doc: explain QQItem event delivery, handlers, setAcceptTouchEvents()

We quietly recommended calling setAcceptTouchEvents() in the Qt 5.10
release notes in any Item subclass that wants to receive touch events,
and in the docs for setAcceptTouchEvents() itself; but the message about
the impending behavior change might not have been obvious enough.
In Qt 6 it becomes mandatory, so clearer docs will hopefully help to
stave off bogus bug reports.

We also never had a great overview of event handling from an Item's
perspective; now it's a little better.

Followup to ab91e7fa02a562d80fd0747f28a60e00c3b45a01 and
a97759a336c597327cb82eebc9f45c793aec32c9

[ChangeLog][QtQuick][QQuickItem] When subclassing QQuickItem, you
should call setAcceptTouchEvents(true) if you need the item to receive
touch events. It will be required in Qt 6.

Task-number: QTBUG-87018
Task-number: QTBUG-87082
Change-Id: I1c7a43979e3665778d61949c9d37c1d085ed594b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 7c648280bb53c4276ba4ae2abf26d070fedde71a)
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

0 files changed, 0 insertions, 0 deletions