* QApplication::setFallbackSessionManagementEnabled has been removed
* QString::medRef() has been removed. Use QString::mid() again.
* QTextStream::setCodec has been removed
* Use operator QVariant of the QFont class to make code Qt5 and Qt6 compatible
* Signature of QTreeWidget::mimeData() has changed in Qt6. Remove TreeWidget::mimeData() because it doesn't change the implementation
* QLayout::setMargin() is deprecated in Qt5 and has been removed in Qt6. Use QLayout::setContentsMargins()
* QDateTime::toTime_t() is deprecated in Qt5 and has been removed in Qt6. Use QDateTime::toSecsSinceEpoch()
* QDesktopWidget is deprecated in Qt5 and has been removed in Qt6. Use QScreen
* Use multi-arg instead [-Wclazy-qstring-arg]
* Use an empty QLatin1String instead of an empty QStringLiteral [-Wclazy-empty-qstringliteral]
* getter Gui::ProgressBar::canAbort possibly mismarked as a slot [-Wclazy-const-signal-or-slot]
* Missing emit keyword on signal call [-Wclazy-incorrect-emit]
Replace the int of the 'resolve' argument of several functions with a proper enum class.
* This avoids the inconsistencies in client code where often true/false is passed when an int is expected
* This avoids the use of magic numbers like 0, 1, 2 or the undocumented 3
The SelectionView dock window was already an observer of the current selection
when it was showing. This changes it to continuously monitor the selection even
when invisible. If the user sets the parameter
BaseApp/Preferences/Selection/AutoShowSelectionView to true, when there is an item
selected, the view will show itself if it was hidden, and will re-hide itself when
the selection is cleared. The option has no effect if the user had chosen to manually
show the selection view prior to beginning a selection.
Mostly about API changes to SelectionSingleton. Also include related
changes to SelectionObject, SelectionChange, and SelectionView.
Please check out the summary of changes [here](https://git.io/fjimC)
