How to lock expanding/collapsing action programmatically?

Question

I would like to keep this layout on specific action:

Nowadays, I can collapse or expand this CoordinatorLayout by performing swipe on it. I want to block this behavior.

Answer 1

I assume your list is using a RecyclerView.

You can turn off nested scrolling on your RecyclerView which will disable the toolbar collapse:

recyclerView.setNestedScrollingEnabled(false);

You can lock the toolbar by clearing the scroll flags:

CollapsingToolbarLayout toolbar = findViewById(R.id.collapsingToolbar);  // or however you need to do it for your code
AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) toolbar.getLayoutParams();
params.setScrollFlags(0);  // clear all scroll flags