TTreeGetNodeAt (C++)

Description

The following code uses GetNodeAt to add a dragged node as a child of the node under the mouse, when it is dropped. This example requires a populated TreeView. Also, the TTreeView DragMode property must be set to dmAutomatic, and the TTreeView OnDragOver event handler must be implemented to accept the drop.

Code

void __fastcall TForm1::TreeView1DragDrop(TObject *Sender, TObject *Source,
      int X, int Y)
{
  if (Source != dynamic_cast<TObject *>(TreeView1) || TreeView1->Selected == NULL)
    return;
  THitTests HT = TreeView1->GetHitTestInfoAt(X, Y);
  TNodeAttachMode AttachMode;
  TTreeNode *Item = TreeView1->GetNodeAt(X, Y);
  if (HT.Contains(htOnItem) || HT.Contains(htOnIcon))
	AttachMode = naAddChild;
  else if (HT.Contains(htNowhere))
    AttachMode = naAdd;
  else if (HT.Contains(htOnIndent))
    AttachMode = naInsert;
  else
	return;
  TreeView1->Selected->MoveTo(Item, AttachMode);
}

void __fastcall TForm1::TreeView1DragOver(TObject *Sender, TObject *Source,
	  int X, int Y, TDragState State, bool &Accept)
{
  Accept = (Source == dynamic_cast<TObject *>(TreeView1));
}

Uses

• Vcl.ComCtrls.TCustomTreeView.GetNodeAt ( fr | de | ja )
• Vcl.ComCtrls.TTreeNode.MoveTo ( fr | de | ja )
• Vcl.ComCtrls.TCustomTreeView.Selected ( fr | de | ja )
• Vcl.ComCtrls.TCustomTreeView.GetHitTestInfoAt ( fr | de | ja )
• Vcl.Controls.TControl.DragMode ( fr | de | ja )
• Vcl.ComCtrls.THitTests ( fr | de | ja )