Speedup room switching by forcing a bigger initial item size

CMakeLists.txt

@@ -4,7 +4,6 @@ option(APPVEYOR_BUILD "Build on appveyor" OFF)
 option(CI_BUILD "Set when building in CI. Enables -Werror where possible" OFF)
 option(ASAN "Compile with address sanitizers" OFF)
 option(QML_DEBUGGING "Enable qml debugging" OFF)
-option(COMPILE_QML "Compile Qml. It will make Nheko faster, but you will need to recompile it, when you update Qt." OFF)
 if(UNIX AND NOT APPLE)
     option(MAN "Build man page" ON)
 else()
@@ -241,7 +240,6 @@ endif()
 # Discover Qt dependencies.
 #
 find_package(Qt6 6.5 COMPONENTS Core Widgets Gui LinguistTools Svg Multimedia Qml QuickControls2 REQUIRED)
-#find_package(Qt6QuickCompiler)
 find_package(Qt6DBus)
 
 if(USE_BUNDLED_QTKEYCHAIN)
@@ -633,11 +631,7 @@ endif()
 #
 # Bundle resources
 #
-if(Qt6QuickCompiler_FOUND AND COMPILE_QML)
-    qtquick_compiler_add_resources(QRC resources/res.qrc)
-else()
-    qt_add_resources(QRC resources/res.qrc)
-endif()
+qt_add_resources(QRC resources/res.qrc)
 
 if(APPLE)
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -framework Foundation -framework Cocoa -framework UserNotifications")

resources/qml/MessageView.qml

@@ -47,7 +47,7 @@ Item {
         anchors.rightMargin: scrollbar.interactive ? scrollbar.width : 0
         // reuseItems still has a few bugs, see https://bugreports.qt.io/browse/QTBUG-95105 https://bugreports.qt.io/browse/QTBUG-95107
         //onModelChanged: if (room) room.sendReset()
-        //reuseItems: true
+        reuseItems: true
         boundsBehavior: Flickable.StopAtBounds
         displayMarginBeginning: height / 4
         displayMarginEnd: height / 4

resources/qml/TimelineBubbleMessageStyle.qml

@@ -11,7 +11,9 @@ TimelineEvent {
     id: wrapper
     ListView.delayRemove: true
     width: chat.delegateMaxWidth
-    height: Math.max((section.item?.height ?? 0) + gridContainer.implicitHeight + reactionRow.implicitHeight + unreadRow.height, 10)
+    // We return a larger size for any item but the most bottom one, if it isn't initialized yet, since otherwise Qt will create way too many items.
+    // If we did that also for the first item, it would mess with the scroll location a bit, so we don't do it for that item.
+    height: Math.max((section.item?.height ?? 0) + ((gridContainer.implicitHeight < 1 && index != 0) ? 100 : gridContainer.implicitHeight) + reactionRow.implicitHeight + unreadRow.height, 10)
     anchors.horizontalCenter: ListView.view.contentItem.horizontalCenter
     //room: chatRoot.roommodel
 

resources/qml/TimelineDefaultMessageStyle.qml

@@ -11,7 +11,9 @@ TimelineEvent {
     id: wrapper
     ListView.delayRemove: true
     width: chat.delegateMaxWidth
-    height: Math.max((section.item?.height ?? 0) + gridContainer.implicitHeight + reactionRow.implicitHeight + unreadRow.height, 10)
+    // We return a larger size for any item but the most bottom one, if it isn't initialized yet, since otherwise Qt will create way too many items.
+    // If we did that also for the first item, it would mess with the scroll location a bit, so we don't do it for that item.
+    height: Math.max((section.item?.height ?? 0) + ((gridContainer.implicitHeight < 1 && index != 0) ? 100 : gridContainer.implicitHeight) + reactionRow.implicitHeight + unreadRow.height, 10)
     anchors.horizontalCenter: ListView.view.contentItem.horizontalCenter
     //room: chatRoot.roommodel
 

resources/qml/delegates/PlayableMediaMessage.qml

@@ -35,6 +35,7 @@ Item {
 
         // TODO: Show error in overlay or so?
         roomm: room
+        // FIXME: This takes 500ms on my device, why and how can we avoid that?
         audioOutput: AudioOutput {
             muted: mediaControls.muted
             volume: mediaControls.desiredVolume

src/main.cpp

@@ -47,7 +47,7 @@
 
 #ifdef QML_DEBUGGING
 #include <QQmlDebuggingEnabler>
-QQmlDebuggingEnabler enabler;
+QQmlTriviallyDestructibleDebuggingEnabler enabler;
 #endif
 
 #if HAVE_BACKTRACE_SYMBOLS_FD

src/timeline/TimelineModel.cpp

@@ -997,6 +997,8 @@ TimelineModel::multiData(const QModelIndex &index, QModelRoleDataSpan roleDataSp
         return;
     }
 
+    // nhlog::db()->debug("MultiData called for {}", index.row());
+
     // HACK(Nico): fetchMore likes to break with dynamically sized delegates and reuseItems
     if (index.row() + 1 == rowCount() && !m_paginationInProgress)
         const_cast<TimelineModel *>(this)->fetchMore(index);
@@ -1025,6 +1027,8 @@ TimelineModel::multiData(const QString &id,
         return;
     }
 
+    // nhlog::db()->debug("MultiData called for {}", id.toStdString());
+
     auto event = events.get(id.toStdString(), relatedTo.toStdString());
 
     if (!event) {