Unify "variant" and "var" properties in QML

variant and var properties differ in two important ways:
- variant properties trigger "magic" string conversions:
  variant v1: "red" // contains a QColor
  var     v2: "red" // contains a string
- variant properties behave differently for value types: they create
  copies, instead of references.

However, as variant properties were marked as obsolete and this
behavior was effetively undocumented, it should be safe to give "variant"
"var semantics".

With this change, we can also avoid doing magic conversions when storing
data in QVariant properties of QObjects/QGadgets

Change-Id: I549b1beb98e6af9639c1ee81f316bda513d5ff65
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 0 insertions, 95 deletions

diff --git a/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc b/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc
index ae3337f838..5716f6c386 100644
--- a/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc
+++ b/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc
@@ -513,101 +513,6 @@ property is only invoked when the property is reassigned to a different object v
 */
 
 /*!
-    \obsolete
-    \qmlbasictype variant
-    \ingroup qmlbasictypes
-    \brief a generic property type.
-
-    The \c variant type is a generic property type. It is obsolete and exists only to
-    support old applications; new applications should use \l var type
-    properties instead.
-
-    A variant type property can hold any of the \l {QML Basic Types}{basic type}
-    values:
-
-    \qml
-    Item {
-        property variant aNumber: 100
-        property variant aString: "Hello world!"
-        property variant aBool: false
-    }
-    \endqml
-
-    When integrating with C++, note that any QVariant value
-    \l{qtqml-cppintegration-data.html}{passed into QML from C++} is automatically
-    converted into a \c variant value, and vice-versa.
-
-
-    \section1 Using Scarce Resources with the variant Type
-
-    A \c variant type property can also hold an image or pixmap.
-    A \c variant which contains a QPixmap or QImage is known as a
-    "scarce resource" and the declarative engine will attempt to
-    automatically release such resources after evaluation of any JavaScript
-    expression which requires one to be copied has completed.
-
-    Clients may explicitly release such a scarce resource by calling the
-    "destroy" method on the \c variant property from within JavaScript.  They
-    may also explicitly preserve the scarce resource by calling the
-    "preserve" method on the \c variant property from within JavaScript.
-
-    \section1 Storing Arrays and Objects
-
-    The \c variant type can also hold:
-
-    \list
-    \li An array of \l {QML Basic Types}{basic type} values
-    \li A map of key-value pairs with \l {QML Basic Types}{basic-type} values
-    \endlist
-
-    For example, below is an \c items array and an \c attributes map. Their
-    contents can be examined using JavaScript \c for loops. Individual array
-    values are accessible by index, and individual map values are accessible
-    by key:
-
-    \qml
-    Item {
-        property variant items: [1, 2, 3, "four", "five"]
-        property variant attributes: { 'color': 'red', 'width': 100 }
-
-        Component.onCompleted: {
-            for (var i = 0; i < items.length; i++)
-                console.log(items[i])
-
-            for (var prop in attributes)
-                console.log(prop, "=", attributes[prop])
-        }
-    }
-    \endqml
-
-    While this is a convenient way to store array and map-type values, you
-    must be aware that the \c items and \c attributes properties above are \e not
-    QML objects (and certainly not JavaScript object either) and the key-value
-    pairs in \c attributes are \e not QML properties. Rather, the \c items
-    property holds an array of values, and \c attributes holds a set of key-value
-    pairs.
-
-    Additionally, since \c items and \c attributes are not QML objects, changing
-    the values they contain does not trigger property change notifications. If
-    the above example had \c onItemsChanged or \c onAttributesChanged signal
-    handlers, they would not be called when assigning individual entries in
-    either property.  If, however, the \c items or \c attributes properties
-    themselves were reassigned to different values, then such handlers would be
-    called.
-
-    JavaScript programmers should also note that when a JavaScript object is
-    copied to an array or map property, the \e contents of the object (that is,
-    its key-value properties) are copied, rather than the object itself. The
-    property does not hold a reference to the original JavaScript object, and
-    extra data such as the object's JavaScript prototype chain is also lost in
-    the process.
-
-    This basic type is provided by the QML language.
-
-    \sa {QML Basic Types}
-*/
-
-/*!
     \qmlbasictype enumeration
     \ingroup qmlbasictypes
     \brief a named enumeration value.