Mega Code Archive
Superscript and subscript in a TLabel
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Title: Superscript and subscript in a TLabel
Question: How to write text in superscript and/or subscript in a TLabel
Answer:
For those who had to write a superscript or subscript text in a TLabel, I have written a easy to use free component similar to Tlabel. It is called TSuperSubLabel.
In its caption property,
To superscript, use "^" before the char
To subscript, use "_" before the char
For example, the chemical formula (SO4)2- would be written:
SuperSubLabel1.Caption := '(SO_4)^2^-';
You can use it at design AND runtime.
You can download full component at http://www.ezboo.com
Here is the main procedure of this component:
///////////////////////////////////////////////////////////////////////////////
procedure SuperSubLabelOut(Canvas:TCanvas; const aRect:TRect; X, Y:integer; text:String);
var i,xx:integer;
// s:string[16];
subScript, superScript:boolean;
DefFont:TFont;
begin
Canvas.FillRect(aRect);
DefFont:=TFont.Create;
DefFont.Assign(Canvas.Font);
with Canvas do begin
xx:=X;
for i:=1 to length(text) do
begin
if text[i-1] = '_' then subScript:=true
else subScript:=false;
if text[i-1] = '^' then superScript:=true
else superScript:=false;
if (text[i] '_' ) and (text[i] '^' ) then
begin
if ( subScript ) then
begin
Canvas.Font.Height:=Canvas.Font.Height*8 div 10;
TextRect(Rect(xx,aRect.Top,xx+TextWidth(text[i]),aRect.Bottom),xx, Y+abs(8*Canvas.Font.Height-10*DefFont.Height) div 10, text[i]);
inc(xx,TextWidth(text[i]));
end;
if ( not subScript) and ( not superScript ) then
begin
Canvas.Font:=DefFont;
TextRect(Rect(xx,aRect.Top,xx+TextWidth(text[i]),aRect.Bottom),xx, Y, text[i]);
inc(xx,TextWidth(text[i]));
end;
if ( superScript ) then
begin
Canvas.Font.Height:=Canvas.Font.Height*9 div 10;
TextRect(Rect(xx,aRect.Top,xx+TextWidth(text[i]),aRect.Bottom),xx, Y-abs(8*Canvas.Font.Height-10*DefFont.Height) div 20, text[i]);
inc(xx,TextWidth(text[i]));
end;
Canvas.Font:=DefFont;
end;
end; //for loop
end; // with
DefFont.Free;
end;
///////////////////////////////////////////////////////////////////////////////
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