Invalidate the timeline when the DM state changes for a room

We need to redraw messages when this changes, since we use different
layouts for DMs and non-direct chats.

Change-Id: Icf2df3a14655f7c9b6e5f7cdb29b590f393de4fd

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/timeline/Timeline.kt

@@ -95,6 +95,11 @@ interface Timeline {
      */
     fun getTimelineEventWithId(eventId: String?): TimelineEvent?
 
+    /**
+     * Called when the DM flag of the room is changed
+     */
+    fun onDmStateChanged()
+
     interface Listener {
         /**
          * Call when the timeline has been updated through pagination or sync.
@@ -112,6 +117,11 @@ interface Timeline {
          * Called when new events come through the sync
          */
         fun onNewTimelineEvents(eventIds: List<String>)
+
+        /**
+         * Called when the DM flag of the room is changed
+         */
+        fun onDmStateChanged()
     }
 
     /**

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/DefaultTimeline.kt

@@ -285,6 +285,12 @@ internal class DefaultTimeline(
         }
     }
 
+    override fun onDmStateChanged() {
+        listeners.forEach {
+            it.onDmStateChanged()
+        }
+    }
+
     override fun rebuildEvent(eventId: String, builder: (TimelineEvent) -> TimelineEvent?): Boolean {
         return tryOrNull {
             builtEventsIdMap[eventId]?.let { builtIndex ->

vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewModel.kt

@@ -1498,6 +1498,7 @@ class RoomDetailViewModel @AssistedInject constructor(
 
     private fun observeSummaryState() {
         asyncSubscribe(RoomDetailViewState::asyncRoomSummary) { summary ->
+            val previousSummary = roomSummariesHolder.get(summary.roomId)
             roomSummariesHolder.set(summary)
             setState {
                 val typingMessage = typingHelper.getTypingMessage(summary.typingUsers)
@@ -1516,6 +1517,9 @@ class RoomDetailViewModel @AssistedInject constructor(
             room.getStateEvent(EventType.STATE_ROOM_TOMBSTONE)?.also {
                 setState { copy(tombstoneEvent = it) }
             }
+            if (previousSummary == null || previousSummary.isDirect != summary.isDirect) {
+                timeline.onDmStateChanged()
+            }
         }
     }
 
@@ -1567,4 +1571,8 @@ class RoomDetailViewModel @AssistedInject constructor(
         callManager.removePstnSupportListener(this)
         super.onCleared()
     }
+
+    override fun onDmStateChanged() {
+        // No-op
+    }
 }

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/TimelineEventController.kt

@@ -46,6 +46,7 @@ import im.vector.app.features.home.room.detail.timeline.helper.TimelineEventDiff
 import im.vector.app.features.home.room.detail.timeline.helper.TimelineEventVisibilityHelper
 import im.vector.app.features.home.room.detail.timeline.helper.TimelineEventVisibilityStateChangedListener
 import im.vector.app.features.home.room.detail.timeline.factory.TimelineItemFactoryParams
+import im.vector.app.features.home.room.detail.timeline.helper.InvalidateTimelineEventDiffUtilCallback
 import im.vector.app.features.home.room.detail.timeline.helper.TimelineMediaSizeProvider
 import im.vector.app.features.home.room.detail.timeline.item.AbsMessageItem
 import im.vector.app.features.home.room.detail.timeline.item.BasedMergedItem
@@ -292,6 +293,18 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
         // no-op, already handled
     }
 
+    override fun onDmStateChanged() {
+        backgroundHandler.post {
+            inSubmitList = true
+            // Invalidate all timeline events to rebuild the whole Room/DM layout
+            val diffCallback = InvalidateTimelineEventDiffUtilCallback(currentSnapshot)
+            val diffResult = DiffUtil.calculateDiff(diffCallback)
+            diffResult.dispatchUpdatesTo(listUpdateCallback)
+            requestModelBuild()
+            inSubmitList = false
+        }
+    }
+
     private fun submitSnapshot(newSnapshot: List<TimelineEvent>) {
         backgroundHandler.post {
             inSubmitList = true

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/helper/InvalidateTimelineEventDiffUtilCallback.kt

@@ -0,0 +1,25 @@
+package im.vector.app.features.home.room.detail.timeline.helper
+
+import androidx.recyclerview.widget.DiffUtil
+import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
+
+class InvalidateTimelineEventDiffUtilCallback(private val oldAndNewList: List<TimelineEvent>): DiffUtil.Callback() {
+
+    override fun getOldListSize(): Int {
+        return oldAndNewList.size
+    }
+
+    override fun getNewListSize(): Int {
+        return oldAndNewList.size
+    }
+
+    override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
+        // We want to 'fake' updated items with this class - updated means in this case, not completely invalidated.
+        return oldItemPosition == newItemPosition
+    }
+
+    override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
+        // We want to 'fake' updated items with this class.
+        return false
+    }
+}