autograph-context/dev.ynagai.autograph.context/ScreenHistory

ScreenHistory

The most recently viewed screen, so the next screen view can be enriched with previous_screen and an autocaptured event can fall back to a screen when no ScopeStack frame supplies one.

This lives beside ScopeStack rather than inside a UI framework for the same reason ScopeStack does: previous_screen has to stay continuous across a Compose↔native transition, and it cannot be if only one of the two pipelines can reach the history. Every surface that emits a screen view records it here, whichever framework produced the screen.

This is history, not current state. lastScreen deliberately outlives the screen it names — that is the whole point of previous_screen. Ask ScopeStack.current for what is on screen now; ask this for what came before.

Threading. record is expected on the main thread, alongside ScopeStack's mutators. Reads are safe from any thread: lastScreen is a single volatile reference, so a reader sees either the old name or the new one, never a torn value.

Constructors

ScreenHistory

constructor()

Properties

lastScreen

@Volatile

var lastScreen: String?

The last screen recorded, or null before any screen has been viewed.

Functions

record

fun record(name: String): String?

Records name as the most recently viewed screen, returning the screen it replaces — i.e. exactly the previous_screen of the view being recorded, or null if this is the first.