StateEventBase::replacedState()

Brings event id of the state event that was in effect before this one arrived. This key is not specced but it's used in the wild since forever.

2 files changed, 6 insertions, 0 deletions

diff --git a/lib/events/stateevent.cpp b/lib/events/stateevent.cpp
index 280c334c..fd8079be 100644
--- a/lib/events/stateevent.cpp
+++ b/lib/events/stateevent.cpp
@@ -29,6 +29,11 @@ bool StateEventBase::repeatsState() const
     return fullJson().value(ContentKeyL) == prevContentJson;
 }
 
+QString StateEventBase::replacedState() const
+{
+    return unsignedJson().value("replaces_state"_ls).toString();
+}
+
 void StateEventBase::dumpTo(QDebug dbg) const
 {
     if (!stateKey().isEmpty())
diff --git a/lib/events/stateevent.h b/lib/events/stateevent.h
index d50500f2..d4a7e8b3 100644
--- a/lib/events/stateevent.h
+++ b/lib/events/stateevent.h
@@ -30,6 +30,7 @@ namespace QMatrixClient {
             ~StateEventBase() override = default;
 
             bool isStateEvent() const override { return true; }
+            QString replacedState() const;
             void dumpTo(QDebug dbg) const override;
 
             virtual bool repeatsState() const;