Making this a top level discussion.

# compose-wear

[yschimke]

Making this a top level discussion.

[yschimke]

@Jonathan I doubt there is guidance, but can talk through the model a bit.

[yschimke]

Wear Compose uses the focus system (like Mobile Compose, and Views) which enables direct physical input like keyboard and Rotary (RSB/mousewheel?). This means FocusRequester, and Modifier.focusable()/focusRequester().

[yschimke]

On mobile you may want to manually move it around with focusRequester.requestFocus()

[yschimke]

But on Wear we want to direct scroll events typically to a screen sized component like ScalingLazyColumn. so we use HierarchicalFocusCoordinator, and it's built into standard components like PickerGroup and SwipeToDismissBox

[yschimke]

While you can manually call requestFocus() you can't ignore the hierarchical nature, which means that your Composable may be composed, but not active to the user (background in the nav host, or another page of HorizontalPager).

[yschimke]

So what I'd suggest is wrapping your Picker with

ScalingLazyColumn or VerticalPager {
  // higher content

  HierarchicalFocusRequester(requiresFocus = { shouldFocusOnPicker }) {
    // Picker goes here
  }

  // lower content
}

And toggle shouldFocusOnPicker. But unless you demonstrate it visually, I suspect it will be confusing for the user.

[yschimke]

@stevebower raised a good point, you are a bit off the beaten track. It's possible you hit issues with nested scrolling, or LazyList inside LazyLists. Or the reviewer doesn't feel it's following guidance. So just go in with open eyes.

[yschimke]

I think Misha was right, that it's generally safer to get a design that fits on screen.

[Jonathan]

@yschimke
The particular screen would be really, really cramped if everything fit on it. I was incorrect, in what composables my UI was using (originally it was pickers) but I currently have three focusable elements (outline in red, but when focused they have a gold border). When any of these three elements have focus, scrolling the RSB will slide through a predefined range of values. Beneath these focusable elements are a cancel and save button, which definitely are needed.