Force last owner of a room to pass ownership when leaving (#5094)

* Move `ChangeRoles*` classes to their own module so they can be shared

* Hook the change roles screen to the leave room action, add confirmation dialogs

* Use enum instead of sealed interface for `ChangeRoomMemberRolesListType`

* Try to improve communications between nodes

* refactor (leave room) : makes sure to expose only necessary code from api module

* Add `:libraries:previewutils` module to share some test fixtures used for UI previews

* Update screenshots

---------

Co-authored-by: ElementBot <android@element.io>
Co-authored-by: ganfra <francoisg@matrix.org>

libraries/architecture/build.gradle.kts

@@ -19,6 +19,7 @@ dependencies {
     api(libs.dagger)
     api(libs.appyx.core)
     api(libs.androidx.lifecycle.runtime)
+    api(libs.molecule.runtime)
 
     testImplementation(libs.test.junit)
     testImplementation(libs.coroutines.test)

libraries/architecture/src/main/kotlin/io/element/android/libraries/architecture/appyx/NodeExt.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+@file:OptIn(InternalComposeApi::class)
+
+package io.element.android.libraries.architecture.appyx
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.InternalComposeApi
+import androidx.compose.runtime.currentComposer
+import androidx.lifecycle.compose.LocalLifecycleOwner
+import androidx.lifecycle.lifecycleScope
+import app.cash.molecule.AndroidUiDispatcher
+import app.cash.molecule.RecompositionMode
+import app.cash.molecule.launchMolecule
+import com.bumble.appyx.core.node.Node
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.StateFlow
+
+fun <State> Node.launchMolecule(body: @Composable () -> State): StateFlow<State> {
+    val scope = CoroutineScope(lifecycleScope.coroutineContext + AndroidUiDispatcher.Main)
+    return scope.launchMolecule(mode = RecompositionMode.ContextClock) {
+        currentComposer.startProviders(
+            values = arrayOf(LocalLifecycleOwner provides this),
+        )
+        val state = body()
+        currentComposer.endProviders()
+        state
+    }
+}

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/powerlevels/MatrixRoomMembersWithRole.kt

@@ -9,21 +9,33 @@ package io.element.android.libraries.matrix.api.room.powerlevels
 
 import io.element.android.libraries.matrix.api.room.BaseRoom
 import io.element.android.libraries.matrix.api.room.RoomMember
+import io.element.android.libraries.matrix.api.room.RoomMembersState
 import io.element.android.libraries.matrix.api.room.activeRoomMembers
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.toPersistentList
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onStart
 
 /**
  * Return a flow of the list of active room members who have the given role.
  */
 fun BaseRoom.usersWithRole(role: RoomMember.Role): Flow<ImmutableList<RoomMember>> {
+    // Ensure the room members flow is ready
+    val readyMembersFlow = membersStateFlow
+        .onStart {
+            if (membersStateFlow.value is RoomMembersState.Unknown) {
+                updateMembers()
+            }
+        }
+        .filter { it is RoomMembersState.Ready }
+
     return roomInfoFlow
         .map { roomInfo -> roomInfo.usersWithRole(role) }
-        .combine(membersStateFlow) { powerLevels, membersState ->
+        .combine(readyMembersFlow) { powerLevels, membersState ->
             membersState.activeRoomMembers()
                 .filter { powerLevels.contains(it.userId) }
                 .toPersistentList()

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/room/RoomMemberFixture.kt

@@ -10,6 +10,7 @@ package io.element.android.libraries.matrix.test.room
 import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.room.RoomMember
 import io.element.android.libraries.matrix.api.room.RoomMembershipState
+import kotlinx.collections.immutable.persistentListOf
 
 fun aRoomMember(
     userId: UserId = UserId("@alice:server.org"),
@@ -34,3 +35,31 @@ fun aRoomMember(
     role = role,
     membershipChangeReason = membershipChangeReason,
 )
+
+fun aRoomMemberList() = persistentListOf(
+    anAlice(),
+    aBob(),
+    aRoomMember(UserId("@carol:server.org"), "Carol"),
+    aRoomMember(UserId("@david:server.org"), "David"),
+    aRoomMember(UserId("@eve:server.org"), "Eve"),
+    aRoomMember(UserId("@justin:server.org"), "Justin"),
+    aRoomMember(UserId("@mallory:server.org"), "Mallory"),
+    aRoomMember(UserId("@susie:server.org"), "Susie"),
+    aVictor(),
+    aWalter(),
+)
+
+fun anAlice() = aRoomMember(UserId("@alice:server.org"), "Alice", role = RoomMember.Role.Admin)
+fun aBob() = aRoomMember(UserId("@bob:server.org"), "Bob", role = RoomMember.Role.Moderator)
+
+fun aVictor() = aRoomMember(
+    UserId("@victor:server.org"),
+    "Victor",
+    membership = RoomMembershipState.INVITE
+)
+
+fun aWalter() = aRoomMember(
+    UserId("@walter:server.org"),
+    "Walter",
+    membership = RoomMembershipState.INVITE
+)

