Live location : ensure it's not sorted randomly

features/location/impl/src/main/kotlin/io/element/android/features/location/impl/show/LiveLocationShareComparator.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.features.location.impl.show
+
+import io.element.android.libraries.matrix.api.core.UserId
+import io.element.android.libraries.matrix.api.room.location.LiveLocationShare
+
+class LiveLocationShareComparator(private val currentUser: UserId) : Comparator<LiveLocationShare> {
+    override fun compare(p0: LiveLocationShare, p1: LiveLocationShare): Int {
+        val p0IsCurrentUser = p0.userId == currentUser
+        val p1IsCurrentUser = p1.userId == currentUser
+        if (p0IsCurrentUser != p1IsCurrentUser) return if (p0IsCurrentUser) -1 else 1
+        return p1.startTimestamp.compareTo(p0.startTimestamp)
+    }
+}

features/location/impl/src/main/kotlin/io/element/android/features/location/impl/show/ShowLocationPresenter.kt

@@ -133,35 +133,39 @@ class ShowLocationPresenter(
             }
             is ShowLocationMode.Live -> {
                 produceState(persistentListOf()) {
+                    val comparator = LiveLocationShareComparator(currentUser = joinedRoom.sessionId)
                     val liveLocationSharesFlow = joinedRoom.subscribeToLiveLocationShares()
                     val membersStateFlow = joinedRoom.membersStateFlow.mapState { it.joinedRoomMembers() }
                     combine(liveLocationSharesFlow, membersStateFlow) { liveShares, members ->
-                        liveShares.mapNotNull { share ->
+                        liveShares
-                            val lastLocation = share.lastLocation ?: return@mapNotNull null
+                            .sortedWith(comparator)
-                            val location = Location.fromGeoUri(lastLocation.geoUri) ?: return@mapNotNull null
+                            .mapNotNull { share ->
-                            val member = members.find { it.userId == share.userId }
+                                val lastLocation = share.lastLocation ?: return@mapNotNull null
-                            val displayName = member?.getBestName() ?: share.userId.value
+                                val location = Location.fromGeoUri(lastLocation.geoUri) ?: return@mapNotNull null
-                            val avatarUrl = member?.avatarUrl
+                                val member = members.find { it.userId == share.userId }
-                            val relativeTime = dateFormatter.format(timestamp = lastLocation.timestamp, mode = DateFormatterMode.Full, useRelative = true)
+                                val displayName = member?.getBestName() ?: share.userId.value
-                            val formattedTimestamp = stringProvider.getString(
+                                val avatarUrl = member?.avatarUrl
-                                CommonStrings.screen_static_location_sheet_timestamp_description,
+                                val relativeTime = dateFormatter.format(timestamp = lastLocation.timestamp, mode = DateFormatterMode.Full, useRelative = true)
-                                relativeTime
+                                val formattedTimestamp = stringProvider.getString(
-                            )
+                                    CommonStrings.screen_static_location_sheet_timestamp_description,
-                            LocationShareItem(
+                                    relativeTime
-                                userId = share.userId,
+                                )
-                                displayName = displayName,
+                                LocationShareItem(
-                                avatarData = AvatarData(
+                                    userId = share.userId,
-                                    id = share.userId.value,
+                                    displayName = displayName,
-                                    name = displayName,
+                                    avatarData = AvatarData(
-                                    url = avatarUrl,
+                                        id = share.userId.value,
-                                    size = AvatarSize.UserListItem,
+                                        name = displayName,
-                                ),
+                                        url = avatarUrl,
-                                formattedTimestamp = formattedTimestamp,
+                                        size = AvatarSize.UserListItem,
-                                location = location,
+                                    ),
-                                isLive = true,
+                                    formattedTimestamp = formattedTimestamp,
-                                assetType = lastLocation.assetType,
+                                    location = location,
-                            )
+                                    isLive = true,
-                        }.toImmutableList()
+                                    assetType = lastLocation.assetType,
+                                )
+                            }
+                            .toImmutableList()
                     }.collect { value = it }
                 }.value
             }

features/location/impl/src/test/kotlin/io/element/android/features/location/impl/show/LiveLocationShareComparatorTest.kt

