如何将JTextPane / JPanel正确地打包到JPanel到JScrollPane中？

Question

Below is the answer specific to my original question, but if you're trying to achieve a similar structure in general, it'd probably be more practical follow camickr's method below. To do it the way I originally wanted, you have to override JPanel and implement Scrollable for the outer container. (credit to user Kylar - JTextArea on JPanel inside JScrollPane does not resize properly )

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

public class MyEditor extends JTextPane {
    JFrame window;
    JScrollPane editScroll;
    NumberLines numPane;
    HoldMe please;

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

MyEditor() {

    setOpaque(false);
    setEditorKit(new TextWrapKit());

    numPane = new NumberLines();
    numPane.setPreferredSize(new Dimension(50,100));
    please = new HoldMe();

    please.setLayout(new BorderLayout());
    please.add(this,BorderLayout.CENTER);
    please.add(numPane,BorderLayout.WEST);

    editScroll = new JScrollPane(please);
    editScroll.setPreferredSize(new Dimension(500,500));
    editScroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
    editScroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); 

    window = new JFrame();
    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    window.getContentPane().add(editScroll);
    window.pack();
    window.setVisible(true);
}

private class HoldMe extends JPanel implements Scrollable{
    public Dimension getPreferredScrollableViewportSize() {
    return super.getPreferredSize(); //tell the JScrollPane that we want to be our 'preferredSize' - but later, we'll say that vertically, it should scroll.
    }

     public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
    return 16;//set to 16 because that's what you had in your code.
    }

    public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {
    return 16;//set to 16 because that's what you had set in your code.
    }

    public boolean getScrollableTracksViewportWidth() {
    return true;//track the width, and re-size as needed.
    }

    public boolean getScrollableTracksViewportHeight() {
    return false; //we don't want to track the height, because we want to scroll vertically.
 }   
}


private class NumberLines extends JPanel {
NumberLines() {
        setBackground(new Color(120,120,120));
        setOpaque(false);
        repaint();
    } 
@Override
protected void paintComponent(Graphics g) {
    g.fillRect(0,0,this.getWidth(),this.getHeight());

}

}

private class TextWrapKit extends StyledEditorKit {
    ViewFactory defaultFactory=new TextWrapFactory();
    public ViewFactory getViewFactory() {
        return defaultFactory;
    }
}

private class TextWrapFactory implements ViewFactory {
    public View create(Element elem) {
        String kind = elem.getName();
        if (kind != null) {
            if (kind.equals(AbstractDocument.ContentElementName)) {
                return new TextWrapView(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);
    }
}

private class TextWrapView extends LabelView {
    public TextWrapView(Element elem) {
        super(elem);
    }

    public float getMinimumSpan(int axis) {
        switch (axis) {
            case View.X_AXIS:
                return 0;
            case View.Y_AXIS:
                return super.getMinimumSpan(axis);
            default:
                throw new IllegalArgumentException("Invalid axis: " + axis);
        }
    }

}

}   

EDIT: code replaced with SCCE, sorry for the trouble

Okay, so it's structured like this...

• Top class - extends JTextPane

• Place this JTextPane into a JPanel set to BorderLayout CENTER

• Place another JPanel into the same JPanel set to WEST

• Place the JPanel holding the two into a JScrollPane

• Ready for deployment (nope)

Basically, I can't figure out a way to do this without losing out on something critical. I can get them all together, but I'll lose scrolling. Or I'll get scrolling back, but then lose text wrapping. One time I got wrapping, and technically it scrolled but not as it should have, in otherwords, the scrollpane didn't detect the size of the text. I need the nested JPanel (1st one) to scroll with the JTextPane

The problem area is in the constructor below, sorry it's such a mess but I'm losing it over here trying different things... Probably isn't helping. I'd be so grateful if somebody could help me figure this out.

Thank you for reading.

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

public class MyEditor extends JTextPane {
JFrame window;
JScrollPane editScroll;


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

MyEditor() {
    setOpaque(false);
    setEditorKit(new TextWrapKit());

    JPanel numPane = new JPanel();
    JPanel packEdit = new JPanel();

    packEdit.setLayout(new BorderLayout());
    packEdit.add(this,BorderLayout.CENTER);
    packEdit.add(numPane,BorderLayout.WEST);

    editScroll = new JScrollPane(packEdit);
    editScroll.setPreferredSize(new Dimension(500,500));        
    editScroll.setViewportView(packEdit);
    editScroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
    editScroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); 

    window = new JFrame();
    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    window.add(editScroll);
    window.pack();
    window.setVisible(true);
}

private class TextWrapKit extends StyledEditorKit {
    ViewFactory defaultFactory=new TextWrapFactory();
    public ViewFactory getViewFactory() {
        return defaultFactory;
    }
}

private class TextWrapFactory implements ViewFactory {
    public View create(Element elem) {
        String kind = elem.getName();
        if (kind != null) {
            if (kind.equals(AbstractDocument.ContentElementName)) {
                return new TextWrapView(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);
    }
}

private class TextWrapView extends LabelView {
    public TextWrapView(Element elem) {
        super(elem);
    }

    public float getMinimumSpan(int axis) {
        switch (axis) {
            case View.X_AXIS:
                return 0;
            case View.Y_AXIS:
                return super.getMinimumSpan(axis);
            default:
                throw new IllegalArgumentException("Invalid axis: " + axis);
        }
    }

}

}

Answer 1

extends JTextPane

Why?

setEditorKit(new TextWrapKit());

Why?

Get the scroll pane working with the default components. Then if for some reason you still need to customize you make the changes one at a time to make sure it still works. If it doesn't work any more then you know what the problem is.

packEdit.add(numPane,BorderLayout.WEST);

Looks to me like you are trying to add line number. The standard way to do this is to add your component to the row header of the scrollpane, instead of making it part of the panel added to the viewport. See Text Component Line Number for an example of this approach.

In the future a SSCCE should be posted with every question. You get one free (attempted) answer without a SSCCE .