Adds a Marketplace tab to Discovery

app/src/main/java/com/vitorpamplona/amethyst/service/NostrDiscoveryDataSource.kt

@@ -9,6 +9,7 @@ import com.vitorpamplona.amethyst.service.relays.TypedFilter
 import com.vitorpamplona.quartz.events.ChannelCreateEvent
 import com.vitorpamplona.quartz.events.ChannelMessageEvent
 import com.vitorpamplona.quartz.events.ChannelMetadataEvent
+import com.vitorpamplona.quartz.events.ClassifiedsEvent
 import com.vitorpamplona.quartz.events.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.events.CommunityPostApprovalEvent
 import com.vitorpamplona.quartz.events.LiveActivitiesChatMessageEvent
@@ -42,6 +43,54 @@ object NostrDiscoveryDataSource : NostrDataSource("DiscoveryFeed") {
         job?.cancel()
     }
 
+    fun createMarketplaceFilter(): List<TypedFilter> {
+        val follows = account.liveDiscoveryFollowLists.value?.users?.toList()
+        val hashToLoad = account.liveDiscoveryFollowLists.value?.hashtags?.toList()
+        val geohashToLoad = account.liveDiscoveryFollowLists.value?.geotags?.toList()
+
+        return listOfNotNull(
+            TypedFilter(
+                types = setOf(FeedType.GLOBAL),
+                filter = JsonFilter(
+                    authors = follows,
+                    kinds = listOf(ClassifiedsEvent.kind),
+                    limit = 300,
+                    since = latestEOSEs.users[account.userProfile()]?.followList?.get(account.defaultDiscoveryFollowList.value)?.relayList
+                )
+            ),
+            hashToLoad?.let {
+                TypedFilter(
+                    types = setOf(FeedType.GLOBAL),
+                    filter = JsonFilter(
+                        kinds = listOf(ClassifiedsEvent.kind),
+                        tags = mapOf(
+                            "t" to it.map {
+                                listOf(it, it.lowercase(), it.uppercase(), it.capitalize())
+                            }.flatten()
+                        ),
+                        limit = 300,
+                        since = latestEOSEs.users[account.userProfile()]?.followList?.get(account.defaultDiscoveryFollowList.value)?.relayList
+                    )
+                )
+            },
+            geohashToLoad?.let {
+                TypedFilter(
+                    types = setOf(FeedType.GLOBAL),
+                    filter = JsonFilter(
+                        kinds = listOf(ClassifiedsEvent.kind),
+                        tags = mapOf(
+                            "g" to it.map {
+                                listOf(it, it.lowercase(), it.uppercase(), it.capitalize())
+                            }.flatten()
+                        ),
+                        limit = 300,
+                        since = latestEOSEs.users[account.userProfile()]?.followList?.get(account.defaultDiscoveryFollowList.value)?.relayList
+                    )
+                )
+            }
+        )
+    }
+
     fun createLiveStreamFilter(): List<TypedFilter> {
         val follows = account.liveDiscoveryFollowLists.value?.users?.toList()
 
@@ -238,16 +287,19 @@ object NostrDiscoveryDataSource : NostrDataSource("DiscoveryFeed") {
     }
 
     override fun updateChannelFilters() {
-        discoveryFeedChannel.typedFilters = createLiveStreamFilter().plus(createPublicChatFilter()).plus(
+        discoveryFeedChannel.typedFilters = createLiveStreamFilter()
-            listOfNotNull(
+            .plus(createPublicChatFilter())
-                createLiveStreamTagsFilter(),
+            .plus(createMarketplaceFilter())
-                createLiveStreamGeohashesFilter(),
+            .plus(
-                createCommunitiesFilter(),
+                listOfNotNull(
-                createPublicChatsTagsFilter(),
+                    createLiveStreamTagsFilter(),
-                createCommunitiesTagsFilter(),
+                    createLiveStreamGeohashesFilter(),
-                createCommunitiesGeohashesFilter(),
+                    createCommunitiesFilter(),
-                createPublicChatsGeohashesFilter()
+                    createCommunitiesTagsFilter(),
-            )
+                    createCommunitiesGeohashesFilter(),
-        ).ifEmpty { null }
+                    createPublicChatsTagsFilter(),
+                    createPublicChatsGeohashesFilter()
+                )
+            ).ifEmpty { null }
     }
 }

app/src/main/java/com/vitorpamplona/amethyst/ui/dal/DiscoverMarketplaceFeedFilter.kt

