Hi guys! I've a little question about returning a Modifier from interface function. If I have someth...

# compose

[Adrián Lázaro]

Hi guys! I've a little question about returning a Modifier from interface function. If I have something like this:

interface SampleInterface {
     fun modifier(param1, params...): Modifier
}

The function is showing a warning: "Modifier factory functions should be extensions on Modifier". If the function was a normal extension function over Modifier this was not a problem, but it's a function of an interface, so you do know how I can avoid this warning?

All implementatios of the interface, starts from the original Modifier and adds some params.

[Jorn Hertsig]

In Kotlin, even instance methods can have receivers:

interface Sample {
  fun Modifier.something(param1: Type): Modifier
}

[Adrián Lázaro]

thanks! And how I could start the modifier params chainning of a composable with this implementation?

[Jorn Hertsig]

The same way you do it with any other Modifier? If you are looking for examples, BoxScope has Modifier methods as well, for example Modifier.align.

[Adrián Lázaro]

perfect, thanks! I suppose that there is not any other way to use that sample interface without making a custom scope for a component that needs to use the implementation, no?

[Jorn Hertsig]

Well, you could do with(mySample) { Modifier.something(...) }

[Stylianos Gakis]

with(YourSampleImplementation) {
  Modifier.something()
}

You need to have your Sample interface in the context, same with how BoxScope is in the context when you’re inside the Box composable lambda

[Stylianos Gakis]

And to use it in a Modifier chain use then

Modifier.fillMaxSize().then(with(mySample) { Modifier.something(...) })

[Adrián Lázaro]

thanks so much! 😊

[ephemient]

or put the whole chain inside the scope,

with(mySample) {
    Modifier
        .fillMaxSize()
        .something()