如何在Java Swing中创建圆角BevelBorder？

Question

我希望使用斜面边框，因为它有点像三维，但我不知道如何创建带有圆角的BevelBorder。 SoftBevelBorder不起作用，因为圆角半径太小了。如何使角落更加圆润？

- Bashir Beikzadeh

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可能是带有背景图像的JTextArea的内部填充的重复问题。 - trashgod

Answer 1

这里有一个圆角边框的示例，您可以调整半径： http://java-swing-tips.blogspot.co.at/2012/03/rounded-border-for-jtextfield.html 不是斜面，但您可以在SoftBevelBorder的源代码中看到如何实现“斜面”。如果您设法做到这一点，我会对代码感兴趣 :)

- lbalazscs

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我知道这已经过了几年了，但如果您仍然感兴趣，请查看我的答案。 - Dan

Answer 2

为了获得正确的边框形状，您需要覆盖 AbstractBorder.paintBorder(...) 方法。当您这样做时，可以在方法中添加类似于以下代码的内容。

super.paintBorder(c, g, x, y, width, height);

Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON));

Shape clip = g2d.getClip();
Area rect = new Area(clip);
rect.subtract(new Area(new RoundRectangle2D.Double(x, y, width, height, radii, radii)));
g2d.setClip(rect);
g2d.setColor(c.getParent().getBackground());
g2d.fillRect(0, 0, width, height);
g2d.setClip(clip);
g2d.draw(rect);

现在有两种主要方法可以在边框周围绘制斜角效果，但取决于您想要的斜角复杂程度，取决于使用哪种方式。对于使用2种颜色的简单斜角边框，您可以使用类似于以下内容的东西。

g2d.setColor(inner); //Inner Rectangle
g2d.draw(new RoundRectangle2D.Double(x + 1, y + 1, width - 2, height - 2, radii, radii));

g2d.setColor(outer); //Outer Rectangle
g2d.draw(new RoundRectangle2D.Double(x, y, width - 2, height - 2, radii, radii));

然而，如果你想使用一个更复杂的斜角边框，它需要使用4种不同的颜色，那么你需要查看javax.swing.border.BevelBorder的源代码。这将向你展示你需要类似于以下代码：

double offset = radii / 2;
//Outer
g2d.setColor(outerH);
g2d.draw(new Line2D.Double(0, offset, 0, height - 2 - offset)); //Left
g2d.draw(new Line2D.Double(1 + offset, 0, width - 2 - offset, 0)); //Top
g2d.draw(new Arc2D.Double(width - radii - 1, 0, radii, radii, 0, 90, Arc2D.OPEN)); //Top Right
g2d.draw(new Arc2D.Double(0, 0, radii, radii, 90, 90, Arc2D.OPEN)); //Top Left

//Inner
g2d.setColor(innerH);
g2d.draw(new Line2D.Double(1, 1 + offset, 1, height - 3 - offset)); //Left
g2d.draw(new Line2D.Double(2 + offset, 1, width - 3 - offset, 1)); //Top
g2d.draw(new Arc2D.Double(width - radii - 2, 1, radii, radii, 0, 90, Arc2D.OPEN)); //Top Right
g2d.draw(new Arc2D.Double(1, 1, radii, radii, 90, 90, Arc2D.OPEN)); //Top Left

//Outer
g2d.setColor(outer);
g2d.draw(new Line2D.Double(offset, height - 1, width - 1 - offset, height - 1)); //Bottom
g2d.draw(new Line2D.Double(width - 1, offset, width - 1, height - 2 - offset)); //Right
g2d.draw(new Arc2D.Double(width - radii - 1, height - radii - 1, radii, radii, 270, 90, Arc2D.OPEN)); //Bottom Right
g2d.draw(new Arc2D.Double(0, height - radii - 1, radii, radii, 180, 90, Arc2D.OPEN)); //Bottom Left

//Inner
g2d.setColor(inner);
g2d.draw(new Line2D.Double(1 + offset, height - 2, width - 2 - offset, height - 2)); //Bottom
g2d.draw(new Line2D.Double(width - 2, 1 + offset, width - 2, height - 3 - offset)); //Right
g2d.draw(new Arc2D.Double(width - radii - 2, height - radii - 2, radii, radii, 270, 90, Arc2D.OPEN)); //Bottom Right
g2d.draw(new Arc2D.Double(1, height - radii - 2, radii, radii, 180, 90, Arc2D.OPEN)); //Bottom Left

