/// <summary>
/// Changes the browse position.
/// </summary>
/// <param name="direction">The direction.</param>
/// <param name="qualifiedName">The qualified area name.</param>
private bool ChangeBrowsePosition(OPCAEBROWSEDIRECTION direction, string qualifiedName)
{
string methodName = "IOPCEventAreaBrowser.CreateAreaBrowser";
try
{
IOPCEventAreaBrowser server = BeginComCall <IOPCEventAreaBrowser>(methodName, true);
server.ChangeBrowsePosition(direction, qualifiedName);
return(true);
}
catch (Exception e)
{
if (ComUtils.IsUnknownError(e, ResultIds.E_FAIL))
{
ComCallError(methodName, e);
}
return(false);
}
finally
{
EndComCall(methodName);
}
}
/// <summary>
/// Provides a way to move �up� or �down� in a hierarchical space from the current position, or a way to move to a specific position in the area space tree. The target szString must represent an area, rather than a source.
/// </summary>
/// <param name="dwBrowseDirection">OPCAE_BROWSE_UP, OPCAE_BROWSE_DOWN, or OPCAE_BROWSE_TO</param>
/// <param name="szString">
/// For DOWN, the partial area name of the area to move into. This would be one of the strings returned from BrowseOPCAreas.
/// For UP this parameter is ignored and should point to a NULL string.
/// For BROWSE_TO, the fully qualified area name (as obtained from GetQualifiedAreaName method) or a pointer to a NUL string to go to the root.
/// </param>
public void ChangeBrowsePosition(OPCAEBROWSEDIRECTION dwBrowseDirection, string szString)
{
lock (m_lock)
{
try
{
switch (dwBrowseDirection)
{
// move to a specified position or root.
case OPCAEBROWSEDIRECTION.OPCAE_BROWSE_TO:
{
try
{
// move to root.
if (String.IsNullOrEmpty(szString))
{
m_browseStack.Clear();
m_browseStack.Push(m_session.NodeCache.Find(Objects.Server));
break;
}
// Translate the fully qualified area name to NodeId
List<string> szAreas = new List<string>();
szAreas.Add(szString);
BrowsePathResultCollection results = m_server.GetBrowseTargets(szAreas);
if (StatusCode.IsBad(results[0].StatusCode))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
BrowsePathTarget target = results[0].Targets[0];
INode node = m_session.NodeCache.Find(target.TargetId);
if (node == null)
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// build a new browse stack.
Stack<INode> browseStack = new Stack<INode>();
if (!FindPathToNode(node, browseStack))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// push target node onto stack.
browseStack.Push(node);
m_browseStack = browseStack;
}
catch
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
break;
}
// move to a child branch.
case OPCAEBROWSEDIRECTION.OPCAE_BROWSE_DOWN:
{
// check for invalid name.
if (String.IsNullOrEmpty(szString))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// find the current node.
INode parent = m_browseStack.Peek();
if (parent == null)
{
throw ComUtils.CreateComException(ResultIds.E_FAIL);
}
// find the child.
INode child = FindChildByName(parent.NodeId, szString);
if (child == null)
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// save the new position.
m_browseStack.Push(child);
break;
}
// move to a parent branch.
case OPCAEBROWSEDIRECTION.OPCAE_BROWSE_UP:
{
// check for invalid name.
if (!String.IsNullOrEmpty(szString))
{
throw ComUtils.CreateComException(ResultIds.E_FAIL);
}
// can't move up from root.
if (m_browseStack.Count <= 1)
{
throw ComUtils.CreateComException(ResultIds.E_FAIL);
}
// move up the stack.
m_browseStack.Pop();
break;
}
default:
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDARG);
}
}
}
catch (COMException e)
{
throw ComUtils.CreateComException(e);
}
catch (Exception e)
{
Utils.Trace(e, "Unexpected error in ChangeBrowsePosition");
throw ComUtils.CreateComException(e);
}
}
}
/// <summary>
/// Provides a way to move �up� or �down� in a hierarchical space from the current position, or a way to move to a specific position in the area space tree. The target szString must represent an area, rather than a source.