@@ -0,0 +1,72 @@
+package com.vitorpamplona.amethyst.ui.dal
+
+import com.vitorpamplona.amethyst.model.Account
+import com.vitorpamplona.amethyst.model.GLOBAL_FOLLOWS
+import com.vitorpamplona.amethyst.model.LocalCache
+import com.vitorpamplona.amethyst.model.Note
+import com.vitorpamplona.quartz.events.ClassifiedsEvent
+import com.vitorpamplona.quartz.events.MuteListEvent
+import com.vitorpamplona.quartz.events.PeopleListEvent
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+open class DiscoverMarketplaceFeedFilter(
+    val account: Account
+) : AdditiveFeedFilter<Note>() {
+    override fun feedKey(): String {
+        return account.userProfile().pubkeyHex + "-" + followList()
+    }
+
+    open fun followList(): String {
+        return account.defaultDiscoveryFollowList.value
+    }
+
+    override fun showHiddenKey(): Boolean {
+        return followList() == PeopleListEvent.blockListFor(account.userProfile().pubkeyHex) ||
+            followList() == MuteListEvent.blockListFor(account.userProfile().pubkeyHex)
+    }
+
+    override fun feed(): List<Note> {
+        val classifieds = LocalCache.addressables
+            .filter { it.value.event is ClassifiedsEvent }
+            .map { it.value }
+
+        val notes = innerApplyFilter(classifieds)
+
+        return sort(notes)
+    }
+
+    override fun applyFilter(collection: Set<Note>): Set<Note> {
+        return innerApplyFilter(collection)
+    }
+
+    protected open fun innerApplyFilter(collection: Collection<Note>): Set<Note> {
+        val now = TimeUtils.now()
+        val isGlobal = account.defaultDiscoveryFollowList.value == GLOBAL_FOLLOWS
+        val isHiddenList = showHiddenKey()
+
+        val followingKeySet = account.liveDiscoveryFollowLists.value?.users ?: emptySet()
+        val followingTagSet = account.liveDiscoveryFollowLists.value?.hashtags ?: emptySet()
+        val followingGeohashSet = account.liveDiscoveryFollowLists.value?.geotags ?: emptySet()
+
+        val activities = collection
+            .asSequence()
+            .filter {
+                it.event is ClassifiedsEvent &&
+                    it.event?.hasTagWithContent("image") == true &&
+                    it.event?.hasTagWithContent("price") == true &&
+                    it.event?.hasTagWithContent("title") == true
+            }
+            .filter {
+                isGlobal || it.author?.pubkeyHex in followingKeySet || it.event?.isTaggedHashes(followingTagSet) == true || it.event?.isTaggedGeoHashes(followingGeohashSet) == true
+            }
+            .filter { isHiddenList || it.author?.let { !account.isHidden(it.pubkeyHex) } ?: true }
+            .filter { (it.createdAt() ?: 0) <= now }
+            .toSet()
+
+        return activities
+    }
+
+    override fun sort(collection: Set<Note>): List<Note> {
+        return collection.sortedWith(compareBy({ it.createdAt() }, { it.idHex })).reversed()
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -26,6 +26,7 @@ import com.vitorpamplona.amethyst.ui.screen.NostrChatroomListNewFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverChatFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverCommunityFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverLiveFeedViewModel
+import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverMarketplaceFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrHomeFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrHomeRepliesFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrVideoFeedViewModel
@@ -61,6 +62,7 @@ fun AppNavigation(
     knownFeedViewModel: NostrChatroomListKnownFeedViewModel,
     newFeedViewModel: NostrChatroomListNewFeedViewModel,
     videoFeedViewModel: NostrVideoFeedViewModel,
+    discoverMarketplaceFeedViewModel: NostrDiscoverMarketplaceFeedViewModel,
     discoveryLiveFeedViewModel: NostrDiscoverLiveFeedViewModel,
     discoveryCommunityFeedViewModel: NostrDiscoverCommunityFeedViewModel,
     discoveryChatFeedViewModel: NostrDiscoverChatFeedViewModel,
@@ -137,6 +139,7 @@ fun AppNavigation(
         Route.Discover.let { route ->
             composable(route.route, route.arguments, content = {
                 DiscoverScreen(
+                    discoveryMarketplaceFeedViewModel = discoverMarketplaceFeedViewModel,
                     discoveryLiveFeedViewModel = discoveryLiveFeedViewModel,
                     discoveryCommunityFeedViewModel = discoveryCommunityFeedViewModel,
                     discoveryChatFeedViewModel = discoveryChatFeedViewModel,

