Darken JButton（s）悬停/点击

Question

ImageIcon backpackImageIcon = new ImageIcon("images/gui/button_backpack.png"); 
JButton backpackButton = new JButton(); 
backpackButton.setBounds(660,686,33,33); 
backpackButton.setBorderPainted(false); 
backpackButton.setFocusPainted(false); 
backpackButton.setVisible(true); 
backpackButton.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("B"), "backpackButtonPress"); 
backpackButton.getActionMap().put("backpackButtonPress", ClassBackpackButton); 
backpackButton.setAction(ClassBackpackButton); 
backpackButton.setIcon(backpackImageIcon); 
backpackButton.setToolTipText("Backpack[B]"); 
panel.add(backpackButton);  

我有多个按钮设置这种确切的方式。我希望能够做的是让他们在悬停时降低10％，而在点击时可能降低20％。我试图找到如何做到这一点，但没有运气（只发现JavaScript的东西）。对不起，如果这已被问及之前，并感谢您的任何帮助。

** 编辑 **

我试图做到这一点，但它只是将图像空白：

BufferedImage bufferedImage = null; 
try { 
    bufferedImage = ImageIO.read(new File("images/gui/button_backpack.png")); 
} catch (IOException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
} 
BufferedImage darkerBackpackBufferedImage = new BufferedImage(32, 32, BufferedImage.TYPE_BYTE_INDEXED); 
RescaleOp op = new RescaleOp(1.3f, 0, null); 
darkerBackpackBufferedImage = op.filter(bufferedImage, null); 
ImageIcon darkerBackpackImageIcon = new ImageIcon((Image) darkerBackpackBufferedImage); 
backpackButton.setRolloverIcon((ImageIcon) darkerBackpackImageIcon); 

** 编辑 **与解决方案

这里是我修改过的shiftColor功能，任何人阅读以上内容...祝你好运:)

public BufferedImage shiftColor(BufferedImage img, int rShift, int gShift, int bShift) { 
    Color tmpCol; 
    int tmpRed, tmpGreen, tmpBlue; 
    for (int x = 0; x < img.getWidth(); x++) { 
     for (int y = 0; y < img.getHeight(); y++) { 
      tmpCol=new Color(img.getRGB(x,y)); 
      tmpRed = (tmpCol.getRed()-rShift < 0) ? 0 : tmpCol.getRed()-rShift; //if shifted color is less than 0 change to 0 
      tmpGreen = (tmpCol.getGreen()-gShift < 0) ? 0 : tmpCol.getGreen()-gShift; //if shifted color is less than 0 change to 0 
      tmpBlue = (tmpCol.getBlue()-bShift < 0) ? 0 : tmpCol.getBlue()-bShift; //if shifted color is less than 0 change to 0 
      tmpCol=new Color(tmpRed, tmpGreen, tmpBlue); 
      img.setRGB(x,y,tmpCol.getRGB()); 
     } 
    } 
    return img; 
} 

Answer 1

该函数将返回一个BufferedImage具有颜色偏移（即。较浅/较深）

public BufferedImage shiftColor(BufferedImage img, int rShift, int gShift,int bShift) { 
    Color tmpCol; 
    for (int x = 0; x < img.getWidth(); x++) { 
     for (int y = 0; y < img.getHeight(); y++) { 
      tmpCol=new Color(img.getRGB(x,y)); 
      tmpCol=new Color(tmpCol.getRed()-rShift,tmpCol.getGreen()-gShift,tmpCol.getBlue()-bShift); 
      img.setRGB(x,y,tmpCol.getRGB()); 
     } 
    } 
    return img; 
} 

即使这会起作用，我仍然建议在图像编辑器中创建明亮和黑暗的图像（即。 Photoshop）并在启动时加载。上面的代码将是过程密集型的，并会减慢你的应用运行时间。

Answer 2

看看这个tutorial。您可能对mouseEntered感兴趣。而不是在Java中改变背包的颜色考虑2个图像，一个轻便背包和另一个黑色背包。当您将鼠标悬停在按钮上时更改它们。

public class MouseEventDemo implements MouseListener { 
    ImageIcon backpackImageIcon = new ImageIcon("images/gui/button_backpack.png"); 
    JButton backpackButton = new JButton(); 
    backpackButton.setBounds(660,686,33,33); 
    backpackButton.setBorderPainted(false); 
    backpackButton.setFocusPainted(false); 
    backpackButton.setVisible(true); 
    backpackButton.addMouseListener(this); 
    addMouseListener(this); 

    backpackButton.setIcon(backpackImageIcon); 
    backpackButton.setToolTipText("Backpack[B]"); 
    panel.add(backpackButton); 

    public void mousePressed(MouseEvent e) {} 

    public void mouseReleased(MouseEvent e) {} 

    public void mouseEntered(MouseEvent e) { 
     //set button color to dark color 
    } 
    public void mouseExited(MouseEvent e) { 
     //set button color to light color 
    } 
    public void mouseClicked(MouseEvent e) {} 

} 

Answer 3

有两种方法

1）使用built-in methods in JButtons API

button.setIcon((Icon i)); 
button.setRolloverIcon((Icon i)); 
button.setPressedIcon(Icon i)); 
button.setDisabledIcon(Icon i)); 

2）使用ButtonModel