How to modify the text being pasted? - delphi

Question

I'm trying to modify the text being pasted inside a TEdit descendant.
When the user paste some text, I want to replace all 'X' chars with an 'Y', without modifying the actual clipboard text content.
I've intercepted the WM_PASTE message, but I'm not aware about any "clean" way to change the text that's being pasted into the control.
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;
type
TMyEdit = class(Vcl.StdCtrls.TEdit)
private
procedure WMPaste(var Msg: TWMPaste); message WM_PASTE;
end;
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses
Clipbrd;
procedure TMyEdit.WMPaste(var Msg: TWMPaste);
begin
inherited;
end;
procedure TForm1.FormCreate(Sender: TObject);
var
Edt : TMyEdit;
begin
Edt := TMyEdit.Create(Self);
Edt.Top := 10;
Edt.Left := 10;
Edt.Parent := Self;
end;
end.
The only working way I've found is to temporarly replace the clipboard content, but I'm looking for a cleaner solution (if there's one...).
procedure TMyEdit.WMPaste(var Msg: TWMPaste);
var
PrevClipboardText : string;
begin
if(IsClipboardFormatAvailable(CF_TEXT)) then
begin
PrevClipboardText := Clipboard.AsText;
try
Clipboard.AsText := StringReplace(Clipboard.AsText, 'X', 'Y', [rfReplaceAll]);
inherited;
finally
Clipboard.AsText := PrevClipboardText;
end;
end else
begin
inherited;
end;
end;

Answer 1

Why not do the obvious thing?
procedure TEdit.WMPaste(var Msg: TWMPaste);
begin
SelText := F(Clipboard.AsText);
end;
where F is your string-transforming function.