Functions in Qt that take a callback need to support callables with or
without context objects, and member functions of an object. The
implementation of those overloads follows a pattern that ultimately
results in a QSlotObjectBase implementation being created and
passed to an implementation helper that takes care of the logic.
Factor that common pattern into a new helper template in QtPrivate
that returns a suitable QSlotObjectBase after checking that the
functor is compatible with the specified argument types.
Use that new helper template in the implementation of
QCoreApplication::requestPermission and QHostInfo::lookupHost.
The only disadvantage of centralizing this logic is that we cannot print
a more detailed error message indicating which argument types the
caller expects. However, that information is visible from the detailed
compiler errors anyway.
Change-Id: I24cf0b2442217857b96ffc4d2d6c997c4fae34e0
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
When a context object is provided, then callers expect that the functor
or slot is executed in the thread of the context object. And if the
context object has been destroyed by the time the permission response
is received, the functor shouldn't be called at all.
To implement this, we either have to plumb the call back through a
signal/slot connection and benefit from QObject's infrastructure. This
is not practical here, as we don't have an "engine QObject" that would
emit a signal.
Instead, we can create a QMetaCallEvent explicitly, following what we do
in e.g. QHostInfo, and using a temporary QObject that handles the event
to then call the functor.
Add test coverage.
Pick-to: 6.5
Change-Id: Id878e45b304857304165ab4a7c6aae76fbee46ce
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
The fact that read-access is always included makes a bool readWrite
property a little awkward to document and explain. An AccessMode enum
with values ReadOnly and ReadWrite is much easier, and will also lend
itself more easily as a constructor argument than a boolean.
Found in API review.
Pick-to: 6.5
Change-Id: I4f20dbe9f19c7bdb52248a6e544e36d731d5a2ee
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
As discussed in API review, the default-constructed T() returned from
a mismatched data<T>() call is indistinguishable from a real T with
default state.
To make them distinguishable, return optional<T>. Call the new
function value<T>(), mimicking QVariant::value<T>(), and suggested in
API review, because data() is usually used to return raw pointers, not
values.
Remove the qWarning() on requestedType and actualType mismatch, as the
new function can be used in std::get_if/dynamic_cast-like if-then-else
chains, in which failure is part of the normal operation, and a
warning message misplaced:
if (auto loc = perm.value<QLocationPermission>())
~~~ use *loc ~~~
else if (auto con = perm.value<QContactsPermission>())
~~~ use *con ~~~
~~~ etc ~~~
Pick-to: 6.5
Change-Id: I799a58e930307323ebce8f9ac50a42455e9c017f
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
The new test:
- checks the properties of stateful Q<Typed>Permissions work
- ensures that piping a Q<Typed>Permission through QPermission
maintains state
- also ensures that assignment of a Q<Typed>Permission to a
QPermission works (via QPermission(Type) + move ctor)
Pick-to: 6.5
Change-Id: I340e49b1ecc665702ccab26d9050ca158b0e7885
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
To be extended as neeeded.
Pick-to: 6.5
Change-Id: I57d2f55f67de073fe3e4916b7ba655342cf661dc
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Volker Hilsheimer
Marc Mutz