[Solved] Custom component with drag-drop: issue on Windows

[AlexTP]

Can somebody please tell me what am I doing wrong?
https://gitlab.com/freepascal.org/lazarus/lazarus/-/issues/39515

This is affecting my main app.

[Mr.Madguy]

First of all you need this:

Code: Pascal  [Select][+][-]

1. procedure TMyPanel.DragOver(Sender, Source: TObject;X,Y: Integer; State: TDragState; var Accept: Boolean);
2. begin
3.   Accept := True;
4. end;  
5.  
6. constructor TMyPanel.Create(TheOwner: TComponent);
7. begin
8.   inherited Create(TheOwner);
9.   FMouseDownPnt:= Point(-1, -1);
10.   Cursor:= crIBeam;
11.   OnDragOver := @DragOver;
12. end;  
13.  

Second - you need to do this:

Code: Pascal  [Select][+][-]

1. procedure TMyPanel.UpdateCursor;
2. begin
3.   if Mouse.IsDragging then
4.   begin
5.     if ssCtrl in GetKeyShiftState then
6.       DragCursor:= crMultiDrag
7.     else
8.       DragCursor:= crDrag;
9.   end;
10. end;
11.  

Please note, that cursor actually changes only after mouse movement. I'm not sure, if it's correct way to do things. Something is still wrong, because cursor flickers. I guess, you mix some "auto" and "manual" drag and drop functionality.

[AlexTP]

You are cool!
Thanks for the hint, I just added overloaded DragOver() method.
And 'DragCursor:=...'. Solved!