Adds working back navigation

vector/src/main/java/im/vector/app/SpaceStateHandlerImpl.kt

@@ -85,8 +85,6 @@ class SpaceStateHandlerImpl @Inject constructor(
 
         if (isForwardNavigation) {
             addToBackstacks(spaceToLeave, spaceToSet)
-        } else {
-            popBackstackUntil(spaceToSet)
         }
 
         if (persistNow) {
@@ -121,19 +119,6 @@ class SpaceStateHandlerImpl @Inject constructor(
         }
     }
 
-    private fun popBackstackUntil(space: RoomSummary?) {
-        val spaceId = space?.roomId
-        while (spaceBackstack.last() != spaceId) {
-            spaceBackstack.removeLast()
-        }
-
-        val currentPersistedBackstack = vectorPreferences.getPersistedSpaceBackstack().toMutableList()
-        while (currentPersistedBackstack.last() != spaceId) {
-            currentPersistedBackstack.removeLast()
-        }
-        vectorPreferences.setPersistedSpaceBackstack(currentPersistedBackstack)
-    }
-
     private fun observeActiveSession() {
         sessionDataSource.stream()
                 .distinctUntilChanged()
@@ -160,7 +145,7 @@ class SpaceStateHandlerImpl @Inject constructor(
     override fun popSpaceBackstack(): String? {
         val poppedSpaceId = spaceBackstack.removeLast()
         vectorPreferences.getPersistedSpaceBackstack().toMutableList().apply {
-            removeLast()
+            removeLastOrNull()
             vectorPreferences.setPersistedSpaceBackstack(this)
         }
         return poppedSpaceId

vector/src/main/java/im/vector/app/features/home/NewHomeDetailFragment.kt

@@ -79,7 +79,6 @@ class NewHomeDetailFragment @Inject constructor(
 
     private val viewModel: HomeDetailViewModel by fragmentViewModel()
     private val unknownDeviceDetectorSharedViewModel: UnknownDeviceDetectorSharedViewModel by activityViewModel()
-    private val unreadMessagesSharedViewModel: UnreadMessagesSharedViewModel by activityViewModel()
     private val serverBackupStatusViewModel: ServerBackupStatusViewModel by activityViewModel()
 
     private lateinit var sharedActionViewModel: HomeSharedActionViewModel
@@ -177,19 +176,6 @@ class NewHomeDetailFragment @Inject constructor(
                 }
     }
 
-    private fun navigateBack() {
-        try {
-            val previousSpaceId = spaceStateHandler.popSpaceBackstack()
-            setCurrentSpace(previousSpaceId)
-        } catch (e: NoSuchElementException) {
-            requireActivity().finish()
-        }
-    }
-
-    private fun setCurrentSpace(spaceId: String?) {
-        spaceStateHandler.setCurrentSpace(spaceId, isForwardNavigation = false)
-    }
-
     private fun handleCallStarted() {
         dismissLoadingDialog()
         val fragmentTag = HomeTab.DialPad.toFragmentTag()
@@ -454,8 +440,11 @@ class NewHomeDetailFragment @Inject constructor(
         return this
     }
 
-    override fun onBackPressed(toolbarButton: Boolean): Boolean {
-        navigateBack()
-        return true
+    override fun onBackPressed(toolbarButton: Boolean) = try {
+        val lastSpace = spaceStateHandler.popSpaceBackstack()
+        spaceStateHandler.setCurrentSpace(lastSpace, isForwardNavigation = false)
+        true
+    } catch (e: NoSuchElementException) {
+        false
     }
 }