How to implement identical methods with 2 and more Classes?

Question

I want to write a TCheckBox and TRadioButton descendants having 3 identical methods.

TMyCheckBox = class(TCheckBox)
  procedure DoS         


        

Answer 1

Define an interface say IDoSomething with the the three method signatures.

Then change your class declaration to

TMyCheckBox = class(TCheckBox, IDoSomething)

and then implement.

If the implementations are common or very close.

Then define a helper class TDoSomething and then delegate the work.

e.g.

Procedure TMyCheckBox.DoSomething1; // implements IDoSomething1
Begin
  TDoSomething.DoSomething1(Self); // given class method will suffice.
End;

Class Methods in delphi, equivalent to static methods in other languages.

Type
    TDoSomethingHelper = Class(TObject)
    Public
      Class Procedure DoSomething1(aComponent : TComponent);
    End;

...
implementation

Class Procedure TDoSomethingHelper.DoSomething1(aComponent : TComponent);
Begin
  aComponent.Tag = 27;
End;