Todo App Step 5 (Removing an Item)

main.dart

// Much like _addTodoItem, this modifies the array of todo strings and
// notifies the app that the state has changed by using setState
void _removeTodoItem(int index) {
  setState(() => _todoItems.removeAt(index));
}

// Show an alert dialog asking the user to confirm that the task is done
void _promptRemoveTodoItem(int index) {
  showDialog(
    context: context,
    builder: (BuildContext context) {
      return new AlertDialog(
        title: new Text('Mark "${_todoItems[index]}" as done?'),
        actions: <Widget>[
          new FlatButton(
            child: new Text('CANCEL'),
            onPressed: () => Navigator.of(context).pop()
          ),
          new FlatButton(
            child: new Text('MARK AS DONE'),
            onPressed: () {
              _removeTodoItem(index);
              Navigator.of(context).pop();
            }
          )
        ]
      );
    }
  );
}

Widget _buildTodoList() {
  return new ListView.builder(
    itemBuilder: (context, index) {
      if(index < _todoItems.length) {
        return _buildTodoItem(_todoItems[index], index);
      }
    },
  );
}

Widget _buildTodoItem(String todoText, int index) {
  return new ListTile(
    title: new Text(todoText),
    onTap: () => _promptRemoveTodoItem(index)
  );
}