public void QueryAllowedDragPositions(QueryAllowedPositionsEventArgs args)
{
args.AllowedCopyPositions = DropLinePosition.None;
args.AllowedMovePositions = DropLinePosition.None;
DesignerNodeData sourceNodeData = args.Source as DesignerNodeData;
if (sourceNodeData != null)
{
INode source = sourceNodeData.TreeNode.Node;
INode target = ((DesignerNode)args.TargetNode).Node;
if (target.IsValidChild(source))
{
args.AllowedCopyPositions |= DropLinePosition.OnNode;
if (!IsNodeContained(source, target, true))
{
args.AllowedMovePositions |= DropLinePosition.OnNode;
}
}
if ((args.TargetNode.Parent != null) && target.Parent.IsValidChild(source))
{
args.AllowedCopyPositions |= (DropLinePosition.AboveNode | DropLinePosition.BelowNode);
if (!IsNodeContained(source, target.Parent, true) && !Object.ReferenceEquals(target, source))
{
int index = target.Parent.Children.IndexOf(target);
if
(
(index == 0) ||
((index > 0) && !ReferenceEquals(target.Parent.Children[index - 1], source))
)
{
args.AllowedMovePositions |= DropLinePosition.AboveNode;
}
if
(
(index == target.Parent.Children.Count - 1) ||
((index < target.Parent.Children.Count - 1) && !ReferenceEquals(target.Parent.Children[index + 1], source))
)
{
args.AllowedMovePositions |= DropLinePosition.BelowNode;
}
}
}
}
}
public void QueryAllowedPalettePositions(QueryAllowedPositionsEventArgs args)
{
args.AllowedCopyPositions = DropLinePosition.None;
args.AllowedMovePositions = DropLinePosition.None;
PaletteItem item = args.Source as PaletteItem;
if (item != null)
{
INode target = ((DesignerNode)args.TargetNode).Node;
Type type = DesignerTree.FormDesigner.FrontendSession.NodeTypeTable.GetClassType(item.ClassName);
if (target.IsValidChild(type))
{
args.AllowedCopyPositions |= DropLinePosition.OnNode;
}
if ((args.TargetNode.Parent != null) && target.Parent.IsValidChild(type))
{
args.AllowedCopyPositions |= (DropLinePosition.AboveNode | DropLinePosition.BelowNode);
}
}
}
// Drag & drop
private void QueryAllowedDragPositions(object sender, QueryAllowedPositionsEventArgs args)
{
((DesignerNode)args.TargetNode).QueryAllowedDragPositions(args);
}
