我有一个尺寸为7 x 6的国际象棋网格，每个方格都有背景，我希望背景在我悬停在其上时将色调改为红色，然后当我悬停在其他东西上时恢复正常，我该如何实现这使用鼠标听众？
这是我的鼠标拖动监听器：
public void mouseDragged(MouseEvent me) {
if (chessPiece == null)
return;
// The drag location should be within the bounds of the chess board
int x = me.getX() + xAdjustment;
int xMax = chessBoard.getWidth() - chessPiece.getWidth();
x = Math.min(x, xMax);
x = Math.max(x, 0);
int y = me.getY() + yAdjustment;
int yMax = chessBoard.getHeight() - chessPiece.getHeight();
y = Math.min(y, yMax);
y = Math.max(y, 0);
chessPiece.setLocation(x, y); //drags the piece as i move, i want to
//change the hue of the square/Jpanel
//under my cursor as i move.
Component c= chessBoard.getComponentAt(chessPiece.getX(),chessPiece.getY());
}
Square是BackgroundPanel
package model.gui;
import java.awt.*;
import java.awt.image.*;
import javax.swing.*;
/*
* Support custom painting on a panel in the form of
*
* a) images - that can be scaled, tiled or painted at original size
* b) non solid painting - that can be done by using a Paint object
*
* Also, any component added directly to this panel will be made
* non-opaque so that the custom painting can show through.
*/
public class BackgroundPanel extends JPanel
{
public static final int SCALED = 0;
public static final int TILED = 1;
public static final int ACTUAL = 2;
private Paint painter;
private Image image;
private int style = SCALED;
private float alignmentX = 0.5f;
private float alignmentY = 0.5f;
private boolean isTransparentAdd = true;
Graphics g;
/*
* Set image as the background with the SCALED style
*/
public BackgroundPanel(Image image)
{
this(image, SCALED);
}
/*
* Set image as the background with the specified style
*/
public BackgroundPanel(Image image, int style)
{
setImage( image );
setStyle( style );
setLayout( new BorderLayout() );
}
/*
* Set image as the backround with the specified style and alignment
*/
public BackgroundPanel(Image image, int style, float alignmentX, float alignmentY)
{
setImage( image );
setStyle( style );
setImageAlignmentX( alignmentX );
setImageAlignmentY( alignmentY );
setLayout( new BorderLayout() );
}
/*
* Use the Paint interface to paint a background
*/
public BackgroundPanel(Paint painter)
{
setPaint( painter );
setLayout( new BorderLayout() );
}
/*
* Set the image used as the background
*/
public void setImage(Image image)
{
this.image = image;
repaint();
}
/*
* Set the style used to paint the background image
*/
public void setStyle(int style)
{
this.style = style;
repaint();
}
/*
* Set the Paint object used to paint the background
*/
public void setPaint(Paint painter)
{
this.painter = painter;
repaint();
}
/*
* Specify the horizontal alignment of the image when using ACTUAL style
*/
public void setImageAlignmentX(float alignmentX)
{
this.alignmentX = alignmentX > 1.0f ? 1.0f : alignmentX < 0.0f ? 0.0f : alignmentX;
repaint();
}
/*
* Specify the horizontal alignment of the image when using ACTUAL style
*/
public void setImageAlignmentY(float alignmentY)
{
this.alignmentY = alignmentY > 1.0f ? 1.0f : alignmentY < 0.0f ? 0.0f : alignmentY;
repaint();
}
/*
* Override method so we can make the component transparent
*/
public void add(JComponent component)
{
add(component, null);
}
/*
* Override to provide a preferred size equal to the image size
*/
@Override
public Dimension getPreferredSize()
{
if (image == null)
return super.getPreferredSize();
else
return new Dimension(image.getWidth(null), image.getHeight(null));
}
/*
* Override method so we can make the component transparent
*/
public void add(JComponent component, Object constraints)
{
if (isTransparentAdd)
{
makeComponentTransparent(component);
}
super.add(component, constraints);
}
/*
* Controls whether components added to this panel should automatically
* be made transparent. That is, setOpaque(false) will be invoked.
* The default is set to true.
*/
public void setTransparentAdd(boolean isTransparentAdd)
{
this.isTransparentAdd = isTransparentAdd;
}
/*
* Try to make the component transparent.
* For components that use renderers, like JTable, you will also need to
* change the renderer to be transparent. An easy way to do this it to
* set the background of the table to a Color using an alpha value of 0.
*/
private void makeComponentTransparent(JComponent component)
{
component.setOpaque( false );
if (component instanceof JScrollPane)
{
JScrollPane scrollPane = (JScrollPane)component;
JViewport viewport = scrollPane.getViewport();
viewport.setOpaque( false );
Component c = viewport.getView();
if (c instanceof JComponent)
{
((JComponent)c).setOpaque( false );
}
}
}
/*
* Add custom painting
*/
@Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
// Invoke the painter for the background
if (painter != null)
{
Dimension d = getSize();
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(painter);
g2.fill( new Rectangle(0, 0, d.width, d.height) );
}
// Draw the image
if (image == null ) return;
switch (style)
{
case SCALED :
drawScaled(g);
break;
case TILED :
drawTiled(g);
break;
case ACTUAL :
drawActual(g);
break;
default:
drawScaled(g);
}
}
/*
* Custom painting code for drawing a SCALED image as the background
*/
private void drawScaled(Graphics g)
{
Dimension d = getSize();
g.drawImage(image, 0, 0, d.width, d.height, null);
}
/*
* Custom painting code for drawing TILED images as the background
*/
private void drawTiled(Graphics g)
{
Dimension d = getSize();
int width = image.getWidth( null );
int height = image.getHeight( null );
for (int x = 0; x < d.width; x += width)
{
for (int y = 0; y < d.height; y += height)
{
g.drawImage( image, x, y, null, null );
}
}
}
/*
* Custom painting code for drawing the ACTUAL image as the background.
* The image is positioned in the panel based on the horizontal and
* vertical alignments specified.
*/
private void drawActual(Graphics g)
{
Dimension d = getSize();
Insets insets = getInsets();
int width = d.width - insets.left - insets.right;
int height = d.height - insets.top - insets.left;
float x = (width - image.getWidth(null)) * alignmentX;
float y = (height - image.getHeight(null)) * alignmentY;
g.drawImage(image, (int)x + insets.left, (int)y + insets.top, this);
}
}