From ca79bdb16b3e31a7067ca17ef97ab0ab988a3448 Mon Sep 17 00:00:00 2001
From: Alex Hart <alex@signal.org>
Date: Wed, 6 Apr 2022 10:34:06 -0300
Subject: [PATCH] Preserve tab state between configuration changes.

---
 .../tabs/ConversationListTabsFragment.kt      | 23 ++++++++++++++-----
 .../tabs/ConversationListTabsViewModel.kt     |  1 +
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsFragment.kt b/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsFragment.kt
index e08eaef165..0c4dbfb62b 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsFragment.kt
@@ -63,10 +63,12 @@ class ConversationListTabsFragment : Fragment(R.layout.conversation_list_tabs) {
       viewModel.onStoriesSelected()
     }
 
-    viewModel.state.observe(viewLifecycleOwner, this::update)
+    update(viewModel.stateSnapshot, true)
+
+    viewModel.state.observe(viewLifecycleOwner) { update(it, false) }
   }
 
-  private fun update(state: ConversationListTabsState) {
+  private fun update(state: ConversationListTabsState, immediate: Boolean) {
     val wasChatSelected = chatsIcon.isSelected
 
     chatsIcon.isSelected = state.tab == ConversationListTab.CHATS
@@ -75,9 +77,18 @@ class ConversationListTabsFragment : Fragment(R.layout.conversation_list_tabs) {
     chatsPill.isSelected = chatsIcon.isSelected
     storiesPill.isSelected = storiesIcon.isSelected
 
-    if (chatsIcon.isSelected xor wasChatSelected) {
+    val hasStateChange = chatsIcon.isSelected xor wasChatSelected
+    if (immediate) {
+      chatsIcon.pauseAnimation()
+      storiesIcon.pauseAnimation()
+
+      chatsIcon.progress = if (chatsIcon.isSelected) 1f else 0f
+      storiesIcon.progress = if (storiesIcon.isSelected) 1f else 0f
+
+      runPillAnimation(0, chatsPill, storiesPill)
+    } else if (hasStateChange) {
       runLottieAnimations(chatsIcon, storiesIcon)
-      runPillAnimation(chatsPill, storiesPill)
+      runPillAnimation(150, chatsPill, storiesPill)
     }
 
     chatsUnreadIndicator.visible = state.unreadChatsCount > 0
@@ -103,12 +114,12 @@ class ConversationListTabsFragment : Fragment(R.layout.conversation_list_tabs) {
     }
   }
 
-  private fun runPillAnimation(vararg toAnimate: ImageView) {
+  private fun runPillAnimation(duration: Long, vararg toAnimate: ImageView) {
     val (selected, unselected) = toAnimate.partition { it.isSelected }
 
     pillAnimator?.cancel()
     pillAnimator = AnimatorSet().apply {
-      duration = 150
+      this.duration = duration
       interpolator = PathInterpolatorCompat.create(0.17f, 0.17f, 0f, 1f)
       playTogether(
         selected.map { view ->
diff --git a/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsViewModel.kt b/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsViewModel.kt
index edb18d0ebc..2109ce4b74 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsViewModel.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/stories/tabs/ConversationListTabsViewModel.kt
@@ -10,6 +10,7 @@ import org.thoughtcrime.securesms.util.livedata.Store
 class ConversationListTabsViewModel(repository: ConversationListTabRepository) : ViewModel() {
   private val store = Store(ConversationListTabsState())
 
+  val stateSnapshot: ConversationListTabsState = store.state
   val state: LiveData<ConversationListTabsState> = store.stateLiveData
   val disposables = CompositeDisposable()