/// <summary>
/// Called when a subscription is added or removed from the control.
/// </summary>
public void OnSubscriptionModified(Subscription subscription, bool deleted)
{
if (subscription == null)
{
return;
}
if (!deleted)
{
// check if the subscription is already added to the control.
if (m_items.Contains(subscription.ClientHandle))
{
return;
}
// register for data updates.
subscription.DataChanged += new OpcDa::DataChangedEventHandler(OnDataChange);
subscription.DeleteSubscription += new System.EventHandler(subscription_DeleteSubscription);
// add to subscription list.
m_subscriptions.Add(subscription.ClientHandle, subscription);
m_items.Add(subscription.ClientHandle, new ArrayList());
}
else
{
// check if the subscription is already removed from the control.
if (!m_items.Contains(subscription.ClientHandle))
{
return;
}
// unregister for data updates.
try
{
subscription.DataChanged -= new OpcDa::DataChangedEventHandler(OnDataChange);
}
catch (System.Exception)
{
//Now we can do nothig abou it
}
subscription.DeleteSubscription -= new System.EventHandler(subscription_DeleteSubscription);
// remove all items for the subscription.
ArrayList existingItemList = (ArrayList)m_items[subscription.ClientHandle];
foreach (ListViewItem listItem in existingItemList)
{
EditComplexValueDlg dialog = (EditComplexValueDlg)m_viewers[listItem];
if (dialog != null)
{
dialog.Close();
m_viewers.Remove(listItem);
}
listItem.Remove();
}
// remove from subscription list.
m_subscriptions.Remove(subscription.ClientHandle);
m_items.Remove(subscription.ClientHandle);
}
}
/// <summary>
/// Called when a data update event is raised by a subscription.
/// </summary>
private void OnDataChange(object subscriptionHandle, object requestHandle, OpcDa::ItemValueResult[] values)
{
// ensure processing is done on the control's main thread.
if (InvokeRequired)
{
BeginInvoke(new OpcDa::DataChangedEventHandler(OnDataChange), new object[] { subscriptionHandle, requestHandle, values });
return;
}
try
{
// find subscription.
ArrayList existingItemList = (ArrayList)m_items[subscriptionHandle];
// check if subscription is still valid.
if (existingItemList == null)
{
return;
}
// change all existing item values for the subscription to 'grey'.
// this indicates an update arrived but the value did not change.
foreach (ListViewItem listItem in existingItemList)
{
if (listItem.ForeColor != Color.Gray)
{
listItem.ForeColor = Color.Gray;
}
}
// do nothing more if only a keep alive callback.
if (values == null || values.Length == 0)
{
OnKeepAlive(subscriptionHandle);
return;
}
if (UpdateEvent != null)
{
UpdateEvent(subscriptionHandle, values);
}
// update list view.
ArrayList newListItems = new ArrayList();
foreach (OpcDa::ItemValueResult value in values)
{
// item value should never have a null client handle.
if (value.ClientHandle == null)
{
continue;
}
// this item can be updated with new values instead of inserting/removing items.
ListViewItem replacableItem = null;
// remove existing items.
if (!m_CMS_KeepValues.Checked)
{
// search list of existing items for previous values for this item.
ArrayList updatedItemList = new ArrayList(existingItemList.Count);
foreach (ListViewItem listItem in existingItemList)
{
OpcDa::ItemValueResult previous = (OpcDa::ItemValueResult)listItem.Tag;
if (!value.ClientHandle.Equals(previous.ClientHandle))
{
updatedItemList.Add(listItem);
continue;
}
if (replacableItem != null)
{
EditComplexValueDlg dialog = (EditComplexValueDlg)m_viewers[replacableItem];
if (dialog != null)
{
dialog.Close();
m_viewers.Remove(replacableItem);
}
replacableItem.Remove();
}
replacableItem = listItem;
}
// the updated list has all values for the current item removed.
existingItemList = updatedItemList;
}
// add value to list.
AddValue(subscriptionHandle, value, ref replacableItem);
// save new list item.
if (replacableItem != null)
{
newListItems.Add(replacableItem);
}
}
// add new items to existing item list.
existingItemList.AddRange(newListItems);
m_items[subscriptionHandle] = existingItemList;
// adjust column widths.
for (int ii = 0; ii < m_ItemListLV.Columns.Count; ii++)
{
if (ii != VALUE && ii != QUALITY)
{
m_ItemListLV.Columns[ii].Width = -2;
}
}
}
catch (System.Exception e)
{
OnException(subscriptionHandle, e);
}
}