如果重要的话，您也可以使用以下代码使颜色仅在拐角处停止一半。

double offset = radii / 2;
//Outer
g2d.setColor(outerH);
g2d.draw(new Line2D.Double(0, offset, 0, height - 2 - offset)); //Left
g2d.draw(new Line2D.Double(1 + offset, 0, width - 2 - offset, 0)); //Top
g2d.draw(new Arc2D.Double(width - radii - 1, 0, radii, radii, 45, 45, Arc2D.OPEN)); //Top Right P1
g2d.draw(new Arc2D.Double(0, 0, radii, radii, 90, 90, Arc2D.OPEN)); //Top Left
g2d.draw(new Arc2D.Double(0, height - radii - 1, radii, radii, 180, 45, Arc2D.OPEN)); //Bottom Left P1

//Inner
g2d.setColor(innerH);
g2d.draw(new Line2D.Double(1, 1 + offset, 1, height - 3 - offset)); //Left
g2d.draw(new Line2D.Double(2 + offset, 1, width - 3 - offset, 1)); //Top
g2d.draw(new Arc2D.Double(width - radii - 2, 1, radii, radii, 45, 45, Arc2D.OPEN)); //Top Right P1
g2d.draw(new Arc2D.Double(1, 1, radii, radii, 90, 90, Arc2D.OPEN)); //Top Left
g2d.draw(new Arc2D.Double(1, height - radii - 2, radii, radii, 180, 45, Arc2D.OPEN)); //Bottom Left P1

//Outer
g2d.setColor(outerS);
g2d.draw(new Line2D.Double(offset, height - 1, width - 1 - offset, height - 1)); //Bottom
g2d.draw(new Line2D.Double(width - 1, offset, width - 1, height - 2 - offset)); //Right
g2d.draw(new Arc2D.Double(width - radii - 1, 0, radii, radii, 0, 45, Arc2D.OPEN)); //Top Right P2
g2d.draw(new Arc2D.Double(width - radii - 1, height - radii - 1, radii, radii, 270, 90, Arc2D.OPEN)); //Bottom Right
g2d.draw(new Arc2D.Double(0, height - radii - 1, radii, radii, 225, 45, Arc2D.OPEN)); //Bottom Left P2

//Inner
g2d.setColor(innerS);
g2d.draw(new Line2D.Double(1 + offset, height - 2, width - 2 - offset, height - 2)); //Bottom
g2d.draw(new Line2D.Double(width - 2, 1 + offset, width - 2, height - 3 - offset)); //Right
g2d.draw(new Arc2D.Double(width - radii - 2, 1, radii, radii, 0, 45, Arc2D.OPEN)); //Top Right P2
g2d.draw(new Arc2D.Double(width - radii - 2, height - radii - 2, radii, radii, 270, 90, Arc2D.OPEN)); //Bottom Right
g2d.draw(new Arc2D.Double(1, height - radii - 2, radii, radii, 225, 45, Arc2D.OPEN)); //Bottom Left P2

当我们把所有这些内容放在一起，你会得到一个看起来像这样的类。

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.Arc2D;
import java.awt.geom.Area;
import java.awt.geom.Line2D;
import java.awt.geom.RoundRectangle2D;

import javax.swing.border.AbstractBorder;

@SuppressWarnings("serial")
public class RoundedBorder extends AbstractBorder {
    private int radii;
    private Insets insets;
    private Color innerS = new Color(166, 166, 166);
    private Color outerS = new Color(116, 116, 116);
    private Color innerH = Color.WHITE; 
    private Color outerH = Color.WHITE;
    private boolean tColor = false;

    public RoundedBorder(int radius) {
        radii = radius;
    }

    public RoundedBorder(int radius, Insets i) {
        radii = radius;
        insets = i;
    }

    public RoundedBorder(int radius, Insets i, Color out, Color in) {
        radii = radius;
        insets = i;
        innerS = in;
        outerS = out;
        tColor = true;
    }

    public RoundedBorder(int radius, Insets i, Color outH, Color inH, Color outS, Color inS) {
        radii = radius;
        insets = i;
        innerS = inS;
        outerS = outS;
        innerH = inH;
        outerH = outH;
    }

    @Override
    public Insets getBorderInsets(Component c) {
        if(insets != null) {
            return insets;
        }
        return new Insets(5, 5, 5, 5);
    }

    @Override
    public Insets getBorderInsets(Component c, Insets insets) {
        return getBorderInsets(c);
    }

    @Override
    public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
        super.paintBorder(c, g, x, y, width, height);

        Graphics2D g2d = (Graphics2D) g;
        g2d.setRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON));

