Support gallery messages (#6519)

* Support gallery messages

* Address review

* Remove unused function

* Fix indent

* Add "Gallery" message prefix

* Support galleries for image editing

* Fix tapping on a tile opens the last item

* Fix overflow count

* Add caption editing to gallery messages

* Use the new gallery string for prefix

* Lock sending galleries behind a feature flag

* Fix detekts

* Fix

* Ensure image edition is saved when navigating

* Fix sending media broken on edited gallery.

* Fix tests

* Order imports

* Remove unused parameters.

* Fix copyright header of new files.

* Fix Konsist test

* Extract new previews to a dedicated file.

* Sync strings

* Remove unused import

* Update screenshots

* Trigger CI

* Remove parameters with default value.

* More cleanup

* Restore sendAsFile behavior.

* Improve Preview.

* Improve Preview.

* Improve Preview.

* Fix gallery sending cancel and retry issue

* Ensure any previous job is cancelled.

* Fix issue in summary message

* Gallery feature is disabled by default.

* Kotlin convention

* Remove useless parenthesis

* Update screenshots

* Fix test

* List -> ImmutableList

* Remove useless code.

* Render formatted caption for attachment list.

* Replace set of Booleans by an enum

* Remove unused model for individual caption in a gallery Event.

* Fix tests

* Fix tests

* Rework MediaViewer entry point.

And ensure that the clicked image from the gallery is displayed first.

* Ensure gallery item can be click in the pinned message list
Improve the gallery item click handling code.

* Improve code and fix separator color
Closes #7101

* React on attachment item click
Improve code

* Improve code and support 0 items in gallery.

* Fix click on attachment item not rendering anything.

---------

Co-authored-by: Benoit Marty <benoitm@element.io>
Co-authored-by: Benoit Marty <benoit@matrix.org>
Co-authored-by: ElementBot <android@element.io>

libraries/mediaupload/impl/src/main/kotlin/io/element/android/libraries/mediaupload/impl/DefaultMediaSender.kt

@@ -27,6 +27,7 @@ import io.element.android.libraries.mediaupload.api.MediaSender
 import io.element.android.libraries.mediaupload.api.MediaSenderFactory
 import io.element.android.libraries.mediaupload.api.MediaSenderRoomFactory
 import io.element.android.libraries.mediaupload.api.MediaUploadInfo
+import io.element.android.libraries.mediaupload.api.toGalleryItemInfo
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Job
 import timber.log.Timber
@@ -167,6 +168,29 @@ class DefaultMediaSender(
             .handleSendResult(mediaId(uri))
     }
 
+    override suspend fun sendGallery(
+        mediaUploadInfos: List<MediaUploadInfo>,
+        caption: String?,
+        formattedCaption: String?,
+        inReplyToEventId: EventId?,
+    ): Result<Unit> {
+        val galleryLogId = "gallery[${mediaUploadInfos.size} items]"
+        Timber.d("Sending $galleryLogId")
+        return getTimeline().flatMap { timeline ->
+            val galleryItems = mediaUploadInfos.map { it.toGalleryItemInfo() }
+            timeline.sendGallery(
+                items = galleryItems,
+                caption = caption,
+                formattedCaption = formattedCaption,
+                inReplyToEventId = inReplyToEventId,
+            )
+        }
+            .flatMapCatching { uploadHandler ->
+                uploadHandler.await()
+            }
+            .handleSendResult(galleryLogId)
+    }
+
     private fun Result<Unit>.handleSendResult(mediaId: String) = this
         .onFailure { error ->
             val job = ongoingUploadJobs.remove(Job)