collapseOnSearchFocus property
Whether this button collapses (hides + frees layout space) when the search field is focused (i.e. the keyboard is visible).
When true (default), the button fades out and its horizontal layout
space spring-animates to zero on keyboard appearance, giving the search
input the full available width — matching native iOS system apps
(Weather, App Store, Apple News).
When false, the button remains fully visible and tappable alongside
the search input. Use this for buttons with contextual relevance during
active search (e.g. a "Filter" action that applies to search results).
Implementation
final bool collapseOnSearchFocus;