Player layout, one song menu, predictive back, swipe actions, cross-device library sync, takeover and playback fixes

android/README.md

@@ -59,7 +59,10 @@ the one core for the process through `CoreHost`:
 - `Event.Backend(BackendCommand)` -> `ExoBackend` -> ExoPlayer. `Load` builds a per-item media
   source through `DefaultMediaSourceFactory` over `CoreStreamDataSourceFactory` (each item carries its
   own headers) plus the gapless follow-up as a second playlist item; `SetNext` replaces everything after the current item; the transition is
-  detected from `onMediaItemTransition(AUTO)` and the played item removed. `PreBuffer` prepares a
+  detected from `onMediaItemTransition(AUTO)`, reported as `Ended` (played item) then
+  `TransitionedToNext`, and the played item removed. The player holds `C.WAKE_MODE_NETWORK` (wake +
+  Wi-Fi lock) so streams keep going with the screen off. Network errors (connection failed/timeout)
+  are retried with `prepare()` on a ~1 min backoff and reported non-fatal; only then fatal. `PreBuffer` prepares a
   second silent ExoPlayer at the requested position (`PreBufferReady` when READY); `DiscardPreBuffer`
   releases it. `gain_db` is applied as `10^(gain/20) * masterVolume` clamped to 1.0 — Media3 has no
   gain stage, so positive gain is an approximation (documented in `ExoBackend`).
@@ -76,13 +79,24 @@ the one core for the process through `CoreHost`:
   is no `CacheDataSource` (the core caches). `NativeCore` implements the `CoreStreams` seam.
 - Reports back: `Ready`, `Playing`, `Paused`, `Buffering`, `Position` every 750 ms while playing and
   on every seek/transition, `Ended`, `TransitionedToNext`, `Error`, `PreBufferReady`,
-  `AudioFocusLost` (transient when Media3 suppresses rather than pauses).
+  `AudioFocusLost` (transient when Media3 suppresses rather than pauses; the core then leaves the
+  player alone so it resumes when focus returns).
 - `Event.MediaSession(state)` -> `MediaSessionBridge` -> `CoreSessionPlayer`, a `SimpleBasePlayer`
   whose state *is* the core's session state (metadata, extrapolated position from the stamp,
   shuffle/repeat, available commands from the customised action list). Custom buttons (love,
   shuffle, repeat, rate) are media button preferences. Controls map to
   `Command.MediaSessionCommand`. Notification, lockscreen, Bluetooth and headset controls come from
-  Media3. Playback resumption from the system is refused (resuming is always explicit).
+  Media3; the service `addSession`s the session in `onCreate` (the UI is not a Media3 controller, so
+  `onGetSession` alone would never register it and no notification or foreground promotion would
+  happen).
+- Remote output: while another Connect device plays, `CoreSessionPlayer` reports
+  `DeviceInfo(PLAYBACK_TYPE_REMOTE, routingControllerId = "hocket-connect")` (fixed volume: Connect
+  volume is per device) and `ConnectRouteProvider` (a `MediaRoute2ProviderService`, API 30+) keeps a
+  routing session with that id, named after the playing device. SystemUI pairs the two and shows the
+  device on the media controls' output chip; the other devices are routes in the system output
+  switcher, and picking one (or this phone) is a `HandoffTo`. `PlaybackService` feeds
+  `ConnectRoutes` from `DevicesChanged`/`TransportChanged`/`MediaSession` and registers the app's
+  MediaRouter2 discovery preference for `app.hocket.feature.CONNECT`, which keeps the provider bound. Playback resumption from the system is refused (resuming is always explicit).
 - `NetworkMonitor` -> `SetNetworkState` (kind, metered, hashed SSID or transport id);
   `BatterySaverMonitor` -> `SetBatterySaver` while `battery.autoSaver` is on.
 - The app binds with `ACTION_BIND_CORE` (plus a per-process token, since the service is exported
@@ -153,6 +167,12 @@ absent.
