Move extension to a common file for code clarity.

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/factories/event/TimelineItemEventFactory.kt

@@ -16,25 +16,17 @@
 
 package io.element.android.features.messages.impl.timeline.factories.event
 
+import io.element.android.features.messages.impl.timeline.groups.canBeDisplayedInBubbleBlock
 import io.element.android.features.messages.impl.timeline.model.AggregatedReaction
 import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.features.messages.impl.timeline.model.TimelineItemGroupPosition
 import io.element.android.features.messages.impl.timeline.model.TimelineItemReactions
+import io.element.android.libraries.core.bool.orTrue
 import io.element.android.libraries.designsystem.components.avatar.AvatarData
 import io.element.android.libraries.designsystem.components.avatar.AvatarSize
 import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
 import io.element.android.libraries.matrix.api.timeline.item.event.EventSendState
-import io.element.android.libraries.matrix.api.timeline.item.event.FailedToParseMessageLikeContent
-import io.element.android.libraries.matrix.api.timeline.item.event.FailedToParseStateContent
-import io.element.android.libraries.matrix.api.timeline.item.event.MessageContent
-import io.element.android.libraries.matrix.api.timeline.item.event.ProfileChangeContent
 import io.element.android.libraries.matrix.api.timeline.item.event.ProfileTimelineDetails
-import io.element.android.libraries.matrix.api.timeline.item.event.RedactedContent
-import io.element.android.libraries.matrix.api.timeline.item.event.RoomMembershipContent
-import io.element.android.libraries.matrix.api.timeline.item.event.StateContent
-import io.element.android.libraries.matrix.api.timeline.item.event.StickerContent
-import io.element.android.libraries.matrix.api.timeline.item.event.UnableToDecryptContent
-import io.element.android.libraries.matrix.api.timeline.item.event.UnknownContent
 import kotlinx.collections.immutable.toImmutableList
 import java.text.DateFormat
 import java.util.Date
@@ -112,8 +104,8 @@ class TimelineItemEventFactory @Inject constructor(
         val previousSender = prevTimelineItem?.event?.sender
         val nextSender = nextTimelineItem?.event?.sender
 
-        val previousIsGroupable = prevTimelineItem.isGroupable()
+        val previousIsGroupable = prevTimelineItem?.canBeDisplayedInBubbleBlock().orTrue()
-        val nextIsGroupable = nextTimelineItem.isGroupable()
+        val nextIsGroupable = nextTimelineItem?.canBeDisplayedInBubbleBlock().orTrue()
 
         return when {
             previousSender != currentSender && nextSender == currentSender -> {
@@ -149,19 +141,3 @@ class TimelineItemEventFactory @Inject constructor(
         }
     }
 }
-
-private fun MatrixTimelineItem.Event?.isGroupable(): Boolean {
-    if (this == null) return true
-    return when (event.content) {
-        is FailedToParseStateContent,
-        is ProfileChangeContent,
-        is RoomMembershipContent,
-        UnknownContent,
-        is StateContent -> false
-        is FailedToParseMessageLikeContent,
-        is MessageContent,
-        RedactedContent,
-        is StickerContent,
-        is UnableToDecryptContent -> true
-    }
-}

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/groups/Groupability.kt

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.groups
+
+import io.element.android.features.messages.impl.timeline.model.TimelineItem
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemEncryptedContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemImageContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemProfileChangeContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemRedactedContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemRoomMembershipContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemStateEventContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemTextBasedContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemUnknownContent
+import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
+import io.element.android.libraries.matrix.api.timeline.item.event.FailedToParseMessageLikeContent
+import io.element.android.libraries.matrix.api.timeline.item.event.FailedToParseStateContent
+import io.element.android.libraries.matrix.api.timeline.item.event.MessageContent
+import io.element.android.libraries.matrix.api.timeline.item.event.ProfileChangeContent
+import io.element.android.libraries.matrix.api.timeline.item.event.RedactedContent
+import io.element.android.libraries.matrix.api.timeline.item.event.RoomMembershipContent
+import io.element.android.libraries.matrix.api.timeline.item.event.StateContent
+import io.element.android.libraries.matrix.api.timeline.item.event.StickerContent
+import io.element.android.libraries.matrix.api.timeline.item.event.UnableToDecryptContent
+import io.element.android.libraries.matrix.api.timeline.item.event.UnknownContent
+
+/**
+ * Return true if the Event can be grouped in a collapse/expand block
+ * When [canBeGrouped] returns a value, [canBeDisplayedInBubbleBlock] MUST return the opposite value.
+ * Since the receiving type are not the same, the two functions exist.
+ */
+internal fun TimelineItem.Event.canBeGrouped(): Boolean {
+    return when (content) {
+        is TimelineItemTextBasedContent,
+        is TimelineItemEncryptedContent,
+        is TimelineItemImageContent,
+        TimelineItemRedactedContent,
+        TimelineItemUnknownContent -> false
+        is TimelineItemProfileChangeContent,
+        is TimelineItemRoomMembershipContent,
+        is TimelineItemStateEventContent -> true
+    }
+}
+
+/**
+ * Return true if the Event can be grouped in a block of message bubbles.
+ * When [canBeDisplayedInBubbleBlock] returns a value, [canBeGrouped] MUST return the opposite value.
+ * Since the receiving type are not the same, the two functions exist.
+ */
+internal fun MatrixTimelineItem.Event.canBeDisplayedInBubbleBlock(): Boolean {
+    return when (event.content) {
+        is FailedToParseMessageLikeContent,
+        is MessageContent,
+        RedactedContent,
+        is StickerContent,
+        is UnableToDecryptContent -> true
+        is FailedToParseStateContent,
+        is ProfileChangeContent,
+        is RoomMembershipContent,
+        UnknownContent,
+        is StateContent -> false
+    }
+}

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/groups/TimelineItemGrouper.kt

@@ -17,18 +17,6 @@
 package io.element.android.features.messages.impl.timeline.groups
 
 import io.element.android.features.messages.impl.timeline.model.TimelineItem
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemEmoteContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemEncryptedContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemFileContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemImageContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemNoticeContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemProfileChangeContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemRedactedContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemRoomMembershipContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemStateEventContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemTextContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemUnknownContent
-import io.element.android.features.messages.impl.timeline.model.event.TimelineItemVideoContent
 import kotlinx.collections.immutable.toImmutableList
 import javax.inject.Inject
 
@@ -57,23 +45,6 @@ class TimelineItemGrouper @Inject constructor() {
         }
         return result
     }
-
-    private fun TimelineItem.Event.canBeGrouped(): Boolean {
-        return when (content) {
-            is TimelineItemEncryptedContent,
-            is TimelineItemImageContent,
-            TimelineItemRedactedContent,
-            is TimelineItemEmoteContent,
-            is TimelineItemNoticeContent,
-            is TimelineItemTextContent,
-            is TimelineItemFileContent,
-            is TimelineItemVideoContent,
-            TimelineItemUnknownContent -> false
-            is TimelineItemProfileChangeContent,
-            is TimelineItemRoomMembershipContent,
-            is TimelineItemStateEventContent -> true
-        }
-    }
 }
 
 /**