Use Subscript or Superscript in a TRichEdit

Author: Thomas Stutz

// yOffset values

type

TCharacterFormat = (CFM_Superscript, CFM_Subscript, CFM_Normal);

procedure RE_SetCharFormat(RichEdit: TRichEdit; CharacterFormat: TCharacterFormat);

var

// The CHARFORMAT structure contains information about

// character formatting in a rich edit control.

Format: TCharFormat;

begin

FillChar(Format, SizeOf(Format), 0);

with Format do

begin

cbSize := SizeOf(Format);

dwMask := CFM_OFFSET;

// Character offset, in twips, from the baseline.

// If the value of this member is positive,

// the character is a superscript;

// if it is negative, the character is a subscript.

case CharacterFormat of

CFM_Superscript: yOffset := 60;

CFM_Subscript: yOffset := -60;

CFM_Normal: yOffset := 0;

end;

end;

// The EM_SETCHARFORMAT message sets character formatting in a rich edit control.

// SCF_SELECTION: Applies the formatting to the current selection

Richedit.Perform(EM_SETCHARFORMAT, SCF_SELECTION, Longint(@Format));

end;

// Examples:

// Beispiele:

// Apply Superscript to the current selection

// Markierte Zeichen hoch stellen

procedure TForm1.Button1Click(Sender: TObject);

begin

RE_SetCharFormat(RichEdit1, CFM_Superscript);

end;

// Apply Subscript to the current selection

// Markierte Zeichen tief stellen

procedure TForm1.Button2Click(Sender: TObject);

begin

RE_SetCharFormat(RichEdit1, CFM_Subscript);

end;