// Constructor.
public NodeEnumeratorEx(TreeNodeExCollection nodes)
{
this.nodes = nodes;
Reset();
}
public TreeViewEx()
: base()
{
hideSelection = true;
indent = 19;
itemHeight = -1;
scrollable = true;
showLines = true;
showPlusMinus = true;
showRootLines = true;
root = new TreeNodeEx(this);
root.Expand();
nodes = new TreeNodeExCollection(root);
BackColor = SystemColors.Window;
ForeColor = SystemColors.WindowText;
SetStyle(Forms.ControlStyles.StandardClick, false);
// Switch on double buffering.
SetStyle(Forms.ControlStyles.DoubleBuffer | Forms.ControlStyles.AllPaintingInWmPaint | Forms.ControlStyles.UserPaint, true);
}
public void EnsureVisible()
{
TreeViewEx.NodeEnumeratorEx nodes;
int nodeFromTop;
int nodeNo;
while (true)
{
// Find "this" node number and position from the top control.
nodeFromTop = -1;
nodeNo = 0;
bool nodeFound = false;
nodes = new TreeViewEx.NodeEnumeratorEx(treeView.nodes);
while (nodes.MoveNext())
{
if (nodes.currentNode == treeView.topNode)
{
// We are at the top of the control.
nodeFromTop = 0;
}
if (nodes.currentNode == this)
{
if (nodeFromTop < 0)
{
treeView.topNode = this;
treeView.Invalidate();
return;
}
nodeFound = true;
break;
}
if (nodeFromTop >= 0)
{
nodeFromTop++;
}
nodeNo++;
}
if (nodeFound)
{
break;
}
else
{
// Make sure all parents are expanded and see if its now visible.
TreeNodeEx node = this;
TreeNodeEx highestNode = node;
for (; node != null; node = node.Parent)
{
node.expanded = true;
highestNode = node;
}
treeView.InvalidateDown(highestNode);
}
}
int visibleNodes = treeView.VisibleCountActual;
// See if its already visible.
if (nodeFromTop < visibleNodes)
{
return;
}
// Set the top node no we want to make this node 1 up from the bottom.
nodeFromTop = nodeNo - visibleNodes + 1;
if (nodeFromTop < 0)
{
nodeFromTop = 0;
}
// Find the node corresponding to this node no.
nodes.Reset();
nodeNo = 0;
while (nodes.MoveNext())
{
if (nodeFromTop == nodeNo)
{
treeView.topNode = nodes.currentNode;
treeView.Invalidate();
break;
}
nodeNo++;
}
}
