Content scanner (Element Pro): scan timeline events for unsafe content (#7159)

* Simplify how event content with captions are displayed

The caption component will now be added in `TimelineItemEventContentView` instead of separately in each `TimelineItem__View` component

* Make sure `CoilMediaFetcher` methods to fetch media throw errors

We need to catch them later to check if the content scanner marked some thumbnails or medias as invalid/unsafe in `AsyncImage` instances

* Add a `ContentScannerService` that allows us to manually scan a list of medias in an event and then update and store the results

The results take the form of `ContentValidationValue`, stored in a `ContentValidationState` instance tied to the event

* Create `EventContentValidationCache` to keep the `ContentValidationStates` for events in a room

* Expose `EventContentValidationCache` to Compose using `LocalEventContentValidationState`

Also add a couple of helper functions to avoid having to manually remember the states

* Use the new components to display invalid content in the timeline items

* Add `blurhash` to most media items so we can use it while validating the thumbnails/medias

* Fix custom layout issues with screenshot and UI tests

* Also check the validation state for replied-to events in the composer

* Fix and add tests

* Handle unrecoverable content validation errors too: display a 'not found' UI

* Improve the performance of `EqualWidthColumn` for the single item case

* Update screenshots

---------

Co-authored-by: ElementBot <android@element.io>

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/DefaultMediaViewerEntryPoint.kt

@@ -27,6 +27,8 @@ class DefaultMediaViewerEntryPoint : MediaViewerEntryPoint {
             ),
             mediaSource = MediaSource(url = avatarUrl),
             thumbnailSource = null,
+            // Maybe add avatar blurhash if available?
+            blurHash = null,
         )
     }
 

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/datasource/EventItemFactory.kt

@@ -116,6 +116,7 @@ class EventItemFactory(
                                         ),
                                         mediaSource = c.source,
                                         thumbnailSource = c.info?.thumbnailSource,
+                                        blurHash = c.info?.blurhash,
                                     )
                                 }
                                 is GalleryItemType.Video -> {
@@ -136,6 +137,7 @@ class EventItemFactory(
                                         ),
                                         mediaSource = c.source,
                                         thumbnailSource = c.info?.thumbnailSource,
+                                        blurHash = c.info?.blurhash,
                                     )
                                 }
                                 is GalleryItemType.Audio -> {
@@ -242,6 +244,7 @@ class EventItemFactory(
                         ),
                         mediaSource = type.source,
                         thumbnailSource = type.info?.thumbnailSource,
+                        blurHash = type.info?.blurhash,
                     ))
                     is StickerMessageType -> listOf(MediaItem.Image(
                         id = currentTimelineItem.uniqueId,
@@ -264,6 +267,7 @@ class EventItemFactory(
                         ),
                         mediaSource = type.source,
                         thumbnailSource = type.info?.thumbnailSource,
+                        blurHash = type.info?.blurhash,
                     ))
                     is VideoMessageType -> listOf(MediaItem.Video(
                         id = currentTimelineItem.uniqueId,
@@ -286,6 +290,7 @@ class EventItemFactory(
                         ),
                         mediaSource = type.source,
                         thumbnailSource = type.info?.thumbnailSource,
+                        blurHash = type.info?.blurhash,
                     ))
                     is VoiceMessageType -> listOf(MediaItem.Voice(
                         id = currentTimelineItem.uniqueId,

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/gallery/root/MediaGalleryFlowNode.kt

@@ -34,6 +34,7 @@ import io.element.android.libraries.mediaviewer.api.MediaInfo
 import io.element.android.libraries.mediaviewer.api.MediaViewerEntryPoint
 import io.element.android.libraries.mediaviewer.impl.gallery.MediaGalleryNode
 import io.element.android.libraries.mediaviewer.impl.model.MediaItem
+import io.element.android.libraries.mediaviewer.impl.model.blurHash
 import io.element.android.libraries.mediaviewer.impl.model.eventId
 import io.element.android.libraries.mediaviewer.impl.model.mediaInfo
 import io.element.android.libraries.mediaviewer.impl.model.mediaSource
@@ -68,6 +69,7 @@ class MediaGalleryFlowNode(
             val mediaInfo: MediaInfo,
             val mediaSource: MediaSource,
             val thumbnailSource: MediaSource?,
+            val blurHash: String?,
         ) : NavTarget
     }
 
