如何在Java swing中使用GradientPaint實現陰影效果？

Question

我要實現這種類型的文本字段的在我的項目

我寫了一個畫家類設置背景爲我的文本字段。

這是我主類我在其中設置雨雲爲外觀和感覺：

import java.awt.FlowLayout; 
import javax.swing.JFrame; 
import javax.swing.JTextField; 
import javax.swing.UIManager; 

class NimbusBaseDemo extends JFrame { 
    /** 
    * 
    */ 
    private static final long serialVersionUID = 1L; 
    JTextField jtxt, txtDisEnabled; 
    int i; 

    private UIManager.LookAndFeelInfo[] lafs; 

    public NimbusBaseDemo() { 
     try { 

      // Set nimbus look and feel. nimbusBase works only for it. 
      new NimbusBaseUI(); 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 

     setTitle("Nimbus Base Demo"); 
     setSize(400, 400); 
     setLayout(new FlowLayout()); 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setVisible(true); 
     jtxt = new JTextField(); 
     jtxt = new JTextField("Enabled Text Field"); 
     jtxt.setEnabled(true); 
     add(jtxt); 
     // Disabled text field 
     txtDisEnabled = new JTextField("Disabled Text Field"); 
     txtDisEnabled.setEnabled(false); 
     add(txtDisEnabled); 

    } 

    public static void main(String args[]) { 

     new NimbusBaseDemo(); 
    } 
} 

，這是我的靈氣主題類，在這裏我向NimbusLookAndFell類和setdefaults因爲我想要的。

import javax.swing.UIManager; 
import javax.swing.plaf.nimbus.NimbusLookAndFeel; 
public class NimbusBaseUI extends NimbusLookAndFeel { 
    public NimbusBaseUI() { 
     super(); // Initialisation and installating 
     try { 
      new TextFieldTheme(this); 
      UIManager.setLookAndFeel(this); 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    @Override 
    public void initialize() { 
     // TODO Auto-generated method stub 
     super.initialize(); 
    } 

} 

這是我文本字段主題類，這是我在NimbusBaseUI類使用

import java.awt.BasicStroke; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.Font; 
import java.awt.GradientPaint; 
import java.awt.Graphics2D; 
import java.awt.Insets; 
import java.awt.RenderingHints; 

import javax.swing.Painter; 

public class TextFieldTheme { 

    public TextFieldTheme(NimbusBaseUI nimbusUI) { 
     nimbusUI.getDefaults().put("TextField.opaque", false); 
     nimbusUI.getDefaults().put("TextField.font", 
       new Font("Myriad Pro Light", Font.PLAIN, 13)); 
     nimbusUI.getDefaults().put("TextField[Enabled].textForeground", 
       new Color(0, 0, 0)); 

     nimbusUI.getDefaults().put("TextField.contentMargins", 
       new Insets(2, 10, 2, 2)); 
     nimbusUI.getDefaults().put("TextField[Enabled].contentMargins", 
       new Insets(2, 10, 2, 2)); 
     nimbusUI.getDefaults().put("TextField[Disabled].contentMargins", 
       new Insets(2, 10, 2, 2)); 
     nimbusUI.getDefaults().put(
       "TextField[Enabled].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Focused].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Selected].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[MouseOver].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Enabled+Focused].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Enabled+Selected].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Enabled+MouseOver].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 

     nimbusUI.getDefaults().put("TextField[Disabled].textForeground", 
       new Color(0, 0, 0)); 
     nimbusUI.getDefaults().put(
       "TextField[Disabled].backgroundPainter", 
       new TextFeildPaintBorder(new Color(255, 255, 255), new Color(
         255, 255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Disabled+Focused].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Disabled+Selected].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 
     nimbusUI.getDefaults().put(
       "TextField[Disabled+MouseOver].backgroundPainter", 
       new TextFeildPaintBorder(new Color(0, 0, 255), new Color(255, 
         255, 255))); 

    } 

    public class TextFeildPaintBorder implements Painter { 

     private Color light, dark; 
     private GradientPaint gradPaint; 
     protected int strokeSize = 1; 
     /** Color of shadow */ 

     /** Color of shadow */ 
     protected Color shadowColor = new Color(128, 128, 128, 140); 

     /** Sets if it drops shadow */ 
     protected boolean shady = true; 
     /** Sets if it has an High Quality view */ 
     protected boolean highQuality = false; 
     /** Double values for Horizontal and Vertical radius of corner arcs */ 
     protected Dimension arcs = new Dimension(10, 10); 
     /** Distance between shadow border and opaque panel border */ 
     protected int shadowGap = 1; 
     /** The offset of shadow. */ 
     protected int shadowOffset = 1; // width of the shadow 
     /** The transparency value of shadow. (0 - 255) */ 
     protected int shadowAlpha = 130; 

     public TextFeildPaintBorder(Color light, Color dark) { 
      this.light = light; 
      this.dark = dark; 
     } 

