Question

I’ve been trying to create a class which can do the following:

• Set: Font, Alignment (left, center, right, justified)
• An efficient way to append text to the document.
The text does not need to be selectable or editable.
I have to be able to override the painting / rendering of the text.

I find that the JDK JTextComponent classes are difficult to use efficiently, as this is what I have so far but it is far from what I’m trying to achieve:

public class Paragraph extends JTextPane{

    public Paragraph(){
        this.setFont(Fonts.PARAGRAPH);
        this.setOpaque(false);
    }

   // ridiculously slow
   public void append(String s) {
     SimpleAttributeSet def = new SimpleAttributeSet();
     StyleConstants.setForeground(def, Colors.PARAGRAPH);
     Document d = getDocument();
     try {
       d.insertString(d.getLength(), s, def);
     } catch (BadLocationException ble) {
   }
 }  
}

Question: Are there any libraries which could save me time re-inventing the wheel?
If not, how can I go about extending the JDK implementations? Thanks

Answer 1

Your Document should be StyledDocument instance. Then just use setParagraphAttributes() method of the Document instance.

For multiple appends use a separate document (not set to the JTextPane instance.

Use the kit ot create a new empty Document instance. Call all your appends and then setDocument(theDocInstance) to the JTextPane.