UiEvents.kt

Each line, with the release that last changed it.

0.5.0	1	package dev.stave.ui.events
	2
	3	import kotlinx.coroutines.channels.BufferOverflow
	4	import kotlinx.coroutines.flow.MutableSharedFlow
	5	import kotlinx.coroutines.flow.SharedFlow
	6	import kotlinx.coroutines.flow.asSharedFlow
	7
	8	/**
	9	* App-wide bus for transient user-facing notifications. Emitters post strings;
	10	* [dev.stave.desktop.ui.ToastHost] in StaveApp collects them into a small stack of
	11	* Material Snackbar-style banners.
	12	*
	13	* Design. MutableSharedFlow with replay=0 (a toast that arrives before a
	14	* collector is ready is dropped — we don't want last week's error flashing up on
	15	* today's launch) and extraBufferCapacity=4 so a brief burst (e.g. three playlist
	16	* loads failing in quick succession) queues rather than dropping.
	17	*
	18	* What goes here. Non-blocking informational messages that the user can safely
	19	* ignore. Examples: "Lyrics unavailable for this track", "Couldn't reach LRCLIB",
	20	* "Playlist saved to library", "Tag reader timed out". Not here: fatal errors
	21	* that should prevent a user action from completing (those deserve a dialog), or
	22	* status that's not time-bounded (those belong in the relevant screen's persistent
	23	* UI).
	24	*/
	25	class UiEvents {
	26	private val _messages = MutableSharedFlow<String>(
	27	replay = 0,
	28	extraBufferCapacity = 4,
	29	onBufferOverflow = BufferOverflow.DROP_OLDEST,
	30	)
	31
	32	/** Observe toast messages. Collectors are fire-and-forget; missed emissions
	33	* while no collector is attached stay missed, which is what we want. */
	34	val messages: SharedFlow<String> = _messages.asSharedFlow()
	35
	36	/** Post a toast. Non-suspending for convenience in non-coroutine call sites
	37	* (IO error handlers, VLCJ callbacks). Drops on overflow — at which point the
	38	* user probably has bigger problems than one dropped toast. */
	39	fun post(message: String) {
	40	_messages.tryEmit(message)
	41	}
	42	}