public class TextLengthDocFilter extends DocumentFilter { private int maxTextLength;
/**
* Limita a x caracteres el Document que tenga asignado esta clase.
* @param maxTextLength - El numero maximo de caracteres
*/
public TextLengthDocFilter(int maxTextLength) { this.maxTextLength = maxTextLength;
}
private boolean verifyText(String text) { return text.length() <= maxTextLength;
}
@Override
public void insertString(FilterBypass fb, int offset, String string,
AttributeSet attr) throws BadLocationException {
Document doc = fb.getDocument();
String oldText = doc.getText(0, doc.getLength());
StringBuilder sb = new StringBuilder(oldText);
sb.insert(offset, string);
if (verifyText(sb.toString())) { super.insertString(fb, offset, string, attr);
}
}
@Override
public void replace(FilterBypass fb, int offset, int length, String text, AttributeSet attrs)
throws BadLocationException { Document doc = fb.getDocument();
String oldText = doc.getText(0, doc.getLength());
StringBuilder sb = new StringBuilder(oldText);
sb.replace(offset, offset + length, text);
if (verifyText(sb.toString())) { super.replace(fb, offset, length, text, attrs);
}
}
@Override
public void remove(FilterBypass fb, int offset, int length) throws BadLocationException { Document doc = fb.getDocument();
String oldText = doc.getText(0, doc.getLength());
StringBuilder sb = new StringBuilder(oldText);
sb.replace(offset, offset + length, "");
if (verifyText(sb.toString())) { super.remove(fb, offset, length);
}
}
}
