Add a checkmark to messages that have been received by the server (#93)

include/timeline/TimelineItem.h

@@ -84,6 +84,7 @@ public:
         DescInfo descriptionMessage() const { return descriptionMsg_; }
         QString eventId() const { return event_id_; }
         void setEventId(const QString &event_id) { event_id_ = event_id; }
+        void markReceived();
 
         ~TimelineItem();
 

src/timeline/TimelineItem.cc

@@ -340,6 +340,16 @@ TimelineItem::TimelineItem(const mtx::events::RoomEvent<mtx::events::msg::Text>
         mainLayout_->addLayout(messageLayout_);
 }
 
+void
+TimelineItem::markReceived()
+{
+        auto checkmark = new QLabel("✓", this);
+        checkmark->setStyleSheet(QString("font-size: %1px;").arg(conf::timeline::fonts::timestamp));
+        checkmark->setAlignment(Qt::AlignTop);
+
+        messageLayout_->insertWidget(1, checkmark);
+}
+
 // Only the body is displayed.
 void
 TimelineItem::generateBody(const QString &body)

src/timeline/TimelineView.cc

@@ -461,8 +461,10 @@ TimelineView::updatePendingMessage(int txn_id, QString event_id)
                 auto msg     = pending_msgs_.dequeue();
                 msg.event_id = event_id;
 
-                if (msg.widget)
+                if (msg.widget) {
                         msg.widget->setEventId(event_id);
+                        msg.widget->markReceived();
+                }
 
                 pending_sent_msgs_.append(msg);
         }