Lazarus Hacks

Exposing TCustomEdit properties

In some applications we need constantly convert TCustomEdit descendants Text property for or to numeric values:

 TCustomEditFilters = (cefNone, cefInteger, cefUnsigned, cefCurrency, cefFloat);

 { TCustomEdit }

 TCustomEdit = class(TWinControl)
 private
   ...
   FTmpModified : Boolean;
   FceFilter : TCustomEditFilters;
   procedure SetceFilter(aCeFilter: TCustomEditFilters);
   function GetAsInteger:Integer;
   procedure SetAsInteger(aVal: Integer);
   function GetAsFloat:Extended;
   procedure SetAsFloat(aVal: Extended);
   function GetAsCurrency:Currency;
   procedure SetAsCurrency(aVal: Currency);

 public
   ...
   property TmpModified: Boolean read FTmpModified write FTmpModified;
   property AsInteger: Integer read getAsInteger write setAsInteger;
   property AsFloat: Extended read getAsFloat write setAsFloat;
   property AsCurrency: Currency read getAsCurrency write setAsCurrency;
 published
   property Alignment: TAlignment read FAlignment write SetAlignment default taLeftJustify;
   property ceFilter : TCustomEditFilters read FceFilter write SetceFilter default cefNone;
 end;

On the implementation part tcustomedit.inc:

 resourcestring
   rsInvalidNumbe = 'Invalid number !';

 procedure TCustomEdit.SetceFilter(aCeFilter: TCustomEditFilters);
 begin
   FCeFilter := aCeFilter;
   if FCeFilter = cefNone then Alignment := taLeftJustify
   else Alignment := taRightJustify;
 end;

 function TCustomEdit.GetAsInteger:Integer;
 begin
   TryStrToInt(Text, result);
 end;

 procedure TCustomEdit.SetAsInteger(aVal: Integer);
 begin
    Text := IntToStr(aVal);
 end;

 function TCustomEdit.GetAsFloat:Extended;
 begin
   if not TryStrToFloat(Text, result) then
     Raise Exception.Create(rsInvalidNumbe);
 end;

 procedure TCustomEdit.SetAsFloat(aVal: Extended);
 begin
    Text := FloatToStr(aVal);
 end;

 function TCustomEdit.GetAsCurrency:Currency;
 begin
   if not TryStrToCurr(Text, result) then
     raise Exception.Create(rsInvalidNumbe);
 end;

 procedure TCustomEdit.SetAsCurrency(aVal: Currency);
 begin
    Text := CurrToStr(aVal);
 end;