Enable switching active category and updating mailbox content accordingly.

- Allow selecting a new active category from mailbox - Propagate category selection through UI, vm and domain layers - Update Rust scroller to reflect active category change - Handle errors and provide user feedback on failure ET-6046
2026-05-15 09:50:40 +00:00 · 2026-04-28 15:54:16 +01:00
parent 693aeab3fa
commit 601131afb0
25 changed files with 257 additions and 5 deletions
@@ -51,6 +51,8 @@ fun LocalCategoryLabel.toCategoryLabel(): CategoryLabel {

 fun LocalCategoryLabelId.toCategoryLabelId(): CategoryLabelId = CategoryLabelId(this.value.toString())

+fun CategoryLabelId.toLocalCategoryLabelId(): LocalCategoryLabelId = LocalCategoryLabelId(this.id.toULong())
+
 fun ConversationScrollerCategoryViewResult.toCategoryViewStatus(): CategoryViewStatus = when (this) {
    is ConversationScrollerCategoryViewResult.Ok -> {
        v1.toCategoryViewStatus()
@@ -49,3 +49,5 @@ fun CategoryLabel.toUiModel(): CategoryItemUiModel {
 }

 fun CategoryLabelId.toUiModel(): CategoryLabelIdUiModel = CategoryLabelIdUiModel(id = id)
+
+fun CategoryLabelIdUiModel.toDomainModel(): CategoryLabelId = CategoryLabelId(id = id)
@@ -20,6 +20,7 @@ package ch.protonmail.android.mailconversation.data.local

 import arrow.core.Either
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversation
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversationId
 import ch.protonmail.android.mailcommon.data.mapper.LocalLabelId
@@ -132,4 +133,6 @@ interface RustConversationDataSource {
    fun observeScrollerFetchNewStatus(): Flow<ConversationScrollerFetchNewStatus>

    fun observeCategoryViewStatus(): Flow<CategoryViewStatus>
+
+    fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit>
 }
@@ -21,6 +21,7 @@ package ch.protonmail.android.mailconversation.data.local
 import arrow.core.Either
 import arrow.core.left
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversation
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversationId
 import ch.protonmail.android.mailcommon.data.mapper.LocalLabelId
@@ -345,4 +346,6 @@ class RustConversationDataSourceImpl @Inject constructor(
    override fun observeCategoryViewStatus(): Flow<CategoryViewStatus> =
        rustConversationsQuery.observeCategoryViewStatus()

+    override fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> =
+        rustConversationsQuery.setActiveCategoryLabel(categoryLabelId)
 }
@@ -20,6 +20,7 @@ package ch.protonmail.android.mailconversation.data.local

 import arrow.core.Either
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversation
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversationId
 import ch.protonmail.android.mailconversation.data.wrapper.ConversationCursorWrapper
@@ -53,4 +54,5 @@ interface RustConversationsQuery {

    fun observeScrollerFetchNewStatus(): Flow<ConversationScrollerStatusUpdate>
    fun observeCategoryViewStatus(): Flow<CategoryViewStatus>
+    fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit>
 }
@@ -22,6 +22,7 @@ import arrow.core.Either
 import arrow.core.left
 import ch.protonmail.android.mailcategory.data.mapper.toCategoryViewStatus
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversation
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversationId
 import ch.protonmail.android.mailcommon.domain.model.DataError
@@ -298,6 +299,10 @@ class RustConversationsQueryImpl @Inject constructor(

    override fun observeCategoryViewStatus(): Flow<CategoryViewStatus> = categoryViewStatusFlow.filterNotNull()

+    override fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> =
+        paginatorState?.paginatorWrapper?.changeCategoryView(categoryLabelId)
+            ?: PaginationError.Other(DataError.Local.IllegalStateError).left()
+
    private fun destroy() {
        if (paginatorState == null) {
            Timber.d("rust-conversation-query: no paginator to destroy")
@@ -21,6 +21,8 @@ package ch.protonmail.android.mailconversation.data.repository
 import arrow.core.Either
 import arrow.core.flatMap
 import arrow.core.right
+import ch.protonmail.android.mailcategory.data.mapper.toLocalCategoryLabelId
+import ch.protonmail.android.mailcategory.domain.model.CategoryLabelId
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
 import ch.protonmail.android.mailcommon.domain.model.ConversationCursorError
 import ch.protonmail.android.mailcommon.domain.model.ConversationId
@@ -245,4 +247,7 @@ class RustConversationRepositoryImpl @Inject constructor(

