feat: Allow the user to chose behaviour when tapping a tab (#955)

Previously, tapping a tab would jump to the top of the loaded content,
which might trigger a load of a fresh page.

Provide a preference to control this; the default is the current
behaviour, the user can also choose to discard the current content and
load the newest content.

Fixes #939

app/src/main/java/app/pachli/components/notifications/NotificationsFragment.kt

@@ -61,6 +61,7 @@ import app.pachli.core.network.model.Filter
 import app.pachli.core.network.model.Notification
 import app.pachli.core.network.model.Poll
 import app.pachli.core.network.model.Status
+import app.pachli.core.preferences.TabTapBehaviour
 import app.pachli.core.ui.ActionButtonScrollListener
 import app.pachli.core.ui.BackgroundMessage
 import app.pachli.core.ui.extensions.getErrorString
@@ -671,7 +672,10 @@ class NotificationsFragment :
 
     override fun onReselect() {
         if (isAdded) {
-            layoutManager.scrollToPosition(0)
+            when (viewModel.uiState.value.tabTapBehaviour) {
+                TabTapBehaviour.JUMP_TO_NEXT_PAGE -> layoutManager.scrollToPosition(0)
+                TabTapBehaviour.JUMP_TO_NEWEST -> viewModel.accept(InfallibleUiAction.LoadNewest)
+            }
         }
     }
 

app/src/main/java/app/pachli/components/notifications/NotificationsViewModel.kt

@@ -41,6 +41,7 @@ import app.pachli.core.network.model.Notification
 import app.pachli.core.network.model.Poll
 import app.pachli.core.preferences.PrefKeys
 import app.pachli.core.preferences.SharedPreferencesRepository
+import app.pachli.core.preferences.TabTapBehaviour
 import app.pachli.network.FilterModel
 import app.pachli.usecase.TimelineCases
 import app.pachli.util.deserialize
@@ -82,6 +83,9 @@ data class UiState(
 
     /** True if the FAB should be shown while scrolling */
     val showFabWhileScrolling: Boolean = true,
+
+    /** User's preference for behaviour when tapping a tab. */
+    val tabTapBehaviour: TabTapBehaviour = TabTapBehaviour.JUMP_TO_NEXT_PAGE,
 )
 
 /** Preferences the UI reacts to */
@@ -92,6 +96,7 @@ data class UiPrefs(
         /** Relevant preference keys. Changes to any of these trigger a display update */
         val prefKeys = setOf(
             PrefKeys.FAB_HIDE,
+            PrefKeys.TAB_TAP_BEHAVIOUR,
         )
     }
 }
@@ -384,6 +389,7 @@ class NotificationsViewModel @Inject constructor(
                     account.lastNotificationId = "0"
                     accountManager.saveAccount(account)
                     reload.getAndUpdate { it + 1 }
+                    repository.invalidate()
                 }
         }
 
@@ -506,10 +512,11 @@ class NotificationsViewModel @Inject constructor(
                 getNotifications(filters = action.filter, initialKey = getInitialKey())
             }.cachedIn(viewModelScope)
 
-        uiState = combine(notificationFilter, getUiPrefs()) { filter, prefs ->
+        uiState = combine(notificationFilter, getUiPrefs()) { filter, _ ->
             UiState(
                 activeFilter = filter.filter,
-                showFabWhileScrolling = prefs.showFabWhileScrolling,
+                showFabWhileScrolling = !sharedPreferencesRepository.getBoolean(PrefKeys.FAB_HIDE, false),
+                tabTapBehaviour = sharedPreferencesRepository.tabTapBehaviour,
             )
         }.stateIn(
             scope = viewModelScope,
@@ -557,10 +564,5 @@ class NotificationsViewModel @Inject constructor(
      */
     private fun getUiPrefs() = sharedPreferencesRepository.changes
         .filter { UiPrefs.prefKeys.contains(it) }
-        .map { toPrefs() }
+        .onStart { emit(null) }
-        .onStart { emit(toPrefs()) }
-
-    private fun toPrefs() = UiPrefs(
-        showFabWhileScrolling = !sharedPreferencesRepository.getBoolean(PrefKeys.FAB_HIDE, false),
-    )
 }

app/src/main/java/app/pachli/components/preference/PreferencesFragment.kt

@@ -54,6 +54,7 @@ import app.pachli.core.preferences.AppTheme
 import app.pachli.core.preferences.DownloadLocation
 import app.pachli.core.preferences.PrefKeys
 import app.pachli.core.preferences.SharedPreferencesRepository
+import app.pachli.core.preferences.TabTapBehaviour
 import app.pachli.core.ui.extensions.await
 import app.pachli.core.ui.makeIcon
 import app.pachli.databinding.AccountNotificationDetailsListItemBinding
@@ -195,15 +196,6 @@ class PreferencesFragment : PreferenceFragmentCompat() {
                     icon = makeIcon(GoogleMaterial.Icon.gmd_format_size)
                 }
 
