Darken JButton（s）懸停/點擊

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);  

我有多個按鈕設置這種確切的方式。我希望能夠做的是讓他們在懸停時降低10％，而在點擊時可能降低20％。我試圖找到如何做到這一點，但沒有運氣（只發現JavaScript的東西）。對不起，如果這已被問及之前，並感謝您的任何幫助。

** 編輯 **

我試圖做到這一點，但它只是將圖像空白：

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); 

** 編輯 **與解決方案

這裏是我修改過的shiftColor功能，任何人閱讀以上內容...祝你好運:)

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

該函數將返回一個BufferedImage具有顏色偏移（即。較淺/較深）

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; 
} 

即使這會起作用，我仍然建議在圖像編輯器中創建明亮和黑暗的圖像（即。 Photoshop）並在啓動時加載。上面的代碼將是過程密集型的，並會減慢你的應用運行時間。

Answer 2

看看這個tutorial。您可能對mouseEntered感興趣。而不是在Java中改變揹包的顏色考慮2個圖像，一個輕便揹包和另一個黑色揹包。當您將鼠標懸停在按鈕上時更改它們。

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

有兩種方法

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