Make initStyleOption virtual for various classes

Often a simple change in the styleoptions is needed in e.g a paintEvent,
but it was impossible without copying the whole paint-function which
is not always trivial and also wouldn't be kept up-to-date if it was
changed in Qt.
The initStyleOption is similar to viewOptions in QAbstractTableView
and it is handy that this function is virtual. Furthermore
QStyledItemDelegate::initStyleOption is already virtual.

This change only makes initStyleOption virtual for public classes.

[ChangeLog][QtWidgets] InitStyleOption has been made virtual in
public Qt classes to make override of stylebehavior more simple.

Change-Id: I38974c6d4dd0793ca5976ecf3aa28892215a1579
Task-number: QTBUG-77642
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index 3c5469f128..fcb74370c7 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -3385,6 +3385,14 @@ void QHeaderView::initStyleOption(QStyleOptionHeader *option) const
     option->section = 0;
 }
 
+void QHeaderView::initStyleOption(QStyleOptionFrame *option) const
+{
+    // The QFrame version is only here to avoid compiler warnings.
+    // If invoked (it can be invoked with QFrame *f = headerview; f->initStyleOption()),
+    // and here we just pass it on to the frame version.
+    QFrame::initStyleOption(option);
+}
+
 bool QHeaderViewPrivate::isSectionSelected(int section) const
 {
     int i = section * 2;