Fraction,Decimal, Millimeter ..on the fly conversions. 1

[Mezzzo]

Hi Group

I found this code and but don`t have a clue how to incorporate it into a project.
I wanted to have a set of option buttons that the user can select to pick the
format of all data displayed in the form controls. i.e.. 1/8 or .125 or 7mm.
This novice needs your expert help on this one. Thanks

___________________________________________________________
Is there any way to streamline this implementation section of the code. I have
to write quite a few formula functions based off of this fractional code. As it is it looks
now it will be very inconvient to deal with this long winded syntax

procedure TForm1.Button2Click(Sender: TObject);
begin
edDSDest.Text := DS(StrToFloat(edDSSource.Text),radDSConvMode.ItemIndex);
end;
___________________________________________________________
end.

unit Numerics;

interface

const
cmSTRING_TO_NUMERIC = 0;
cmFRACTION_TO_DECIMAL = 1;
cmMETRIC_TO_IMPERIAL = 2;

nfDECIMAL = 0;
nfFRACTION = 1;
nfMETRIC = 2;

MM_PER_INCH = 25.4;


function Convert(S : String; OrgMode : Integer; ToMode : Integer) : String;
function CV( S : String; Mode : Integer) : Double;
function ds(d : Double; Mode : Integer) : String;
function DecimalToFraction(wn : Double) : string;
function fraction2dec(s : string) : Double;


implementation

uses
SysUtils;
function fraction2dec(s : string) : Double;
var
PosDiv : integer;
PosSpace : Integer;
Num : string;
Den : string;
Int : string;
Fract : string;
begin
try
S := trim(s);
if Length(s) = 0 then begin
Result := 0;
Exit;
end;

PosDiv := pos('/',S);
if PosDiv = 0 then
// String holds an integer.
Result := StrToFloat(s)
else begin
Num := trim(copy(s,1,PosDiv-1));
Den := trim(copy(s,PosDiv+1,length(s)-PosDiv));
PosSpace := pos(' ',Num);
if PosSpace = 0 then
Result := StrToInt(Num)/StrToInt(Den)
else begin
Int := trim(copy(Num,1,PosSpace-1));
Fract := trim(copy(Num,PosSpace+1,Length(Num)-PosSpace));
Result := StrToInt(Int) + StrToint(Fract)/StrtoInt(Den);
end;
end;
except
on EConvertError do
Result := 0;
end;
end;

function CV( S : String; Mode : Integer) : Double;
begin
S := Trim(S);
If Length(s) > 0 Then
case Mode of
cmSTRING_TO_NUMERIC : Result := StrToFloat(s);
cmFRACTION_TO_DECIMAL : Result := fraction2dec(s);
cmMETRIC_TO_IMPERIAL : Result := StrToFloat(s)/MM_PER_INCH;
else Result := 0;
end // Case
else // DMc 22/01/03
Result := 0;
end;




function DecimalToFraction(wn : Double) : string;
var
tn : Integer;
bn : Integer;
dv : Integer;
begin
dv := 64;
tn := Trunc(wn);
bn := trunc(0.5+(wn - tn) * dv); // DMc 22/01/03

if bn > 0 then begin

while trunc(bn/2) = (bn/2) do begin
bn := trunc(bn/2);
dv := trunc(dv/2);
end;

if tn = 0 then
Result := Format('%d/%d',[bn,dv])
else
result := Format('%d %d/%d',[tn,bn,dv]);

end

else
Result := IntToStr(tn);

end;




function Convert(S : String; OrgMode : Integer; ToMode : Integer) : String;
begin
s := trim(s);
if Length(s) = 0 then begin
Result := ''
end
else
if orgmode = tomode then
Result := s
else begin

if (OrgMode = nfDECIMAL) and (ToMode = nfFRACTION) then
Result := DecimalToFraction(StrToFloat(S))

else if (OrgMode = nfDECIMAL) and (ToMode = nfMETRIC) then
Result := FloatToStr(StrToFloat(S)*MM_PER_INCH)

else if (OrgMode = nfFRACTION) and (Tomode = nfDECIMAL) then
Result := FloatToStr(fraction2dec(s))

else if (OrgMode = nfFraction) and (ToMode = nfMETRIC) then
Result :=FloatToStr(fraction2dec(s)*MM_PER_INCH)

else if (orgmode = nfMETRIC) and (tomode = nfDECIMAL) then
Result := FloatToStr(StrToFloat(s)/MM_PER_INCH)

else if (OrgMode = nfMetric) and (ToMode = nfFraction) then
Result := DecimalToFraction(StrToFloat(s) / MM_PER_INCH)

end;
end;




function ds(d : Double; Mode : Integer) : String;
begin
case Mode of
0 : Result := FloatToStr(d);
1 : Result := DecimalToFraction(d);
2 : Result := FloatToStr(d*MM_PER_INCH);
end;
end;

end.

 

[sggaunt]

The functions in your numerics module are untyped, this is not a problem keep them as a seperate file and add this to you project with the project manager, also add Numerics to your 'uses' clause.

Rather than changing the text on each control 'one at a time' you can use the forms 'components' array, and componentcount properties to loop though all the componets and apply the change to each text or caption property, you will have to be careful with this as it can only be done by typecasting.

e.g Adapted from the Delphi Help

var
I: Integer;
Temp: TComponent;
begin
for I := ComponentCount - 1 downto 0 do
begin
Temp := Components;
if (Temp is TEdit) then
(Temp as TEdit).text := 'New text';
end;
end;

Steve..