自定义边框外的组件绘画
在这个自定义边框类中，我定义了一个RoundRectangle2D形状。 此对象用于绘制边框。 不幸的是，由于JComponent的paint方法在paintBorder之前调用paintComponent ，因此将Graphics剪辑设置为RoundRectangle2D形状没有任何效果; 即使我发出repaint 。 因此，组件将在其边界外部绘制，这是可以理解的不合需要的。
所以，我想知道：如何让组件专门在自定义边框内绘制？
我考虑的一种方法是在paintComponent方法中获取组件的Border对象。 然后将此对象转换为适当的类，其中我定义将影响剪辑的参数。 但这似乎不是一个“声音”设计。
编辑 –
import java.awt.BasicStroke; import java.awt.Color; import java.awt.Component; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Insets; import java.awt.RenderingHints; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.SwingUtilities; import javax.swing.border.AbstractBorder; class JRoundedCornerBorder extends AbstractBorder { private static final long serialVersionUID = 7644739936531926341L; private static final int THICKNESS = 2; JRoundedCornerBorder() { super(); } @Override public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) { Graphics2D g2 = (Graphics2D)g.create(); g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); if(c.hasFocus()) { g2.setColor(Color.BLUE); } else { g2.setColor(Color.BLACK); } g2.setStroke(new BasicStroke(THICKNESS, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND)); g2.drawRoundRect(THICKNESS, THICKNESS, width - THICKNESS - 2, height - THICKNESS - 2, 20, 20); g2.dispose(); } @Override public Insets getBorderInsets(Component c) { return new Insets(THICKNESS, THICKNESS, THICKNESS, THICKNESS); } @Override public Insets getBorderInsets(Component c, Insets insets) { insets.left = insets.top = insets.right = insets.bottom = THICKNESS; return insets; } public boolean isBorderOpaque() { return false; } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { final JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new FlowLayout()); // Add button with custom border final JButton button = new JButton("Hello"); button.setBorder(new JRoundedCornerBorder()); button.setBackground(Color.YELLOW); button.setPreferredSize(new Dimension(200, 200)); frame.add(button); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } }
红色圆圈突出显示组件延伸到其边界之外的位置。
啊……最后我得到了它（由于某种原因错过了roundBorder，我的错:-)按钮只是遵守它的合同：它说明是不透明的，所以必须填满它的完整区域，包括边界的区域。 所以设置一个剪辑（你可以在paintComponent中做）会违反合同：
// DO NOT - a opaque component violates its contract, as it will not fill // its complete area @Override protected void paintComponent(Graphics g) { if (getBorder() instanceof JRoundedCornerBorder) { Shape borderShape = ((JRoundedCornerBorder) getBorder()). getBorderShape(getWidth(), getHeight()); g.setClip(borderShape); } super.paintComponent(g); }
丑陋但安全的是将自己报告为透明并自己接管背景画：
@Override protected void paintComponent(Graphics g) { if (getBorder() instanceof JRoundedCornerBorder) { g.setColor(getBackground()); Shape borderShape = ((JRoundedCornerBorder) getBorder()) .getBorderShape(getWidth(), getHeight()); ((Graphics2D) g).fill(borderShape); } super.paintComponent(g); } @Override public boolean isContentAreaFilled() { if (getBorder() instanceof JRoundedCornerBorder) return false; return super.isContentAreaFilled(); } // using button.setOpaque(false);
不是你的问题的答案，只是另一个想法如何做到这一点
从非常长的代码
import java.awt.*; import java.awt.geom.*; import javax.swing.*; import javax.swing.event.