    override fun observeCategoryViewStatus(): Flow<CategoryViewStatus> =
        rustConversationDataSource.observeCategoryViewStatus()
+
+    override fun setActiveCategoryLabel(categoryLabelId: CategoryLabelId): Either<PaginationError, Unit> =
+        rustConversationDataSource.setActiveCategoryLabel(categoryLabelId.toLocalCategoryLabelId())
 }
@@ -23,11 +23,13 @@ import arrow.core.left
 import arrow.core.right
 import ch.protonmail.android.mailcategory.data.mapper.toCategoryViewStatus
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversationId
 import ch.protonmail.android.mailpagination.data.mapper.toPaginationError
 import ch.protonmail.android.mailpagination.domain.model.PaginationError
 import timber.log.Timber
 import uniffi.mail_uniffi.ConversationScroller
+import uniffi.mail_uniffi.ConversationScrollerChangeCategoryViewResult
 import uniffi.mail_uniffi.ConversationScrollerCursorResult
 import uniffi.mail_uniffi.ConversationScrollerFetchMoreResult
 import uniffi.mail_uniffi.ConversationScrollerGetItemsResult
@@ -83,4 +85,10 @@ class ConversationPaginatorWrapper(private val rustPaginator: ConversationScroll
    fun getScrollerId(): String = rustPaginator.id()

    suspend fun getCategoryViewStatus(): CategoryViewStatus = rustPaginator.categoryView().toCategoryViewStatus()
+
+    fun changeCategoryView(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> =
+        when (val result = rustPaginator.changeCategoryView(categoryLabelId)) {
+            is ConversationScrollerChangeCategoryViewResult.Error -> result.v1.toPaginationError().left()
+            is ConversationScrollerChangeCategoryViewResult.Ok -> Unit.right()
+        }
 }
@@ -19,6 +19,7 @@
 package ch.protonmail.android.mailconversation.domain.repository

 import arrow.core.Either
+import ch.protonmail.android.mailcategory.domain.model.CategoryLabelId
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
 import ch.protonmail.android.mailcommon.domain.model.ConversationCursorError
 import ch.protonmail.android.mailcommon.domain.model.ConversationId
@@ -124,4 +125,6 @@ interface ConversationRepository {
    fun observeScrollerFetchNewStatus(): Flow<ConversationScrollerFetchNewStatus>

    fun observeCategoryViewStatus(): Flow<CategoryViewStatus>
+
+    fun setActiveCategoryLabel(categoryLabelId: CategoryLabelId): Either<PaginationError, Unit>
 }
@@ -107,6 +107,7 @@ import ch.protonmail.android.mailattachments.presentation.model.FileContent
 import ch.protonmail.android.mailattachments.presentation.ui.OpenAttachmentInput
 import ch.protonmail.android.mailattachments.presentation.ui.fileOpener
 import ch.protonmail.android.mailattachments.presentation.ui.fileSaver
+import ch.protonmail.android.mailcategory.presentation.model.CategoryItemUiModel
 import ch.protonmail.android.mailcommon.presentation.AdaptivePreviews
 import ch.protonmail.android.mailcommon.presentation.ConsumableLaunchedEffect
 import ch.protonmail.android.mailcommon.presentation.ConsumableTextEffect
@@ -288,7 +289,8 @@ fun MailboxScreen(
        onClearAllConfirmed = { viewModel.submit(MailboxViewAction.ClearAllConfirmed) },
        onClearAllDismissed = { viewModel.submit(MailboxViewAction.ClearAllDismissed) },
        onSnooze = { viewModel.submit(MailboxViewAction.RequestSnoozeBottomSheet) },
-        validateUserSession = { viewModel.submit(MailboxViewAction.ValidateUserSession) }
+        validateUserSession = { viewModel.submit(MailboxViewAction.ValidateUserSession) },
+        onCategoryItemClicked = { viewModel.submit(MailboxViewAction.OnCategoryItemClicked(it)) }
    )