 - Now-playing sheet: `AnchoredDraggable` with a velocity-aware fling, scrim, corners morphing from
   pill to square, the artwork scaling from the 48 dp thumbnail to the hero; predictive back drags
   it down with the gesture.
+- Page navigation (`ui/nav/Transitions.kt`): pushes use a shared X axis, bar switches a short
+  fade-through. Predictive back (after Navic) scrubs its own transition on every screen: the page
+  shrinks into a rounded card that follows the finger away from the swipe edge while the previous
+  page slides in from a short offset; releasing finishes it, cancelling runs it back. Reduced
+  motion makes it a crossfade. Holding the bottom bar does nothing special: it is edited from
+  Settings > Customise or the account sheet.
 - Mini player: tap to expand, swipe left/right to skip with resistance past the threshold, a thin
   wavy progress line.
 - Hero artwork: horizontal swipe to skip (springs back); long-press toggles a whole-app dynamic

android/app/src/main/java/app/hocket/ui/components/Rows.kt

@@ -58,6 +58,7 @@ import app.hocket.R
 import app.hocket.core.ActionIds
 import app.hocket.core.ArtworkSizes
 import app.hocket.core.Commands
+import app.hocket.core.SwipeOptions
 import app.hocket.core.api.ActionTarget
 import app.hocket.ui.LocalCoreClient
 import app.hocket.ui.LocalDetailNavigator
@@ -196,57 +197,73 @@ fun TrackRow(
     actionTarget: ActionTarget? = null,
     /** Row-specific accessibility actions (the queue's move and remove), added to the row menu's. */
     extraActions: List<CustomAccessibilityAction> = emptyList(),
+    /** Whose swipe settings the row follows; rows with a menu swipe like song lists, read-only rows not at all. */
+    swipe: SwipeSurface? = if (onMore != null) SwipeSurface.List else null,
 ) {
     val artist = track.artist ?: stringResource(R.string.unknown_artist)
     val label = trackLabel(track)
     var rating by remember { mutableStateOf(false) }
+    var playlistPicker by remember { mutableStateOf(false) }
     val target = actionTarget ?: Commands.tracks(listOf(track.id))
     // Rows with a menu offer it as actions; read-only rows (stats, filter previews) offer none.
     val actions = if (onMore != null) trackRowActions(track, target, onRate = { rating = true }, onMore = onMore, extra = extraActions) else extraActions
+    val (startId, endId) = if (swipe != null) swipeActionIds(swipe) else SwipeOptions.NONE to SwipeOptions.NONE
+    // The row (and the caller's modifier) stays the one merged accessibility item; only its content
+    // slides under the swipe.
     SelectableRow(
-        selected, selectionActive, onClick, onToggleSelect, label, modifier,
+        selected, selectionActive, onClick, onToggleSelect, label,
+        modifier = modifier,
         // "playing, downloaded": the row's state, merged with its label into one item.
         state = listOfNotNull(if (nowPlaying) stringResource(R.string.row_state_playing) else null, offlineStateText(track.offline))
             .joinToString(", ").ifEmpty { null },
         actions = actions,
         clickLabel = stringResource(R.string.action_play),
     ) {
-        Row(Modifier.heightIn(min = 64.dp).padding(horizontal = 16.dp, vertical = 8.dp), verticalAlignment = Alignment.CenterVertically) {
-            leading?.invoke()
-            if (showArtwork) {
-                Box(Modifier.size(48.dp)) {
-                    Artwork(track.coverArt, ArtworkSizes.THUMB, null, Modifier.size(48.dp), RoundedCornerShape(ListArtCorner))
-                    if (selected) Box(Modifier.size(48.dp).clip(RoundedCornerShape(ListArtCorner)), contentAlignment = Alignment.Center) {
-                        Surface(shape = CircleShape, color = MaterialTheme.colorScheme.primary) { Icon(Icons.Filled.Check, null, Modifier.padding(4.dp), tint = MaterialTheme.colorScheme.onPrimary) }
+        SwipeActionBox(
+            startToEnd = trackSwipeAction(startId, track, target, onAddToPlaylist = { playlistPicker = true }),
+            endToStart = trackSwipeAction(endId, track, target, onAddToPlaylist = { playlistPicker = true }),
+            // Not while selecting: rows toggle then, and a stray swipe must not act on one of them.
