Swing GUI appending colored text in JTextPane

Question

public static void setJTextPaneFont(JTextPane jtp, Color c, int from, int to) {
    // Start with the current input attributes for the JTextPane. This
    // should ensure that we do not wipe out any existing attributes
    // (such as alignment or other paragraph attributes) currently
    // set on the text area.
    MutableAttributeSet attrs = jtp.getInputAttributes();

    // Set the font color
    StyleConstants.setForeground(attrs, c);

    // Retrieve the pane's document object
    StyledDocument doc = jtp.getStyledDocument();

    // Replace the style for the entire document. We exceed the length
    // of the document by 1 so that text entered at the end of the
    // document uses the attributes.
    doc.setCharacterAttributes(from, to, attrs, false);
}

The purpose of the above piece of code is to change the color of a particular line of code between two indices, from and to. After the call to this function, the text and color in JTextPane gets updated correctly(a particular line).

However, when I try to refresh the JTextPane with new texts(by emptying the jtextpane and re-appending new text), all text automatically gets painted into the color last assigned when called with setJTextPaneFont.

Basically, instead of just having a few colored lines, the whole document(new one) becomes colored without ever making a call to the function above. Therefore I suspect that the attributes of JTextPane somehow got modified.

So the question is, how would I be able to reset the JTextPane back to default attributes?

Answer 1

Try this one

public void setJTextPaneFont(JTextPane jtp, Color c, int from, int to) {
            // Start with the current input attributes for the JTextPane. This
            // should ensure that we do not wipe out any existing attributes
            // (such as alignment or other paragraph attributes) currently
            // set on the text area.

            StyleContext sc = StyleContext.getDefaultStyleContext();

          // MutableAttributeSet attrs = jtp.getInputAttributes();

            AttributeSet attrs = sc.addAttribute(SimpleAttributeSet.EMPTY, StyleConstants.Foreground, c);
            // Set the font color
            //StyleConstants.setForeground(attrs, c);

            // Retrieve the pane's document object
            StyledDocument doc = jtp.getStyledDocument();
            // System.out.println(doc.getLength());

            // Replace the style for the entire document. We exceed the length
            // of the document by 1 so that text entered at the end of the
            // document uses the attributes.
            doc.setCharacterAttributes(from, to, attrs, true);
        }