//The actual drawing code
bool Infragistics.Win.IUIElementDrawFilter.DrawElement(Infragistics.Win.DrawPhase drawPhase, ref Infragistics.Win.UIElementDrawParams drawParams)
{
Infragistics.Win.UIElement aUIElement;
System.Drawing.Graphics g;
UltraTreeNode aNode;
//If there's no DropHighlight node or no position specified, then we don't need to draw anything special.
//Just exit Function
if ((mvarDropHighLightNode == null) || (mvarDropLinePosition == DropLinePositionEnum.None))
{
return(false);
}
//Create a new QueryStateAllowedForNodeEventArgs object to pass to the event
QueryStateAllowedForNodeEventArgs eArgs = new QueryStateAllowedForNodeEventArgs();
//Initialize the object with the correct info
eArgs.Node = mvarDropHighLightNode;
eArgs.DropLinePosition = this.mvarDropLinePosition;
//Default to all states allowed.
eArgs.StatesAllowed = DropLinePositionEnum.All;
//Raise the event
this.QueryStateAllowedForNode(this, eArgs);
//Check to see if the user allowed the current state for this node. If not, exit function
if ((eArgs.StatesAllowed & mvarDropLinePosition) != mvarDropLinePosition)
{
return(false);
}
//Get the element being drawn
aUIElement = drawParams.Element;
//Determine which drawing phase we are in.
switch (drawPhase)
{
case Infragistics.Win.DrawPhase.BeforeDrawElement:
{
//We are in BeforeDrawElement, so we are only concerned with drawing the OnNode state.
if ((mvarDropLinePosition & DropLinePositionEnum.OnNode) == DropLinePositionEnum.OnNode)
{
//Check to see if we are drawing a NodeTextUIElement
if (aUIElement.GetType() == typeof(Infragistics.Win.UltraWinTree.NodeTextUIElement))
{
//Get a reference to the node that this NodeTextUIElement is associated with
aNode = (UltraTreeNode)aUIElement.GetContext(typeof(UltraTreeNode));
//See if this is the DropHighlightNode
if (aNode.Equals(mvarDropHighLightNode))
{
//Set the ForeColor and Backcolor of the node to the DropHighlight colors
//Note that AppearanceData only affects the node for this one paint. It will not
//change any properties of the node
drawParams.AppearanceData.BackColor = mvarDropHighLightBackColor;
drawParams.AppearanceData.ForeColor = mvarDropHighLightForeColor;
}
}
}
break;
}
case Infragistics.Win.DrawPhase.AfterDrawElement:
{
//We're in AfterDrawElement. So the only states we are conderned with are Below and Above
//Check to see if we are drawing the Tree Element
if (aUIElement.GetType() == typeof(Infragistics.Win.UltraWinTree.UltraTreeUIElement))
{
//Declare a pen to us for drawing Droplines
System.Drawing.Pen p = new System.Drawing.Pen(mvarDropLineColor, mvarDropLineWidth);
//Get a reference to the Graphics object we are drawing to.
g = drawParams.Graphics;
// Get the NodeSelectableAreaUIElement for the current DropNode. We will use this for
// positioning and sizing the DropLine
Infragistics.Win.UltraWinTree.NodeSelectableAreaUIElement tElement;
tElement = (Infragistics.Win.UltraWinTree.NodeSelectableAreaUIElement)drawParams.Element.GetDescendant(typeof(Infragistics.Win.UltraWinTree.NodeSelectableAreaUIElement), mvarDropHighLightNode);
if (tElement == null)
{
return(false);
}
//The left edge of the DropLine
int LeftEdge = tElement.Rect.Left - 4;
//We need a reference to the control to determine the right edge of the line
UltraTree aTree;
aTree = (UltraTree)tElement.GetContext(typeof(UltraTree));
int RightEdge = aTree.DisplayRectangle.Right - 4;
//Used to store the Vertical position of the DropLine
int LineVPosition;
if ((mvarDropLinePosition & DropLinePositionEnum.AboveNode) == DropLinePositionEnum.AboveNode)
{
//Draw line above node
LineVPosition = mvarDropHighLightNode.Bounds.Top;
g.DrawLine(p, LeftEdge, LineVPosition, RightEdge, LineVPosition);
p.Width = 1;
g.DrawLine(p, LeftEdge, LineVPosition - 3, LeftEdge, LineVPosition + 2);
g.DrawLine(p, LeftEdge + 1, LineVPosition - 2, LeftEdge + 1, LineVPosition + 1);
g.DrawLine(p, RightEdge, LineVPosition - 3, RightEdge, LineVPosition + 2);
g.DrawLine(p, RightEdge - 1, LineVPosition - 2, RightEdge - 1, LineVPosition + 1);
}
if ((mvarDropLinePosition & DropLinePositionEnum.BelowNode) == DropLinePositionEnum.BelowNode)
{
//Draw Line below node
LineVPosition = mvarDropHighLightNode.Bounds.Bottom;
g.DrawLine(p, LeftEdge, LineVPosition, RightEdge, LineVPosition);
p.Width = 1;
g.DrawLine(p, LeftEdge, LineVPosition - 3, LeftEdge, LineVPosition + 2);
g.DrawLine(p, LeftEdge + 1, LineVPosition - 2, LeftEdge + 1, LineVPosition + 1);
g.DrawLine(p, RightEdge, LineVPosition - 3, RightEdge, LineVPosition + 2);
g.DrawLine(p, RightEdge - 1, LineVPosition - 2, RightEdge - 1, LineVPosition + 1);
}
}
break;
}
}
return(false);
}
/// <summary>
/// Called during the drawing operation of a UIElement for a specific phase
/// of the operation. This will only be called for the phases returned
/// from the GetPhasesToFilter method.
/// </summary>
/// <param name="drawPhase">Contains a single bit which identifies the current draw phase.</param>
/// <param name="drawParams">The <see cref="T:Infragistics.Win.UIElementDrawParams" /> used to provide rendering information.</param>
/// <returns>
/// Returning true from this method indicates that this phase has been handled and the default processing should be skipped.
/// </returns>
public bool DrawElement(Infragistics.Win.DrawPhase drawPhase, ref Infragistics.Win.UIElementDrawParams drawParams)
{
return(true);
}
