GWT 1.7 using ChangeHandler on ListBox (drop-down)

Here is a simple example of how to listen to the change event.
This functionality replaces the deprecated listBox.addChangeListener(new ChangeListener(){//implementation} );


private ListBox populateLearningLanguage()
{
final ListBox listBox = new ListBox();
addLanguages(listBox);
listBox.setSelectedIndex(2);

listBox.addChangeHandler(new ChangeHandler()
{
public void onChange(ChangeEvent event)
{
int selectedIndex = listBox.getSelectedIndex();
if (selectedIndex > 0)
Window.alert("Something got selected " + listBox.getValue(selectedIndex));
}
});
return listBox;
}


As an Amazon Associate I earn from qualifying purchases.

3 comments:

  1. I think your if-statement should be:

    if (selectedIndex>-1) ..

    ReplyDelete
  2. Hi Willem,
    thank you for the correction, yes you are right if the first item is a valid selection and not "please select .."

    ReplyDelete

Please be polite.

Post Scriptum

The views in this article are mine and do not reflect those of my employer.
I am preparing to cancel the subscription to the e-mail newsletter that sends my articles.
Follow me on:
X.com (Twitter)
LinkedIn
Google Scholar

My favorite quotations..


“A man should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.”  by Robert A. Heinlein

"We are but habits and memories we chose to carry along." ~ Uki D. Lucas


Popular Recent Posts

Most Popular Articles