QAbstractProxyModel: Use QCompatProperty with custom getter

Use new API for QCompatProperty with custom getter instead of ad-hoc
solution.

Task-number: QTBUG-89655
Change-Id: I06481ad4d360b178be001ceb9c6c8460b73391f6
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

2 files changed, 5 insertions, 68 deletions

diff --git a/src/corelib/itemmodels/qabstractproxymodel.cpp b/src/corelib/itemmodels/qabstractproxymodel.cpp
index 837d283e6d..39fe44464c 100644
--- a/src/corelib/itemmodels/qabstractproxymodel.cpp
+++ b/src/corelib/itemmodels/qabstractproxymodel.cpp
@@ -161,8 +161,7 @@ QAbstractItemModel *QAbstractProxyModel::sourceModel() const
 QBindable<QAbstractItemModel *> QAbstractProxyModel::bindableSourceModel()
 {
     Q_D(QAbstractProxyModel);
-    return QBindable<QAbstractItemModel *>(QAbstractProxyModelBindable(
-            &d->model, &QtPrivate::QBindableInterfaceForSourceModel::iface));
+    return QBindable<QAbstractItemModel *>(&d->model);
 }
 
 /*!
diff --git a/src/corelib/itemmodels/qabstractproxymodel_p.h b/src/corelib/itemmodels/qabstractproxymodel_p.h
index 350735afd1..2ddd2428dc 100644
--- a/src/corelib/itemmodels/qabstractproxymodel_p.h
+++ b/src/corelib/itemmodels/qabstractproxymodel_p.h
@@ -59,16 +59,6 @@ QT_REQUIRE_CONFIG(proxymodel);
 
 QT_BEGIN_NAMESPACE
 
-class QAbstractProxyModelBindable : public QUntypedBindable
-{
-public:
-    explicit QAbstractProxyModelBindable(QUntypedPropertyData *d,
-                                         const QtPrivate::QBindableInterface *i)
-        : QUntypedBindable(d, i)
-    {
-    }
-};
-
 class Q_CORE_EXPORT QAbstractProxyModelPrivate : public QAbstractItemModelPrivate
 {
     Q_DECLARE_PUBLIC(QAbstractProxyModel)
@@ -82,69 +72,17 @@ public:
     {
         Q_EMIT q_func()->sourceModelChanged(QAbstractProxyModel::QPrivateSignal());
     }
+    QAbstractItemModel *getModelForwarder() const { return q_func()->sourceModel(); }
+
     Q_OBJECT_COMPAT_PROPERTY_WITH_ARGS(QAbstractProxyModelPrivate, QAbstractItemModel *, model,
                                        &QAbstractProxyModelPrivate::setModelForwarder,
-                                       &QAbstractProxyModelPrivate::modelChangedForwarder, nullptr)
+                                       &QAbstractProxyModelPrivate::modelChangedForwarder,
+                                       &QAbstractProxyModelPrivate::getModelForwarder, nullptr)
     virtual void _q_sourceModelDestroyed();
     void mapDropCoordinatesToSource(int row, int column, const QModelIndex &parent,
                                     int *source_row, int *source_column, QModelIndex *source_parent) const;
-
-    using ModelPropertyType = decltype(model);
-};
-
-namespace QtPrivate {
-
-/*!
-    The biggest trick for adding new QProperty binding support here is the
-    getter for the sourceModel property (QAbstractProxyModel::sourceModel),
-    which returns nullptr, while internally using a global staticEmptyModel()
-    instance.
-    This lead to inconsistency while binding to a proxy model without source
-    model. The bound object would point to staticEmptyModel() instance, while
-    sourceModel() getter returns nullptr.
-    To solve this issue we need to implement a custom QBindableInterface, with
-    custom getter and makeBinding methods, that would introduce the required
-    logic.
-*/
-
-inline QAbstractItemModel *normalizePotentiallyEmptyModel(QAbstractItemModel *model)
-{
-    if (model == QAbstractItemModelPrivate::staticEmptyModel())
-        return nullptr;
-    return model;
-}
-
-class QBindableInterfaceForSourceModel
-{
-    using PropertyType = QAbstractProxyModelPrivate::ModelPropertyType;
-    using Parent = QBindableInterfaceForProperty<PropertyType>;
-    using T = typename PropertyType::value_type;
-
-public:
-    static constexpr QBindableInterface iface = {
-        [](const QUntypedPropertyData *d, void *value) -> void {
-            const auto val = static_cast<const PropertyType *>(d)->value();
-            *static_cast<T *>(value) = normalizePotentiallyEmptyModel(val);
-        },
-        Parent::iface.setter,
-        Parent::iface.getBinding,
-        Parent::iface.setBinding,
-        [](const QUntypedPropertyData *d,
-           const QPropertyBindingSourceLocation &location) -> QUntypedPropertyBinding {
-            return Qt::makePropertyBinding(
-                    [d]() -> T {
-                        return normalizePotentiallyEmptyModel(
-                                static_cast<const PropertyType *>(d)->value());
-                    },
-                    location);
-        },
-        Parent::iface.setObserver,
-        Parent::iface.metaType
-    };
 };
 
-} // namespace QtPrivate
-
 QT_END_NAMESPACE
 
 #endif // QABSTRACTPROXYMODEL_P_H