So far QPropertyAlias was limited to working with QProperty<T>.
Change the implementation, so it can be constructed from any
property or even a QBindable<T>.
Change-Id: I175cffe94a9ef332367d39faa976eb065b0e6ffe
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Add a new BINDABLE declaration to the Q_PROPERTY() macro that tells moc
where to find the QBindable for the property.
Add a QUntypedBindable base class to QBindable<T> that gives access to
generic functionality and checks argument compatibility at runtime.
QBindable<T> will still do static checking at compile time.
Add QMetaProperty::isBindable() and QMetaProperty::bindable()
to be able to dynamically access the binding functionality.
Change-Id: Ic7b08ae2cde83fd43e627d813a886e1de01fa3dc
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Add a compatibility property class that makes porting to the new
property system as simple as possible.
Binding evaluation for those compat properties is eager, as we
do not control possible side effects of the code in the existing
setters.
Change-Id: Ic56347abb49e40631ec73e88c6d40d4bdb05ca29
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Add a QObjectComputedProperty. This class doesn't store the data
itself, instead relies on a getter method to compute it's value.
As the property is read-only, one can not bind to it, but it can
be used in other property bindings.
Change-Id: I0f6bffdd9f80f1d0829826f93a47257f2b3127af
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Add Q_OBJECT_BINDABLE_PROPERTY() macro that can be used to define
a bindable property inside QObject.
The macro and the class behind it creates storage for a property
that is bindable inside a QObject or QObjectPrivate. The property
only uses as much space as the data contained, ie. it has no
storage overhead, as long as no bindings are being used.
Bindings are being stored and looked up in the QBindingStorage
associated with the owning object.
Change-Id: I1dadd7bddbad6fbf10cfa791d6461574b9db82dd
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Add a private QBindableInterface and a public QBindable<T>
class, that will be the API interface for accessing bindings
for properties in QObject.
The QBindable class gives access to all aspects of
the property related to bindings. This includes setting
and retrieving bindings, installing observers and creating
a direct binding on this property.
Change-Id: Iaead54d2bd6947bd2cda5052142b2a47dd8bf7c4
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
These look rather weird, an explicit property.setBinding() call
is simply better in this case, and also more aligned with the API
we can offer in QObject.
Change-Id: Ifb00fd47a75e6b3bc94e34bf49e4f13249565bfe
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
And all related functionality. This is being replaced by
Q_BINDABLE_PROPERTY and Q_OBJECT_BINDABLE_PROPERTY in the
next few commits. The new infrastructure coming will play
nicer along with the existing property system.
Commented out some autotests, that will get reimplemented
with the updated infrastructure.
Change-Id: I50c30bd4d5c6c6b6471f8eb93870e27d86f5a009
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Rename QPropertyBase to QPropertyBindingData, as it contains the
data related to bindings. The new name fits better, as the data
can now also live somewhere else than the data strored in the
property.
Change-Id: I489efb86ad2e0bad2740c9d1aa74506fe103d343
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Since we will be storing property data differently in most cases,
having this special case would create too many additional complications.
Change-Id: I27042b0730559bb375d8e3c07324398403a9885d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Enable the arrow operator for all types that could have members, so
that one can e.g. write myStringProperty->size() instead of having to
use the less convenient myStringProperty.value().size().
Also cleaned up the rvalue ref overloads to be
disabled for basic types. For those we now also
return by value, for more complex types we
return a const reference.
Change-Id: If6a75898dc0a097f57052488f0af0cd7166b3393
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
We can end up in a situation where a (soon to be destroyed) observer is
owned by a binding which is about to be deleted. If in that situation
the binding is destroyed first, we end up with a dangling pointer
and ensuing memory corruption. Instead, we now first transfer the
ownership of the observer and only destroy the binding afterwards.
Fixes: QTBUG-85824
Change-Id: I721c0319281ada981ae7896bd2e02e9a0cc901b8
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
For types that don't have an operator==(), always trigger the binding
and the changed notification.
Task-number: QTBUG-85578
Change-Id: I41374f6d13c88106f4de83864e82172f3a248150
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
And mark some methods as inline.
Performance is critical for our new property system. Compiling
it in one unit makes it possible for the compiler to do a much
better job at inlining and generating optimized code.
Improves performance of binding evaluations by another 20%.
Change-Id: I5a2aa93c74d2b68418b0a9d2e34d8199bb71e3ad
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Avoid any QVariant or type dependent code in the cpp files.
Instead, let the binding wrapper determine if the value
has changed and return true/false accordingly.
This required also some reworking of the guard mechanism
for notified properties, where the guard function wrapper
now calls first the binding evaluation function and then
passes the result to the guard.
Change-Id: I350d07a508ccc0c5db7054a0efa4f270b6a78ec3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
There's no point in returning a usually empty error when
evaluating bindings, adding overhead to the regular code
path.
Instead, the error can be set on the currently evaluating
binding if required. This streamlines the functor used to
wrap the binding and should thus expand to less code and
execute faster in the regular case.
To achieve this, expose a pointer to the currently evaluating
binding in the private API (as QtQml needs it to be able to
report errors).
The error case now requires one additional TLS lookup, but
we don't really care about performance in that case anyway.
Change-Id: Iecb450e765244930a41d813fcf8eb4013957a6a3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Remove location(). The method would always return an empty value. If you need the location,
the binding itself has it.
