Fix assignment to QObject pointer properties

This commit ammends 59ed8c355b99df0b949003a438ab850274261aa0 to always query
the Qt meta-type registry to retrieve the QMetaObject for a QObject pointer
type.

Change-Id: I70d876a5acfa23967fd1a57c96fcd5ac853eaf49
Task-number: QTBUG-39614
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Reviewed-by: Ulf Hermann <ulf.hermann@digia.com>
Doc: Fixed an error in the QML snippet

Also updated the C++ snippet to look like a
gui app that shows the QML example, instead of
a console app that just provides the context data
to the QML example.

Change-Id: I17aca9f03521cfcadba1a965a4924e87cbf14c62
Task-number: QTBUG-41699
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Remove unnecessary doneCurrent in QQuickWidget

Excessive makeCurrent - doneCurrent pairs should be avoided. We already
do this in QOpenGLWidget and the QPlatformBackingStore composition code.
Remove the doneCurrent from QQuickWidget too.

Change-Id: I6f998d381c33880c470f34d7c8462b6ed8cd8ae9
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>
Relayout rich text when width increases

In updateSize() we were trying to force relayouts for RichText
when the width changes by always setting widthExceeded to true.
But further down in the same function, we overwrote this
with textWidth() < idealWidth(), which doesn't work, because
both properties are the wrapped width of the document and
should only differ if the text cannot be wrapped properly.

The result was that when increasing the width of a Text element,
we would hit the optimization and skip the relayout.

[ChangeLog][Text] Fixed Text with the RichText format to
correctly update wrapping when the width of the element grows.

Change-Id: I5fd87052a5ba7e8ee2549be0cfac4adc8ddf8290
Task-number: QTBUG-33020
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Fix pixelgrid snapping of native text on retina displays.

Change 63e6c9ada82dc8f16e705cef5f89292784b7ace4 introduced snapping to
the pixel grid in the vertex shader for native text, but this code was
broken on retina displays because it assumed integer only positions.
Fix it by including the retina scale factor into the rounding.

Task-number: QTBUG-38702
Change-Id: I84492b02d64f263c9fe030790e04cf79b0dc4e2f
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@theqtcompany.com>