public int selectionForKey(char aKey,
    ComboBoxModel aModel) 
{
             
            if (lastTime == 0L) {
                prefix = "";
                typedString = "";
            }
            boolean startingFromSelection = true;
            int startIndex = comboBox.getSelectedIndex();
            if (time - lastTime <  timeFactor) {
                typedString += aKey;
                if((prefix.length() == 1) && (aKey == prefix.charAt(0))) {
                    // Subsequent same key presses move the keyboard focus to the next
                    // object that starts with the same letter.
                    startIndex++;
                } else {
                    prefix = typedString;
                }
            } else {
                startIndex++;
                typedString = "" + aKey;
                prefix = typedString;
            }
            lastTime = time;
            if (startIndex <  0 || startIndex  >= aModel.getSize()) {
                startingFromSelection = false;
                startIndex = 0;
            }
            int index = listBox.getNextMatch(prefix, startIndex,
                                             Position.Bias.Forward);
            if (index <  0 && startingFromSelection) { // wrap
                index = listBox.getNextMatch(prefix, 0,
                                             Position.Bias.Forward);
            }
            return index;
}