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.features.location.impl.show
+
+import com.google.common.truth.Truth.assertThat
+import io.element.android.libraries.matrix.api.core.UserId
+import io.element.android.libraries.matrix.api.room.location.LiveLocationShare
+import org.junit.Test
+
+class LiveLocationShareComparatorTest {
+    private val currentUser = UserId("@me:matrix.org")
+    private val comparator = LiveLocationShareComparator(currentUser)
+
+    @Test
+    fun `compare returns zero when comparing the same current user share`() {
+        val share = aLiveLocationShare(userId = currentUser, startTimestamp = 123L)
+
+        val result = comparator.compare(share, share)
+
+        assertThat(result).isEqualTo(0)
+    }
+
+    @Test
+    fun `compare orders current user share before another user share`() {
+        val otherShare = aLiveLocationShare(userId = UserId("@alice:matrix.org"), startTimestamp = 200L)
+        val currentUserShare = aLiveLocationShare(userId = currentUser, startTimestamp = 100L)
+
+        val sortedShares = listOf(otherShare, currentUserShare).sortedWith(comparator)
+
+        assertThat(sortedShares).containsExactly(currentUserShare, otherShare).inOrder()
+    }
+
+    @Test
+    fun `compare orders current user shares by newest start timestamp first`() {
+        val newerShare = aLiveLocationShare(userId = currentUser, startTimestamp = 200L)
+        val olderShare = aLiveLocationShare(userId = currentUser, startTimestamp = 100L)
+
+        val sortedShares = listOf(olderShare, newerShare).sortedWith(comparator)
+
+        assertThat(sortedShares).containsExactly(newerShare, olderShare).inOrder()
+    }
+
+    @Test
+    fun `compare orders non current user shares by newest start timestamp first`() {
+        val newerShare = aLiveLocationShare(userId = UserId("@alice:matrix.org"), startTimestamp = 200L)
+        val olderShare = aLiveLocationShare(userId = UserId("@bob:matrix.org"), startTimestamp = 100L)
+
+        val sortedShares = listOf(olderShare, newerShare).sortedWith(comparator)
+
+        assertThat(sortedShares).containsExactly(newerShare, olderShare).inOrder()
+    }
+}
+
+private fun aLiveLocationShare(
+    userId: UserId,
+    startTimestamp: Long,
+): LiveLocationShare {
+    return LiveLocationShare(
+        userId = userId,
+        lastLocation = null,
+        startTimestamp = startTimestamp,
+        endTimestamp = startTimestamp + 1_000L,
+    )
+}

features/location/impl/src/test/kotlin/io/element/android/features/location/impl/show/ShowLocationPresenterTest.kt

@@ -469,6 +469,7 @@ private fun aLiveLocationShare(
     userId: UserId,
     geoUri: String = "geo:48.8584,2.2945",
     timestamp: Long = 0L,
+    startTimestamp: Long = 0L,
     endTimestamp: Long = Long.MAX_VALUE,
     assetType: AssetType = AssetType.SENDER,
 ): LiveLocationShare {
@@ -479,6 +480,7 @@ private fun aLiveLocationShare(
             timestamp = timestamp,
             assetType = assetType,
         ),
+        startTimestamp = startTimestamp,
         endTimestamp = endTimestamp,
     )
 }

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/location/LiveLocationShare.kt

@@ -17,6 +17,8 @@ data class LiveLocationShare(
     val userId: UserId,
     /** The last known location if any. */
     val lastLocation: LastLocation?,
+    /** The timestamp when location sharing started, in milliseconds.*/
+    val startTimestamp: Long,
     /** The timestamp when location sharing ends, in milliseconds. */
     val endTimestamp: Long,
 )

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/location/LiveLocationSharesFlow.kt

@@ -68,6 +68,7 @@ private fun RustLiveLocationShare.into(): LiveLocationShare {
                 assetType = it.location.asset.into(),
             )
         },
+        startTimestamp = startTs.toLong(),
         endTimestamp = (startTs + timeout).toLong()
     )
 }