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ComCtrls.THitTest Enumeration
ComCtrls | Description
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THitTest and THitTests are used in the GetHitTestInfoAt method.

Pascal
THitTest = (
  htAbove,
  htBelow,
  htNowhere,
  htOnItem,
  htOnButton,
  htOnIcon,
  htOnIndent,
  htOnLabel,
  htOnRight,
  htOnStateIcon,
  htToLeft,
  htToRight
);
C++
enum THitTest {
  htAbove,
  htBelow,
  htNowhere,
  htOnItem,
  htOnButton,
  htOnIcon,
  htOnIndent,
  htOnLabel,
  htOnRight,
  htOnStateIcon,
  htToLeft,
  htToRight
};
File
Description

THitTests is a set of THitTest values. THitTest can have any of the following values:

Value 
Means the point is 
htAbove  
Above the client area.  
htBelow  
Below the client area.  
htNowhere  
Inside the control, but not on an item.  
htOnItem  
On an item, its text, or its bitmap.  
htOnButton  
On a button.  
htOnIcon  
On an icon.  
htOnIndent  
On the indented area of an item.  
htOnLabel  
On a label.  
htOnRight  
On the right side of an item.  
htOnStateIcon  
On a state icon or bitmap associated with an item.  
htToLeft  
To the left of the client area.  
htToRight  
To the right of the client area.  

 

Delphi Examples: 

Copy Code
{
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.
}
procedure TForm1.TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);
var 
  AnItem: TTreeNode;
  AttachMode: TNodeAttachMode;
  HT: THitTests;
begin
  if TreeView1.Selected = nil then Exit;
  HT := TreeView1.GetHitTestInfoAt(X, Y);
  AnItem := TreeView1.GetNodeAt(X, Y);
  if (HT - [htOnItem, htOnIcon, htNowhere, htOnIndent] <> HT) then 
  begin
    if (htOnItem in HT) or (htOnIcon in HT) then
      AttachMode := naAddChild
    else if htNowhere in HT then AttachMode := naAdd
    else if htOnIndent in HT then AttachMode := naInsert;
    TreeView1.Selected.MoveTo(AnItem, AttachMode); 
  end;
end;

procedure TForm1.TreeView1DragOver(Sender, Source: TObject; X, Y: Integer;
  State: TDragState; var Accept: Boolean);
begin
  Accept := Source is TTreeView;
end;

 

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