Remove setDescription() and require that the description gets passed
in the constructor. Never create a d pointer if type is NoError, so we
can quickly check for it inline.
Change-Id: I7eb8a94786281069d6ea2d82567c09aa50c52ef6
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Adding support for a static notifier within QProperty itself - through a
QProperty "sister" class - is more efficient in terms of memory
consumption and run-time performance.
The MemberChangeHandler permanently takes up at least three pointers,
while the notified properties only cost one pointer in the binding.
Change-Id: Ia1a8c2b66f1f3c2fe13ae0ad9f12cdb6bdcc35ef
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
A guard callback is a predicate which takes the new value set by
setValue or computed as the result of a binding expression. If it
returns false, the value is discarded and the old value is kept.
Note that due to lazyness, when setting a binding, we still notify
everyone as the binding is only evaluated on demand, and the guard can
thus only run when someone actually queries the value.
Note further that a guard is allowed to modify the value that is passed
to it (e.g. to clamp it to a certain range).
Task-number: QTBUG-85032
Change-Id: I3551e4357fe5780fb75da80bf8be208ec152dc2a
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Check at compile time whether the static callback takes an argument
(which has to be of the same time as the type of the property). If so,
retrieve the old value and pass it to the callback.
Change-Id: Ib1c4c9e05b826b6be492b03f66fa72ad015963ee
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
The static observer can live in a union with the inline observers. We
only need to take care of calling the ctors and dtors manually then.
In order for any observers to be called in the presence of a static
observer, the static observer has to be called after the other
observers.
Change-Id: I2f56fa64f3fe6fcd7f06cc403929362da7d86f65
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
A common pattern in Qt Quick will be QProperty members that are
connected to a callback that needs to perform something when the value
changes, for example emitting a compatibility signal or marking scene
graph node data dirty.
To make such a pattern more efficient, a new QNotifiedProperty type is
introduced that offers the same API as QProperty<T>, with two changes:
(1) The template instantiation not only takes the property type as
parameter but also a callback pointer-to-member.
(2) Since that member itself cannot be called without an instance
and to avoid storing an instance pointer permanently, the API for
setBinding and setValue are adjusted to also take the instance
pointer. For the former it gets stored in the binding, for the
latter it is used to invoke the callback after setting the new
value.
Change-Id: I85cc1d1d1c0472164c4ae87808cfdc0d0b1475e1
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
A property alias is the equivalent of the "alias" keyword in QML. It
provides the same API as QProperty, but redirects any access to the
QProperty it was initialized with. When the original property is
destroyed the binding becomes invalid and ignores any further acccess.
Task-number: QTBUG-84370
Change-Id: I0aef8d50e73a2aa9e7703d51194d4c5480573578
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Previously, only the first observer would get notified. Also, make sure
that the notifiers are always retained when switching between bindings
and values.
Change-Id: I9c25c0f2e288dac3a335b68e618f7ddeb44be25a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
We must move the functor properly into the binding object, otherwise we
end up with stale pointers as pointed out by ASAN.
Change-Id: Icd84f4c113dd48e1e3e2d744abac0902cdf9339e
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Instead of requiring the implementation to do the compare dance, let's
do this in the library. This reduces the amount of duplicated code
slightly and makes it easier to generate binding code from qml files.
Change-Id: Ia3b16cf9769e74d076b669efe4119ab84af3cdf0
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
When a class has multiple QProperty members to implement functionality,
it is common to have functions in the class that react to changes. For
example to emit a compatibility signal, in case of Qt Quick to mark the
scene graph as dirty, etc. etc.
To faciliate this use-case, this patch adds an internal
QPropertyMemberChangeHandler template that allows connecting a QProperty
field to a member function callback.
At the moment that callback is still 3 * sizeof(pointer). This could in
theory be reduced to 2 by eliminating the back-pointer (prev) as the
observer lives as long as the property. That however belongs into maybe
a future patch.
In order to get a pointer back to the surrounding object that holds the
QProperty as well as provides the callback function, the property system
was changed to pass through the address of the QProperty member at
run-time, and at compile time the delta from the QProperty member to the
beginning of the surrounding class is calculated. Through subtraction we
obtain the pointer to the owning object.
Change-Id: Ia2976357053f474ff44d0d6f60527c3b8e1f613a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
QtQml needs the private just for one detail which nobody else should
need it for: Tracking additional dependencies and marking the binding as
dirty. Exporting the private requires hiding some variables and
providing accessors, to compile with MSVC - including the removal of
QVarLengthArray usage. Upside: The binding structure shrinks by 8 bytes
and the encapsulation makes it a little easier to change things without
breaking declarative, ... in the unlikely event ;-)
Also remove setDirty() from the public API as it's not needed by QtQml
and using it is dangerous, because it means that there's a risk of
somebody keeping a reference (count) to the untyped binding from within
the binding closure, which introduces a memory leak.
Change-Id: I43bd56f4bdf218efb54fa23e2d627ad3acfafeb5
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
A generic binding allows implementing the binding function in a way that
enables the QML engine to run binding scripts and convert the V4::Value
into a QVariant and then assign the value to the property with the help
of QMetaType::construct.
Change-Id: Id4807be92eee7e3501908e6c5e4c861cfcb7772a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
This implements the core value based property binding system with
automatic dependency tracking. More features are to be added later, and
the documentation will need further improvements as well.
Change-Id: I77ec9163ba4dace6c4451f5933962ebe1b3b4b14
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
