//******************************************************************
/// <summary>
/// Raises the DrawNode event.
/// </summary>
protected virtual void OnDrawNode(TreeViewerNodeEventArgs oArgs)
{
try
{
Debug.Assert(oArgs != null);
if (DrawNode != null)
{
DrawNode(this, oArgs);
}
}
catch (Exception oException)
{
LogException(oException);
}
}
//******************************************************************
/// <summary>
/// Raises the DrawNode event (this event comes from nodes in the
/// tree). If the event handlers do not set the oArgs.Handled
/// property to true, default node drawing is performed.
/// </summary>
protected virtual void OnDrawNode(TreeViewerNodeEventArgs oArgs)
{
try
{
Debug.Assert(oArgs != null);
Debug.Assert(oArgs.Node != null);
//**********************************************************
// Raise the DrawNode event.
if (DrawNode != null)
{
DrawNode(this,oArgs);
}
//**********************************************************
// If the oArgs.Handled property was not set to true by an
// event handler, perform default node drawing.
if (! oArgs.Handled)
{
//******************************************************
// Determine the background, foreground and border
// colors.
Color oBackColor = oArgs.Node.BackColor;
Color oForeColor = oArgs.Node.ForeColor;
Color oBorderColor = oArgs.Node.BackColor;
//******************************************************
// Use different colors to highlight the selected node.
if (oArgs.Node == SelectedNode)
{
if (oArgs.Node.ContainsFocus)
{
//**********************************************
// Selected-node colors when the TreeViewer
// contains focus.
if (oBackColor == BackColor)
{
oBackColor = SystemColors.Highlight;
oForeColor = SystemColors.HighlightText;
}
oBorderColor = SystemColors.Highlight;
}
else
{
//**********************************************
// Selected-node colors when the TreeViewer does
// not contain focus.
if (oBackColor == BackColor)
{
oBackColor = SystemColors.Control;
oForeColor = SystemColors.ControlText;
}
oBorderColor = SystemColors.ControlDark;
}
}
//******************************************************
// The border color should be different than the
// TreeViewer's backround color.
if (oBorderColor == BackColor)
{
oBorderColor = oArgs.Node.ForeColor;
}
//******************************************************
// Create a graphics object. Get the width and height
// for drawing inside the node.
Graphics oGraphics = oArgs.Node.CreateGraphics();
int iWidth = oArgs.Node.Width - 1;
int iHeight = oArgs.Node.Height - 1;
//******************************************************
// Draw the background (background color).
Brush oBrush = new SolidBrush(oBackColor);
oGraphics.FillRectangle(oBrush,0,0,iWidth,iHeight);
//******************************************************
// Draw the text (foreground color), starting at offset
// (1,1) just inside the border.
oBrush = new SolidBrush(oForeColor);
string sText = oArgs.Node.Text;
if (sText == null)
{
sText = "";
}
oGraphics.DrawString(sText,oArgs.Node.Font,oBrush,1,1);
//******************************************************
// Draw the border (border color).
Pen oPen = new Pen(oBorderColor,1);
oGraphics.DrawLine(oPen,0,0,iWidth,0);
oGraphics.DrawLine(oPen,iWidth,0,iWidth,iHeight);
oGraphics.DrawLine(oPen,iWidth,iHeight,0,iHeight);
oGraphics.DrawLine(oPen,0,iHeight,0,0);
}
}
catch (Exception oException)
{
LogException(oException);
}
}
//******************************************************************
/// <summary>
/// Raises the MeasureNode event (this event comes from nodes in the
/// tree). If the event handlers do not set the oArgs.Handled
/// property to true, default node resizing is performed.
/// </summary>
private void OnMeasureNode(object oSender,
TreeViewerNodeEventArgs oArgs)
{
OnMeasureNode(oArgs);
}
//******************************************************************
/// <summary>
/// Raises the DrawNode event (this event comes from nodes in the
/// tree). If the event handlers do not set the oArgs.Handled
/// property to true, default node drawing is performed.
/// </summary>
private void OnDrawNode(object oSender,
TreeViewerNodeEventArgs oArgs)
{
OnDrawNode(oArgs);
}
//******************************************************************
/// <summary>
/// Raises the MeasureNode event (this event comes from nodes in the
/// tree). If the event handlers do not set the oArgs.Handled
/// property to true, default node resizing is performed.
/// </summary>
protected virtual void OnMeasureNode(TreeViewerNodeEventArgs oArgs)
{
try
{
Debug.Assert(oArgs != null);
Debug.Assert(oArgs.Node != null);
//**********************************************************
// Call BeginUpdate() to disable redrawing the tree, but not
// if redrawing was already disabled by the calling code.
bool bCallEndUpdate = false;
if (! IsUpdating)
{
BeginUpdate();
bCallEndUpdate = true;
}
//**********************************************************
// Raise the MeasureNode event.
if (MeasureNode != null)
{
MeasureNode(this,oArgs);
}
//**********************************************************
// If the oArgs.Handled property was not set to true by an
// event handler, perform default node resizing.
if (! oArgs.Handled)
{
//******************************************************
// Create a graphics object.
Graphics oGraphics = oArgs.Node.CreateGraphics();
//******************************************************
// Measure the size of the node's text.
string sText = oArgs.Node.Text;
if (sText == null)
{
sText = "";
}
SizeF oSizeF = oGraphics.MeasureString(
sText,oArgs.Node.Font);
float nWidth = oSizeF.Width;
float nHeight = oSizeF.Height;
//******************************************************
// Make sure we use at least a minimum size.
const string sMinimum = ".";
oSizeF = oGraphics.MeasureString(
sMinimum,oArgs.Node.Font);
if (nWidth < oSizeF.Width)
{
nWidth = oSizeF.Width;
}
if (nHeight < oSizeF.Height)
{
nHeight = oSizeF.Height;
}
//******************************************************
// Add a little width for italics or overhangs.
const int iExtraWidth = 1;
nWidth = nWidth + iExtraWidth;
//******************************************************
// Increase the size to include the borders.
nWidth = nWidth + 2;
nHeight = nHeight + 2;
//******************************************************
// Round up to an integer size.
oSizeF = new SizeF(nWidth,nHeight);
Size oSize = Size.Ceiling(oSizeF);
//******************************************************
// Resize the node.
oArgs.Node.Size = oSize;
//******************************************************
// Invalidate the control so the node will be repainted.
oArgs.Node.Invalidate();
}
//**********************************************************
// Call EndUpdate() to redraw the tree, but not if redrawing
// was already disabled by the calling code.
if (bCallEndUpdate)
{
EndUpdate();
}
}
catch (Exception oException)
{
LogException(oException);
}
}
//******************************************************************
/// <summary>
/// Raises the MeasureNode event.
/// </summary>
protected virtual void OnMeasureNode(TreeViewerNodeEventArgs oArgs)
{
try
{
Debug.Assert(oArgs != null);
if (MeasureNode != null)
{
MeasureNode(this,oArgs);
}
}
catch (Exception oException)
{
LogException(oException);
}
}
