unwrappedimagepanel.java

JAVA 实现虹膜识别（完整）

package IrisRecog;

/**
 * ImagePanel.java
 * 
 * Extends the functionality of the JPanel swing component to be able to draw
 * centered images in the panel. This class overrides the paintComponent method
 * and handles its own drawing.
 *
 * @owner Michael Huffman
 * @author Team 6: A. Bare, I. Chaugule,M. Huffman, M. Pearson, C. Schell
 * @version 0.0.1
 *
 * 	CSC 480 Section 2
 * 	Fall 2005
 * 	10/8/05
 *
 * Edit History:
 *  10/8/05 - created
 *  10/9/05 - documented and commented
 */
 
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;

public class UnwrappedImagePanel extends JPanel 
{
	private Image img;
	
	/** 
	 * Creates an image panel with lowered bevel and white background.
	 */
	public UnwrappedImagePanel()
	{		
		this.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED));
		this.setBackground(Constants.CLR_DEFAULT_BACKGROUND);
		
		img = null;
	}
	
	public void setImage(Image i)
	{
		img = i;
		
		this.repaint();
	}

	public void paintComponent(Graphics g) 
	{ 
		//Clear the contents of the panel
		g.clearRect(0, 0, this.getWidth(), this.getHeight());
		
		//If the image of the panel has been set
		if(img!=null)  
		{
			ImageIcon scaledImage; //the image icon used to scale
			double scaleFactor;	   //the percentage amount of scaling exhbited to fit in the panel
			int yOffset;		   //the amount the image is shifted down to be centered vertically

			scaledImage = new ImageIcon(img.getScaledInstance(this.getWidth(), -1, Image.SCALE_DEFAULT));

			//Calculate the distance the image needs to be shifted down
			yOffset = (this.getHeight() / 2) - (scaledImage.getIconHeight() / 2);

			//Calculate the amount that the image is scaled
			scaleFactor = (this.getWidth() * 1.0) / img.getWidth(null);

			//Scale the image and paint it using the graphics object of this panel component
			scaledImage.paintIcon(this, g, 0, yOffset);
		}
  	} 
}