TRichEdit

Code:

uses

RichEdit;

procedure TForm1.RichEdit1MouseMove(Sender: TObject; Shift: TShiftState;

X, Y: Integer);

var

iCharIndex, iLineIndex, iCharOffset, i, j: Integer;

Pt: TPoint;

s: string;

begin

with TRichEdit(Sender) do

begin

   Pt := Point(X, Y);

   // Get Character Index from word under the cursor

   iCharIndex := Perform(Messages.EM_CHARFROMPOS, 0, Integer(@Pt));

   if iCharIndex < 0 then Exit;

   // Get line Index

   iLineIndex  := Perform(EM_EXLINEFROMCHAR, 0, iCharIndex);

   iCharOffset := iCharIndex - Perform(EM_LINEINDEX, iLineIndex, 0);

   if Lines.Count - 1 < iLineIndex then Exit;

   // store the current line in a variable

   s := Lines[iLineIndex];

   // Search the beginning of the word

   i := iCharOffset + 1;

   while (i > 0) and (s[i] <> ' ') do Dec(i);

   // Search the end of the word

   j := iCharOffset + 1;

   while (j <= Length(s)) and (s[j] <> ' ') do Inc(j);

   // Display Text under Cursor

   Caption := Copy(s, i, j - i);

end;

end;