java - 在 jframe 中的模糊背景上创建一个透明矩形

Question

我在模糊背景上创建透明矩形时遇到问题。我正在尝试在glasspane上执行此任务。这是我的代码片段。

void createBlur() {
    alpha = 1.0f;
    JRootPane root = SwingUtilities.getRootPane(jf);
    blurBuffer = GraphicsUtilities.createCompatibleImage(jf.getWidth(), jf.getHeight());
    Graphics2D g2d = blurBuffer.createGraphics();
    root.paint(g2d);
    g2d.dispose();

    backBuffer = blurBuffer;
    blurBuffer = GraphicsUtilities.createThumbnailFast(blurBuffer, jf.getWidth() / 2);
    blurBuffer = new GaussianBlurFilter(5).filter(blurBuffer, null);
}

其中，backBuffer和blurBuffer是BufferedImage的对象&jf = JFrame，alpha用于不透明度。上述方法很好地创建了模糊效果。

这是在面板上创建透明矩形的代码

protected void paintComponent(Graphics g) {
    int x = 34;
    int y = 34;
    int w = getWidth() - 68;
    int h = getHeight() - 68;
    int arc = 30;

    //Graphics2D g2 = currentGraphics.createGraphics();
    //g2.drawImage(currentGraphics, 0, 0, null);
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

    g2.setColor(new Color(0, 0, 0, 220));
    g2.fillRoundRect(x, y, w, h, arc, arc);

    g2.setStroke(new BasicStroke(1f));
    g2.setColor(Color.WHITE);
    g2.drawRoundRect(x, y, w, h, arc, arc);

    g2.dispose();
}

现在我遇到的问题是如何同时绘制模糊效果和透明矩形。我没有在这里发布完整的代码，如果有人想在这里看到代码link .

这是所需的示例输出图像。提前致谢。

Answer 1

我正在尝试弄清楚您的代码...

您无法调用 super.paintComponent...如果您不小心，这可能会导致您遇到同样严重的问题。一般经验法则，只需调用它即可;)

修改Graphics上下文的状态时要小心，例如......

g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

将影响在此之后绘制的所有组件，并可能导致一些您没有预料到的有趣的图形故障...

jf.getGlassPane().setVisible(false);
glassPanel = new GlassPanel();
jf.getGlassPane().setVisible(true);

似乎毫无意义，因为使用 jf.setGlassPane(glassPanel); 设置的组件仍然是调用 jf.getGlassPane().setVisible(true) 时可见的组件;。这也意味着 GlassPane 组件从未被使用过...

在 paintComponent 中检查 isVisible 是没有意义的，因为 Swing 足够聪明，知道不要绘制不可见的组件...

现在，说了这么多......

如果您想在 BlurPanel 上绘制，您可以...在绘制 blurBuffer 后绘制内容，因此您可以在其上绘制或添加BlurPanel Pane 上的另一个组件，其中包含您要应用的绘图逻辑...

这是该概念的一个基本示例。这会在玻璃板上添加另一个面板，根据我的需要绘制面板的自定义框架。

此示例使用个人库代码，仅作为概念示例，而不是完全可运行的示例。

import core.ui.GlowEffectFactory;
import core.ui.GraphicsUtilities;
import core.util.ByteFormatter;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.text.DateFormat;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRootPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;

public class TransparentTest {

    public static void main(String[] args) {
        new TransparentTest();
    }

    public TransparentTest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private BufferedImage background;
        private BlurredGlassPane blurredGlassPane;

        private InfoPane infoPane;

        public TestPane() {
            try {
                background = ImageIO.read(new File("get your own image"));
            } catch (IOException ex) {
                ex.printStackTrace();
            }

            blurredGlassPane = new BlurredGlassPane();
            blurredGlassPane.setLayout(new GridBagLayout());
            infoPane = new InfoPane();
            infoPane.setFile(new File("get your own image"));
            blurredGlassPane.add(infoPane);