app/src/main/java/com/vitorpamplona/amethyst/ui/note/ChannelCardCompose.kt

@@ -2,6 +2,7 @@ package com.vitorpamplona.amethyst.ui.note
 
 import androidx.compose.animation.Crossfade
 import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.background
 import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -15,8 +16,10 @@ import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.material3.Divider
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Immutable
@@ -39,6 +42,7 @@ import androidx.compose.ui.graphics.compositeOver
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.distinctUntilChanged
@@ -58,23 +62,28 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.EndedFlag
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.LiveFlag
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.OfflineFlag
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.ScheduledFlag
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.showAmountAxis
 import com.vitorpamplona.amethyst.ui.theme.DividerThickness
 import com.vitorpamplona.amethyst.ui.theme.DoubleHorzSpacer
 import com.vitorpamplona.amethyst.ui.theme.DoubleVertSpacer
+import com.vitorpamplona.amethyst.ui.theme.HalfPadding
 import com.vitorpamplona.amethyst.ui.theme.QuoteBorder
 import com.vitorpamplona.amethyst.ui.theme.Size35dp
+import com.vitorpamplona.amethyst.ui.theme.Size5dp
 import com.vitorpamplona.amethyst.ui.theme.StdHorzSpacer
 import com.vitorpamplona.amethyst.ui.theme.StdPadding
 import com.vitorpamplona.amethyst.ui.theme.StdVertSpacer
 import com.vitorpamplona.amethyst.ui.theme.newItemBackgroundColor
 import com.vitorpamplona.amethyst.ui.theme.placeholderText
 import com.vitorpamplona.quartz.events.ChannelCreateEvent
+import com.vitorpamplona.quartz.events.ClassifiedsEvent
 import com.vitorpamplona.quartz.events.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.events.LiveActivitiesEvent
 import com.vitorpamplona.quartz.events.LiveActivitiesEvent.Companion.STATUS_ENDED
 import com.vitorpamplona.quartz.events.LiveActivitiesEvent.Companion.STATUS_LIVE
 import com.vitorpamplona.quartz.events.LiveActivitiesEvent.Companion.STATUS_PLANNED
 import com.vitorpamplona.quartz.events.Participant
+import com.vitorpamplona.quartz.events.Price
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.persistentListOf
 import kotlinx.collections.immutable.toImmutableList
@@ -95,7 +104,7 @@ fun ChannelCardCompose(
 ) {
     val hasEvent by baseNote.live().hasEvent.observeAsState(baseNote.event != null)
 
-    Crossfade(targetState = hasEvent) {
+    Crossfade(targetState = hasEvent, label = "ChannelCardCompose") {
         if (it) {
             if (forceEventKind == null || baseNote.event?.kind() == forceEventKind) {
                 CheckHiddenChannelCardCompose(
@@ -155,7 +164,7 @@ fun CheckHiddenChannelCardCompose(
             note.isHiddenFor(it)
         }.distinctUntilChanged().observeAsState(accountViewModel.isNoteHidden(note))
 
-        Crossfade(targetState = isHidden) {
+        Crossfade(targetState = isHidden, label = "CheckHiddenChannelCardCompose") {
             if (!it) {
                 LoadedChannelCardCompose(
                     note,
@@ -195,7 +204,7 @@ fun LoadedChannelCardCompose(
         }
     }
 
-    Crossfade(targetState = state) {
+    Crossfade(targetState = state, label = "CheckHiddenChannelCardCompose") {
         RenderChannelCardReportState(
             it,
             note,
@@ -220,7 +229,7 @@ fun RenderChannelCardReportState(
 ) {
     var showReportedNote by remember { mutableStateOf(false) }
 
-    Crossfade(targetState = !state.isAcceptable && !showReportedNote) { showHiddenNote ->
+    Crossfade(targetState = !state.isAcceptable && !showReportedNote, label = "CheckHiddenChannelCardCompose") { showHiddenNote ->
         if (showHiddenNote) {
             HiddenNote(
                 state.relevantReports,
@@ -334,6 +343,28 @@ fun InnerChannelCardWithReactions(
     baseNote: Note,
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit
+) {
+    when (remember { baseNote.event }) {
+        is LiveActivitiesEvent -> {
+            InnerCardRow(baseNote, accountViewModel, nav)
+        }
+        is CommunityDefinitionEvent -> {
+            InnerCardRow(baseNote, accountViewModel, nav)
+        }
+        is ChannelCreateEvent -> {
+            InnerCardRow(baseNote, accountViewModel, nav)
+        }
+        is ClassifiedsEvent -> {
+            InnerCardBox(baseNote, accountViewModel, nav)
+        }
+    }
+}
+
+@Composable
+fun InnerCardRow(
+    baseNote: Note,
+    accountViewModel: AccountViewModel,
+    nav: (String) -> Unit
 ) {
     Column(StdPadding) {
         SensitivityWarning(
@@ -353,6 +384,22 @@ fun InnerChannelCardWithReactions(
     )
 }
 
+@Composable
+fun InnerCardBox(
+    baseNote: Note,
+    accountViewModel: AccountViewModel,
+    nav: (String) -> Unit
+) {
+    Column(HalfPadding) {
+        SensitivityWarning(
+            note = baseNote,
+            accountViewModel = accountViewModel
+        ) {
+            RenderClassifiedsThumb(baseNote, accountViewModel, nav)
+        }
+    }
+}
+
 @Composable
 private fun RenderNoteRow(
     baseNote: Note,
@@ -372,6 +419,116 @@ private fun RenderNoteRow(
     }
 }
 
+@Immutable
+data class ClassifiedsThumb(
+    val image: String?,
+    val title: String?,
+    val price: Price?
+)
+
+@Composable
+fun RenderClassifiedsThumb(baseNote: Note, accountViewModel: AccountViewModel, nav: (String) -> Unit) {
+    val noteEvent = baseNote.event as? ClassifiedsEvent ?: return
+
+    val card by baseNote.live().metadata.map {
+        val noteEvent = it.note.event as? ClassifiedsEvent
+
+        ClassifiedsThumb(
+            image = noteEvent?.image(),
+            title = noteEvent?.title(),
+            price = noteEvent?.price()
+        )
+    }.distinctUntilChanged().observeAsState(
+        ClassifiedsThumb(
+            image = noteEvent.image(),
+            title = noteEvent.title(),
+            price = noteEvent.price()
+        )
+    )
+
+    RenderClassifiedsThumb(card, baseNote.author)
+}
+
+@Preview
+@Composable
+fun RenderClassifiedsThumbPreview() {
+    Surface(Modifier.size(200.dp)) {
+        RenderClassifiedsThumb(
+            card = ClassifiedsThumb(
+                image = null,
+                title = "Like New",
+                price = Price("800000", "SATS", null)
+            ),
+            author = null
+        )
+    }
+}
+
+@Composable
+fun RenderClassifiedsThumb(card: ClassifiedsThumb, author: User?) {
+    Box(
+        Modifier
+            .fillMaxWidth()
+            .aspectRatio(1f),
+        contentAlignment = BottomStart
+    ) {
+        card.image?.let {
+            AsyncImage(
+                model = it,
+                contentDescription = null,
+                contentScale = ContentScale.Crop,
+                modifier = Modifier.fillMaxSize()
+            )
+        } ?: run {
+            author?.let {
+                DisplayAuthorBanner(it)
+            }
+        }
+
+        Row(
+            Modifier
+                .fillMaxWidth()
+                .background(Color.Black.copy(0.6f))
+                .padding(Size5dp),
+            horizontalArrangement = Arrangement.SpaceBetween
+        ) {
+            card.title?.let {
+                Text(
+                    text = it,
+                    fontWeight = FontWeight.Medium,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    color = Color.White,
+                    modifier = Modifier.weight(1f)
+                )
+            }
+
+            card.price?.let {
+                val priceTag = remember(card) {
+                    val newAmount = it.amount.toBigDecimalOrNull()?.let {
+                        showAmountAxis(it)
+                    } ?: it.amount
+
+                    if (it.frequency != null && it.currency != null) {
+                        "$newAmount ${it.currency}/${it.frequency}"
+                    } else if (it.currency != null) {
+                        "$newAmount ${it.currency}"
+                    } else {
+                        newAmount
+                    }
+                }
+
+                Text(
+                    text = priceTag,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                    color = Color.White
+                )
+            }
+        }
+    }
+}
+
 @Immutable
 data class LiveActivityCard(
     val name: String,

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/FeedView.kt

@@ -13,6 +13,8 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.grid.LazyGridState
+import androidx.compose.foundation.lazy.grid.rememberLazyGridState
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material3.Button
@@ -64,7 +66,9 @@ fun RefresheableView(
 
     val modifier = remember {
         if (enablePullRefresh) {
-            Modifier.fillMaxSize().pullRefresh(pullRefreshState)
+            Modifier
+                .fillMaxSize()
+                .pullRefresh(pullRefreshState)
         } else {
             Modifier.fillMaxSize()
         }
@@ -115,6 +119,23 @@ fun SaveableFeedState(
     content(listState)
 }
 
+@Composable
+fun SaveableGridFeedState(
+    viewModel: FeedViewModel,
+    scrollStateKey: String? = null,
+    content: @Composable (LazyGridState) -> Unit
+) {
+    val gridState = if (scrollStateKey != null) {
+        rememberForeverLazyGridState(scrollStateKey)
+    } else {
+        rememberLazyGridState()
+    }
+
+    WatchScrollToTop(viewModel, gridState)
+
+    content(gridState)
+}
+
 @Composable
 private fun RenderFeed(
     viewModel: FeedViewModel,
@@ -174,6 +195,21 @@ private fun WatchScrollToTop(
     }
 }
 
+@Composable
+private fun WatchScrollToTop(
+    viewModel: FeedViewModel,
+    listState: LazyGridState
+) {
+    val scrollToTop by viewModel.scrollToTop.collectAsStateWithLifecycle()
+
+    LaunchedEffect(scrollToTop) {
+        if (scrollToTop > 0 && viewModel.scrolltoTopPending) {
+            listState.scrollToItem(index = 0)
+            viewModel.sentToTop()
+        }
+    }
+}
+
 @OptIn(ExperimentalFoundationApi::class, ExperimentalTime::class)
 @Composable
 private fun FeedLoaded(
@@ -190,7 +226,9 @@ private fun FeedLoaded(
         itemsIndexed(state.feed.value, key = { _, item -> item.idHex }) { _, item ->
             val (value, elapsed) = measureTimedValue {
                 val defaultModifier = remember {
-                    Modifier.fillMaxWidth().animateItemPlacement()
+                    Modifier
+                        .fillMaxWidth()
+                        .animateItemPlacement()
                 }
 
                 Row(defaultModifier) {

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/FeedViewModel.kt

@@ -26,6 +26,7 @@ import com.vitorpamplona.amethyst.ui.dal.CommunityFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.DiscoverChatFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.DiscoverCommunityFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.DiscoverLiveFeedFilter
+import com.vitorpamplona.amethyst.ui.dal.DiscoverMarketplaceFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.FeedFilter
 import com.vitorpamplona.amethyst.ui.dal.GeoHashFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.HashtagFeedFilter
@@ -72,6 +73,16 @@ class NostrVideoFeedViewModel(val account: Account) : FeedViewModel(VideoFeedFil
     }
 }
 
+class NostrDiscoverMarketplaceFeedViewModel(val account: Account) : FeedViewModel(
+    DiscoverMarketplaceFeedFilter(account)
+) {
+    class Factory(val account: Account) : ViewModelProvider.Factory {
+        override fun <NostrDiscoverMarketplaceFeedViewModel : ViewModel> create(modelClass: Class<NostrDiscoverMarketplaceFeedViewModel>): NostrDiscoverMarketplaceFeedViewModel {
+            return NostrDiscoverMarketplaceFeedViewModel(account) as NostrDiscoverMarketplaceFeedViewModel
+        }
+    }
+}
+
 class NostrDiscoverLiveFeedViewModel(val account: Account) : FeedViewModel(DiscoverLiveFeedFilter(account)) {
     class Factory(val account: Account) : ViewModelProvider.Factory {
         override fun <NostrDiscoverLiveFeedViewModel : ViewModel> create(modelClass: Class<NostrDiscoverLiveFeedViewModel>): NostrDiscoverLiveFeedViewModel {

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/RememberForeverStates.kt

@@ -2,6 +2,7 @@ package com.vitorpamplona.amethyst.ui.screen
 
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.grid.LazyGridState
 import androidx.compose.foundation.pager.PagerState
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.runtime.Composable
@@ -22,6 +23,7 @@ object ScrollStateKeys {
     val HOME_FOLLOWS = Route.Home.base + "Follows"
     val HOME_REPLIES = Route.Home.base + "FollowsReplies"
 
+    val DISCOVER_MARKETPLACE = Route.Home.base + "Marketplace"
     val DISCOVER_LIVE = Route.Home.base + "Live"
     val DISCOVER_COMMUNITY = Route.Home.base + "Communities"
     val DISCOVER_CHATS = Route.Home.base + "Chats"
@@ -32,6 +34,31 @@ object PagerStateKeys {
     const val DISCOVER_SCREEN = "PagerDiscover"
 }
 
+@Composable
+fun rememberForeverLazyGridState(
+    key: String,
+    initialFirstVisibleItemIndex: Int = 0,
+    initialFirstVisibleItemScrollOffset: Int = 0
+): LazyGridState {
+    val scrollState = rememberSaveable(saver = LazyGridState.Saver) {
+        val savedValue = savedScrollStates[key]
+        val savedIndex = savedValue?.index ?: initialFirstVisibleItemIndex
+        val savedOffset = savedValue?.scrollOffsetFraction ?: initialFirstVisibleItemScrollOffset.toFloat()
+        LazyGridState(
+            savedIndex,
+            savedOffset.roundToInt()
+        )
+    }
+    DisposableEffect(scrollState) {
+        onDispose {
+            val lastIndex = scrollState.firstVisibleItemIndex
+            val lastOffset = scrollState.firstVisibleItemScrollOffset
+            savedScrollStates[key] = ScrollState(lastIndex, lastOffset.toFloat())
+        }
+    }
+    return scrollState
+}
+
 @Composable
 fun rememberForeverLazyListState(
     key: String,

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/DiscoverScreen.kt

@@ -3,6 +3,7 @@ package com.vitorpamplona.amethyst.ui.screen.loggedIn
 import androidx.compose.animation.Crossfade
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.gestures.ScrollableState
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxHeight
@@ -18,8 +19,8 @@ import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.pager.HorizontalPager
 import androidx.compose.foundation.pager.PagerState
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ScrollableTabRow
 import androidx.compose.material3.Tab
-import androidx.compose.material3.TabRow
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
@@ -47,14 +48,17 @@ import com.vitorpamplona.amethyst.ui.screen.LoadingFeed
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverChatFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverCommunityFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverLiveFeedViewModel
+import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverMarketplaceFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.PagerStateKeys
 import com.vitorpamplona.amethyst.ui.screen.RefresheableView
 import com.vitorpamplona.amethyst.ui.screen.SaveableFeedState
+import com.vitorpamplona.amethyst.ui.screen.SaveableGridFeedState
 import com.vitorpamplona.amethyst.ui.screen.ScrollStateKeys
 import com.vitorpamplona.amethyst.ui.screen.rememberForeverPagerState
 import com.vitorpamplona.amethyst.ui.theme.FeedPadding
 import com.vitorpamplona.amethyst.ui.theme.TabRowHeight
 import com.vitorpamplona.quartz.events.ChannelCreateEvent
+import com.vitorpamplona.quartz.events.ClassifiedsEvent
 import com.vitorpamplona.quartz.events.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.events.LiveActivitiesEvent
 import kotlinx.collections.immutable.ImmutableList
@@ -64,6 +68,7 @@ import kotlinx.coroutines.launch
 @OptIn(ExperimentalFoundationApi::class)
 @Composable
 fun DiscoverScreen(
+    discoveryMarketplaceFeedViewModel: NostrDiscoverMarketplaceFeedViewModel,
     discoveryLiveFeedViewModel: NostrDiscoverLiveFeedViewModel,
     discoveryCommunityFeedViewModel: NostrDiscoverCommunityFeedViewModel,
     discoveryChatFeedViewModel: NostrDiscoverChatFeedViewModel,
@@ -75,6 +80,7 @@ fun DiscoverScreen(
     val tabs by remember(discoveryLiveFeedViewModel, discoveryCommunityFeedViewModel, discoveryChatFeedViewModel) {
         mutableStateOf(
             listOf(
+                TabItem(R.string.discover_marketplace, discoveryMarketplaceFeedViewModel, Route.Discover.base + "Marketplace", ScrollStateKeys.DISCOVER_MARKETPLACE, ClassifiedsEvent.kind),
                 TabItem(R.string.discover_live, discoveryLiveFeedViewModel, Route.Discover.base + "Live", ScrollStateKeys.DISCOVER_LIVE, LiveActivitiesEvent.kind),
                 TabItem(R.string.discover_community, discoveryCommunityFeedViewModel, Route.Discover.base + "Community", ScrollStateKeys.DISCOVER_COMMUNITY, CommunityDefinitionEvent.kind),
                 TabItem(R.string.discover_chat, discoveryChatFeedViewModel, Route.Discover.base + "Chats", ScrollStateKeys.DISCOVER_CHATS, ChannelCreateEvent.kind)
@@ -85,6 +91,7 @@ fun DiscoverScreen(
     val pagerState = rememberForeverPagerState(key = PagerStateKeys.DISCOVER_SCREEN) { tabs.size }
 
     WatchAccountForDiscoveryScreen(
+        discoverMarketplaceFeedViewModel = discoveryMarketplaceFeedViewModel,
         discoveryLiveFeedViewModel = discoveryLiveFeedViewModel,
         discoveryCommunityFeedViewModel = discoveryCommunityFeedViewModel,
         discoveryChatFeedViewModel = discoveryChatFeedViewModel,
@@ -122,11 +129,12 @@ private fun DiscoverPages(
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit
 ) {
-    TabRow(
+    ScrollableTabRow(
         containerColor = MaterialTheme.colorScheme.background,
         contentColor = MaterialTheme.colorScheme.onBackground,
         selectedTabIndex = pagerState.currentPage,
-        modifier = TabRowHeight
+        modifier = TabRowHeight,
+        edgePadding = 8.dp
     ) {
         val coroutineScope = rememberCoroutineScope()
 
@@ -145,15 +153,28 @@ private fun DiscoverPages(
 
     HorizontalPager(state = pagerState) { page ->
         RefresheableView(tabs[page].viewModel, true) {
-            SaveableFeedState(tabs[page].viewModel, scrollStateKey = tabs[page].scrollStateKey) { listState ->
+            if (tabs[page].viewModel is NostrDiscoverMarketplaceFeedViewModel) {
-                RenderDiscoverFeed(
+                SaveableGridFeedState(tabs[page].viewModel, scrollStateKey = tabs[page].scrollStateKey) { listState ->
-                    viewModel = tabs[page].viewModel,
+                    RenderDiscoverFeed(
-                    routeForLastRead = tabs[page].routeForLastRead,
+                        viewModel = tabs[page].viewModel,
-                    forceEventKind = tabs[page].forceEventKind,
+                        routeForLastRead = tabs[page].routeForLastRead,
-                    listState = listState,
+                        forceEventKind = tabs[page].forceEventKind,
-                    accountViewModel = accountViewModel,
+                        listState = listState,
-                    nav = nav
+                        accountViewModel = accountViewModel,
-                )
+                        nav = nav
+                    )
+                }
+            } else {
+                SaveableFeedState(tabs[page].viewModel, scrollStateKey = tabs[page].scrollStateKey) { listState ->
+                    RenderDiscoverFeed(
+                        viewModel = tabs[page].viewModel,
+                        routeForLastRead = tabs[page].routeForLastRead,
+                        forceEventKind = tabs[page].forceEventKind,
+                        listState = listState,
+                        accountViewModel = accountViewModel,
+                        nav = nav
+                    )
+                }
             }
         }
     }
@@ -164,7 +185,7 @@ private fun RenderDiscoverFeed(
     viewModel: FeedViewModel,
     routeForLastRead: String?,
     forceEventKind: Int?,
-    listState: LazyListState,
+    listState: ScrollableState,
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit
 ) {
@@ -189,14 +210,25 @@ private fun RenderDiscoverFeed(
             }
 
             is FeedState.Loaded -> {
-                DiscoverFeedLoaded(
+                if (listState is LazyGridState) {
-                    state,
+                    DiscoverFeedColumnsLoaded(
-                    routeForLastRead,
+                        state,
-                    listState,
+                        routeForLastRead,
-                    forceEventKind,
+                        listState,
-                    accountViewModel,
+                        forceEventKind,
-                    nav
+                        accountViewModel,
-                )
+                        nav
+                    )
+                } else if (listState is LazyListState) {
+                    DiscoverFeedLoaded(
+                        state,
+                        routeForLastRead,
+                        listState,
+                        forceEventKind,
+                        accountViewModel,
+                        nav
+                    )
+                }
             }
 
             is FeedState.Loading -> {
@@ -208,6 +240,7 @@ private fun RenderDiscoverFeed(
 
 @Composable
 fun WatchAccountForDiscoveryScreen(
+    discoverMarketplaceFeedViewModel: NostrDiscoverMarketplaceFeedViewModel,
     discoveryLiveFeedViewModel: NostrDiscoverLiveFeedViewModel,
     discoveryCommunityFeedViewModel: NostrDiscoverCommunityFeedViewModel,
     discoveryChatFeedViewModel: NostrDiscoverChatFeedViewModel,
@@ -217,6 +250,7 @@ fun WatchAccountForDiscoveryScreen(
 
