Is there any way to skip code by checking if I'm currently in the preview? I have code that uses `Em...

# compose

[Paul Woitaschek]

Is there any way to skip code by checking if I'm currently in the preview? I have code that uses EmojiCompat.get() and that breaks the preview because EmojiCompat wasnt initialized because as we're inside the preview the application wasn't created.
(sth like View.isInEditMode but statically available?)

[Adam Powell]

Can always declare your own CompositionLocal for it

[Paul Woitaschek]

My code is completely compose unrelated

[Paul Woitaschek]

It's inside an EmojiDrawable class

[Paul Woitaschek]

I think this is something that compose needs in some way

[Mark Murphy]

Is your composable attempting to use your EmojiDrawable directly?

If so, could you change it such that it receives the drawable (or supplier of drawables) as a parameter? Then, if you set up a default value of the parameter that does not use EmojiDrawable itself, the preview should be isolated from EmojiDrawable and should not need EmojiCompat.

Or, as Adam suggests, perhaps your supplier of drawables could be provided by a CompositionLocal, with a default implementation that does not depend upon EmojiCompat. The preview would use that default implementation, and higher-level composables would provide the EmojiDrawable-based implementation.

On the whole, the advice seems to be: if you are encountering preview problems because of platform considerations, your composable is insufficiently isolated from the platform.

[Paul Woitaschek]

Hm that issue happens in various places. For example it's the same with accompanist image integrations. That makes me think that this needs some form of global handling

[Paul Woitaschek]

Found it. It's called LocalInspectionMode 🙂

[Paul Woitaschek]

@Composable
internal fun rememberEmojiPainter(emoji: Emoji): Painter {
  val useEmojiCompat = !LocalInspectionMode.current
  return remember(emoji) {
    val drawable = EmojiDrawable(emoji, useEmojiCompat = useEmojiCompat)
    DrawablePainter(drawable)
  }
}