    val lifecycle = LocalLifecycleOwner.current
@@ -458,7 +460,7 @@ fun MailboxScreen(
        onSpamTrashFilterDisabled = actions.onDisableSpamTrashFilter,
        onSelectAllClicked = actions.onSelectAllClicked,
        onDeselectAllClicked = actions.onDeselectAllClicked,
-        onCategoryItemClicked = {}
+        onCategoryItemClicked = actions.onCategoryItemClicked
    )

    val fileSaver = fileSaver(
@@ -1211,7 +1213,8 @@ object MailboxScreen {
        val onSnooze: () -> Unit,
        val onCustomizeToolbar: () -> Unit,
        val validateUserSession: () -> Unit,
-        val onShowRatingBooster: () -> Unit
+        val onShowRatingBooster: () -> Unit,
+        val onCategoryItemClicked: (CategoryItemUiModel) -> Unit
    ) {

        companion object {
@@ -1275,7 +1278,8 @@ object MailboxScreen {
                onSnooze = {},
                onCustomizeToolbar = {},
                validateUserSession = {},
-                onShowRatingBooster = {}
+                onShowRatingBooster = {},
+                onCategoryItemClicked = {}
            )
        }
    }
@@ -36,6 +36,7 @@ import ch.protonmail.android.mailattachments.domain.model.AttachmentId
 import ch.protonmail.android.mailattachments.domain.model.AttachmentOpenMode
 import ch.protonmail.android.mailattachments.domain.usecase.GetAttachmentIntentValues
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcategory.presentation.mapper.toDomainModel
 import ch.protonmail.android.mailcategory.presentation.model.CategoryViewState
 import ch.protonmail.android.mailcommon.domain.coroutines.AppScope
 import ch.protonmail.android.mailcommon.domain.model.Action
@@ -104,6 +105,7 @@ import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ObserveCat
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ObserveValidSenderAddress
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ObserveViewModeChanged
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.RecordRatingBoosterTriggered
+import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.SetActiveCategoryLabel
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ShouldShowRatingBooster
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.UpdateShowSpamTrashFilter
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.UpdateUnreadFilter
@@ -228,6 +230,7 @@ class MailboxViewModel @Inject constructor(
    private val shouldShowRatingBooster: ShouldShowRatingBooster,
    private val recordRatingBoosterTriggered: RecordRatingBoosterTriggered,
    private val observeCategoryViewStatus: ObserveCategoryViewStatus,
+    private val setActiveCategoryLabel: SetActiveCategoryLabel,
    @IsCategoryViewEnabled private val categoryViewEnabled: FeatureFlag<Boolean>
 ) : ViewModel() {

@@ -469,10 +472,30 @@ class MailboxViewModel @Inject constructor(
                is MailboxViewAction.SignalLabelAsCompleted -> handleLabelAsCompleted(viewAction)
                is MailboxViewAction.ValidateUserSession -> handleValidateUserSession()
                is MailboxViewAction.NavigateToComposer -> handleNavigateToComposer()
+                is MailboxViewAction.OnCategoryItemClicked -> handleCategoryItemClicked(viewAction)
            }
        }
    }

+    private suspend fun handleCategoryItemClicked(viewAction: MailboxViewAction.OnCategoryItemClicked) {
+        val categoryItem = viewAction.categoryItem
+
+        if (categoryItem.isActive) {
+            Timber.d("Category ${categoryItem.id} is already active, ignoring click")
+            return
+        }
+
+        val viewMode = getViewModeForCurrentLocation(getSelectedMailLabelId())
+
+        setActiveCategoryLabel(
+            categoryLabelId = categoryItem.id.toDomainModel(),
+            viewMode = viewMode
+        ).onLeft { error ->
+            Timber.e("Failed to set active category label: $error")
+            emitNewStateFrom(MailboxEvent.ErrorChangingCategory)
+        }
+    }
+
    private fun handleNavigateToComposer() {
        if (state.value.composerNavigationState is MailboxComposerNavigationState.Disabled) {
            emitNewStateFrom(MailboxEvent.ErrorComposing)
@@ -21,6 +21,7 @@ package ch.protonmail.android.mailmailbox.presentation.mailbox.model
 import ch.protonmail.android.mailattachments.domain.model.OpenAttachmentIntentValues
 import ch.protonmail.android.mailattachments.presentation.model.AttachmentIdUiModel
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcategory.presentation.model.CategoryItemUiModel
 import ch.protonmail.android.mailcommon.presentation.model.BottomBarEvent
 import ch.protonmail.android.mailcommon.presentation.model.BottomSheetOperation
 import ch.protonmail.android.maillabel.domain.model.LabelId
@@ -182,6 +183,8 @@ internal sealed interface MailboxViewAction : MailboxOperation {
        AffectingBottomAppBar

