Question

我有两个不同的编辑器使用JTextPane和Java 7中的奇怪错误，这些错误在以前的JVM版本中没有出现。它出现在包含样式文本或组件的长行中。

以下是演示此错误的示例。在此示例中，每次插入字符时，都会对所有文本应用默认样式。我用JDK 1.7.0_04测试了它。

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

public class BugWrapJava7 extends JFrame {

    JTextPane jtp;
    StyledDocument doc;

    public BugWrapJava7() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
        jtp = new JTextPane();
        add(jtp, BorderLayout.CENTER);
        jtp.setText("\ntype some text in the above empty line and check the wrapping behavior");
        doc = jtp.getStyledDocument();
        doc.addDocumentListener(new DocumentListener() {
            public void insertUpdate(DocumentEvent e) {
                insert();
            }
            public void removeUpdate(DocumentEvent e) {
            }
            public void changedUpdate(DocumentEvent e) {
            }
        });
        setSize(200, 200);
        setVisible(true);
    }
    public void insert() {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                Style defaultStyle = jtp.getStyle(StyleContext.DEFAULT_STYLE);
                doc.setCharacterAttributes(0, doc.getLength(), defaultStyle, false);
            }
        });
    }
    public static void main(String[] args) {
        new BugWrapJava7();
    }
}

我的问题是：我的代码中有什么问题，或者它确实是Java 7中引入的新错误？如果它是一个新的JVM错误，是否有解决方法？

它可能与question 8666727有关，但问题在于错误的包装而不是滚动条的外观。

Answer 1

期货读者，bug is still present in JDK 1.7.0_04.，

比较Java7和稳定的Java6，

enter image description here ＆lt; ------ Java7 v.s. Java6 ---＆gt;

来自代码

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

public class BugWrapJava7 {

    private JFrame frame = new JFrame();
    private JTextPane jtp;
    private StyledDocument doc;

    public BugWrapJava7() {
        jtp = new JTextPane();
        jtp.setText("\ntype some text in the above empty line and check the wrapping behavior");
        doc = jtp.getStyledDocument();
        doc.addDocumentListener(new DocumentListener() {

            public void insertUpdate(DocumentEvent e) {
                insert();
            }

            public void removeUpdate(DocumentEvent e) {
                insert();
            }

            public void changedUpdate(DocumentEvent e) {
                insert();
            }

            public void insert() {
                SwingUtilities.invokeLater(new Runnable() {

                    public void run() {
                        Style defaultStyle = jtp.getStyle(StyleContext.DEFAULT_STYLE);
                        doc.setCharacterAttributes(0, doc.getLength(), defaultStyle, false);
                    }
                });
            }
        });
        JScrollPane scroll = new JScrollPane(jtp);
        scroll.setPreferredSize(new Dimension(200, 200));
        frame.add(scroll);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                BugWrapJava7 bugWrapJava7 = new BugWrapJava7();
            }
        });
    }
}

Answer 2

调查此事。原因是breakSpots缓存。看起来LabelView存储它们并且不会重新计算previos文本编辑的偏移量。如果我手动重置它们，则不会发生错误。

解决方法（由于私有breakSpots字段而非常脏）正在跟随

import java.awt.Dimension;
import java.lang.reflect.Field;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;

public class BugWrapJava7 {

    private JFrame frame = new JFrame();
    private JTextPane jtp;
    private StyledDocument doc;

    public BugWrapJava7() {
        jtp = new JTextPane();
        jtp.setEditorKit(new MyStyledEditorKit());
        jtp.setText("\ntype some text in the above empty line and check the wrapping behavior");
        doc = jtp.getStyledDocument();
        doc.addDocumentListener(new DocumentListener() {

            public void insertUpdate(DocumentEvent e) {
                insert();
            }

            public void removeUpdate(DocumentEvent e) {
                insert();
            }

            public void changedUpdate(DocumentEvent e) {
                insert();
            }

            public void insert() {
                SwingUtilities.invokeLater(new Runnable() {

                    public void run() {
                        Style defaultStyle = jtp.getStyle(StyleContext.DEFAULT_STYLE);
                        doc.setCharacterAttributes(0, doc.getLength(), defaultStyle, false);
                    }
                });
            }
        });
        JScrollPane scroll = new JScrollPane(jtp);
        scroll.setPreferredSize(new Dimension(200, 200));
        frame.add(scroll);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                BugWrapJava7 bugWrapJava7 = new BugWrapJava7();
            }
        });
    }
}

class MyStyledEditorKit extends StyledEditorKit {
    private MyFactory factory;

    public ViewFactory getViewFactory() {
        if (factory == null) {
            factory = new MyFactory();
        }
        return factory;
    }
}

class MyFactory implements ViewFactory {
    public View create(Element elem) {
        String kind = elem.getName();
        if (kind != null) {
            if (kind.equals(AbstractDocument.ContentElementName)) {
                return new MyLabelView(elem);
            } else if (kind.equals(AbstractDocument.ParagraphElementName)) {
                return new ParagraphView(elem);
            } else if (kind.equals(AbstractDocument.SectionElementName)) {
                return new BoxView(elem, View.Y_AXIS);
            } else if (kind.equals(StyleConstants.ComponentElementName)) {
                return new ComponentView(elem);
            } else if (kind.equals(StyleConstants.IconElementName)) {
                return new IconView(elem);
            }
        }