     @Override 
     public void paint(Graphics2D g, Object object, int w, int h) { 

      Color shadowColorA = new Color(shadowColor.getRed(), 
        shadowColor.getGreen(), shadowColor.getBlue(), shadowAlpha); 
      if (highQuality) { 
       g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
         RenderingHints.VALUE_ANTIALIAS_ON); 
      } 
      if (shady) { 
       g.setColor(shadowColorA); 
       g.fillRoundRect(0, 0, w - shadowGap, h - shadowGap, arcs.width, 
         arcs.height); 
      } else { 
       shadowGap = 1; 
      } 
      gradPaint = new GradientPaint((w/2.0f), 0, new Color(255, 255, 
        255), (w/2.0f), (h/2.0f), new Color(255, 255, 255), 
        false); 
      g.setPaint(gradPaint); 

      g.fillRoundRect(shadowOffset,// X position 
        shadowOffset,// Y position 
        w - strokeSize - shadowOffset, // width 
        h - strokeSize - shadowOffset, // height 
        arcs.width, arcs.height);// arc Dimension 
      g.setColor(new Color(188, 188, 187, 130)); 
      g.setStroke(new BasicStroke(strokeSize)); 
      g.drawRoundRect(shadowOffset,// X position 
        shadowOffset,// Y position 
        w - strokeSize - shadowOffset, // width 
        h - strokeSize - shadowOffset, // height 
        arcs.width, arcs.height);// arc Dimension 
      g.setStroke(new BasicStroke()); 

     } 

    } 

} 

compaile和運行我得到這個後：

Answer 1

你會需要使用jtxt.setBorder(BorderFactory.createEmptyBorder(2, 10, 2, 2))而不是d.put("TextField.contentMargins", new Insets(2, 10, 2, 2))：

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 

public class NimbusBaseDemo2 { 
    public JComponent makeUI() { 
    //UIDefaults d = UIManager.getLookAndFeelDefaults(); 
    UIDefaults d = new UIDefaults(); 
    //d.put("TextField.opaque", false); 
    //d.put("TextField.font", new Font("Myriad Pro Light", Font.PLAIN, 13)); 
    //d.put("TextField[Enabled].textForeground", new Color(0, 0, 0)); 
    //d.put("TextField[Disabled].textForeground", new Color(0, 0, 0)); 

    //Insets ins = new Insets(2, 10, 2, 2); 
    //d.put("TextField.contentMargins", ins); 
    //d.put("TextField[Enabled].contentMargins", ins); 
    //d.put("TextField[Disabled].contentMargins", ins); 

    Painter<JComponent> painter = new TextFeildPaintBorder(
     new Color(220, 220, 220), new Color(255, 255, 255)); 
    d.put("TextField[Enabled].backgroundPainter", painter); 
    d.put("TextField[Focused].backgroundPainter", painter); 
    d.put("TextField[Selected].backgroundPainter", painter); 

    Painter<JComponent> painter2 = new TextFeildPaintBorder(
     new Color(200, 200, 200), new Color(220, 220, 220)); 
    d.put("TextField[Disabled].backgroundPainter", painter2); 
    d.put("TextField[Disabled+Focused].backgroundPainter", painter2); 
    d.put("TextField[Disabled+Selected].backgroundPainter", painter2); 

    //TEST: 
    //Painter<JComponent> painter3 = new Painter<JComponent>() { 
    // @Override public void paint(Graphics2D g, JComponent c, int w, int h) { 
    // } 
    //}; 
    //d.put("TextField[Disabled].borderPainter", painter3); 
    //d.put("TextField[Enabled].backgroundPainter", painter3); 
    //d.put("TextField[Focused].backgroundPainter", painter3); 

    JTextField jtxt = new JTextField("Enabled Text Field"); 
    jtxt.setBorder(BorderFactory.createEmptyBorder(2, 10, 2, 2)); 
    jtxt.putClientProperty("Nimbus.Overrides", d); 

    JTextField txtDisEnabled = new JTextField("Disabled Text Field"); 
    txtDisEnabled.setEnabled(false); 

    JTextField txtDisEnabled2 = new JTextField("Disabled Text Field"); 
    txtDisEnabled2.setBorder(BorderFactory.createEmptyBorder(2, 10, 2, 2)); 
    txtDisEnabled2.putClientProperty("Nimbus.Overrides", d); 
    txtDisEnabled2.setEnabled(false); 

    Box box = Box.createVerticalBox(); 
    box.add(new JSeparator()); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(new JTextField("Enabled Text Field")); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(jtxt); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(new JSeparator()); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(txtDisEnabled); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(txtDisEnabled2); 
    box.add(Box.createVerticalStrut(5)); 
    JPanel p = new JPanel(new BorderLayout()); 
    p.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10)); 
    p.add(box, BorderLayout.NORTH); 
    return p; 
    } 
    public static void main(String... args) { 
    EventQueue.invokeLater(() -> { 
     try { 
     for (UIManager.LookAndFeelInfo laf : UIManager.getInstalledLookAndFeels()) { 
      if ("Nimbus".equals(laf.getName())) { 
      UIManager.setLookAndFeel(laf.getClassName()); 
      } 
     } 
     } catch (Exception e) { 
     e.printStackTrace(); 
     } 
     JFrame f = new JFrame(); 
     f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); 
     f.getContentPane().add(new NimbusBaseDemo2().makeUI()); 
     f.setSize(320, 240); 
     f.setLocationRelativeTo(null); 
     f.setVisible(true); 
    }); 
    } 
} 

class TextFeildPaintBorder implements Painter<JComponent> { 
    private Color light, dark; 
    private GradientPaint gradPaint; 
    protected int strokeSize = 1; 
    /** Color of shadow */ 
    protected Color shadowColor = new Color(128, 128, 128, 140); 

    /** Sets if it drops shadow */ 
    protected boolean shady = true; 
    /** Sets if it has an High Quality view */ 
    protected boolean highQuality = false; 
    /** Double values for Horizontal and Vertical radius of corner arcs */ 
    protected Dimension arcs = new Dimension(10, 10); 
    /** Distance between shadow border and opaque panel border */ 
    protected int shadowGap = 1; 
    /** The offset of shadow. */ 
    protected int shadowOffset = 1; // width of the shadow 
    /** The transparency value of shadow. (0 - 255) */ 
    protected int shadowAlpha = 130; 

    public TextFeildPaintBorder(Color light, Color dark) { 
    this.light = light; 
    this.dark = dark; 
    } 

    @Override 
    public void paint(Graphics2D g, JComponent c, int w, int h) { 
    Color shadowColorA = new Color(
     shadowColor.getRed(), 
     shadowColor.getGreen(), 
     shadowColor.getBlue(), 
     shadowAlpha); 
    if (highQuality) { 
     g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
         RenderingHints.VALUE_ANTIALIAS_ON); 
    } 
    if (shady) { 
     g.setColor(shadowColorA); 
     g.fillRoundRect(
     0, 0, w - shadowGap, h - shadowGap, arcs.width, arcs.height); 
    } else { 
     shadowGap = 1; 
    } 
    gradPaint = new GradientPaint(0, 0, light, 0, h * .5f, dark, false); 
    g.setPaint(gradPaint); 

    g.fillRoundRect(shadowOffset,// X position 
        shadowOffset,// Y position 
        w - strokeSize - shadowOffset, // width 
        h - strokeSize - shadowOffset, // height 
        arcs.width, arcs.height);// arc Dimension 
    g.setColor(new Color(188, 188, 187, 130)); 
    g.setStroke(new BasicStroke(strokeSize)); 
    g.drawRoundRect(shadowOffset,// X position 
        shadowOffset,// Y position 
        w - strokeSize - shadowOffset, // width 
        h - strokeSize - shadowOffset, // height 
        arcs.width, arcs.height);// arc Dimension 
    g.setStroke(new BasicStroke()); 
    } 
} 

地址：

我需要應用相同的文本字段主題中的所有文本字段在我的項目。

另一種選擇是使用TextField[Focused].borderPainter和TextField.contentMargins：

d.put("TextField.contentMargins", insets); 
d.put("TextField[Focused].borderPainter", emptyPainter); 

NimbusBaseDemo3

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 

public class NimbusBaseDemo3 { 
    public JComponent makeUI() { 
    JTextField jtxt = new JTextField("Enabled Text Field"); 

    JTextField txtDisEnabled = new JTextField("Disabled Text Field"); 
    txtDisEnabled.setEnabled(false); 

    JTextField txtDisEnabled2 = new JTextField("Disabled Text Field"); 
    txtDisEnabled2.setEnabled(false); 

