Long live QML inline components

[ChangeLog][QtQml] It is now possible to declare new QML components in
a QML file via the component keyword. They can be used just as if they
were declared in another file, with the only difference that the type
name needs to be prefixed with the name of the containing type outside
of the file were the inline component has been declared.

Notably, inline components are not closures: In the following
example, the output would be 42

// MyItem.qml
Item {
    property int i: 33
    component IC: Item {
        Component.onCompleted: console.log(i)
    }
}
// user.qml
Item {
    property int i: 42
    MyItem.IC {}
}

Fixes: QTBUG-79382
Change-Id: I6a5ffc43f093a76323f435cfee9bab217781b8f5
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/qml/qml/qqmltype_p.h b/src/qml/qml/qqmltype_p.h
index af134b21f1..387baa74bb 100644
--- a/src/qml/qml/qqmltype_p.h
+++ b/src/qml/qml/qqmltype_p.h
@@ -74,6 +74,7 @@ class QQmlPropertyCache;
 namespace QV4 {
 struct String;
 }
+struct CompositeMetaTypeIds;
 
 class Q_QML_PRIVATE_EXPORT QQmlType
 {
@@ -144,6 +145,9 @@ public:
 
     int index() const;
 
+    bool isInlineComponentType() const;
+    int inlineComponendId() const;
+
     struct Q_QML_PRIVATE_EXPORT SingletonInstanceInfo
     {
         QJSValue (*scriptCallback)(QQmlEngine *, QJSEngine *) = nullptr;
@@ -166,6 +170,8 @@ public:
     int scopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &, bool *ok) const;
     int scopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &, const QByteArray &, bool *ok) const;
     int scopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &, const QStringRef &, bool *ok) const;
+    int inlineComponentObjectId();
+    void setInlineComponentObjectId(int id) const; // TODO: const setters are BAD
 
     const QQmlTypePrivate *priv() const { return d.data(); }
     static void refHandle(const QQmlTypePrivate *priv);
@@ -178,9 +184,19 @@ public:
         InterfaceType = 2,
         CompositeType = 3,
         CompositeSingletonType = 4,
+        InlineComponentType = 5,
         AnyRegistrationType = 255
     };
 
+    QQmlType containingType() const;
+    int lookupInlineComponentIdByName(const QString &name) const;
+    QQmlType lookupInlineComponentById(int objectid) const;
+    int generatePlaceHolderICId() const;
+
+    void associateInlineComponent(const QString &name, int objectID, const CompositeMetaTypeIds &metaTypeIds, QQmlType existingType);
+    void setPendingResolutionName(const QString &name);
+    QString pendingResolutionName() const;
+
 private:
     friend class QQmlTypePrivate;
     friend uint qHash(const QQmlType &t, uint seed);