            JButton click = new JButton("Click");
            click.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    Window win = SwingUtilities.getWindowAncestor(TestPane.this);
                    if (win instanceof JFrame) {
                        JFrame frame = (JFrame) win;
                        frame.setGlassPane(blurredGlassPane);
                        blurredGlassPane.setVisible(true);
                    }
                }
            });

            setLayout(new GridBagLayout());
            add(click);
        }

        @Override
        public Dimension getPreferredSize() {
            return background == null ? new Dimension(200, 200) : new Dimension(background.getWidth(), background.getHeight());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            if (background != null) {
                Graphics2D g2d = (Graphics2D) g.create();
                int x = (getWidth() - background.getWidth()) / 2;
                int y = (getHeight() - background.getHeight()) / 2;
                g2d.drawImage(background, x, y, this);
                g2d.dispose();
            }
        }
    }

    public static class InfoPane extends JPanel {

        protected static final int RADIUS = 20;
        protected static final int FRAME = 4;
        protected static final int INSET = RADIUS + FRAME;
        protected static final DateFormat DATE_FORMAT = DateFormat.getDateTimeInstance();

        private JLabel name;
        private JLabel path;
        private JLabel length;
        private JLabel lastModified;
        private JLabel canExecute;
        private JLabel canRead;
        private JLabel canWrite;
        private JLabel isDirectory;
        private JLabel isHidden;

        public InfoPane() {
            setBorder(new EmptyBorder(INSET, INSET, INSET, INSET));
            setOpaque(false);
            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.weightx = 1;
            gbc.anchor = GridBagConstraints.WEST;
            gbc.gridwidth = GridBagConstraints.REMAINDER;

            name = createLabel(Font.BOLD, 48);
            add(name, gbc);

            gbc.gridy++;
            path = createLabel();
            add(path, gbc);

            gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 2;
            gbc.anchor = GridBagConstraints.WEST;

            length = createLabel();
            lastModified = createLabel();
            add(createLabel("Size: "), gbc);

            gbc.gridx++;
            gbc.insets = new Insets(0, 0, 0, 10);
            add(length, gbc);

            gbc.insets = new Insets(0, 0, 0, 0);
            gbc.gridx++;
            add(createLabel("Last Modified: "), gbc);

            gbc.gridx++;
            add(lastModified, gbc);
        }

        public JLabel createLabel(String text) {

            JLabel label = new JLabel(text);
            label.setForeground(Color.WHITE);
            return label;

        }

        public JLabel createLabel() {

            return createLabel("");

        }

        public JLabel createLabel(int style, float size) {

            JLabel label = createLabel();
            label.setFont(label.getFont().deriveFont(style, size));
            return label;
        }

        public void setFile(File file) {

            name.setText(file.getName());
            try {
                path.setText(file.getParentFile().getCanonicalPath());
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            length.setText(ByteFormatter.format(file.length()));
            lastModified.setText(DATE_FORMAT.format(new Date(file.lastModified())));
            file.canExecute();
            file.canRead();
            file.canWrite();
            file.isDirectory();
            file.isHidden();

        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g); 
            Graphics2D g2d = (Graphics2D) g.create();
            GraphicsUtilities.applyQualityRenderingHints(g2d);
            int width = getWidth() - 1;
            int height = getHeight() - 1;
            int buffer = FRAME / 2;
            RoundRectangle2D base = new RoundRectangle2D.Double(buffer, buffer, width - FRAME, height - FRAME, RADIUS, RADIUS);
            g2d.setColor(new Color(0, 0, 0, 128));
            g2d.fill(base);
            g2d.setColor(Color.WHITE);
            g2d.setStroke(new BasicStroke(FRAME, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
            g2d.draw(base);
            g2d.dispose();
        }

    }

    public class BlurredGlassPane extends JPanel {

        private BufferedImage background;

        @Override
        public void setVisible(boolean visible) {
            if (visible) {
                Container parent = SwingUtilities.getAncestorOfClass(JRootPane.class, this);
                if (parent != null) {
                    JRootPane rootPane = (JRootPane) parent;

                    BufferedImage img = new BufferedImage(rootPane.getWidth(), rootPane.getHeight(), BufferedImage.TYPE_INT_ARGB);
                    Graphics2D g2d = img.createGraphics();
                    rootPane.printAll(g2d);
                    g2d.dispose();

                    background = GlowEffectFactory.generateBlur(img, 40);
                }
            }
            super.setVisible(visible);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(background, 0, 0, this);
        }

    }

}