/// </summary>
/// <param name="dwBrowseDirection">OPCAE_BROWSE_UP, OPCAE_BROWSE_DOWN, or OPCAE_BROWSE_TO</param>
/// <param name="szString">
/// For DOWN, the partial area name of the area to move into. This would be one of the strings returned from BrowseOPCAreas.
/// For UP this parameter is ignored and should point to a NULL string.
/// For BROWSE_TO, the fully qualified area name (as obtained from GetQualifiedAreaName method) or a pointer to a NUL string to go to the root.
/// </param>
public void ChangeBrowsePosition(OPCAEBROWSEDIRECTION dwBrowseDirection, string szString)
{
lock (m_lock)
{
try
{
switch (dwBrowseDirection)
{
// move to a specified position or root.
case OPCAEBROWSEDIRECTION.OPCAE_BROWSE_TO:
{
try
{
// move to root.
if (String.IsNullOrEmpty(szString))
{
m_browseStack.Clear();
m_browseStack.Push(m_session.NodeCache.Find(Objects.Server));
break;
}
// Translate the fully qualified area name to NodeId
List <string> szAreas = new List <string>();
szAreas.Add(szString);
BrowsePathResultCollection results = m_server.GetBrowseTargets(szAreas);
if (StatusCode.IsBad(results[0].StatusCode))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
BrowsePathTarget target = results[0].Targets[0];
INode node = m_session.NodeCache.Find(target.TargetId);
if (node == null)
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// build a new browse stack.
Stack <INode> browseStack = new Stack <INode>();
if (!FindPathToNode(node, browseStack))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// push target node onto stack.
browseStack.Push(node);
m_browseStack = browseStack;
}
catch
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
break;
}
// move to a child branch.
case OPCAEBROWSEDIRECTION.OPCAE_BROWSE_DOWN:
{
// check for invalid name.
if (String.IsNullOrEmpty(szString))
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// find the current node.
INode parent = m_browseStack.Peek();
if (parent == null)
{
throw ComUtils.CreateComException(ResultIds.E_FAIL);
}
// find the child.
INode child = FindChildByName(parent.NodeId, szString);
if (child == null)
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDBRANCHNAME);
}
// save the new position.
m_browseStack.Push(child);
break;
}
// move to a parent branch.
case OPCAEBROWSEDIRECTION.OPCAE_BROWSE_UP:
{
// check for invalid name.
if (!String.IsNullOrEmpty(szString))
{
throw ComUtils.CreateComException(ResultIds.E_FAIL);
}
// can't move up from root.
if (m_browseStack.Count <= 1)
{
throw ComUtils.CreateComException(ResultIds.E_FAIL);
}
// move up the stack.
m_browseStack.Pop();
break;
}
default:
{
throw ComUtils.CreateComException(ResultIds.E_INVALIDARG);
}
}
}
catch (COMException e)
{
throw ComUtils.CreateComException(e);
}
catch (Exception e)
{
Utils.Trace(e, "Unexpected error in ChangeBrowsePosition");
throw ComUtils.CreateComException(e);
}
}
}
/// <summary>
/// Changes the browse position.
/// </summary>
/// <param name="direction">The direction.</param>
/// <param name="qualifiedName">The qualified area name.</param>
private bool ChangeBrowsePosition(OPCAEBROWSEDIRECTION direction, string qualifiedName)
{
string methodName = "IOPCEventAreaBrowser.CreateAreaBrowser";
try
{
IOPCEventAreaBrowser server = BeginComCall<IOPCEventAreaBrowser>(methodName, true);
server.ChangeBrowsePosition(direction, qualifiedName);
return true;
}
catch (Exception e)
{
if (ComUtils.IsUnknownError(e, ResultIds.E_FAIL))
{
ComCallError(methodName, e);
}
return false;
}
finally
{
EndComCall(methodName);
}
}
