RosettaCodeData/Task/Add-a-variable-to-a-class-i.../Pascal/add-a-variable-to-a-class-i...

101 lines
2.4 KiB
ObjectPascal

unit MyObjDef;
{$mode objfpc}{$h+}{$interfaces com}
interface
function MyObjCreate: Variant;
implementation
uses
Variants, Generics.Collections;
var
MyObjType: TInvokeableVariantType;
type
IMyObj = interface
procedure SetVar(const aName: string; const aValue: Variant);
function GetVar(const aName: string): Variant;
end;
TMyObj = class(TInterfacedObject, IMyObj)
strict private
FMap: specialize TDictionary<string, Variant>;
public
constructor Create;
destructor Destroy; override;
procedure SetVar(const aName: string; const aValue: Variant);
function GetVar(const aName: string): Variant;
end;
TMyData = packed record
VType: TVarType;
Dummy1: array[0..5] of Byte;
Dummy2: Pointer;
FObj: IMyObj;
end;
TMyObjType = class(TInvokeableVariantType)
procedure Clear(var V: TVarData); override;
procedure Copy(var aDst: TVarData; const aSrc: TVarData; const Indir: Boolean); override;
function GetProperty(var aDst: TVarData; const aData: TVarData; const aName: string): Boolean; override;
function SetProperty(var V: TVarData; const aName: string; const aData: TVarData): Boolean; override;
end;
function MyObjCreate: Variant;
begin
VarClear(Result);
TMyData(Result).VType := MyObjType.VarType;
TMyData(Result).FObj := TMyObj.Create;
end;
constructor TMyObj.Create;
begin
FMap := specialize TDictionary<string, Variant>.Create;
end;
destructor TMyObj.Destroy;
begin
FMap.Free;
inherited;
end;
procedure TMyObj.SetVar(const aName: string; const aValue: Variant);
begin
FMap.AddOrSetValue(LowerCase(aName), aValue);
end;
function TMyObj.GetVar(const aName: string): Variant;
begin
if not FMap.TryGetValue(LowerCase(aName), Result) then Result := Null;
end;
procedure TMyObjType.Clear(var V: TVarData);
begin
TMyData(V).FObj := nil;
V.VType := varEmpty;
end;
procedure TMyObjType.Copy(var aDst: TVarData; const aSrc: TVarData; const Indir: Boolean);
begin
VarClear(Variant(aDst));
TMyData(aDst) := TMyData(aSrc);
end;
function TMyObjType.GetProperty(var aDst: TVarData; const aData: TVarData; const aName: string): Boolean;
begin
Result := True;
Variant(aDst) := TMyData(aData).FObj.GetVar(aName);
end;
function TMyObjType.SetProperty(var V: TVarData; const aName: string; const aData: TVarData): Boolean;
begin
Result := True;
TMyData(V).FObj.SetVar(aName, Variant(aData));
end;
initialization
MyObjType := TMyObjType.Create;
finalization
MyObjType.Free;
end.