/// <summary>
/// Sends an item picked event.
/// </summary>
private void BrowseTV_DoubleClick(object sender, System.EventArgs e)
{
try
{
// check if current selection is valid.
TreeNode node = BrowseTV.SelectedNode;
if (node == null || !typeof(TsCHdaBrowseElement).IsInstanceOfType(node.Tag))
{
return;
}
// check if selection is an item.
TsCHdaBrowseElement element = (TsCHdaBrowseElement)node.Tag;
if (element.IsItem)
{
if (ItemPicked != null)
{
ItemPicked(new OpcItem[] { element });
}
}
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
}
/// <summary>
/// Sends an item selected event.
/// </summary>
private void BrowseTV_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
{
try
{
// ignore event if no listeners.
if (ItemSelected == null)
{
return;
}
// check if the current selection is an item.
TsCHdaBrowseElement element = null;
TreeNode node = BrowseTV.SelectedNode;
if (node != null && typeof(TsCHdaBrowseElement).IsInstanceOfType(node.Tag))
{
if (((TsCHdaBrowseElement)node.Tag).IsItem)
{
element = (TsCHdaBrowseElement)node.Tag;
}
}
// fire the event.
ItemSelected(element);
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
}
/// <summary>
/// Causes an item selected event to be sent for the current node.
/// </summary>
private void PickMI_Click(object sender, System.EventArgs e)
{
try
{
// check if current selection is valid.
TreeNode node = BrowseTV.SelectedNode;
if (node == null || node.Tag == null || node.Tag.GetType() != typeof(TsCHdaBrowseElement))
{
return;
}
// raise event if selected element is an item.
TsCHdaBrowseElement element = (TsCHdaBrowseElement)node.Tag;
if (element.IsItem)
{
if (ItemPicked != null)
{
ItemPicked(new OpcItem[] { element });
}
}
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
}
/// <summary>
/// Updates the state of context menus based on the current selection.
/// </summary>
private void BrowseTV_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// ignore left button actions.
if (e.Button != MouseButtons.Right)
{
return;
}
// selects the item that was right clicked on.
TreeNode clickedNode = BrowseTV.GetNodeAt(e.X, e.Y);
// no item clicked on - do nothing.
if (clickedNode == null)
{
return;
}
// force selection to clicked node.
BrowseTV.SelectedNode = clickedNode;
// disable everything.
PickMI.Enabled = false;
PickChildrenMI.Enabled = false;
EditFiltersMI.Enabled = false;
RefreshMI.Enabled = false;
// setup menu for browse element nodes.
if (typeof(TsCHdaBrowseElement).IsInstanceOfType(clickedNode.Tag))
{
TsCHdaBrowseElement element = (TsCHdaBrowseElement)clickedNode.Tag;
PickMI.Enabled = element.IsItem;
PickChildrenMI.Enabled = element.HasChildren;
EditFiltersMI.Enabled = element.HasChildren;
RefreshMI.Enabled = element.HasChildren;
return;
}
// setup menu for server nodes.
if (typeof(TsCHdaServer).IsInstanceOfType(clickedNode.Tag))
{
PickMI.Enabled = false;
PickChildrenMI.Enabled = true;
EditFiltersMI.Enabled = true;
RefreshMI.Enabled = true;
return;
}
}
/// <summary>
/// Causes an item selected event to be sent for each child of of the current node.
/// </summary>
private void PickChildrenMI_Click(object sender, System.EventArgs e)
{
try
{
// check if current selection is valid.
TreeNode node = BrowseTV.SelectedNode;
if (node == null || node.Nodes.Count == 0)
{
return;
}
// build list of items contained in the selected branch.
ArrayList items = new ArrayList();
foreach (TreeNode child in node.Nodes)
{
if (typeof(TsCHdaBrowseElement).IsInstanceOfType(child.Tag))
{
TsCHdaBrowseElement element = (TsCHdaBrowseElement)child.Tag;
if (element.IsItem)
{
items.Add(element);
}
}
}
// raise event at least one child item was found.
if (items.Count > 0)
{
if (ItemPicked != null)
{
ItemPicked((OpcItem[])items.ToArray(typeof(OpcItem)));
}
}
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
}
/// <summary>
/// Called before a node is about to expand.
