue = Math.max( newValue, maxValue );
       }
       curValue = newValue;
       sbar.setValue( toIntValue( curValue ) );
    }
    //---------- getValue( ) ------------------
    public float getValue( float newVal )
    {
       return curValue;
    }
    //---------- resetSlider( event ) ------------------
    public void resetSlider( MouseEvent e )
    {
       if ( ! curValueSet )// hack because mouseReleased not called
          return;
       curValueSet = false;
       listenerList.reset();
       for (int i=0; i < listenerList.length(); i++ )
          ((FloatListener) listenerList.next()).reset( );
    }
    //---------- valueChanged( float ) ------------------
    public void valueChanged( float newVal )
    {
       curValue = newVal;
       curValueSet = true; // hack because mouseReleased not called
       listenerList.reset();
       for (int i=0; i < listenerList.length(); i++ )
          ((FloatListener) listenerList.next()).valueChanged( curValue );
    }
    //---------- addFloatListener( ) ------------------
    public void addFloatListener( FloatListener listener)
    {
       listenerList.add( listener );
    }

  //=================== internal class FloatAL ========================
  class FloatAL implements AdjustmentListener
  {
    private float	sbarRange;	// sbar max- min value
    private float	floatMin;	// desired min value
    private float	floatMax;	// desired max value
    private float	floatRange;	// floatMax - floatMin
    private float	floatVal;	// desired value
    private float	scaleFactor;	// desired value

    public FloatAL( int min, int max, float fmin, float fmax)
    {
        sbarRange = (float)( max - min );
        floatMin = fmin;
        floatMax = fmax;
        scaleFactor = (fmax - fmin) / sbarRange;
    }
    public void adjustmentValueChanged( AdjustmentEvent event )
    {
        float val = (float) event.getValue();
        floatVal = val * scaleFactor + floatMin;
        valueChanged( floatVal );
    }
  }
} // end Slider