feat(ffi): Create Room::new_latest_event + LatestEventValue.

This patch creates the `LatestEventValue` in `matrix_sdk_ffi` and
exposes it via `Room::new_latest_event`.

bindings/matrix-sdk-ffi/src/room/mod.rs

@@ -48,7 +48,7 @@ use crate::{
     runtime::get_runtime_handle,
     timeline::{
         configuration::{TimelineConfiguration, TimelineFilter},
-        EventTimelineItem, ReceiptType, SendHandle, Timeline,
+        EventTimelineItem, LatestEventValue, ReceiptType, SendHandle, Timeline,
     },
     utils::{u64_to_uint, AsyncRuntimeDropped},
     TaskHandle,
@@ -305,7 +305,7 @@ impl Room {
     }
 
     async fn new_latest_event(&self) -> LatestEventValue {
-        self.inner.new_latest_event().await.map(Into::into)
+        self.inner.new_latest_event().await.into()
     }
 
     pub async fn latest_encryption_state(&self) -> Result<EncryptionState, ClientError> {

bindings/matrix-sdk-ffi/src/timeline/mod.rs

@@ -31,8 +31,8 @@ use matrix_sdk_common::{
 };
 use matrix_sdk_ui::timeline::{
     self, AttachmentConfig, AttachmentSource, EventItemOrigin,
-    MediaUploadProgress as SdkMediaUploadProgress, Profile, TimelineDetails,
-    TimelineUniqueId as SdkTimelineUniqueId,
+    LatestEventValue as UiLatestEventValue, MediaUploadProgress as SdkMediaUploadProgress, Profile,
+    TimelineDetails, TimelineUniqueId as SdkTimelineUniqueId,
 };
 use mime::Mime;
 use reply::{EmbeddedEventDetails, InReplyToDetails};
@@ -1285,6 +1285,30 @@ impl LazyTimelineItemProvider {
     }
 }
 
+/// Mimic the [`UiLatestEventValue`] type.
+#[derive(Clone, uniffi::Enum)]
+pub enum LatestEventValue {
+    None,
+    Remote { timestamp: Timestamp, sender: String, content: TimelineItemContent },
+    Local { timestamp: Timestamp, content: TimelineItemContent, is_sending: bool },
+}
+
+impl From<UiLatestEventValue> for LatestEventValue {
+    fn from(value: UiLatestEventValue) -> Self {
+        match value {
+            UiLatestEventValue::None => Self::None,
+            UiLatestEventValue::Remote { timestamp, sender, content } => Self::Remote {
+                timestamp: timestamp.into(),
+                sender: sender.to_string(),
+                content: content.into(),
+            },
+            UiLatestEventValue::Local { timestamp, content, is_sending } => {
+                Self::Local { timestamp: timestamp.into(), content: content.into(), is_sending }
+            }
+        }
+    }
+}
+
 #[cfg(feature = "unstable-msc4274")]
 mod galleries {
     use std::{panic, sync::Arc};