feat(StatusQ): Generic attachd type for providing model count

Closes: #15374

ui/StatusQ/CMakeLists.txt

@@ -101,6 +101,7 @@ add_library(StatusQ SHARED
         include/StatusQ/formatteddoubleproperty.h
         include/StatusQ/functionaggregator.h
         include/StatusQ/leftjoinmodel.h
+        include/StatusQ/modelcount.h
         include/StatusQ/modelentry.h
         include/StatusQ/modelsyncedcontainer.h
         include/StatusQ/modelutilsinternal.h
@@ -128,6 +129,7 @@ add_library(StatusQ SHARED
         src/formatteddoubleproperty.cpp
         src/functionaggregator.cpp
         src/leftjoinmodel.cpp
+        src/modelcount.cpp
         src/modelentry.cpp
         src/modelutilsinternal.cpp
         src/movablemodel.cpp

ui/StatusQ/include/StatusQ/modelcount.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <QObject>
+#include <QQmlEngine>
+
+class ModelCount : public QObject {
+    Q_OBJECT
+    Q_PROPERTY(int count READ count NOTIFY countChanged)
+
+public:
+    explicit ModelCount(QObject* parent = nullptr);
+
+    static ModelCount* qmlAttachedProperties(QObject* object);
+
+    int count() const;
+
+signals:
+    void countChanged();
+};
+
+QML_DECLARE_TYPEINFO(ModelCount, QML_HAS_ATTACHED_PROPERTIES)

ui/StatusQ/src/modelcount.cpp

@@ -0,0 +1,29 @@
+#include "StatusQ/modelcount.h"
+
+#include <QAbstractItemModel>
+
+ModelCount::ModelCount(QObject* parent) : QObject(parent)
+{
+    auto model = qobject_cast<QAbstractItemModel*>(parent);
+
+    if (model == nullptr)
+        return;
+
+    connect(model, &QAbstractItemModel::rowsInserted, this, &ModelCount::countChanged);
+    connect(model, &QAbstractItemModel::rowsRemoved, this, &ModelCount::countChanged);
+    connect(model, &QAbstractItemModel::modelReset, this, &ModelCount::countChanged);
+    connect(model, &QAbstractItemModel::layoutChanged, this, &ModelCount::countChanged);
+}
+
+ModelCount* ModelCount::qmlAttachedProperties(QObject* object)
+{
+    return new ModelCount(object);
+}
+
+int ModelCount::count() const
+{
+    if (auto model = qobject_cast<QAbstractItemModel*>(parent()))
+        return model->rowCount();
+
+    return 0;
+}

ui/StatusQ/src/plugin.cpp

@@ -11,6 +11,8 @@
 #include "StatusQ/formatteddoubleproperty.h"
 #include "StatusQ/functionaggregator.h"
 #include "StatusQ/leftjoinmodel.h"
+#include "StatusQ/modelcount.h"
+#include "StatusQ/modelentry.h"
 #include "StatusQ/modelutilsinternal.h"
 #include "StatusQ/movablemodel.h"
 #include "StatusQ/objectproxymodel.h"
@@ -69,6 +71,9 @@ public:
         qmlRegisterType<ModelEntry>("StatusQ", 0, 1, "ModelEntry");
         qmlRegisterType<SnapshotObject>("StatusQ", 0, 1, "SnapshotObject");
 
+        qmlRegisterUncreatableType<ModelCount>("StatusQ", 0, 1,
+                                               "ModelCount", "This is attached type, cannot be created directly.");
+
         qmlRegisterSingletonType<ModelUtilsInternal>(
             "StatusQ.Internal", 0, 1, "ModelUtils", &ModelUtilsInternal::qmlInstance);