Fix loading events when scrolling or opening a room for the first time

Fix #362


(cherry picked from commit bae7813f68)

imports/NeoChat/Page/RoomPage.qml

@@ -232,20 +232,17 @@ Kirigami.ScrollablePage {
 
         model: !isLoaded ? undefined : sortedMessageEventModel
 
-        onContentYChanged: fetchMoreContent()
-
-        function fetchMoreContent() {
-            if(!noNeedMoreContent && contentY - 5000 < originY) {
-                currentRoom.getPreviousContent(20);
-            }
-        }
-
         MessageEventModel {
             id: messageEventModel
 
             room: currentRoom
         }
 
+        // HACK: The view should do this automatically but doesn't.
+        onAtYBeginningChanged: if (atYBeginning && messageEventModel.canFetchMore(messageEventModel.index(0, 0))) {
+            messageEventModel.fetchMore(messageEventModel.index(0, 0));
+        }
+
         QQC2.Popup {
             anchors.centerIn: parent
 
@@ -596,7 +593,11 @@ Kirigami.ScrollablePage {
 
             DelegateChoice {
                 roleValue: "other"
-                delegate: Item {}
+                delegate: Rectangle {
+                    height: 10
+                    width: ListView.view.width
+                    color: "red"
+                }
             }
         }
 
@@ -646,10 +647,10 @@ Kirigami.ScrollablePage {
         }
 
         Component.onCompleted: {
-            updateReadMarker()
             if (currentRoom) {
-                if (currentRoom.timelineSize < 20)
+                if (currentRoom.timelineSize < 20) {
-                    currentRoom.getPreviousContent(50)
+                    currentRoom.getPreviousContent(50);
+                }
             }
 
             positionViewAtBeginning();

src/messageeventmodel.cpp

@@ -370,6 +370,20 @@ int MessageEventModel::rowCount(const QModelIndex &parent) const
 
 }
 
+bool MessageEventModel::canFetchMore(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent);
+
+    return m_currentRoom && !m_currentRoom->eventsHistoryJob() && !m_currentRoom->allHistoryLoaded();
+}
+
+void MessageEventModel::fetchMore(const QModelIndex &parent)
+{
+    Q_UNUSED(parent);
+    m_currentRoom->getPreviousContent(20);
+}
+
+
 inline QVariantMap userAtEvent(NeoChatUser *user, NeoChatRoom *room, const RoomEvent &evt)
 {
     Q_UNUSED(evt)

src/messageeventmodel.h

@@ -76,6 +76,9 @@ private:
     [[nodiscard]] QDateTime makeMessageTimestamp(const Quotient::Room::rev_iter_t &baseIt) const;
     [[nodiscard]] static QString renderDate(const QDateTime &timestamp);
 
+    bool canFetchMore(const QModelIndex &parent) const override;
+    void fetchMore(const QModelIndex &parent) override;
+
     void refreshLastUserEvents(int baseTimelineRow);
     void refreshEventRoles(int row, const QVector<int> &roles = {});
     int refreshEventRoles(const QString &eventId, const QVector<int> &roles = {});