feat(edit): Add edit revisions list

Signed-off-by: bxdxnn <267911624+bxdxnn@users.noreply.github.com>

Author: bxdxnn

bindings/matrix-sdk-ffi/changelog.d/6630.added.md

@@ -0,0 +1 @@
+Added a new `revisions` field for `EventTimelineItem` that stores the edit revisions of the item.

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

@@ -1022,6 +1022,7 @@ pub struct EventTimelineItem {
     read_receipts: HashMap<String, Receipt>,
     origin: Option<EventItemOrigin>,
     can_be_replied_to: bool,
+    revisions: Vec<EditRevisionRecord>,
     lazy_provider: Arc<LazyTimelineItemProvider>,
 }
 
@@ -1048,6 +1049,10 @@ impl From<matrix_sdk_ui::timeline::EventTimelineItem> for EventTimelineItem {
             read_receipts,
             origin: item.origin(),
             can_be_replied_to: item.can_be_replied_to(),
+            revisions: item.edit_revisions().iter().map(|r| EditRevisionRecord {
+                body: r.body.clone(),
+                timestamp: r.timestamp.0.into(),
+            }).collect(),
             lazy_provider,
         }
     }
@@ -1064,6 +1069,12 @@ impl From<ruma::events::receipt::Receipt> for Receipt {
     }
 }
 
+#[derive(Clone, uniffi::Record)]
+pub struct EditRevisionRecord {
+    body: String,
+    timestamp: u64,
+}
+
 #[derive(Clone, uniffi::Record)]
 pub struct EventTimelineItemDebugInfo {
     model: String,

crates/matrix-sdk-ui/changelog.d/6630.added.md

@@ -0,0 +1 @@
+Added a new `revisions` field for `EventTimelineItem` that stores the edit revisions of the item.

crates/matrix-sdk-ui/src/timeline/controller/aggregations.rs

@@ -54,8 +54,8 @@ use tracing::{error, info, trace, warn};
 
 use super::{ObservableItemsTransaction, rfind_event_by_item_id};
 use crate::timeline::{
-    BeaconInfo, EventTimelineItem, LiveLocationState, MsgLikeContent, MsgLikeKind, PollState,
-    ReactionInfo, ReactionStatus, TimelineEventItemId, TimelineItem, TimelineItemContent,
+    BeaconInfo, EditRevision, EventTimelineItem, LiveLocationState, MsgLikeContent, MsgLikeKind,
+    PollState, ReactionInfo, ReactionStatus, TimelineEventItemId, TimelineItem, TimelineItemContent,
     event_item::beacon_info_matches,
 };
 
@@ -943,9 +943,31 @@ fn edit_item(
             let mut new_msg = msg.clone();
             new_msg.apply_edit(replacement.new_content);
 
+            let edit_revision = if is_local_echo {
+                // For local echoes, we don't have the edit JSON yet,
+                // but record the edit to avoid capturing the already-edited
+                // content as the original when the server echo arrives.
+                Some(EditRevision {
+                    body: new_msg.body().to_owned(),
+                    timestamp: item.timestamp(),
+                    edit_json: None,
+                })
+            } else {
+                edit_json.as_ref().map(|json| {
+                    let ts: Option<MilliSecondsSinceUnixEpoch> =
+                        json.get_field("origin_server_ts").ok().flatten()
+                            .map(|v: ruma::UInt| MilliSecondsSinceUnixEpoch(v.into()));
+                    EditRevision {
+                        body: new_msg.body().to_owned(),
+                        timestamp: ts.unwrap_or(item.timestamp()),
+                        edit_json: edit_json.clone(),
+                    }
+                })
+            };
+
             let new_item = item.with_content_and_latest_edit(
                 TimelineItemContent::MsgLike(content.with_kind(MsgLikeKind::Message(new_msg))),
-                edit_json,
+                edit_revision,
             );
             *item = Cow::Owned(new_item);
         }
@@ -960,7 +982,7 @@ fn edit_item(
                     TimelineItemContent::MsgLike(
                         content.with_kind(MsgLikeKind::Poll(new_poll_state)),
                     ),
-                    edit_json,
+                    None,
                 );
                 *item = Cow::Owned(new_item);
             } else {

crates/matrix-sdk-ui/src/timeline/controller/decryption_retry_task.rs

@@ -255,7 +255,7 @@ mod tests {
             is_highlighted: false,
             encryption_info: None,
             original_json: None,
-            latest_edit_json: None,
+            edit_revisions: vec![],
             origin: RemoteEventOrigin::Sync,
         });
 