        // default to text display
        return new LabelView(elem);
    }
}

class MyLabelView extends LabelView {
    public MyLabelView(Element elem) {
        super(elem);
    }
    public View breakView(int axis, int p0, float pos, float len) {
        if (axis == View.X_AXIS) {
            resetBreakSpots();
        }
        return super.breakView(axis, p0, pos, len);
    }

    private void resetBreakSpots() {
        try {
            // HACK the breakSpots private fields
            Field f=GlyphView.class.getDeclaredField("breakSpots");
            f.setAccessible(true);
            f.set(this, null);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

没有反思就少了黑客。基于模型更改时breakSpots的通常重置。

class MyLabelView extends LabelView {

    boolean isResetBreakSpots=false;

    public MyLabelView(Element elem) {
        super(elem);
    }
    public View breakView(int axis, int p0, float pos, float len) {
        if (axis == View.X_AXIS) {
            resetBreakSpots();
        }
        return super.breakView(axis, p0, pos, len);
    }

    private void resetBreakSpots() {
        isResetBreakSpots=true;
        removeUpdate(null, null, null);
        isResetBreakSpots=false;

//        try {
//            Field f=GlyphView.class.getDeclaredField("breakSpots");
//            f.setAccessible(true);
//            f.set(this, null);
//        } catch (Exception e) {
//            e.printStackTrace();
//        }
    }

    public void removeUpdate(DocumentEvent e, Shape a, ViewFactory f) {
        super.removeUpdate(e, a, f);
    }

    public void preferenceChanged(View child, boolean width, boolean height) {
        if (!isResetBreakSpots) {
            super.preferenceChanged(child, width, height);
        }
    }
}

更新：这个也修复了TextSamplerDemo。我重置了所有标签视图的所有位置。

class MyStyledEditorKit extends StyledEditorKit {
    private MyFactory factory;

    public ViewFactory getViewFactory() {
        if (factory == null) {
            factory = new MyFactory();
        }
        return factory;
    }
}

class MyFactory implements ViewFactory {
    public View create(Element elem) {
        String kind = elem.getName();
        if (kind != null) {
            if (kind.equals(AbstractDocument.ContentElementName)) {
                return new MyLabelView(elem);
            } else if (kind.equals(AbstractDocument.ParagraphElementName)) {
                return new MyParagraphView(elem);
            } else if (kind.equals(AbstractDocument.SectionElementName)) {
                return new BoxView(elem, View.Y_AXIS);
            } else if (kind.equals(StyleConstants.ComponentElementName)) {
                return new ComponentView(elem);
            } else if (kind.equals(StyleConstants.IconElementName)) {
                return new IconView(elem);
            }
        }

        // default to text display
        return new LabelView(elem);
    }
}

class MyParagraphView extends ParagraphView {

    public MyParagraphView(Element elem) {
        super(elem);
    }
public void removeUpdate(DocumentEvent e, Shape a, ViewFactory f) {
    super.removeUpdate(e, a, f);
    resetBreakSpots();
}
public void insertUpdate(DocumentEvent e, Shape a, ViewFactory f) {
    super.insertUpdate(e, a, f);
    resetBreakSpots();
}

private void resetBreakSpots() {
    for (int i=0; i<layoutPool.getViewCount(); i++) {
        View v=layoutPool.getView(i);
        if (v instanceof MyLabelView) {
            ((MyLabelView)v).resetBreakSpots();
        }
    }
}

}

class MyLabelView extends LabelView {

    boolean isResetBreakSpots=false;

    public MyLabelView(Element elem) {
        super(elem);
    }
    public View breakView(int axis, int p0, float pos, float len) {
        if (axis == View.X_AXIS) {
            resetBreakSpots();
        }
        return super.breakView(axis, p0, pos, len);
    }

    public void resetBreakSpots() {
        isResetBreakSpots=true;
        removeUpdate(null, null, null);
        isResetBreakSpots=false;
   }

    public void removeUpdate(DocumentEvent e, Shape a, ViewFactory f) {
        super.removeUpdate(e, a, f);
    }

    public void preferenceChanged(View child, boolean width, boolean height) {
        if (!isResetBreakSpots) {
            super.preferenceChanged(child, width, height);
        }
    }
}

Answer 3

我的HTMLDocument是按字母换行的。我安装了StanislavL的上述解决方案。没什么好高兴的，仍然在元素内按字母包裹。因此，我修复了StanislavL代码中的一个错误。喜悦;到处都是按字换行。然后我发现我的程序没有使用StanislavL代码！看来我的修修补补在我自己的代码中修复了相同的错误。

问题在于存在两种不同类型的Element（在javax.swing.text和javax.swing.text.html.parser中），并且都具有带有字符串值“ content”的标记类型名称。方法Element.getName通过返回一个String而不是一个Object来混淆它。

因此，代码显示为“ .equals（）”

    String kind = elem.getName();
    if (kind != null) {
        if (kind.equals(AbstractDocument.ContentElementName)) {
    ...

它应该说“ ==“

    Object absDocName = attrs.getAttribute(AbstractDocument.ElementNameAttribute)
    if (absDocName != null){
        if (kind == AbstractDocument.ContentElementName) {
    ...

使用Java 7在JTextPane中使用样式文本进行奇怪的文本包装

3 个答案: