Main.java Source code

Introduction

Here is the source code for Main.java

Source

import javax.swing.JFrame;
import javax.swing.JTextPane;
import javax.swing.text.AbstractDocument;
import javax.swing.text.BoxView;
import javax.swing.text.ComponentView;
import javax.swing.text.Element;
import javax.swing.text.IconView;
import javax.swing.text.LabelView;
import javax.swing.text.ParagraphView;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyledDocument;
import javax.swing.text.StyledEditorKit;
import javax.swing.text.View;
import javax.swing.text.ViewFactory;

public class Main {
    JTextPane edit = new JTextPane();

    public Main() throws Exception {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(edit);
        edit.setEditorKit(new MyEditorKit());
        SimpleAttributeSet attrs = new SimpleAttributeSet();
        StyleConstants.setAlignment(attrs, StyleConstants.ALIGN_CENTER);
        StyledDocument doc = (StyledDocument) edit.getDocument();
        doc.insertString(0, "111\n2222222\n3333", attrs);
        doc.setParagraphAttributes(0, doc.getLength() - 1, attrs, false);

        frame.setSize(300, 300);
        frame.setVisible(true);
    }

    public static void main(String[] args) throws Exception {
        new Main();
    }
}

class MyEditorKit extends StyledEditorKit {

    public ViewFactory getViewFactory() {
        return new StyledViewFactory();
    }

    static class StyledViewFactory implements ViewFactory {

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

                    return new LabelView(elem);
                } else if (kind.equals(AbstractDocument.ParagraphElementName)) {
                    return new ParagraphView(elem);
                } else if (kind.equals(AbstractDocument.SectionElementName)) {

                    return new CenteredBoxView(elem, View.Y_AXIS);
                } else if (kind.equals(StyleConstants.ComponentElementName)) {
                    return new ComponentView(elem);
                } else if (kind.equals(StyleConstants.IconElementName)) {

                    return new IconView(elem);
                }
            }

            return new LabelView(elem);
        }

    }
}

class CenteredBoxView extends BoxView {
    public CenteredBoxView(Element elem, int axis) {

        super(elem, axis);
    }

    protected void layoutMajorAxis(int targetSpan, int axis, int[] offsets, int[] spans) {

        super.layoutMajorAxis(targetSpan, axis, offsets, spans);
        int textBlockHeight = 0;
        int offset = 0;

        for (int i = 0; i < spans.length; i++) {
            textBlockHeight += spans[i];
        }
        offset = (targetSpan - textBlockHeight) / 2;
        for (int i = 0; i < offsets.length; i++) {
            offsets[i] += offset;
        }

    }
}