*; public class Panel2Test { public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { ShadeOptionsPanel shadeOptions = new ShadeOptionsPanel(); ShadowSelector shadowSelector = new ShadowSelector(shadeOptions); //ComponentSource componentSource = new ComponentSource(shadeOptions); JFrame f = new JFrame("Rounded Concept Demo with Shadows"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.add(shadowSelector, "North"); f.add(shadeOptions); //f.add(componentSource, "South"); f.setSize(300, 200); f.setLocation(150, 150); f.setVisible(true); } }); } private Panel2Test() { } } class ShadeOptionsPanel extends JPanel { private static final long serialVersionUID = 1L; private final int PAD, DIA, BORDER; private Color colorIn, colorOut; private int xc, yc; private Ellipse2D eIn, eOut; private GradientPaint gradient; private CustomPaint customPaint; private Area arcBorder; private int width, height; private Point2D neOrigin, nwOrigin, swOrigin, seOrigin, neDiag, nwDiag, swDiag, seDiag; private final static int NORTHEAST = 0, NORTHWEST = 1, SOUTHWEST = 2, SOUTHEAST = 3; public int shadowVertex = 3; public ShadeOptionsPanel() { PAD = 25; DIA = 75; BORDER = 10; colorIn = Color.black; colorOut = getBackground(); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D) g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); width = getWidth(); height = getHeight(); g2.drawRoundRect(PAD, PAD, width - 2 * PAD, height - 2 * PAD, DIA, DIA); calculateArcOrigins(); calculateCardinalDiagonals(); drawVertexArc(g2, shadowVertex); switch (shadowVertex) { case NORTHEAST: drawNorthSide(g2); drawEastSide(g2); xc = PAD + DIA / 2; // draw northwest arc yc = PAD + DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(nwOrigin, nwDiag); eOut = getOuterEllipse(nwOrigin, nwDiag); arcBorder = getArcArea(eIn, eOut, 90.0); g2.fill(arcBorder); xc = width - PAD - DIA / 2; // draw southeast arc yc = height - PAD - DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(seOrigin, seDiag); eOut = getOuterEllipse(seOrigin, seDiag); arcBorder = getArcArea(eIn, eOut, 270.0); g2.fill(arcBorder); break; case NORTHWEST: drawNorthSide(g2); drawWestSide(g2); xc = width - PAD - DIA / 2;// draw northeast arc yc = PAD + DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(neOrigin, neDiag); eOut = getOuterEllipse(neOrigin, neDiag); arcBorder = getArcArea(eIn, eOut, 0.0); g2.fill(arcBorder); xc = PAD + DIA / 2;// draw southwest arc yc = height - PAD - DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(swOrigin, swDiag); eOut = getOuterEllipse(swOrigin, swDiag); arcBorder = getArcArea(eIn, eOut, 180.0); g2.fill(arcBorder); break; case SOUTHWEST: drawWestSide(g2); drawSouthSide(g2); xc = PAD + DIA / 2; // draw northwest arc yc = PAD + DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(nwOrigin, nwDiag); eOut = getOuterEllipse(nwOrigin, nwDiag); arcBorder = getArcArea(eIn, eOut, 90.0); g2.fill(arcBorder); xc = width - PAD - DIA / 2; // draw the southeast arc yc = height - PAD - DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(seOrigin, seDiag); eOut = getOuterEllipse(seOrigin, seDiag); arcBorder = getArcArea(eIn, eOut, 270.0); g2.fill(arcBorder); break; case SOUTHEAST: drawEastSide(g2); drawSouthSide(g2); xc = width - PAD - DIA / 2; // draw northeast arc yc = PAD + DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(neOrigin, neDiag); eOut = getOuterEllipse(neOrigin, neDiag); arcBorder = getArcArea(eIn, eOut, 0.0); g2.fill(arcBorder); xc = PAD + DIA / 2; // draw southwest arc yc = height - PAD - DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = getInnerEllipse(swOrigin, swDiag); eOut = getOuterEllipse(swOrigin, swDiag); arcBorder = getArcArea(eIn, eOut, 180.0); g2.fill(arcBorder); } } private Ellipse2D getInnerEllipse(Point2D center, Point2D corner) { return new Ellipse2D.Double(center.getX() - DIA / 2, center.getY() - DIA / 2, DIA, DIA); } private Ellipse2D getOuterEllipse(Point2D center, Point2D corner) { int w = DIA, h = DIA; if (shadowVertex < 2) { if (center.getY() > corner.getY()) { h += 2 * BORDER; } else { w += 2 * BORDER; } } else if (center.getY() > corner.getY()) { w += 2 * BORDER; } else { h += 2 * BORDER; } return new Ellipse2D.Double(center.getX() - w / 