IssueTracker

Jetpack Compose release version: 1.0.x

Right now, since RowScope and ColumnScope are two separate interfaces, code can't be shared across the scopes. For example, if I want to layout a group of buttons, this way:

@Composable
fun Buttons() {
  Button1()
  Spacer(Modifier.weight(2f))
  Button2()
  Spacer(Modifier.weight(2f))
  Button3()
} 

Ideally I would like to use the same composable in both row and column configuration:

if (isLandscape) {
  Column {
    Buttons()
  }
} else {
  Row {
    Buttons()
  }
} 

But since the weight modifier requires a scope, we need to either

1. create two versions of Buttons: RowScope.Buttons and ColumnScope.Buttons

or

2. pass the scope as Any parameter and then do some runtime introspection / casting on the type of scope.

This duplication / introspection needs to be done throughout the view hierarchy which is a lot of effort.

It would be nice if RowScope and ColumnScope had a common interface, such as LinearScope. Then one could write code such as:

@Composable
fun LinearScope.Buttons() {
  Button1()
  Spacer(Modifier.weight(2f))
  Button2()
  Spacer(Modifier.weight(2f))
  Button3()
}