Getting Started

Displaying the Selected Item

When the user selects an item in the list widget, we would like to update the nameLabel and emailLabel at the bottom of the form. This requires another slot to be added to the AddressBook class.

In the addressbook.h file, add the following code in the private slots section of the class:

 void on_addressList_currentItemChanged();

Then add the block of code below to addressbook.cpp:

 void AddressBook::on_addressList_currentItemChanged()
 {
     QListWidgetItem *curItem = ui.addressList->currentItem();

         if (curItem) {
                 ui.nameLabel->setText("Name: " + curItem->text());
                 ui.emailLabel->setText("Email: " + curItem->data(Qt::UserRole).toString());
         } else {
                 ui.nameLabel->setText("<No item selected>");
                 ui.emailLabel->clear();
         }
 }

Thanks to the naming convention, this slot will automatically be connected to addressList's currentItemChanged() signal, and will be invoked whenever the selected item in the list changes.

Earlier, we added some code by double-clicking the Add button. This automatically creates a slot corresponding to the widget's default signal - the signal that you are most likely to be interested in - for example, clicked() for QPushButton. If you want to connect to another signal, you must write the code manually as we have done for the addressList's currentItemChanged() signal.

 QListWidgetItem *curItem = ui.addressList->currentItem();

     if (curItem) {
             int row = ui.addressList->row(curItem);
             ui.addressList->takeItem(row);
             delete curItem;

             if (ui.addressList->count() > 0)
                     ui.addressList->setCurrentRow(0);
             else
                     on_addressList_currentItemChanged();
     }