implement ability to dynamically change class of script objects

With an object created by QScriptEngine::newObject(), it should
be possible to call QScriptValue::setClass() to dynamically
change the behavior of that object. Similarly, it should be
possible to promote plain script objects to QObject (QVariant)
wrappers by calling the overload of QScriptEngine::newQObject()
(newVariant()) that takes a script object as the first argument.
This commit implements this capability.

The premise is the (internal) QScriptObject class, which inherits
JSC::JSObject. It reimplements all the methods for getting/setting
properties etc. Then there's a level of indirection to facilitate
dynamic change of the class: Each QScriptObject can have a
delegate associated with it that will handle operations on the
object. By default there is no delegate, so the object behaves as
a normal JS object, as you expect. However, once a delegate is set
(e.g., when QScriptValue::setScriptClass() is called),
QScriptObject will give the delegate the chance to handle the
object operation.

In addition to a delegate implementation for QScriptClass-based
objects, there are also delegates for QObject and QVariant
wrappers. These replace the QObjectWrapperObject and
QVariantWrapperObject classes.

1 files changed, 2 insertions, 0 deletions

diff --git a/tests/auto/qscriptclass/tst_qscriptclass.cpp b/tests/auto/qscriptclass/tst_qscriptclass.cpp
index 963b2212d9..e587b51f67 100644
--- a/tests/auto/qscriptclass/tst_qscriptclass.cpp
+++ b/tests/auto/qscriptclass/tst_qscriptclass.cpp
@@ -607,7 +607,9 @@ void tst_QScriptClass::newInstance()
     QVERIFY(arr.isArray());
     QCOMPARE(arr.scriptClass(), (QScriptClass*)0);
     arr.setScriptClass(&cls);
+    QEXPECT_FAIL("", "Changing class of arbitrary script object is not allowed (it's OK)", Continue);
     QCOMPARE(arr.scriptClass(), (QScriptClass*)&cls);
+    QEXPECT_FAIL("", "Changing class of arbitrary script object is not allowed (it's OK)", Continue);
     QVERIFY(!arr.isArray());
     QVERIFY(arr.isObject());
 }