/// </summary>
private void BrowseTV_BeforeExpand(object sender, System.Windows.Forms.TreeViewCancelEventArgs e)
{
TreeNode node = e.Node;
if (node == null || node.Tag == null)
{
return;
}
if (node.Tag.GetType() == typeof(TsCHdaBrowseElement))
{
TsCHdaBrowseElement element = (TsCHdaBrowseElement)node.Tag;
// fetch children if they have not already been fetched.
if (element.HasChildren && node.Nodes.Count == 1 && node.Nodes[0].Tag == null)
{
Browse(node, element);
}
}
}
/// <summary>
/// Called when the browse filters have changed.
/// </summary>
private void OnBrowseFiltersChanged(int maxElements, TsCHdaBrowseFilter[] filters)
{
try
{
// release existing browser.
if (m_browser != null)
{
m_browser.Dispose();
m_browser = null;
}
// create a new browser.
OpcResult[] results = null;
m_browser = m_server.CreateBrowser(filters, out results);
// save maximum elements to return in a single call.
m_maxElements = maxElements;
// update chidren of selected node.
TreeNode node = BrowseTV.SelectedNode;
if (node != null)
{
TsCHdaBrowseElement branch = null;
if (node.Tag != null && node.Tag.GetType() == typeof(TsCHdaBrowseElement))
{
branch = (TsCHdaBrowseElement)node.Tag;
}
Browse(node, branch);
}
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
/// <summary>
/// Browses for child nodes and populates the tree.
/// </summary>
private void Browse(TreeNode parent, TsCHdaBrowseElement branch)
{
// clear existing children.
parent.Nodes.Clear();
// browse for the children of the node.
TsCHdaBrowseElement[] children = null;
IOpcBrowsePosition position = null;
do
{
// fetch next batch of elements from the server.
try
{
if (position == null)
{
children = m_browser.Browse(branch, m_maxElements, out position);
}
else
{
children = m_browser.BrowseNext(m_maxElements, ref position);
}
}
catch (Exception e)
{
MessageBox.Show(e.Message);
break;
}
// nothing more to do.
if (children == null)
{
break;
}
// create a tree node for each child.
foreach (TsCHdaBrowseElement child in children)
{
// create new node.
TreeNode node = new TreeNode(child.Name);
// set node icon.
if (child.IsItem)
{
node.ImageIndex = Resources.IMAGE_GREEN_SCROLL;
node.SelectedImageIndex = Resources.IMAGE_GREEN_SCROLL;
}
else
{
node.ImageIndex = Resources.IMAGE_CLOSED_YELLOW_FOLDER;
node.SelectedImageIndex = Resources.IMAGE_CLOSED_YELLOW_FOLDER;
}
// save element.
node.Tag = child;
// add dummy child node for branches.
if (child.HasChildren)
{
node.Nodes.Add(new TreeNode());
}
// add top level node to root node.
parent.Nodes.Add(node);
}
// prompt use to continue browse operation.
if (position != null)
{
if (MessageBox.Show("More items exist. Continue browsing?", "Browse Items", MessageBoxButtons.YesNo) == DialogResult.No)
{
break;
}
}
}while (position != null);
// release browse position object if browse halted.
if (position != null)
{
position.Dispose();
position = null;
}
}
/// <summary>
/// Fetches the element names and item ids for each element.
/// </summary>
private ArrayList FetchElements(EnumString enumerator, int maxElements, bool isBranch)
{
ArrayList elements = new ArrayList();
while (elements.Count < maxElements)
{
// fetch next batch of element names.
int count = BLOCK_SIZE;
if (elements.Count + count > maxElements)
{
count = maxElements - elements.Count;
}
string[] names = null;
names = enumerator.Next(count);
// check if no more elements found.
if (names == null || names.Length == 0)
{
break;
}
// create new element objects.
foreach (string name in names)
{
TsCHdaBrowseElement element = new TsCHdaBrowseElement();
element.Name = name;
// lookup item id for element.
try
{
string itemID = null;
m_browser.GetItemID(name, out itemID);
element.ItemName = itemID;
element.ItemPath = null;
element.HasChildren = isBranch;
}
catch
{
// ignore errors.
}
elements.Add(element);
}
}
// validate items - this is necessary to set the IsItem flag correctly.
OpcItemResult[] results = m_server.ValidateItems((OpcItem[])elements.ToArray(typeof(OpcItem)));
if (results != null)
{
for (int ii = 0; ii < results.Length; ii++)
{
if (results[ii].Result.Succeeded())
{
((TsCHdaBrowseElement)elements[ii]).IsItem = true;
}
}
}
// return results.
return(elements);
}
