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Errors in addListener method

Valentin Grigoriev
1 decade ago Jul 05, 2012 1:45pm


I do exercises from the book "Book of Vaadin".
I don't know why there are errors in the next example:

import com.vaadin.Application;
import com.vaadin.ui.*;

CheckBox switchEditable = new CheckBox("Editable");
switchEditable.addListener(new Property.ValueChangeListener() {
	public void valueChange(ValueChangeEvent event) {			


  • The method addListener(Button.ClickListener) in the type Button is not applicable for the arguments (new ValueChangeListener(){})
  • Property cannot be resolved to a type
  • ValueChangeEvent cannot be resolved to a type
  • I think, I have to import something. But I don't know what.

    Last updated on Jul, 5th 2012
    Jens Jansson
    1 decade ago Jul 05, 2012 2:17pm
    import com.vaadin.data.Property;
    import com.vaadin.data.Property.ValueChangeEvent;

    I usually write it in form:

    switchEditable.addListener(new ValueChangeListener() {
        public void valueChange(ValueChangeEvent event) {

    (missing "Property." in Listener)
    which means that the import would be:

    import com.vaadin.data.Property.ValueChangeEvent;
    import com.vaadin.data.Property.ValueChangeListener;

    Guessing from your error messages, I'd guess you are using Eclipse, correct? In eclipse you can press ctrl+shift+o, which tries to resolve the imports, and gives you an list of possibilities if there are multiple that match. Very handy tool.

    Henri Sara
    1 decade ago Jul 06, 2012 6:51am
    Valentin Grigoriev
    1 decade ago Jul 06, 2012 7:07am