/// <summary>
/// Gets the state of the treeview nodes.
/// Use with ApplyOldStateInfo to restore state after repopulating controll.
/// </summary>
/// <param name="tv"></param>
/// <returns></returns>
public static TreeViewState GetState(this TreeView tv)
{
TreeViewState state = new TreeViewState();
//initial list of nodes
List <TreeNode> nodes = new List <TreeNode>();
foreach (TreeNode node in tv.Nodes)
{
nodes.Add(node);
}
//interate all nodes
while (nodes.Count > 0)
{
TreeNode node = nodes[0];
nodes.RemoveAt(0);
//add state to results
TreeNodePath path = new TreeNodePath(node);
TreeViewState.TreeNodeState tns = new TreeViewState.TreeNodeState(node);
if (!state.nodes.ContainsKey(path))
{
state.nodes.Add(path, tns);
}
else
{
WDAppLog.logError(ErrorLevel.SmallError, "tree view has two identical node pathways");
continue; //loop back rather then examine children, so as to stop any infinite loops.
}
//add child nodes to list
foreach (TreeNode childNode in node.Nodes)
{
nodes.Add(childNode);
}
}
//store selected node
state.selectedNode = GetPath(tv.SelectedNode);
return(state);
}
/// <summary>
/// Uses existing state info to relayout a treeview, that was assumably repopulated.
/// Is fairly tolerant of nodes that are new or missing.
/// Not accurate when notes .Text feild changes
/// Uses .Text not .Name
/// </summary>
/// <param name="tv"></param>
/// <param name="oldState"></param>
/// <param name="restoreExpansion"></param>
/// <param name="restoreCheckBox"></param>
/// <param name="restoreSelection"></param>
public static void ApplyOldStateInfo(this TreeView tv,
TreeViewState oldState,
bool restoreExpansion,
bool restoreCheckBox,
bool restoreSelection)
{
//initial list of nodes
List <TreeNode> nodes = new List <TreeNode>();
foreach (TreeNode node in tv.Nodes)
{
nodes.Add(node);
}
//interate all nodes
while (nodes.Count > 0)
{
TreeNode node = nodes[0];
nodes.RemoveAt(0);
//restore old state
TreeNodePath path = new TreeNodePath(node);
if (oldState.nodes.ContainsKey(path))
{
TreeViewState.TreeNodeState tns = oldState.nodes[path];
if (restoreExpansion)
{
if (tns.isExpanded && (!node.IsExpanded))
{
node.Expand();
}
else if ((!tns.isExpanded) && node.IsExpanded)
{
node.Collapse(true);
}
}
if (restoreCheckBox)
{
node.Checked = tns.isChecked;
}
}
//add child nodes to list
foreach (TreeNode childNode in node.Nodes)
{
nodes.Add(childNode);
}
}
//restore selected node
if (restoreSelection)
{
TreeNode selNode = GetNode(tv, oldState.selectedNode);
if (selNode != null)
{
tv.SelectedNode = selNode;
}
}
}
