/// <summary>
/// Sets the selected item in this <code>Choice</code> menu to be the
/// item at the specified position.
///
/// <para>Note that this method should be primarily used to
/// initially select an item in this component.
/// Programmatically calling this method will <i>not</i> trigger
/// an <code>ItemEvent</code>. The only way to trigger an
/// <code>ItemEvent</code> is by user interaction.
///
/// </para>
/// </summary>
/// <param name="pos"> the position of the selected item </param>
/// <exception cref="IllegalArgumentException"> if the specified
/// position is greater than the
/// number of items or less than zero </exception>
/// <seealso cref= #getSelectedItem </seealso>
/// <seealso cref= #getSelectedIndex </seealso>
public virtual void Select(int pos)
{
lock (this)
{
if ((pos >= PItems.Size()) || (pos < 0))
{
throw new IllegalArgumentException("illegal Choice item position: " + pos);
}
if (PItems.Size() > 0)
{
SelectedIndex_Renamed = pos;
ChoicePeer peer = (ChoicePeer)this.Peer_Renamed;
if (peer != null)
{
peer.Select(pos);
}
}
}
}
/// <summary>
/// Inserts an item to this <code>Choice</code>,
/// but does not invalidate the <code>Choice</code>.
/// Client methods must provide their own synchronization before
/// invoking this method. </summary>
/// <param name="item"> the item to be added </param>
/// <param name="index"> the new item position </param>
/// <exception cref="NullPointerException"> if the item's value is equal to
/// <code>null</code> </exception>
private void InsertNoInvalidate(String item, int index)
{
if (item == null)
{
throw new NullPointerException("cannot add null item to Choice");
}
PItems.InsertElementAt(item, index);
ChoicePeer peer = (ChoicePeer)this.Peer_Renamed;
if (peer != null)
{
peer.Add(item, index);
}
// no selection or selection shifted up
if (SelectedIndex_Renamed < 0 || SelectedIndex_Renamed >= index)
{
Select(0);
}
}
/// <summary>
/// Removes an item from the <code>Choice</code> at the
/// specified position, but does not invalidate the <code>Choice</code>.
/// Client methods must provide their
/// own synchronization before invoking this method. </summary>
/// <param name="position"> the position of the item </param>
private void RemoveNoInvalidate(int position)
{
PItems.RemoveElementAt(position);
ChoicePeer peer = (ChoicePeer)this.Peer_Renamed;
if (peer != null)
{
peer.Remove(position);
}
/* Adjust selectedIndex if selected item was removed. */
if (PItems.Size() == 0)
{
SelectedIndex_Renamed = -1;
}
else if (SelectedIndex_Renamed == position)
{
Select(0);
}
else if (SelectedIndex_Renamed > position)
{
Select(SelectedIndex_Renamed - 1);
}
}