     LaunchedEffect(accountViewModel, listState) {
         NostrDiscoveryDataSource.resetFilters()
+        discoverMarketplaceFeedViewModel.checkKeysInvalidateDataAndSendToTop()
         discoveryLiveFeedViewModel.checkKeysInvalidateDataAndSendToTop()
         discoveryCommunityFeedViewModel.checkKeysInvalidateDataAndSendToTop()
         discoveryChatFeedViewModel.checkKeysInvalidateDataAndSendToTop()
@@ -260,7 +294,7 @@ private fun DiscoverFeedLoaded(
 
 @OptIn(ExperimentalFoundationApi::class)
 @Composable
-private fun DiscoverFeedTwoColumnsLoaded(
+private fun DiscoverFeedColumnsLoaded(
     state: FeedState.Loaded,
     routeForLastRead: String?,
     listState: LazyGridState,

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/MainScreen.kt

@@ -82,6 +82,7 @@ import com.vitorpamplona.amethyst.ui.screen.NostrChatroomListNewFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverChatFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverCommunityFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverLiveFeedViewModel
+import com.vitorpamplona.amethyst.ui.screen.NostrDiscoverMarketplaceFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrHomeFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrHomeRepliesFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.NostrVideoFeedViewModel
@@ -169,6 +170,11 @@ fun MainScreen(
         factory = NostrVideoFeedViewModel.Factory(accountViewModel.account)
     )
 
+    val discoverMarketplaceFeedViewModel: NostrDiscoverMarketplaceFeedViewModel = viewModel(
+        key = "NostrDiscoveryMarketplaceFeedViewModel",
+        factory = NostrDiscoverMarketplaceFeedViewModel.Factory(accountViewModel.account)
+    )
+
     val discoveryLiveFeedViewModel: NostrDiscoverLiveFeedViewModel = viewModel(
         key = "NostrDiscoveryLiveFeedViewModel",
         factory = NostrDiscoverLiveFeedViewModel.Factory(accountViewModel.account)
@@ -364,6 +370,7 @@ fun MainScreen(
                         knownFeedViewModel = knownFeedViewModel,
                         newFeedViewModel = newFeedViewModel,
                         videoFeedViewModel = videoFeedViewModel,
+                        discoverMarketplaceFeedViewModel = discoverMarketplaceFeedViewModel,
                         discoveryLiveFeedViewModel = discoveryLiveFeedViewModel,
                         discoveryCommunityFeedViewModel = discoveryCommunityFeedViewModel,
                         discoveryChatFeedViewModel = discoveryChatFeedViewModel,

app/src/main/res/values/strings.xml

@@ -489,6 +489,7 @@
 
     <string name="relay_setup">Relays</string>
 
+    <string name="discover_marketplace">Marketplace</string>
     <string name="discover_live">Live</string>
     <string name="discover_community">Community</string>
     <string name="discover_chat">Chats</string>

quartz/src/main/java/com/vitorpamplona/quartz/events/Event.kt

@@ -64,7 +64,9 @@ open class Event(
 
     override fun toJson(): String = mapper.writeValueAsString(toJsonObject())
 
-    override fun hasAnyTaggedUser() = tags.any { it.size > 1 && it[0] == "p" }
+    override fun hasAnyTaggedUser() = hasTagWithContent("p")
+
+    override fun hasTagWithContent(tagName: String) = tags.any { it.size > 1 && it[0] == tagName }
 
     override fun taggedUsers() = tags.filter { it.size > 1 && it[0] == "p" }.map { it[1] }
     override fun taggedEvents() = tags.filter { it.size > 1 && it[0] == "e" }.map { it[1] }

quartz/src/main/java/com/vitorpamplona/quartz/events/EventInterface.kt

@@ -68,6 +68,7 @@ interface EventInterface {
     fun zapraiserAmount(): Long?
 
     fun hasAnyTaggedUser(): Boolean
+    fun hasTagWithContent(tagName: String): Boolean
 
     fun taggedAddresses(): List<ATag>
     fun taggedUsers(): List<HexKey>