    object ValidateUserSession : MailboxViewAction
+
+    data class OnCategoryItemClicked(val categoryItem: CategoryItemUiModel) : MailboxViewAction
 }

 internal sealed interface MailboxEvent : MailboxOperation {
@@ -351,6 +354,7 @@ internal sealed interface MailboxEvent : MailboxOperation {
    object ErrorRetrievingFolderColorSettings : MailboxEvent, AffectingErrorBar, AffectingBottomSheet
    object ErrorMoving : MailboxEvent, AffectingErrorBar
    object ErrorRetrievingDestinationMailFolders : MailboxEvent, AffectingErrorBar, AffectingBottomSheet
+    object ErrorChangingCategory : MailboxEvent, AffectingErrorBar

    data class AttachmentDownloadStartedEvent(
        val attachmentId: AttachmentIdUiModel
@@ -210,6 +210,7 @@ class MailboxReducer @Inject constructor(

                is MailboxEvent.ErrorDeleting -> R.string.mailbox_action_delete_failed
                is MailboxEvent.ErrorComposing -> R.string.mailbox_action_no_sender_addresses
+                is MailboxEvent.ErrorChangingCategory -> R.string.mailbox_action_change_category_failed
            }
            Effect.of(TextUiModel(textResource))
        } else {
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2026 Proton Technologies AG
+ * This file is part of Proton Technologies AG and Proton Mail.
+ *
+ * Proton Mail is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Proton Mail is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Proton Mail. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package ch.protonmail.android.mailmailbox.presentation.mailbox.usecase
+
+import arrow.core.Either
+import ch.protonmail.android.mailcategory.domain.model.CategoryLabelId
+import ch.protonmail.android.mailconversation.domain.repository.ConversationRepository
+import ch.protonmail.android.maillabel.domain.model.ViewMode
+import ch.protonmail.android.mailmessage.domain.repository.MessageRepository
+import ch.protonmail.android.mailpagination.domain.model.PaginationError
+import javax.inject.Inject
+
+class SetActiveCategoryLabel @Inject constructor(
+    private val conversationRepository: ConversationRepository,
+    private val messageRepository: MessageRepository
+) {
+
+    operator fun invoke(categoryLabelId: CategoryLabelId, viewMode: ViewMode): Either<PaginationError, Unit> =
+        when (viewMode) {
+            ViewMode.ConversationGrouping ->
+                conversationRepository.setActiveCategoryLabel(categoryLabelId)
+
+            ViewMode.NoConversationGrouping ->
+                messageRepository.setActiveCategoryLabel(categoryLabelId)
+        }
+}
@@ -112,6 +112,8 @@

    <!--    Storage Quota Over Warning-->
    <string name="mailbox_action_delete_failed">Failed to delete message</string>
+    <string name="mailbox_action_change_category_failed">Failed to change the active category</string>
+