    Box box = Box.createVerticalBox(); 
    box.add(new JSeparator()); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(new JTextField("Enabled Text Field")); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(jtxt); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(new JSeparator()); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(txtDisEnabled); 
    box.add(Box.createVerticalStrut(5)); 
    box.add(txtDisEnabled2); 
    box.add(Box.createVerticalStrut(5)); 
    JPanel p = new JPanel(new BorderLayout()); 
    p.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10)); 
    p.add(box, BorderLayout.NORTH); 
    return p; 
    } 
    public static void main(String... args) { 
    EventQueue.invokeLater(() -> { 
     try { 
     for (UIManager.LookAndFeelInfo laf : UIManager.getInstalledLookAndFeels()) { 
      if ("Nimbus".equals(laf.getName())) { 
      UIManager.setLookAndFeel(laf.getClassName()); 

      UIDefaults d = UIManager.getLookAndFeelDefaults(); 

      Insets ins = new Insets(2, 10, 2, 2); 
      d.put("TextField.contentMargins", ins); 
      d.put("TextField[Enabled].contentMargins", ins); 
      d.put("TextField[Disabled].contentMargins", ins); 

      Painter<JComponent> painter = new TextFeildPaintBorder(
       new Color(220, 220, 220), new Color(255, 255, 255)); 
      d.put("TextField[Enabled].backgroundPainter", painter); 
      d.put("TextField[Focused].backgroundPainter", painter); 
      d.put("TextField[Selected].backgroundPainter", painter); 

      Painter<JComponent> painter2 = new TextFeildPaintBorder(
       new Color(200, 200, 200), new Color(220, 220, 220)); 
      d.put("TextField[Disabled].backgroundPainter", painter2); 

      Painter<JComponent> painter3 = new Painter<JComponent>() { 
       @Override public void paint(Graphics2D g, JComponent c, int w, int h) {} 
      }; 
      d.put("TextField[Disabled].borderPainter", painter3); 
      d.put("TextField[Enabled].borderPainter", painter3); 
      d.put("TextField[Focused].borderPainter", painter3); 
      } 
     } 
     } catch (Exception e) { 
     e.printStackTrace(); 
     } 
     JFrame f = new JFrame(); 
     f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); 
     f.getContentPane().add(new NimbusBaseDemo3().makeUI()); 
     f.setSize(320, 240); 
     f.setLocationRelativeTo(null); 
     f.setVisible(true); 
    }); 
    } 
} 

class TextFeildPaintBorder implements Painter<JComponent> { 
    private Color light, dark; 
    private GradientPaint gradPaint; 
    protected int strokeSize = 1; 
    /** Color of shadow */ 
    protected Color shadowColor = new Color(128, 128, 128, 140); 

    /** Sets if it drops shadow */ 
    protected boolean shady = true; 
    /** Sets if it has an High Quality view */ 
    protected boolean highQuality = false; 
    /** Double values for Horizontal and Vertical radius of corner arcs */ 
    protected Dimension arcs = new Dimension(10, 10); 
    /** Distance between shadow border and opaque panel border */ 
    protected int shadowGap = 1; 
    /** The offset of shadow. */ 
    protected int shadowOffset = 1; // width of the shadow 
    /** The transparency value of shadow. (0 - 255) */ 
    protected int shadowAlpha = 130; 

    public TextFeildPaintBorder(Color light, Color dark) { 
    this.light = light; 
    this.dark = dark; 
    } 

    @Override 
    public void paint(Graphics2D g, JComponent c, int w, int h) { 
    Color shadowColorA = new Color(
     shadowColor.getRed(), 
     shadowColor.getGreen(), 
     shadowColor.getBlue(), 
     shadowAlpha); 
    if (highQuality) { 
     g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
         RenderingHints.VALUE_ANTIALIAS_ON); 
    } 
    if (shady) { 
     g.setColor(shadowColorA); 
     g.fillRoundRect(
     0, 0, w - shadowGap, h - shadowGap, arcs.width, arcs.height); 
    } else { 
     shadowGap = 1; 
    } 
    gradPaint = new GradientPaint(0, 0, light, 0, h * .5f, dark, false); 
    g.setPaint(gradPaint); 

    g.fillRoundRect(shadowOffset,// X position 
        shadowOffset,// Y position 
        w - strokeSize - shadowOffset, // width 
        h - strokeSize - shadowOffset, // height 
        arcs.width, arcs.height);// arc Dimension 
    g.setColor(new Color(188, 188, 187, 130)); 
    g.setStroke(new BasicStroke(strokeSize)); 
    g.drawRoundRect(shadowOffset,// X position 
        shadowOffset,// Y position 
        w - strokeSize - shadowOffset, // width 
        h - strokeSize - shadowOffset, // height 
        arcs.width, arcs.height);// arc Dimension 
    g.setStroke(new BasicStroke()); 
    } 
}