        Shape clip = g2d.getClip();
        Area rect = new Area(clip);
        rect.subtract(new Area(new RoundRectangle2D.Double(x, y, width, height, radii, radii)));
        g2d.setClip(rect);
        g2d.setColor(c.getParent().getBackground());
        g2d.fillRect(0, 0, width, height);
        g2d.setClip(clip);
        g2d.draw(rect);

        if(!tColor) {
            double offset = radii / 2;
            //Outer
            g2d.setColor(outerH);
            g2d.draw(new Line2D.Double(0, offset, 0, height - 2 - offset)); //Left
            g2d.draw(new Line2D.Double(1 + offset, 0, width - 2 - offset, 0)); //Top
            g2d.draw(new Arc2D.Double(width - radii - 1, 0, radii, radii, 45, 45, Arc2D.OPEN)); //Top Right P1
            g2d.draw(new Arc2D.Double(0, 0, radii, radii, 90, 90, Arc2D.OPEN)); //Top Left
            g2d.draw(new Arc2D.Double(0, height - radii - 1, radii, radii, 180, 45, Arc2D.OPEN)); //Bottom Left P1

            //Inner
            g2d.setColor(innerH);
            g2d.draw(new Line2D.Double(1, 1 + offset, 1, height - 3 - offset)); //Left
            g2d.draw(new Line2D.Double(2 + offset, 1, width - 3 - offset, 1)); //Top
            g2d.draw(new Arc2D.Double(width - radii - 2, 1, radii, radii, 45, 45, Arc2D.OPEN)); //Top Right P1
            g2d.draw(new Arc2D.Double(1, 1, radii, radii, 90, 90, Arc2D.OPEN)); //Top Left
            g2d.draw(new Arc2D.Double(1, height - radii - 2, radii, radii, 180, 45, Arc2D.OPEN)); //Bottom Left P1

            //Outer
            g2d.setColor(outerS);
            g2d.draw(new Line2D.Double(offset, height - 1, width - 1 - offset, height - 1)); //Bottom
            g2d.draw(new Line2D.Double(width - 1, offset, width - 1, height - 2 - offset)); //Right
            g2d.draw(new Arc2D.Double(width - radii - 1, 0, radii, radii, 0, 45, Arc2D.OPEN)); //Top Right P2
            g2d.draw(new Arc2D.Double(width - radii - 1, height - radii - 1, radii, radii, 270, 90, Arc2D.OPEN)); //Bottom Right
            g2d.draw(new Arc2D.Double(0, height - radii - 1, radii, radii, 225, 45, Arc2D.OPEN)); //Bottom Left P2

            //Inner
            g2d.setColor(innerS);
            g2d.draw(new Line2D.Double(1 + offset, height - 2, width - 2 - offset, height - 2)); //Bottom
            g2d.draw(new Line2D.Double(width - 2, 1 + offset, width - 2, height - 3 - offset)); //Right
            g2d.draw(new Arc2D.Double(width - radii - 2, 1, radii, radii, 0, 45, Arc2D.OPEN)); //Top Right P2
            g2d.draw(new Arc2D.Double(width - radii - 2, height - radii - 2, radii, radii, 270, 90, Arc2D.OPEN)); //Bottom Right
            g2d.draw(new Arc2D.Double(1, height - radii - 2, radii, radii, 225, 45, Arc2D.OPEN)); //Bottom Left P2
        } else {
            g2d.setColor(innerS); //Inner Rectangle
            g2d.draw(new RoundRectangle2D.Double(x + 1, y + 1, width - 2, height - 2, radii, radii));

            g2d.setColor(outerS); //Outer Rectangle
            g2d.draw(new RoundRectangle2D.Double(x, y, width - 2, height - 2, radii, radii));
        }
    }
}

现在，您可以通过执行yourComponent.setBorder(new RoundedBorder(10))或使用RoundedBorder类的其他构造函数，在您的组件上实现此类。请注意保留HTML标签。

- Dan

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我尝试了一下，它看起来确实是圆角的，但至少不像BevelBorder那样有斜角... - lbalazscs

@lbalazscs 谢谢您的反馈。在发布之前，我应该尝试使用初始斜角边框颜色。我已经编辑了代码，这样当您使用 yourComponent.setBorder(new RoundedBorder(10)); 时，它将默认看起来更加“斜角”（我很确定这不是一个词 :P）。 - Dan

@lbalazscs，您是否认为它看起来更好，或者我需要以某种方式进行修改？ - Dan

现在好多了，更“斜角”了 :) 这应该是被接受的答案，而不是我的。 - lbalazscs

@lbalazscs 我很高兴它是你的，因为我是从你的回答中得到这个想法的。我只是实现了它 :) 再次感谢反馈。 - Dan

非常感谢，这个类写得非常好，功能也很多样化。 - JFreeman