@@ -308,7 +308,7 @@ mod tests {
                 verification_state: VerificationState::Verified,
             })),
             original_json: None,
-            latest_edit_json: None,
+            edit_revisions: vec![],
             origin: RemoteEventOrigin::Sync,
         });
 

crates/matrix-sdk-ui/src/timeline/controller/observable_items.rs

@@ -756,7 +756,7 @@ mod observable_items_tests {
                     is_highlighted: false,
                     encryption_info: None,
                     original_json: None,
-                    latest_edit_json: None,
+                    edit_revisions: vec![],
                     origin: RemoteEventOrigin::Sync,
                 }),
                 false,

crates/matrix-sdk-ui/src/timeline/date_dividers.rs

@@ -677,7 +677,7 @@ mod tests {
             is_highlighted: false,
             encryption_info: None,
             original_json: None,
-            latest_edit_json: None,
+            edit_revisions: vec![],
             origin: crate::timeline::event_item::RemoteEventOrigin::Sync,
         });
         EventTimelineItem::new(

crates/matrix-sdk-ui/src/timeline/event_handler.rs

@@ -994,7 +994,7 @@ impl<'a, 'o> TimelineEventHandler<'a, 'o> {
                     is_highlighted: self.ctx.is_highlighted,
                     encryption_info: encryption_info.clone(),
                     original_json: Some(raw_event.clone()),
-                    latest_edit_json: None,
+                    edit_revisions: vec![],
                     origin,
                 }
                 .into()

crates/matrix-sdk-ui/src/timeline/event_item/mod.rs

@@ -124,6 +124,23 @@ pub(crate) enum TimelineItemHandle<'a> {
     Local(&'a SendHandle),
 }
 
+/// A single revision in the edit history of a message.
+#[derive(Clone, Debug)]
+pub struct EditRevision {
+    /// The body text of the message after this revision.
+    pub body: String,
+    /// The timestamp of the event that created this revision.
+    pub timestamp: MilliSecondsSinceUnixEpoch,
+    /// The raw JSON of the edit event, if available.
+    /// This is `None` for the original revision and for local echoes
+    /// that haven't been echoed by the server yet.
+    ///
+    /// Only the latest revision retains its `edit_json`; all earlier
+    /// revisions have this field cleared to `None` to avoid storing
+    /// copies of raw event JSON for every edit.
+    pub edit_json: Option<Raw<AnySyncTimelineEvent>>,
+}
+
 /// A container for temporarily holding onto data that is going to be erased by
 /// a redaction once the server plays it back.
 #[derive(Clone, Debug)]
@@ -134,8 +151,8 @@ pub(super) struct UnredactedEventTimelineItem {
     /// JSON of the original event.
     pub(crate) original_json: Option<Raw<AnySyncTimelineEvent>>,
 
-    /// JSON of the latest edit to this item.
-    pub(crate) latest_edit_json: Option<Raw<AnySyncTimelineEvent>>,
+    /// All edits to this item, in chronological order.
+    pub(crate) edit_revisions: Vec<EditRevision>,
 }
 
 impl EventTimelineItem {
@@ -453,10 +470,20 @@ impl EventTimelineItem {
     }
 
     /// Get the raw JSON representation of the latest edit, if any.
+    /// Returns the raw JSON of the most recent edit revision, if available.
+    /// Use `edit_revisions()` for structured access to the full edit history.
     pub fn latest_edit_json(&self) -> Option<&Raw<AnySyncTimelineEvent>> {
+        self.edit_revisions().last()?.edit_json.as_ref()
+    }
+
+    /// Get all revisions of this item, in chronological order.
+    ///
+    /// The first entry is the original revision, followed by each edit
+    /// in the order they were applied.
+    pub fn edit_revisions(&self) -> &[EditRevision] {
         match &self.kind {
-            EventTimelineItemKind::Local(_) => None,
-            EventTimelineItemKind::Remote(remote_event) => remote_event.latest_edit_json.as_ref(),
+            EventTimelineItemKind::Local(_) => &[],
+            EventTimelineItemKind::Remote(remote_event) => &remote_event.edit_revisions,
         }
     }
 
