Is such a thing possible?

General
1

I have a e.g. class TestClass with several properties and constructors. The class has for example the property BackgroundColor As Color.

If I now have another class MyClass which have a property Fill As TestClass, is it possible and if so, how, to use MyClass.Fill = Color.Red which then automatically creates an instance of TestClass and sets the BackgroundColor to Color.Red?

Thanks

EDIT: I’ve created a small sample Project. Had no luck until now. Where am I wrong? I think it is about the fact that I will use several subclasses and the right one has to be assigned.

Test Project.xojo_binary_project

2

Sure. What you’re looking for is the Operator_Convert method. Put it on the TestClass Class and have it take a color.

Var t as new TestClass
T.backgroundColor = newColor
Return t
1 Like
3

I almost thought so. Let’s see if I have success with it :wink:

4

I must be misreading the question. My thought was to make Fill a computed property.

2 Likes
5

I’ve created a small sample Project. Had no luck until now. Where am I wrong? I think it is about the fact that I will use several subclasses and the right one has to be assigned.

Test Project.xojo_binary_project

6

I’ve corrected your project to work, but I don’t think it’s what you really want to do.
OpConv.xojo_binary_project

7

Thanks Tim. You’re right. What I want is something like that:

I have a base class called Shading. There are Subclasses of Shading: ColorShading (with BackgroundColor As Color Property) & PictureShading (with BackgroundPicture As Picture Property). Now I simply want to do something like this for Shading instances:

Var shad As Shading ' Base Class.

shad = Color.Red ' Should return a ColorShading (Subclass of Shading) Instance.

' or

shad = MyPicture ' Should return a PictureShading (Subclass of Shading) Instance.
8

its something like that

Var b As BaseClass
b = SubClass.SharedMethodRed

Var c As SubClass = SubClass(b)
c.SubMethod

whereby the shared method is

Public Shared Function SharedMethodRed() as SubClass

Return New SubClass

End Function

gregs idea with Operator_Convert is better and would direct convert the Color into your class

9

Hi Markus,

thanks. I know, but shared methods are no option at the moment.

The conversion should be done automatically for the users behind the scenes. Kind of magic.

10

so have you tried this Operator_Convert ?

11

Yes I did, but since I have a structure with couple of subclasses, I hadn’t any success until now. Please have a look at my forth post here with more details.

12

I don’t really like the solution approach, but I think I’m going to implement the whole thing using shared methods first.

If someone else comes up with a different approach for the desired scenario, I would be happy to receive a post.

13

seems if you put the Operator_Convert in the colorshading class you can not convert it direct.

'Var b As BaseClass

'b = Color.Red

Var b As ColorShadingClass 'with Super to BaseClass

b = Color.Red

this is inside of colorshading

Public Sub Operator_Convert(col As Color)

  Self.BackgroundColor = col
  
End Sub
14

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