private void TreeView_DragOver(object sender, DragEventArgs e)
{
TreeNode targetCmd = TreeView.GetNodeAt(TreeView.PointToClient(Cursor.Position));
TreeNode movingCmd = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
if (targetCmd == null)
{
TreeView.SelectedNode = null;
}
else if (targetCmd != movingCmd)
{
MovingCmdPosition movingCmdPosition = GetMovingCmdPositionOnTheTargetCmd(targetCmd, TreeView.PointToClient(Cursor.Position).Y);
if (movingNodePositionBackup != movingCmdPosition)
{
TreeView.Refresh(); // Node를 drag 할 때 화면이 깜박이는 것을 방지하기 위해서 node의 위치가 MovingCmdPosition에 준해서 바뀔 때에만 Refresh 한다.
movingNodePositionBackup = movingCmdPosition;
TreeView.SelectedNode = targetCmd;
}
if (movingCmdPosition == MovingCmdPosition.MIDDLE)
{
if (targetCmd.Nodes.Count > 0)
{
tmrNodeOver.Start();
}
else
{
tmrNodeOver.Stop();
DrawAddToFolderPlaceholder(targetCmd);
}
}
else
{
tmrNodeOver.Stop();
DrawPlaceholder(targetCmd, movingCmdPosition);
}
}
}
private void DrawPlaceholder(TreeNode NodeOver, MovingCmdPosition placeHolderPosition)
{
Graphics g = TreeView.CreateGraphics();
int NodeOverImageWidth = TreeView.ImageList.Images[NodeOver.ImageKey].Size.Width + 8;
int LeftPos = NodeOver.Bounds.Left - NodeOverImageWidth;
int RightPos = TreeView.Width - 4;
int yPos = 0;
if (placeHolderPosition == MovingCmdPosition.UPPER)
{
yPos = NodeOver.Bounds.Top;
}
else if (placeHolderPosition == MovingCmdPosition.LOWER)
{
yPos = NodeOver.Bounds.Bottom;
}
Point[] LeftTriangle = new Point[5] {
new Point(LeftPos, yPos - 4),
new Point(LeftPos, yPos + 4),
new Point(LeftPos + 4, yPos),
new Point(LeftPos + 4, yPos - 1),
new Point(LeftPos, yPos - 5)
};
Point[] RightTriangle = new Point[5] {
new Point(RightPos, yPos - 4),
new Point(RightPos, yPos + 4),
new Point(RightPos - 4, yPos),
new Point(RightPos - 4, yPos - 1),
new Point(RightPos, yPos - 5)
};
g.FillPolygon(System.Drawing.Brushes.White, LeftTriangle);
g.FillPolygon(System.Drawing.Brushes.White, RightTriangle);
g.DrawLine(new System.Drawing.Pen(Color.White, 2), new Point(LeftPos, yPos), new Point(RightPos, yPos));
}
private void InsertCmd(TreeView targetTree, TreeNode targetCmd, TreeNode insertCmd, MovingCmdPosition insertNodePosition)
{
if (targetCmd == null)
{
TreeView.Nodes.Add(targetCmd);
}
else
{
TreeNodeCollection targetParentCmd = (targetCmd.Parent == null) ? targetTree.Nodes : targetCmd.Parent.Nodes;
switch (insertNodePosition)
{
case MovingCmdPosition.UPPER:
targetParentCmd.Insert(targetCmd.Index, insertCmd);
break;
case MovingCmdPosition.MIDDLE:
case MovingCmdPosition.OUTSIDE:
targetCmd.Nodes.Add(insertCmd);
break;
case MovingCmdPosition.LOWER:
targetParentCmd.Insert(targetCmd.Index + 1, insertCmd);
break;
}
}
}
