import java.awt.*;
import javax.swing.*;
import java.awt.image.*;
/**
* hana
* An ImagePanel is a Swing component that can display an OFImage.
* It is constructed as a subclass of JComponent with the added functionality
* of setting an OFImage that will be displayed on the surface of this
* component.
*
* @author Michael Kolling and David J. Barnes
* @version 1.0
*/
public class ImagePanel extends JComponent
{
// The current width and height of this panel
private int width, height;
// An internal image buffer that is used for painting. For
// actual display, this image buffer is then copied to screen.
private OFImage panelImage;
/**
* Create a new, empty ImagePanel.
*/
public ImagePanel()
{
width = 360; // arbitrary size for empty panel
height = 240;
panelImage = null;
}
/**
* Set the image that this panel should show.
*
* @param image The image to be displayed.
*/
public void setImage(OFImage image)
{
if(image != null) {
width = image.getWidth();
height = image.getHeight();
panelImage = image;
repaint();
}
}
/**
* Clear the image on this panel.
*/
public void clearImage()
{
Graphics imageGraphics = panelImage.getGraphics();
imageGraphics.setColor(Color.LIGHT_GRAY);
imageGraphics.fillRect(0, 0, width, height);
repaint();
}
// The following methods are redefinitions of methods
// inherited from superclasses.
/**
* Tell the layout manager how big we would like to be.
* (This method gets called by layout managers for placing
* the components.)
*
* @return The preferred dimension for this component.
*/
public Dimension getPreferredSize()
{
return new Dimension(width, height);
}
/**
* This component needs to be redisplayed. Copy the internal image
* to screen. (This method gets called by the Swing screen painter
* every time it want this component displayed.)
*
* @param g The graphics context that can be used to draw on this component.
*/
public void paintComponent(Graphics g)
{
Dimension size = getSize();
g.clearRect(0, 0, size.width, size.height);
if(panelImage != null) {
g.drawImage(panelImage, 0, 0, null);
}
}
}