How do I apply a StyledEditorKit to a JTextPane without having to inherit this class on my screen?

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6

I have a tab problem in JTextPane and I am trying to reduce the default value assigned to it but it is giving an error because I have to inherit two classes (one for JFrame and the other for overwriting the tab functions ) but Java apparently, so I'm trying not to accept this, it follows the code: 

import javax.lang.model.element.Element;
import javax.swing.JFrame;
import javax.swing.text.AbstractDocument;
import javax.swing.text.BoxView;
import javax.swing.text.ComponentView;
import javax.swing.text.IconView;
import javax.swing.text.LabelView;
import javax.swing.text.ParagraphView;
import javax.swing.text.StyleConstants;
import static javax.swing.text.StyleConstants.TabSet;
import javax.swing.text.StyledEditorKit;
import javax.swing.text.TabSet;
import javax.swing.text.View;
import javax.swing.text.ViewFactory;



public class TAB extends javax.swing.JFrame,StyledEditorKit  {
public static final int TAB_SIZE=36;
    /**
     * Creates new form TAB
     */
    public TAB() {
        initComponents();

    }
     @Override
    public ViewFactory getViewFactory() {
        return new MyViewFactory();
    }
    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jScrollPane1 = new javax.swing.JScrollPane();
        jTextPane1 = new javax.swing.JTextPane();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jScrollPane1.setViewportView(jTextPane1);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap(56, Short.MAX_VALUE)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 195, javax.swing.GroupLayout.PREFERRED_SIZE))
        );

        pack();
    }// </editor-fold>                        

    /**
     * @param args the command line arguments
     */





    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(TAB.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(TAB.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(TAB.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(TAB.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {

                new TAB().setVisible(true);
            }
        });
        class MyViewFactory implements ViewFactory {

        @Override
        public View create(javax.swing.text.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 CustomTabParagraphView(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);
                }
            }

            return new LabelView(elem);
        }
    }


    class CustomTabParagraphView extends ParagraphView {

        public CustomTabParagraphView(javax.swing.text.Element elem) {
            super(elem);
        }

        @Override
        public float nextTabStop(float x, int tabOffset) {
            TabSet tabs = getTabSet();
            if(tabs == null) {
                // a tab every 72 pixels.
                return (float)(getTabBase() + (((int)x / TAB_SIZE + 1) * TAB_SIZE));
            }

            return super.nextTabStop(x, tabOffset);
        }

    }

    }

    // Variables declaration - do not modify                     
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextPane jTextPane1;
    // End of variables declaration                   
}

Does anyone know how to solve this problem?

    
asked by anonymous 21.10.2016 / 15:30

2 answers

4

For your code, just separate the TabSizeEditorKit class from your screen class and instantiate within the setEditorKit() , as in the example of another answer .

It would look something like this: 

import java.awt.EventQueue;

import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.text.BadLocationException;
import javax.swing.text.SimpleAttributeSet;

    public class Tela extends JFrame {

        private JPanel contentPane;
        private JEditorPane editorPane;


        public static void main(String[] args) {
            EventQueue.invokeLater(new Runnable() {
                public void run() {
                    try {
                        Tela frame = new Tela();
                        frame.setVisible(true);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            });
        }

        /**
         * Create the frame.
         * @throws BadLocationException 
         */
        public Tela() throws BadLocationException {
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setBounds(100, 100, 332, 300);
            contentPane = new JPanel();
            contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
            setContentPane(contentPane);

            editorPane = new JEditorPane();
            GroupLayout gl_contentPane = new GroupLayout(contentPane);
            gl_contentPane.setHorizontalGroup(
                gl_contentPane.createParallelGroup(Alignment.LEADING)
                    .addGroup(gl_contentPane.createSequentialGroup()
                        .addGap(31)
                        .addComponent(editorPane, GroupLayout.PREFERRED_SIZE, 251, GroupLayout.PREFERRED_SIZE)
                        .addContainerGap(142, Short.MAX_VALUE))
            );
            gl_contentPane.setVerticalGroup(
                gl_contentPane.createParallelGroup(Alignment.LEADING)
                    .addGroup(gl_contentPane.createSequentialGroup()
                        .addGap(37)
                        .addComponent(editorPane, GroupLayout.PREFERRED_SIZE, 186, GroupLayout.PREFERRED_SIZE)
                        .addContainerGap(29, Short.MAX_VALUE))
            );
            contentPane.setLayout(gl_contentPane);
            //aqui que você seta o editorkit customizado
            //para o editorpane
            editorPane.setEditorKit(new TabSizeEditorKit());
        }
    }

and class TabSizeEditorKit you remove main and leave only the essentials for it to work: 

import javax.swing.text.*;


public class TabSizeEditorKit extends StyledEditorKit {

    public static final int TAB_SIZE=36;

    @Override
    public ViewFactory getViewFactory() {
        return new MyViewFactory();
    }

    static class MyViewFactory implements ViewFactory {

        @Override
        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 CustomTabParagraphView(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);
                }
            }

            return new LabelView(elem);
        }
    }


    static class CustomTabParagraphView extends ParagraphView {

        public CustomTabParagraphView(Element elem) {
            super(elem);
        }

        @Override
        public float nextTabStop(float x, int tabOffset) {
            TabSet tabs = getTabSet();
            if(tabs == null) {
                // a tab every 72 pixels.
                return (float)(getTabBase() + (((int)x / TAB_SIZE + 1) * TAB_SIZE));
            }

            return super.nextTabStop(x, tabOffset);
        }

    }
}

As you will only use TabSizeEditorKit just for the spacing issue, you do not have to make it an attribute of the class.

    
21.10.2016 / 15:52
6

Java does not have multiple inheritance by design. Java creators decided that providing multiple inheritance would add a lot of complexity and few benefits to the language.

For example, what to do when two classes define the same method and a third class tried to extend the first two? 

public class Humano {
    public void Andar() {
        // Andar feito Humano
    }
}

public class Robo {
    public void Andar() {
        // Andar feito Robo
    }
}

public class Ciborgue extends Humano, Robo {
    // O ciborgue andaria como robo ou humano? 
}

Consider using composition. Choose a class to TAB extend and maintain a reference to one instance of the other class. Example: 

// imports...

public class TAB extends javax.swing.JFrame {
    private StyledEditorKit editorKit;

    public TAB(){
        editorKit = new StyledEditorKit();
    }

    public void FazerAlgoComEditorKit(){
        // Use a propriedade editorKit
    }
}
    
21.10.2016 / 16:19
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