How can I turn a list of properties into a stringlist?

Question

I have a component with a lot of properties, many of which are types.

For example:

BackgroundStyle = [bsSolid, bsGradient, bsNone]

BorderStyle = [bsNone, bsSingle, bsWide]

I am building a form to allow the user to configure these properties at runtime and I would like to populate some dropdown lists dynamically, rather than having to type all of them in by hand.

Is this possible? Thanks!

Answer 1

Use RTTI for that. Specifically, look at the GetPropInfo() and GetEnumName() functions in the TypInfo unit.

Answer 2

Remy is on the ball with this one. Lately I just happen to do something similar and a bit of refactoring (within a text editor, so you mileage may vary with the complier):

class function TEnumerationRoutines.TitleCaseDescriptionFromOptions<T>: TStrings;
var
  LRttiContext : TRttiContext;
  LRttiEnumerationType: TRttiEnumerationType;
  LTypeInfo : Pointer;
  LPTypeInfo : PTypeInfo;
  lp: Integer;
begin
  LTypeInfo := TypeInfo(T);

  LPTypeInfo := PTypeInfo(LTypeInfo);
  if LPTypeInfo^.Kind <> tkEnumeration then
    raise Exception.Create('Type is not an enum');

  Result := TStringList.Create;

  LRttiEnumerationType := LRttiContext.GetType(LTypeInfo) as TRttiEnumerationType;

  for lp := LRttiEnumerationType.MinValue to LRttiEnumerationType.MaxValue do
    Result.Add(GetEnumName(LTypeInfo, Ord(lp)));
end;

and call it with:

MyStrings := TEnumerationRoutines.TitleCaseDescriptionFromOptions<BackgroundStyle>;

or

MyStrings := TEnumerationRoutines.TitleCaseDescriptionFromOptions<BorderStyle>;