@@ -104,6 +106,7 @@ class MediaGalleryFlowNode(
                                 mediaInfo = item.mediaInfo(),
                                 mediaSource = item.mediaSource(),
                                 thumbnailSource = item.thumbnailSource(),
+                                blurHash = item.blurHash(),
                             )
                         )
                     }
@@ -134,6 +137,7 @@ class MediaGalleryFlowNode(
                         mediaInfo = navTarget.mediaInfo,
                         mediaSource = navTarget.mediaSource,
                         thumbnailSource = navTarget.thumbnailSource,
+                        blurHash = navTarget.blurHash,
                     ),
                     callback = callback,
                 )

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/gallery/ui/VideoItemView.kt

@@ -34,6 +34,7 @@ import coil3.compose.AsyncImage
 import coil3.compose.AsyncImagePainter
 import io.element.android.compound.theme.ElementTheme
 import io.element.android.compound.tokens.generated.CompoundIcons
+import io.element.android.libraries.designsystem.components.blurhash.blurHashBackground
 import io.element.android.libraries.designsystem.modifiers.onKeyboardContextMenuAction
 import io.element.android.libraries.designsystem.preview.ElementPreview
 import io.element.android.libraries.designsystem.preview.PreviewsDayNight
@@ -51,6 +52,7 @@ fun VideoItemView(
 ) {
     Box(
         modifier = modifier
+            .blurHashBackground(blurHash = video.blurHash)
             .aspectRatio(1f)
             .combinedClickable(
                 onClick = onClick,

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/model/MediaItem.kt

@@ -35,6 +35,7 @@ sealed interface MediaItem {
         val mediaInfo: MediaInfo,
         val mediaSource: MediaSource,
         val thumbnailSource: MediaSource?,
+        val blurHash: String?,
     ) : Event {
         val thumbnailMediaRequestData: MediaRequestData
             get() = MediaRequestData(thumbnailSource ?: mediaSource, MediaRequestData.Kind.Thumbnail(100))
@@ -46,6 +47,7 @@ sealed interface MediaItem {
         val mediaInfo: MediaInfo,
         val mediaSource: MediaSource,
         val thumbnailSource: MediaSource?,
+        val blurHash: String?,
     ) : Event {
         val thumbnailMediaRequestData: MediaRequestData
             get() = MediaRequestData(thumbnailSource ?: mediaSource, MediaRequestData.Kind.Thumbnail(100))
@@ -124,3 +126,11 @@ fun MediaItem.Event.thumbnailSource(): MediaSource? {
         is MediaItem.Voice -> null
     }
 }
+
+fun MediaItem.Event.blurHash(): String? {
+    return when (this) {
+        is MediaItem.Image -> blurHash
+        is MediaItem.Video -> blurHash
+        else -> null
+    }
+}

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/model/MediaItemFactories.kt

@@ -34,6 +34,7 @@ fun aMediaItemImage(
         ),
         mediaSource = MediaSource(mediaSourceUrl),
         thumbnailSource = null,
+        blurHash = null,
     )
 }
 
@@ -50,6 +51,7 @@ fun aMediaItemVideo(
         ),
         mediaSource = mediaSource,
         thumbnailSource = null,
+        blurHash = null,
     )
 }
 

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/viewer/GalleryMediaGalleryDataSource.kt

@@ -63,6 +63,7 @@ class GalleryMediaGalleryDataSource(
                         mediaInfo = itemMediaInfo,
                         mediaSource = galleryItem.mediaSource,
                         thumbnailSource = galleryItem.thumbnailSource,
+                        blurHash = galleryItem.blurHash,
                     )
                     GalleryItemData.Type.Audio -> MediaItem.Audio(
                         id = id,
@@ -82,6 +83,7 @@ class GalleryMediaGalleryDataSource(
                         mediaInfo = itemMediaInfo,
                         mediaSource = galleryItem.mediaSource,
                         thumbnailSource = galleryItem.thumbnailSource,
+                        blurHash = galleryItem.blurHash,
                     )
                 }
                 mixedItems.add(mediaItem)