    <string name="select_all">Select All</string>
    <string name="deselect_all">Deselect All</string>
@@ -30,7 +30,9 @@ import ch.protonmail.android.mailattachments.domain.model.OpenAttachmentIntentVa
 import ch.protonmail.android.mailattachments.domain.usecase.GetAttachmentIntentValues
 import ch.protonmail.android.mailattachments.presentation.model.AttachmentIdUiModel
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcategory.presentation.mapper.toDomainModel
 import ch.protonmail.android.mailcategory.presentation.model.CategoryViewState
+import ch.protonmail.android.mailcategory.presentation.sample.CategoryItemUiModelSample
 import ch.protonmail.android.mailcommon.domain.model.Action
 import ch.protonmail.android.mailcommon.domain.model.AllBottomBarActions
 import ch.protonmail.android.mailcommon.domain.model.ConversationId
@@ -44,6 +46,7 @@ import ch.protonmail.android.mailcommon.presentation.model.BottomBarState
 import ch.protonmail.android.mailcommon.presentation.model.BottomBarTarget
 import ch.protonmail.android.mailcommon.presentation.model.BottomSheetState
 import ch.protonmail.android.mailcommon.presentation.model.CappedNumberUiModel
+import ch.protonmail.android.mailcommon.presentation.model.TextUiModel
 import ch.protonmail.android.mailcommon.presentation.model.toCappedNumberUiModel
 import ch.protonmail.android.mailcommon.presentation.sample.ActionUiModelSample
 import ch.protonmail.android.mailcommon.presentation.ui.delete.DeleteDialogState
@@ -111,6 +114,7 @@ import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ObserveCat
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ObserveValidSenderAddress
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ObserveViewModeChanged
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.RecordRatingBoosterTriggered
+import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.SetActiveCategoryLabel
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.ShouldShowRatingBooster
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.UpdateShowSpamTrashFilter
 import ch.protonmail.android.mailmailbox.presentation.mailbox.usecase.UpdateUnreadFilter
@@ -130,6 +134,7 @@ import ch.protonmail.android.mailmessage.domain.usecase.UnStarMessages
 import ch.protonmail.android.mailmessage.presentation.model.bottomsheet.MailboxMoreActionsBottomSheetState
 import ch.protonmail.android.mailmessage.presentation.model.bottomsheet.SnoozeSheetState
 import ch.protonmail.android.mailpagination.domain.model.PageInvalidationEvent
+import ch.protonmail.android.mailpagination.domain.model.PaginationError
 import ch.protonmail.android.mailpagination.domain.usecase.ObservePageInvalidationEvents
 import ch.protonmail.android.mailsession.domain.repository.EventLoopRepository
 import ch.protonmail.android.mailsession.domain.usecase.HasValidUserSession
@@ -364,6 +369,8 @@ internal class MailboxViewModelTest {
        } returns categoryViewStatusFlow
    }

+    private val setActiveCategoryLabel = mockk<SetActiveCategoryLabel>()
+
    private val scope = TestScope(UnconfinedTestDispatcher())

    private val mailboxViewModel by lazy {
@@ -421,7 +428,8 @@ internal class MailboxViewModelTest {
            shouldShowRatingBooster = shouldShowRatingBooster,
            recordRatingBoosterTriggered = recordRatingBoosterTriggered,
            categoryViewEnabled = isCategoryViewEnabled,
-            observeCategoryViewStatus = observeCategoryViewStatus
+            observeCategoryViewStatus = observeCategoryViewStatus,
+            setActiveCategoryLabel = setActiveCategoryLabel
        )
    }

@@ -3881,6 +3889,97 @@ internal class MailboxViewModelTest {
        }
    }

+    @Test
+    fun `when inactive category item is clicked, active category is changed`() = runTest {
+        // Given
+        val categoryItem = CategoryItemUiModelSample.social
+        expectViewModeForCurrentLocation(NoConversationGrouping)
+
+        every {
+            setActiveCategoryLabel(
+                categoryLabelId = categoryItem.id.toDomainModel(),
+                viewMode = NoConversationGrouping
+            )
+        } returns Unit.right()
+
+        // When
+        mailboxViewModel.submit(MailboxViewAction.OnCategoryItemClicked(categoryItem))
+        advanceUntilIdle()
+
+        // Then
+        verify(exactly = 1) {
+            setActiveCategoryLabel(
+                categoryLabelId = categoryItem.id.toDomainModel(),
+                viewMode = NoConversationGrouping
+            )
+        }
+
+        verify(exactly = 0) {
+            mailboxReducer.newStateFrom(any(), MailboxEvent.ErrorChangingCategory)
+        }
+    }
+
+    @Test
+    fun `when active category item is clicked, the request is ignored`() = runTest {
+        // Given
+        val categoryItem = CategoryItemUiModelSample.primary.copy(isActive = true)
+
+        // When
+        mailboxViewModel.submit(MailboxViewAction.OnCategoryItemClicked(categoryItem))
+        advanceUntilIdle()
+
+        // Then
+        verify(exactly = 0) {
+            setActiveCategoryLabel(any(), any())
+        }
+
+        verify(exactly = 0) {
+            mailboxReducer.newStateFrom(any(), MailboxEvent.ErrorChangingCategory)
+        }
+    }
+
+    @Test
+    fun `when changing active category fails, error event is emitted`() = runTest {
+        // Given
+        val categoryItem = CategoryItemUiModelSample.social
+        val expectedState = MailboxStateSampleData.Loading.copy(
+            error = Effect.of(TextUiModel(R.string.mailbox_action_change_category_failed))
+        )
+
+        expectViewModeForCurrentLocation(NoConversationGrouping)
+
+        every {
+            setActiveCategoryLabel(
+                categoryLabelId = categoryItem.id.toDomainModel(),
+                viewMode = NoConversationGrouping
+            )
+        } returns PaginationError.Other(DataError.Local.IllegalStateError).left()
+
+        every {
+            mailboxReducer.newStateFrom(
+                any(),
+                MailboxEvent.ErrorChangingCategory
+            )
+        } returns expectedState
+
+        mailboxViewModel.state.test {
+            awaitItem()
+
+            // When
+            mailboxViewModel.submit(MailboxViewAction.OnCategoryItemClicked(categoryItem))
+            advanceUntilIdle()
+
+            // Then
+            assertEquals(expectedState, awaitItem())
+
+            verify(exactly = 1) {
+                mailboxReducer.newStateFrom(any(), MailboxEvent.ErrorChangingCategory)
+            }
+
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
    private fun returnExpectedStateForBottomBarEvent(
        intermediateState: MailboxState? = null,
        expectedState: MailboxState
@@ -20,6 +20,7 @@ package ch.protonmail.android.mailmessage.data.local