2, center.getY() - h / 2, w, h); } private Area getArcArea(Ellipse2D e1, Ellipse2D e2, double start) { Arc2D arc1 = new Arc2D.Double(e1.getBounds2D(), start, 90.0, Arc2D.PIE); Arc2D arc2 = new Arc2D.Double(e2.getBounds2D(), start, 90.0, Arc2D.PIE); Area arc = new Area(arc2); arc.subtract(new Area(arc1)); return arc; } private void drawNorthSide(Graphics2D g2) { gradient = new GradientPaint(width / 2, PAD - BORDER, colorOut, width / 2, PAD, colorIn); g2.setPaint(gradient); g2.fill(new Rectangle2D.Double(PAD + DIA / 2, PAD - BORDER, width - 2 * (PAD + DIA / 2) + 1, BORDER)); } private void drawWestSide(Graphics2D g2) { gradient = new GradientPaint(PAD - BORDER, height / 2, colorOut, PAD, height / 2, colorIn); g2.setPaint(gradient); g2.fill(new Rectangle2D.Double(PAD - BORDER, PAD + DIA / 2, BORDER, height - 2 * (PAD + DIA / 2) + 1)); } private void drawSouthSide(Graphics2D g2) { gradient = new GradientPaint(width / 2, height - PAD, colorIn, width / 2, height - PAD + BORDER, colorOut); g2.setPaint(gradient); g2.fill(new Rectangle2D.Double(PAD + DIA / 2, height - PAD, width - 2 * (PAD + DIA / 2) + 1, BORDER)); } private void drawEastSide(Graphics2D g2) { gradient = new GradientPaint(width - PAD, height / 2, colorIn, width - PAD + BORDER, height / 2, colorOut); g2.setPaint(gradient); g2.fill(new Rectangle2D.Double(width - PAD, PAD + DIA / 2, BORDER, height - 2 * (PAD + DIA / 2) + 1)); } /** * Draws the central, full-shaded arc (opposite of the unshaded arc). */ private void drawVertexArc(Graphics2D g2, int index) { switch (index) { case NORTHEAST: xc = width - PAD - DIA / 2; yc = PAD + DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = new Ellipse2D.Double(width - PAD - DIA, PAD, DIA, DIA); eOut = new Ellipse2D.Double(width - PAD - DIA - BORDER, PAD - BORDER, DIA + 2 * BORDER, DIA + 2 * BORDER); arcBorder = getArcArea(eIn, eOut, 0.0); g2.fill(arcBorder); break; case NORTHWEST: xc = PAD + DIA / 2; yc = PAD + DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = new Ellipse2D.Double(PAD, PAD, DIA, DIA); eOut = new Ellipse2D.Double(PAD - BORDER, PAD - BORDER, DIA + 2 * BORDER, DIA + 2 * BORDER); arcBorder = getArcArea(eIn, eOut, 90.0); g2.fill(arcBorder); break; case SOUTHWEST: xc = PAD + DIA / 2; yc = height - PAD - DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = new Ellipse2D.Double(PAD, height - PAD - DIA, DIA, DIA); eOut = new Ellipse2D.Double(PAD - BORDER, height - PAD - DIA - BORDER, DIA + 2 * BORDER, DIA + 2 * BORDER); arcBorder = getArcArea(eIn, eOut, 180.0); g2.fill(arcBorder); break; case SOUTHEAST: xc = width - PAD - DIA / 2; yc = height - PAD - DIA / 2; customPaint = new CustomPaint(xc, yc, new Point2D.Double(0, DIA / 2), DIA / 2, BORDER, colorIn, colorOut); g2.setPaint(customPaint); eIn = new Ellipse2D.Double(width - PAD - DIA, height - PAD - DIA, DIA, DIA); eOut = new Ellipse2D.Double(width - PAD - DIA - BORDER, height - PAD - DIA - BORDER, DIA + 2 * BORDER, DIA + 2 * BORDER); arcBorder = getArcArea(eIn, eOut, 270.0); g2.fill(arcBorder); } } private void calculateArcOrigins() { neOrigin = new Point2D.Double(width - PAD - DIA / 2, PAD + DIA / 2); nwOrigin = new Point2D.Double(PAD + DIA / 2, PAD + DIA / 2); swOrigin = new Point2D.Double(PAD + DIA / 2, height - PAD - DIA / 2); seOrigin = new Point2D.Double(width - PAD - DIA / 2, height - PAD - DIA / 2); } private void calculateCardinalDiagonals() { neDiag = new Point2D.Double(neOrigin.getX() + DIA * Math.cos(Math.toRadians(45)) / 2, neOrigin.getY() - DIA * Math.sin(Math.toRadians(45)) / 2); nwDiag = new Point2D.Double(nwOrigin.getX() + DIA * Math.cos(Math.toRadians(135)) / 2, nwOrigin.getY() - DIA * Math.sin(Math.toRadians(135)) / 2); swDiag = new