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/viewer/SingleMediaGalleryDataSource.kt

@@ -63,6 +63,7 @@ class SingleMediaGalleryDataSource(
                         ),
                         mediaSource = params.mediaSource,
                         thumbnailSource = params.thumbnailSource,
+                        blurHash = params.blurHash,
                     )
                 ),
                 fileItems = persistentListOf(),
@@ -79,6 +80,7 @@ fun MediaViewerEntryPoint.Params.RoomMedia.toMediaItem() = when {
             mediaInfo = mediaInfo,
             mediaSource = mediaSource,
             thumbnailSource = thumbnailSource,
+            blurHash = blurHash,
         )
     }
     mediaInfo.mimeType.isMimeTypeVideo() -> {
@@ -88,6 +90,7 @@ fun MediaViewerEntryPoint.Params.RoomMedia.toMediaItem() = when {
             mediaInfo = mediaInfo,
             mediaSource = mediaSource,
             thumbnailSource = thumbnailSource,
+            blurHash = blurHash,
         )
     }
     mediaInfo.mimeType.isMimeTypeAudio() -> {

libraries/mediaviewer/impl/src/test/kotlin/io/element/android/libraries/mediaviewer/impl/DefaultMediaViewerEntryPointTest.kt

@@ -141,6 +141,7 @@ class DefaultMediaViewerEntryPointTest {
                 avatarInfo = AvatarInfo(filename = "avatar.png"),
                 mediaSource = MediaSource(url = "avatarUrl"),
                 thumbnailSource = null,
+                blurHash = null,
             )
         )
         assertThat(result.plugins).contains(callback)

libraries/mediaviewer/impl/src/test/kotlin/io/element/android/libraries/mediaviewer/impl/datasource/EventItemFactoryTest.kt

@@ -226,6 +226,7 @@ class EventItemFactoryTest {
                 ),
                 mediaSource = MediaSource(""),
                 thumbnailSource = null,
+                blurHash = null,
             )
         )
     }
@@ -326,6 +327,7 @@ class EventItemFactoryTest {
                 ),
                 mediaSource = MediaSource(""),
                 thumbnailSource = null,
+                blurHash = null,
             )
         )
     }
@@ -437,6 +439,7 @@ class EventItemFactoryTest {
                 ),
                 mediaSource = MediaSource("image_url"),
                 thumbnailSource = MediaSource("thumbnail_url"),
+                blurHash = null,
             )
         )
     }
@@ -498,6 +501,7 @@ class EventItemFactoryTest {
                 ),
                 mediaSource = MediaSource("video_url"),
                 thumbnailSource = MediaSource("thumbnail_url"),
+                blurHash = null,
             )
         )
     }
@@ -744,6 +748,7 @@ class EventItemFactoryTest {
                 ),
                 mediaSource = MediaSource(""),
                 thumbnailSource = null,
+                blurHash = null,
             )
         )
     }

libraries/mediaviewer/impl/src/test/kotlin/io/element/android/libraries/mediaviewer/impl/datasource/TimelineMediaGalleryDataSourceTest.kt

@@ -249,6 +249,7 @@ class TimelineMediaGalleryDataSourceTest {
                                 ),
                                 mediaSource = MediaSource("url"),
                                 thumbnailSource = MediaSource("url_thumbnail"),
+                                blurHash = A_BLUR_HASH,
                             )
                         ),
                         fileItems = persistentListOf()

libraries/mediaviewer/impl/src/test/kotlin/io/element/android/libraries/mediaviewer/impl/viewer/GalleryMediaGalleryDataSourceTest.kt