@@ -497,20 +524,42 @@ impl EventTimelineItem {
         new
     }
 
-    /// Clone the current event item, and update its content.
+    /// Clone the current event item, and update its content with an edit.
     ///
-    /// Optionally update `latest_edit_json` if the update is an edit received
-    /// from the server.
+    /// If this is the first edit, the original revision is captured
+    /// automatically from the item's current state. The `edit_revision`
+    /// contains the edit's data (timestamp and the new body).
+    /// If `edit_revision` is `None`, no edit revision is recorded
+    /// (e.g. for non-message edits like polls).
     pub(super) fn with_content_and_latest_edit(
         &self,
         new_content: TimelineItemContent,
-        edit_json: Option<Raw<AnySyncTimelineEvent>>,
+        edit_revision: Option<EditRevision>,
     ) -> Self {
         let mut new = self.clone();
-        new.content = new_content;
         if let EventTimelineItemKind::Remote(r) = &mut new.kind {
-            r.latest_edit_json = edit_json;
+            // If this is the first edit, capture the original as revision 0
+            if edit_revision.is_some() && r.edit_revisions.is_empty() {
+                if let Some(body) = extract_body_from_content(&new.content) {
+                    r.edit_revisions.push(EditRevision {
+                        body,
+                        timestamp: new.timestamp,
+                        edit_json: None,
+                    });
+                }
+            }
+            if let Some(revision) = edit_revision {
+                r.edit_revisions.push(revision);
+                // Keep `edit_json` only on the latest revision to avoid
+                // storing copies of raw edit event JSON for every revision.
+                if r.edit_revisions.len() > 1 {
+                    for rev in r.edit_revisions.iter_mut().rev().skip(1) {
+                        rev.edit_json = None;
+                    }
+                }
+            }
         }
+        new.content = new_content;
         new
     }
 
@@ -534,10 +583,16 @@ impl EventTimelineItem {
 
     /// Create a clone of the current item, with content that's been redacted.
     pub(super) fn redact(&self, rules: &RedactionRules, is_local: bool) -> Self {
-        let unredacted_item = is_local.then(|| UnredactedEventTimelineItem {
-            content: self.content.clone(),
-            original_json: self.original_json().cloned(),
-            latest_edit_json: self.latest_edit_json().cloned(),
+        let unredacted_item = is_local.then(|| {
+            let edit_revisions = match &self.kind {
+                EventTimelineItemKind::Remote(r) => r.edit_revisions.clone(),
+                EventTimelineItemKind::Local(_) => vec![],
+            };
+            UnredactedEventTimelineItem {
+                content: self.content.clone(),
+                original_json: self.original_json().cloned(),
+                edit_revisions,
+            }
         });
         let content = self.content.redact(rules);
         let kind = match &self.kind {
@@ -567,7 +622,7 @@ impl EventTimelineItem {
             EventTimelineItemKind::Remote(r) => {
                 EventTimelineItemKind::Remote(RemoteEventTimelineItem {
                     original_json: unredacted_item.original_json.clone(),
-                    latest_edit_json: unredacted_item.latest_edit_json.clone(),
+                    edit_revisions: unredacted_item.edit_revisions.clone(),
                     ..r.clone()
                 })
             }
@@ -914,6 +969,17 @@ impl From<ShieldStateCode> for TimelineEventShieldStateCode {
     }
 }
 
+/// Extract the body text from a `TimelineItemContent`, if it's a message.
+pub(crate) fn extract_body_from_content(content: &TimelineItemContent) -> Option<String> {
+    match content {
+        TimelineItemContent::MsgLike(msglike) => match &msglike.kind {
+            MsgLikeKind::Message(message) => Some(message.body().to_owned()),
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::time::Duration;
@@ -985,7 +1051,7 @@ mod tests {
                 is_highlighted: false,
                 encryption_info: None,
                 original_json,
-                latest_edit_json: None,
+                edit_revisions: vec![],
                 origin: RemoteEventOrigin::Sync,
             }),
             false,

crates/matrix-sdk-ui/src/timeline/event_item/remote.rs

@@ -50,7 +50,7 @@ pub(in crate::timeline) struct RemoteEventTimelineItem {
 
     /// JSON of the original event.
     ///
-    /// If the event is edited, this *won't* change, instead `latest_edit_json`
+    /// If the event is edited, this *won't* change, instead `edit_revisions`
     /// will be updated.
     ///
     /// This field always starts out as `Some(_)`, but is set to `None` when the
@@ -60,8 +60,8 @@ pub(in crate::timeline) struct RemoteEventTimelineItem {
     /// a clear need for that.
     pub original_json: Option<Raw<AnySyncTimelineEvent>>,
 
-    /// JSON of the latest edit to this item.
-    pub latest_edit_json: Option<Raw<AnySyncTimelineEvent>>,
+    /// All edits to this item, in chronological order.
+    pub edit_revisions: Vec<super::EditRevision>,
 
     /// Where we got this event from: A sync response or pagination.
     pub origin: RemoteEventOrigin,
@@ -70,7 +70,7 @@ pub(in crate::timeline) struct RemoteEventTimelineItem {
 impl RemoteEventTimelineItem {
     /// Clone the current event item, and redacts its fields.
     pub fn redact(&self) -> Self {
-        Self { original_json: None, latest_edit_json: None, ..self.clone() }
+        Self { original_json: None, edit_revisions: vec![], ..self.clone() }
     }
 }
 
@@ -98,7 +98,7 @@ impl fmt::Debug for RemoteEventTimelineItem {
             is_own,
             encryption_info,
             original_json: _,
-            latest_edit_json: _,
+            edit_revisions: _,
             is_highlighted,
             origin,
         } = self;