 import arrow.core.Either
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalLabelAsAction
 import ch.protonmail.android.mailcommon.data.mapper.LocalLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalMessageId
@@ -142,4 +143,7 @@ interface RustMessageDataSource {
    fun observeScrollerFetchNewStatus(): Flow<MessageScrollerFetchNewStatus>

    fun observeCategoryViewStatus(): Flow<CategoryViewStatus>
+
+    fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit>
+
 }
@@ -21,6 +21,7 @@ package ch.protonmail.android.mailmessage.data.local
 import arrow.core.Either
 import arrow.core.left
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalLabelAsAction
 import ch.protonmail.android.mailcommon.data.mapper.LocalLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalMessageId
@@ -456,4 +457,7 @@ class RustMessageDataSourceImpl @Inject constructor(
    override fun observeCategoryViewStatus(): Flow<CategoryViewStatus> =
        rustMessageListQuery.observeCategoryViewStatus()

+    override fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> =
+        rustMessageListQuery.setActiveCategoryLabel(categoryLabelId)
+
 }
@@ -20,6 +20,7 @@ package ch.protonmail.android.mailmessage.data.local

 import arrow.core.Either
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalItemId
 import ch.protonmail.android.maillabel.domain.model.LabelId
 import ch.protonmail.android.mailmessage.data.wrapper.MailMessageCursorWrapper
@@ -49,4 +50,6 @@ interface RustMessageListQuery {
    fun observeScrollerFetchNewStatus(): Flow<MessageScrollerStatusUpdate>

    fun observeCategoryViewStatus(): Flow<CategoryViewStatus>
+
+    fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit>
 }
@@ -22,6 +22,7 @@ import arrow.core.Either
 import arrow.core.left
 import ch.protonmail.android.mailcategory.data.mapper.toCategoryViewStatus
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalConversationId
 import ch.protonmail.android.mailcommon.domain.model.DataError
 import ch.protonmail.android.maillabel.data.local.RustMailboxFactory
@@ -188,6 +189,12 @@ class RustMessageListQueryImpl @Inject constructor(

    override suspend fun supportsIncludeFilter() = paginatorState?.paginatorWrapper?.supportsIncludeFilter() == true

+    override fun setActiveCategoryLabel(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> =
+        paginatorState?.paginatorWrapper?.changeCategoryView(categoryLabelId) ?: run {
+            Timber.w("rust-message-query: No paginator to change category view")
+            PaginationError.Other(DataError.Local.IllegalStateError).left()
+        }
+
    override suspend fun updateUnreadFilter(filterUnread: Boolean) {
        paginatorState?.paginatorWrapper?.filterUnread(filterUnread)
            ?: Timber.w("rust-message-query: No paginator to update unread filter")
@@ -20,6 +20,8 @@ package ch.protonmail.android.mailmessage.data.repository