-                listPreference {
-                    setDefaultValue("top")
-                    setEntries(R.array.pref_main_nav_position_options)
-                    setEntryValues(R.array.pref_main_nav_position_values)
-                    key = PrefKeys.MAIN_NAV_POSITION
-                    setSummaryProvider { entry }
-                    setTitle(R.string.pref_main_nav_position)
-                }
-
                 listPreference {
                     setDefaultValue("disambiguate")
                     setEntries(R.array.pref_show_self_username_names)
@@ -285,6 +277,24 @@ class PreferencesFragment : PreferenceFragmentCompat() {
                     isSingleLineTitle = false
                 }
 
+                switchPreference {
+                    setDefaultValue(false)
+                    key = PrefKeys.SHOW_STATS_INLINE
+                    setTitle(R.string.pref_title_show_stat_inline)
+                    isSingleLineTitle = false
+                }
+            }
+
+            preferenceCategory(app.pachli.core.preferences.R.string.pref_category_tabs) {
+                listPreference {
+                    setDefaultValue("top")
+                    setEntries(R.array.pref_main_nav_position_options)
+                    setEntryValues(R.array.pref_main_nav_position_values)
+                    key = PrefKeys.MAIN_NAV_POSITION
+                    setSummaryProvider { entry }
+                    setTitle(R.string.pref_main_nav_position)
+                }
+
                 switchPreference {
                     setDefaultValue(true)
                     key = PrefKeys.ENABLE_SWIPE_FOR_TABS
@@ -292,11 +302,10 @@ class PreferencesFragment : PreferenceFragmentCompat() {
                     isSingleLineTitle = false
                 }
 
-                switchPreference {
+                enumListPreference<TabTapBehaviour> {
-                    setDefaultValue(false)
+                    setDefaultValue(TabTapBehaviour.JUMP_TO_NEXT_PAGE)
-                    key = PrefKeys.SHOW_STATS_INLINE
+                    setTitle(app.pachli.core.preferences.R.string.pref_title_tab_tap)
-                    setTitle(R.string.pref_title_show_stat_inline)
+                    key = PrefKeys.TAB_TAP_BEHAVIOUR
-                    isSingleLineTitle = false
                 }
             }
 

app/src/main/java/app/pachli/components/timeline/TimelineFragment.kt

@@ -67,6 +67,7 @@ import app.pachli.core.navigation.AttachmentViewData
 import app.pachli.core.navigation.EditFilterActivityIntent
 import app.pachli.core.network.model.Poll
 import app.pachli.core.network.model.Status
+import app.pachli.core.preferences.TabTapBehaviour
 import app.pachli.core.ui.ActionButtonScrollListener
 import app.pachli.core.ui.BackgroundMessage
 import app.pachli.core.ui.extensions.getErrorString
@@ -799,9 +800,15 @@ class TimelineFragment :
 
     override fun onReselect() {
         if (isAdded) {
-            binding.recyclerView.scrollToPosition(0)
+            when (viewModel.uiState.value.tabTapBehaviour) {
-            binding.recyclerView.stopScroll()
+                TabTapBehaviour.JUMP_TO_NEXT_PAGE -> {
-            saveVisibleId()
+                    binding.recyclerView.scrollToPosition(0)
+                    binding.recyclerView.stopScroll()
+                    saveVisibleId()
+                }
+
+                TabTapBehaviour.JUMP_TO_NEWEST -> viewModel.accept(InfallibleUiAction.LoadNewest)
+            }
         }
     }
 

app/src/main/java/app/pachli/components/timeline/viewmodel/TimelineViewModel.kt

@@ -53,6 +53,7 @@ import app.pachli.core.network.model.Poll
 import app.pachli.core.network.model.Status
 import app.pachli.core.preferences.PrefKeys
 import app.pachli.core.preferences.SharedPreferencesRepository
+import app.pachli.core.preferences.TabTapBehaviour
 import app.pachli.network.FilterModel
 import app.pachli.usecase.TimelineCases
 import app.pachli.viewdata.StatusViewData
@@ -85,6 +86,9 @@ data class UiState(
 
     /** True if the timeline should be shown in reverse order (oldest first) */
     val reverseTimeline: Boolean,
+
+    /** User's preference for behaviour when tapping a tab. */
+    val tabTapBehaviour: TabTapBehaviour = TabTapBehaviour.JUMP_TO_NEXT_PAGE,
 )
 
 // TODO: Ui* classes are copied from NotificationsViewModel. Not yet sure whether these actions
@@ -406,13 +410,18 @@ abstract class TimelineViewModel(
             }
         }
 