@@ -91,6 +91,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("image_url"),
                     thumbnailSource = MediaSource("thumbnail_url"),
                     type = GalleryItemData.Type.Image,
+                    blurHash = null,
                 )
             ),
             galleryInfo = aGalleryInfo(),
@@ -104,6 +105,7 @@ class GalleryMediaGalleryDataSourceTest {
                 mediaInfo = expectedMediaInfo("image.jpg", MimeTypes.Jpeg),
                 mediaSource = MediaSource("image_url"),
                 thumbnailSource = MediaSource("thumbnail_url"),
+                blurHash = null,
             )
         )
     }
@@ -119,6 +121,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("video_url"),
                     thumbnailSource = MediaSource("thumbnail_url"),
                     type = GalleryItemData.Type.Video,
+                    blurHash = null,
                 )
             ),
             galleryInfo = aGalleryInfo(),
@@ -132,6 +135,7 @@ class GalleryMediaGalleryDataSourceTest {
                 mediaInfo = expectedMediaInfo("video.mp4", MimeTypes.Mp4),
                 mediaSource = MediaSource("video_url"),
                 thumbnailSource = MediaSource("thumbnail_url"),
+                blurHash = null,
             )
         )
     }
@@ -147,6 +151,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("audio_url"),
                     thumbnailSource = null,
                     type = GalleryItemData.Type.Audio,
+                    blurHash = null,
                 )
             ),
             galleryInfo = aGalleryInfo(),
@@ -174,6 +179,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("file_url"),
                     thumbnailSource = null,
                     type = GalleryItemData.Type.File,
+                    blurHash = null,
                 )
             ),
             galleryInfo = aGalleryInfo(),
@@ -201,6 +207,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("image_url"),
                     thumbnailSource = null,
                     type = GalleryItemData.Type.Image,
+                    blurHash = null,
                 )
             ),
             galleryInfo = aGalleryInfo(),
@@ -222,6 +229,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("image_url"),
                     thumbnailSource = null,
                     type = GalleryItemData.Type.Image,
+                    blurHash = null,
                 ),
                 GalleryItemData(
                     filename = "document.pdf",
@@ -229,6 +237,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("file_url"),
                     thumbnailSource = null,
                     type = GalleryItemData.Type.File,
+                    blurHash = null,
                 ),
                 GalleryItemData(
                     filename = "video.mp4",
@@ -236,6 +245,7 @@ class GalleryMediaGalleryDataSourceTest {
                     mediaSource = MediaSource("video_url"),
                     thumbnailSource = null,
                     type = GalleryItemData.Type.Video,
+                    blurHash = null,
                 ),
             ),
             galleryInfo = aGalleryInfo(),

libraries/mediaviewer/impl/src/test/kotlin/io/element/android/libraries/mediaviewer/impl/viewer/MediaViewerPresenterTest.kt

@@ -114,6 +114,7 @@ class MediaViewerPresenterTest {
                 avatarInfo = AvatarInfo(filename = "avatar.png"),
                 mediaSource = aMediaSource(),
                 thumbnailSource = null,
+                blurHash = null,
             ),
             room = FakeJoinedRoom(
                 baseRoom = FakeBaseRoom(
@@ -983,4 +984,5 @@ internal fun createMediaViewerEntryPointParams(
     mediaInfo = TESTED_MEDIA_INFO,
     mediaSource = aMediaSource(),
     thumbnailSource = null,
+    blurHash = null,
 )

libraries/mediaviewer/impl/src/test/kotlin/io/element/android/libraries/mediaviewer/impl/viewer/SingleMediaGalleryDataSourceTest.kt

@@ -89,6 +89,7 @@ class SingleMediaGalleryDataSourceTest {
                     mediaInfo = params.mediaInfo,
                     mediaSource = params.mediaSource,
                     thumbnailSource = params.thumbnailSource,
+                    blurHash = null,
                 )
             }
         )
@@ -105,6 +106,7 @@ class SingleMediaGalleryDataSourceTest {
                     mediaInfo = params.mediaInfo,
                     mediaSource = params.mediaSource,
                     thumbnailSource = params.thumbnailSource,
+                    blurHash = null,
                 )
             }
         )
@@ -175,5 +177,6 @@ class SingleMediaGalleryDataSourceTest {
         mediaInfo = mediaInfo,
         mediaSource = aMediaSource(url = "aUrl"),
         thumbnailSource = aMediaSource(url = "aThumbnailUrl"),
+        blurHash = null,
     )
 }