Point2D.Double(swOrigin.getX() + DIA * Math.cos(Math.toRadians(225)) / 2, swOrigin.getY() - DIA * Math.sin(Math.toRadians(225)) / 2); seDiag = new Point2D.Double(seOrigin.getX() + DIA * Math.cos(Math.toRadians(315)) / 2, seOrigin.getY() - DIA * Math.sin(Math.toRadians(315)) / 2); } public Dimension getInnerSize() { return new Dimension((int) nwOrigin.distance(neOrigin), (int) nwOrigin.distance(swOrigin)); } } class ShadowSelector extends JPanel { private static final long serialVersionUID = 1L; private ShadeOptionsPanel soPanel; private String[] directions = {"northeast", "northwest", "southwest", "southeast"}; public ShadowSelector(ShadeOptionsPanel sop) { soPanel = sop; final SpinnerListModel model = new SpinnerListModel(directions); model.setValue(directions[3]); JSpinner spinner = new JSpinner(model); spinner.setPreferredSize(new Dimension(90, spinner.getPreferredSize().height)); spinner.addChangeListener(new ChangeListener() { @Override public void stateChanged(ChangeEvent e) { String value = (String) model.getValue(); soPanel.shadowVertex = model.getList().indexOf(value); soPanel.repaint(); } }); add(new JLabel("shadow vertex", JLabel.RIGHT)); add(spinner); } } class CustomPaint implements Paint { Point2D originP, radiusP; int radius, border; Color colorIn, colorOut; public CustomPaint(int x, int y, Point2D radiusP, int radius, int border, Color colorIn, Color colorOut) { originP = new Point2D.Double(x, y); this.radiusP = radiusP; this.radius = radius; this.border = border; this.colorIn = colorIn; this.colorOut = colorOut; } @Override public PaintContext createContext(ColorModel cm, Rectangle deviceBounds, Rectangle2D userBounds, AffineTransform xform, RenderingHints hints) { Point2D xformOrigin = xform.transform(originP, null), xformRadius = xform.deltaTransform(radiusP, null); return new CustomPaintContext(xformOrigin, xformRadius, radius, border, colorIn, colorOut); } @Override public int getTransparency() { int alphaIn = colorIn.getAlpha(); int alphaOut = colorOut.getAlpha(); return (((alphaIn & alphaOut) == 0xff) ? OPAQUE : TRANSLUCENT); } } class CustomPaintContext implements PaintContext { Point2D originP, radiusP; Color colorIn, colorOut; int radius, border; public CustomPaintContext(Point2D originP, Point2D radiusP, int radius, int border, Color colorIn, Color colorOut) { this.originP = originP; this.radiusP = radiusP; this.radius = radius; this.border = border; this.colorIn = colorIn; this.colorOut = colorOut; } @Override public void dispose() { } @Override public ColorModel getColorModel() { return ColorModel.getRGBdefault(); } @Override public Raster getRaster(int x, int y, int w, int h) { WritableRaster raster = getColorModel().createCompatibleWritableRaster(w, h); int[] data = new int[w * h * 4]; for (int j = 0; j < h; j++) { for (int i = 0; i < w; i++) { double distance = originP.distance(x + i, y + j); double r = radiusP.distance(radius, radius); double ratio = distance - r < 0 ? 0.0 : (distance - r) / border; if (ratio > 1.0) { ratio = 1.0; } int base = (j * w + i) * 4; data[base + 0] = (int) (colorIn.getRed() + ratio * (colorOut.getRed() - colorIn.getRed())); data[base + 1] = (int) (colorIn.getGreen() + ratio * (colorOut.getGreen() - colorIn.getGreen())); data[base + 2] = (int) (colorIn.getBlue() + ratio * (colorOut.getBlue() - colorIn.getBlue())); data[base + 3] = (int) (colorIn.getAlpha() + ratio * (colorOut.getAlpha() - colorIn.getAlpha())); } } raster.setPixels(0, 0, w, h, data); return raster; } }
你怎么画边框？ 你实现了Border接口吗？ 有三种方法可以将所有边界逻辑放在那里
void paintBorder(Component c, Graphics g, int x, int y, int width, int height); Insets getBorderInsets(Component c); boolean isBorderOpaque();