-        val watchedPrefs = setOf(PrefKeys.FAB_HIDE, PrefKeys.LAB_REVERSE_TIMELINE)
+        val watchedPrefs = setOf(
+            PrefKeys.FAB_HIDE,
+            PrefKeys.LAB_REVERSE_TIMELINE,
+            PrefKeys.TAB_TAP_BEHAVIOUR,
+        )
         uiState = sharedPreferencesRepository.changes
             .filter { watchedPrefs.contains(it) }
             .map {
                 UiState(
                     showFabWhileScrolling = !sharedPreferencesRepository.getBoolean(PrefKeys.FAB_HIDE, false),
                     reverseTimeline = sharedPreferencesRepository.getBoolean(PrefKeys.LAB_REVERSE_TIMELINE, false),
+                    tabTapBehaviour = sharedPreferencesRepository.tabTapBehaviour,
                 )
             }.stateIn(
                 scope = viewModelScope,
@@ -420,6 +429,7 @@ abstract class TimelineViewModel(
                 initialValue = UiState(
                     showFabWhileScrolling = !sharedPreferencesRepository.getBoolean(PrefKeys.FAB_HIDE, false),
                     reverseTimeline = sharedPreferencesRepository.getBoolean(PrefKeys.LAB_REVERSE_TIMELINE, false),
+                    tabTapBehaviour = sharedPreferencesRepository.tabTapBehaviour,
                 ),
             )
 

app/src/test/java/app/pachli/components/notifications/NotificationsViewModelTestUiState.kt

@@ -21,6 +21,7 @@ import androidx.core.content.edit
 import app.cash.turbine.test
 import app.pachli.core.network.model.Notification
 import app.pachli.core.preferences.PrefKeys
+import app.pachli.core.preferences.TabTapBehaviour
 import com.google.common.truth.Truth.assertThat
 import kotlinx.coroutines.test.runTest
 import org.junit.Test
@@ -36,6 +37,7 @@ class NotificationsViewModelTestUiState : NotificationsViewModelTestBase() {
     private val initialUiState = UiState(
         activeFilter = setOf(Notification.Type.FOLLOW),
         showFabWhileScrolling = true,
+        tabTapBehaviour = TabTapBehaviour.JUMP_TO_NEXT_PAGE,
     )
 
     @Test

core/preferences/src/main/kotlin/app/pachli/core/preferences/SettingsConstants.kt

@@ -110,6 +110,7 @@ object PrefKeys {
     const val USE_PREVIOUS_UNIFIED_PUSH_DISTRIBUTOR = "usePreviousUnifiedPushDistributor"
 
     const val DOWNLOAD_LOCATION = "downloadLocation"
+    const val TAB_TAP_BEHAVIOUR = "tabTapBehaviour"
 
     /** Keys that are no longer used (e.g., the preference has been removed */
     object Deprecated {

core/preferences/src/main/kotlin/app/pachli/core/preferences/SharedPreferencesRepository.kt

@@ -53,6 +53,9 @@ class SharedPreferencesRepository @Inject constructor(
     val downloadLocation: DownloadLocation
         get() = getEnum(PrefKeys.DOWNLOAD_LOCATION, DownloadLocation.DOWNLOADS)
 
+    val tabTapBehaviour: TabTapBehaviour
+        get() = getEnum(PrefKeys.TAB_TAP_BEHAVIOUR, TabTapBehaviour.JUMP_TO_NEXT_PAGE)
+
     // Ensure the listener is retained during minification. If you do not do this the
     // field is removed and eventually garbage collected (because registering it as a
     // change listener does not create a strong reference to it) and then no more

core/preferences/src/main/kotlin/app/pachli/core/preferences/TabTapBehaviour.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2024 Pachli Association
+ *
+ * This file is a part of Pachli.
+ *
+ * This program 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.
+ *
+ * Pachli 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 Pachli; if not,
+ * see <http://www.gnu.org/licenses>.
+ */
+
+package app.pachli.core.preferences
+
+/** Behaviour when the user taps on a tab. */
+enum class TabTapBehaviour(override val displayResource: Int, override val value: String? = null) :
+    PreferenceEnum {
+    /** Jump the user's position to the top, fetching the next page of content. */
+    JUMP_TO_NEXT_PAGE(R.string.tab_tap_behaviour_jump_to_next_page),
+
+    /** Fetch the newest page of content and jump to that. */
+    JUMP_TO_NEWEST(R.string.tab_tap_behaviour_jump_to_newest),
+}

core/preferences/src/main/res/values/strings.xml

@@ -21,9 +21,15 @@
     <string name="download_location_downloads">Downloads folder</string>
     <string name="download_location_per_account">Per-account folders, in Downloads folder</string>
     <string name="download_location_per_sender">Per-sender folders, in Downloads folder</string>
+
     <string name="app_theme_light">Light</string>
     <string name="app_theme_black">Black</string>
     <string name="app_theme_auto">Automatic at sunset</string>
     <string name="app_theme_dark">Dark</string>
     <string name="app_theme_system">Use system design</string>
+
+    <string name="pref_category_tabs">Tabs</string>
+    <string name="pref_title_tab_tap">Action when tapping a tab</string>
+    <string name="tab_tap_behaviour_jump_to_next_page">Jump to next page</string>
+    <string name="tab_tap_behaviour_jump_to_newest">Jump to newest content</string>
 </resources>