+            enabled = swipe != null && !selectionActive,
+            swipeSurface = MaterialTheme.colorScheme.surface,
+        ) {
+            Row(Modifier.heightIn(min = 64.dp).padding(horizontal = 16.dp, vertical = 8.dp), verticalAlignment = Alignment.CenterVertically) {
+                leading?.invoke()
+                if (showArtwork) {
+                    Box(Modifier.size(48.dp)) {
+                        Artwork(track.coverArt, ArtworkSizes.THUMB, null, Modifier.size(48.dp), RoundedCornerShape(ListArtCorner))
+                        if (selected) Box(Modifier.size(48.dp).clip(RoundedCornerShape(ListArtCorner)), contentAlignment = Alignment.Center) {
+                            Surface(shape = CircleShape, color = MaterialTheme.colorScheme.primary) { Icon(Icons.Filled.Check, null, Modifier.padding(4.dp), tint = MaterialTheme.colorScheme.onPrimary) }
+                        }
                     }
+                    Spacer(Modifier.width(14.dp))
                 }
-                Spacer(Modifier.width(14.dp))
-            }
-            Column(Modifier.weight(1f)) {
-                Row(verticalAlignment = Alignment.CenterVertically) {
-                    if (nowPlaying) {
-                        Icon(Icons.Filled.GraphicEq, null, tint = MaterialTheme.colorScheme.primary, modifier = Modifier.size(16.dp))
-                        Spacer(Modifier.width(6.dp))
+                Column(Modifier.weight(1f)) {
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        if (nowPlaying) {
+                            Icon(Icons.Filled.GraphicEq, null, tint = MaterialTheme.colorScheme.primary, modifier = Modifier.size(16.dp))
+                            Spacer(Modifier.width(6.dp))
+                        }
+                        Text(track.title, style = MaterialTheme.typography.bodyLarge, maxLines = 1, overflow = TextOverflow.Ellipsis,
+                            color = if (nowPlaying) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.onSurface)
+                    }
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        OfflineBadge(track.offline, describe = false)
+                        Text(artist, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
                     }
-                    Text(track.title, style = MaterialTheme.typography.bodyLarge, maxLines = 1, overflow = TextOverflow.Ellipsis,
-                        color = if (nowPlaying) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.onSurface)
                 }
-                Row(verticalAlignment = Alignment.CenterVertically) {
-                    OfflineBadge(track.offline, describe = false)
-                    Text(artist, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                if (track.loved) {
+                    Icon(Icons.Filled.Favorite, null, tint = MaterialTheme.colorScheme.tertiary, modifier = Modifier.size(16.dp))
+                    Spacer(Modifier.width(8.dp))
+                }
+                Text(formatClock(track.durationMs), style = MaterialTheme.typography.labelMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1)
+                trailing?.invoke()
+                if (onMore != null) {
+                    IconButton(onClick = onMore) { Icon(Icons.Filled.MoreVert, stringResource(R.string.action_more_for, track.title)) }
                 }
-            }
-            if (track.loved) {
-                Icon(Icons.Filled.Favorite, null, tint = MaterialTheme.colorScheme.tertiary, modifier = Modifier.size(16.dp))
-                Spacer(Modifier.width(8.dp))
-            }
-            Text(formatClock(track.durationMs), style = MaterialTheme.typography.labelMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1)
-            trailing?.invoke()
-            if (onMore != null) {
-                IconButton(onClick = onMore) { Icon(Icons.Filled.MoreVert, stringResource(R.string.action_more_for, track.title)) }
             }
         }
     }
+    if (playlistPicker) PlaylistPicker(target = target, onDismiss = { playlistPicker = false })
     if (rating) {
         val client = LocalCoreClient.current
         RatingDialog(current = track.rating.toInt(), onRate = { stars -> client.dispatch(Commands.runAction(ActionIds.rate(stars), target)); rating = false }, onDismiss = { rating = false })