Move message filtering to C++

The filter callback is called very often (O(messages)). The current
filter model shows some significant overhead in QML internals. Moving
that to C++ makes it quite a bit faster.

imports/NeoChat/Page/RoomPage.qml

@@ -211,25 +211,10 @@ Kirigami.ScrollablePage {
         }
 
 
-        KSortFilterProxyModel {
+        MessageFilterModel {
             id: sortedMessageEventModel
 
             sourceModel: messageEventModel
-
-            filterRowCallback: Config.showLeaveJoinEvent ? dontFilterLeaveJoin : filterLeaveJoin
-
-            function dontFilterLeaveJoin(row, parent) {
-                return messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.SpecialMarksRole) !== EventStatus.Hidden
-                    && messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.MessageRole) !== 0x10
-                    && messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.EventTypeRole) !== "other";
-            }
-
-            function filterLeaveJoin(row, parent) {
-                return messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.SpecialMarksRole) !== EventStatus.Hidden
-                    && messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.MessageRole) !== 0x10
-                    && messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.EventTypeRole) !== "other"
-                    && messageEventModel.data(messageEventModel.index(row, 0), MessageEventModel.EventTypeRole) !== "state";
-            }
         }
 
         //        populate: Transition {

src/CMakeLists.txt

@@ -6,6 +6,7 @@ add_executable(neochat
     clipboard.cpp
     matriximageprovider.cpp
     messageeventmodel.cpp
+    messagefiltermodel.cpp
     roomlistmodel.cpp
     neochatroom.cpp
     neochatuser.cpp

src/main.cpp

@@ -34,6 +34,7 @@
 #include "filetypesingleton.h"
 #include "matriximageprovider.h"
 #include "messageeventmodel.h"
+#include "messagefiltermodel.h"
 #include "neochatconfig.h"
 #include "neochatroom.h"
 #include "neochatuser.h"
@@ -107,6 +108,7 @@ int main(int argc, char *argv[])
     qmlRegisterType<RoomListModel>("org.kde.neochat", 1, 0, "RoomListModel");
     qmlRegisterType<UserListModel>("org.kde.neochat", 1, 0, "UserListModel");
     qmlRegisterType<MessageEventModel>("org.kde.neochat", 1, 0, "MessageEventModel");
+    qmlRegisterType<MessageFilterModel>("org.kde.neochat", 1, 0, "MessageFilterModel");
     qmlRegisterType<PublicRoomListModel>("org.kde.neochat", 1, 0, "PublicRoomListModel");
     qmlRegisterType<UserDirectoryListModel>("org.kde.neochat", 1, 0, "UserDirectoryListModel");
     qmlRegisterType<EmojiModel>("org.kde.neochat", 1, 0, "EmojiModel");

src/messagefiltermodel.cpp

@@ -0,0 +1,34 @@
+/*
+ * SPDX-FileCopyrightText: 2021 Nicolas Fella <nicolas.fella@gmx.de>
+ * SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
+ */
+
+#include "messagefiltermodel.h"
+
+#include "messageeventmodel.h"
+#include "neochatconfig.h"
+
+bool MessageFilterModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const
+{
+    const QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);
+
+    if (index.data(MessageEventModel::SpecialMarksRole).toInt() == EventStatus::Hidden) {
+        return false;
+    }
+
+    if (index.data(MessageEventModel::MessageRole).toInt() == 0x10) {
+        return false;
+    }
+
+    const QString eventType = index.data(MessageEventModel::EventTypeRole).toString();
+
+    if (eventType == QLatin1String("other")) {
+        return false;
+    }
+
+    if (!NeoChatConfig::self()->showLeaveJoinEvent() && eventType == QLatin1String("state")) {
+        return false;
+    }
+
+    return true;
+}

src/messagefiltermodel.h

@@ -0,0 +1,15 @@
+/*
+ * SPDX-FileCopyrightText: 2021 Nicolas Fella <nicolas.fella@gmx.de>
+ * SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
+ */
+#pragma once
+
+#include <QSortFilterProxyModel>
+
+class MessageFilterModel : public QSortFilterProxyModel
+{
+    Q_OBJECT
+public:
+    bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const override;
+
+};