libraries/matrixui/src/main/kotlin/io/element/android/libraries/matrix/ui/room/PowerLevelRoomMemberComparator.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2025 New Vector 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.libraries.matrix.ui.room
+
+import io.element.android.libraries.matrix.api.room.RoomMember
+import java.text.Collator
+
+// Comparator used to sort room members by power level (descending) and then by name (ascending)
+class PowerLevelRoomMemberComparator : Comparator<RoomMember> {
+    // Used to simplify and compare unicode and ASCII chars (á == a)
+    private val collator = Collator.getInstance().apply {
+        decomposition = Collator.CANONICAL_DECOMPOSITION
+    }
+    override fun compare(o1: RoomMember, o2: RoomMember): Int {
+        return when {
+            o1.powerLevel > o2.powerLevel -> return -1
+            o1.powerLevel < o2.powerLevel -> return 1
+            else -> {
+                collator.compare(o1.sortingName(), o2.sortingName())
+            }
+        }
+    }
+}

libraries/previewutils/build.gradle.kts

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2022-2024 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+plugins {
+    id("io.element.android-library")
+}
+
+android {
+    namespace = "io.element.android.libraries.previewutils"
+
+    dependencies {
+        implementation(projects.libraries.designsystem)
+        implementation(projects.libraries.matrix.api)
+
+        implementation(libs.kotlinx.collections.immutable)
+    }
+}

libraries/previewutils/src/main/kotlin/io/element/android/libraries/previewutils/room/RoomMemberFixture.kt

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2023, 2024 New Vector 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.libraries.previewutils.room
+
+import io.element.android.libraries.matrix.api.core.UserId
+import io.element.android.libraries.matrix.api.room.RoomMember
+import io.element.android.libraries.matrix.api.room.RoomMembershipState
+import kotlinx.collections.immutable.persistentListOf
+
+fun aRoomMember(
+    userId: UserId = UserId("@alice:server.org"),
+    displayName: String? = null,
+    avatarUrl: String? = null,
+    membership: RoomMembershipState = RoomMembershipState.JOIN,
+    isNameAmbiguous: Boolean = false,
+    powerLevel: Long = 0L,
+    normalizedPowerLevel: Long = 0L,
+    isIgnored: Boolean = false,
+    role: RoomMember.Role = RoomMember.Role.User,
+    membershipChangeReason: String? = null,
+) = RoomMember(
+    userId = userId,
+    displayName = displayName,
+    avatarUrl = avatarUrl,
+    membership = membership,
+    isNameAmbiguous = isNameAmbiguous,
+    powerLevel = powerLevel,
+    normalizedPowerLevel = normalizedPowerLevel,
+    isIgnored = isIgnored,
+    role = role,
+    membershipChangeReason = membershipChangeReason,
+)
+
+fun aRoomMemberList() = persistentListOf(
+    anAlice(),
+    aBob(),
+    aRoomMember(UserId("@carol:server.org"), "Carol"),
+    aRoomMember(UserId("@david:server.org"), "David"),
+    aRoomMember(UserId("@eve:server.org"), "Eve"),
+    aRoomMember(UserId("@justin:server.org"), "Justin"),
+    aRoomMember(UserId("@mallory:server.org"), "Mallory"),
+    aRoomMember(UserId("@susie:server.org"), "Susie"),
+    aVictor(),
+    aWalter(),
+)
+
+fun anAlice() = aRoomMember(UserId("@alice:server.org"), "Alice", role = RoomMember.Role.Admin)
+fun aBob() = aRoomMember(UserId("@bob:server.org"), "Bob", role = RoomMember.Role.Moderator)
+
+fun aVictor() = aRoomMember(
+    UserId("@victor:server.org"),
+    "Victor",
+    membership = RoomMembershipState.INVITE
+)
+
+fun aWalter() = aRoomMember(
+    UserId("@walter:server.org"),
+    "Walter",
+    membership = RoomMembershipState.INVITE
+)