 import java.io.File
 import arrow.core.Either
+import ch.protonmail.android.mailcategory.data.mapper.toLocalCategoryLabelId
+import ch.protonmail.android.mailcategory.domain.model.CategoryLabelId
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
 import ch.protonmail.android.mailcommon.domain.model.ConversationCursorError
 import ch.protonmail.android.mailcommon.domain.model.CursorId
@@ -187,4 +189,8 @@ class RustMessageRepositoryImpl @Inject constructor(

    override suspend fun isMessageSenderBlocked(userId: UserId, messageId: MessageId): Either<DataError, Boolean> =
        rustMessageDataSource.isMessageSenderBlocked(userId, messageId.toLocalMessageId())
+
+    override fun setActiveCategoryLabel(categoryLabelId: CategoryLabelId): Either<PaginationError, Unit> =
+        rustMessageDataSource.setActiveCategoryLabel(categoryLabelId.toLocalCategoryLabelId())
+
 }
@@ -23,12 +23,14 @@ import arrow.core.left
 import arrow.core.right
 import ch.protonmail.android.mailcategory.data.mapper.toCategoryViewStatus
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalItemId
 import ch.protonmail.android.mailpagination.data.mapper.toPaginationError
 import ch.protonmail.android.mailpagination.domain.model.PaginationError
 import timber.log.Timber
 import uniffi.mail_uniffi.IncludeSwitch
 import uniffi.mail_uniffi.MessageScroller
+import uniffi.mail_uniffi.MessageScrollerChangeCategoryViewResult
 import uniffi.mail_uniffi.MessageScrollerCursorResult
 import uniffi.mail_uniffi.MessageScrollerFetchMoreResult
 import uniffi.mail_uniffi.MessageScrollerGetItemsResult
@@ -94,4 +96,10 @@ class MailboxMessagePaginatorWrapper(
    override suspend fun getCategoryViewStatus(): CategoryViewStatus =
        rustPaginator.categoryView().toCategoryViewStatus()

+    override fun changeCategoryView(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> =
+        when (val result = rustPaginator.changeCategoryView(categoryLabelId)) {
+            is MessageScrollerChangeCategoryViewResult.Error -> result.v1.toPaginationError().left()
+            is MessageScrollerChangeCategoryViewResult.Ok -> Unit.right()
+        }
+
 }
@@ -20,6 +20,7 @@ package ch.protonmail.android.mailmessage.data.wrapper

 import arrow.core.Either
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalItemId
 import ch.protonmail.android.mailpagination.domain.model.PaginationError

@@ -44,4 +45,6 @@ interface MessagePaginatorWrapper {
    fun getScrollerId(): String

    suspend fun getCategoryViewStatus(): CategoryViewStatus
+
+    fun changeCategoryView(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit>
 }
@@ -22,6 +22,7 @@ import arrow.core.Either
 import arrow.core.left
 import arrow.core.right
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
+import ch.protonmail.android.mailcommon.data.mapper.LocalCategoryLabelId
 import ch.protonmail.android.mailcommon.data.mapper.LocalItemId
 import ch.protonmail.android.mailpagination.data.mapper.toPaginationError
 import ch.protonmail.android.mailpagination.domain.model.PaginationError
@@ -89,4 +90,9 @@ class SearchMessagePaginatorWrapper(

    override suspend fun getCategoryViewStatus(): CategoryViewStatus = CategoryViewStatus.NotAvailable

+    override fun changeCategoryView(categoryLabelId: LocalCategoryLabelId): Either<PaginationError, Unit> {
+        Timber.w("search-paginator: Called change category on a search paginator, which is illegal. No-op.")
+        return Unit.right()
+    }
+
 }
@@ -19,6 +19,7 @@
 package ch.protonmail.android.mailmessage.domain.repository

 import arrow.core.Either
+import ch.protonmail.android.mailcategory.domain.model.CategoryLabelId
 import ch.protonmail.android.mailcategory.domain.model.CategoryViewStatus
 import ch.protonmail.android.mailcommon.domain.model.ConversationCursorError
 import ch.protonmail.android.mailcommon.domain.model.CursorId
@@ -168,4 +169,6 @@ interface MessageRepository {
    fun observeScrollerFetchNewStatus(): Flow<MessageScrollerFetchNewStatus>

    fun observeCategoryViewStatus(): Flow<CategoryViewStatus>
+
+    fun setActiveCategoryLabel(categoryLabelId: CategoryLabelId): Either<PaginationError, Unit>
 }