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>

27 files changed, 39 insertions, 23 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;
diff --git a/src/widgets/itemviews/qheaderview.h b/src/widgets/itemviews/qheaderview.h
index 6cfa9a8bf0..6bbfb8449c 100644
--- a/src/widgets/itemviews/qheaderview.h
+++ b/src/widgets/itemviews/qheaderview.h
@@ -230,12 +230,14 @@ protected:
     QModelIndex moveCursor(CursorAction, Qt::KeyboardModifiers) override;
     void setSelection(const QRect& rect, QItemSelectionModel::SelectionFlags flags) override;
     QRegion visualRegionForSelection(const QItemSelection &selection) const override;
-    void initStyleOption(QStyleOptionHeader *option) const;
+    virtual void initStyleOption(QStyleOptionHeader *option) const;
 
     friend class QTableView;
     friend class QTreeView;
 
 private:
+    void initStyleOption(QStyleOptionFrame *option) const override;
+
     // ### Qt6: make them protected slots in QHeaderViewPrivate
     Q_PRIVATE_SLOT(d_func(), void _q_sectionsRemoved(const QModelIndex &parent, int logicalFirst, int logicalLast))
     Q_PRIVATE_SLOT(d_func(), void _q_sectionsAboutToBeMoved(const QModelIndex &sourceParent, int logicalStart, int logicalEnd, const QModelIndex &destinationParent, int logicalDestination))
diff --git a/src/widgets/widgets/qabstractspinbox.cpp b/src/widgets/widgets/qabstractspinbox.cpp
index c9753f5f51..154957eea3 100644
--- a/src/widgets/widgets/qabstractspinbox.cpp
+++ b/src/widgets/widgets/qabstractspinbox.cpp
@@ -1629,6 +1629,8 @@ void QAbstractSpinBoxPrivate::init()
     edit->setValidator(validator);
 
     QStyleOptionSpinBox opt;
+    // ### This is called from the ctor and thus we shouldn't call initStyleOption yet
+    // ### as we only call the base class implementation of initStyleOption called.
     q->initStyleOption(&opt);
     spinClickTimerInterval = q->style()->styleHint(QStyle::SH_SpinBox_ClickAutoRepeatRate, &opt, q);
     spinClickThresholdTimerInterval = q->style()->styleHint(QStyle::SH_SpinBox_ClickAutoRepeatThreshold, &opt, q);
diff --git a/src/widgets/widgets/qabstractspinbox.h b/src/widgets/widgets/qabstractspinbox.h
index 87d46c7326..50c139e066 100644
--- a/src/widgets/widgets/qabstractspinbox.h
+++ b/src/widgets/widgets/qabstractspinbox.h
@@ -160,7 +160,7 @@ protected:
     void timerEvent(QTimerEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
     void showEvent(QShowEvent *event) override;
-    void initStyleOption(QStyleOptionSpinBox *option) const;
+    virtual void initStyleOption(QStyleOptionSpinBox *option) const;
 
     QLineEdit *lineEdit() const;
     void setLineEdit(QLineEdit *edit);
diff --git a/src/widgets/widgets/qcheckbox.h b/src/widgets/widgets/qcheckbox.h
index 80cb22b82e..bb0f303235 100644
--- a/src/widgets/widgets/qcheckbox.h
+++ b/src/widgets/widgets/qcheckbox.h
@@ -81,7 +81,7 @@ protected:
     void nextCheckState() override;
     void paintEvent(QPaintEvent *) override;
     void mouseMoveEvent(QMouseEvent *) override;
-    void initStyleOption(QStyleOptionButton *option) const;
+    virtual void initStyleOption(QStyleOptionButton *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qcombobox.h b/src/widgets/widgets/qcombobox.h
index 1e518fb2c0..75dbb1183d 100644
--- a/src/widgets/widgets/qcombobox.h
+++ b/src/widgets/widgets/qcombobox.h
@@ -230,7 +230,7 @@ protected:
     void contextMenuEvent(QContextMenuEvent *e) override;
 #endif // QT_NO_CONTEXTMENU
     void inputMethodEvent(QInputMethodEvent *) override;
-    void initStyleOption(QStyleOptionComboBox *option) const;
+    virtual void initStyleOption(QStyleOptionComboBox *option) const;
 
 
 protected:
diff --git a/src/widgets/widgets/qdatetimeedit.h b/src/widgets/widgets/qdatetimeedit.h
index e2dfb94b19..a1d9be1088 100644
--- a/src/widgets/widgets/qdatetimeedit.h
+++ b/src/widgets/widgets/qdatetimeedit.h
@@ -193,7 +193,7 @@ protected:
     StepEnabled stepEnabled() const override;
     void mousePressEvent(QMouseEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
-    void initStyleOption(QStyleOptionSpinBox *option) const;
+    void initStyleOption(QStyleOptionSpinBox *option) const override;
 
     QDateTimeEdit(const QVariant &val, QMetaType::Type parserType, QWidget *parent = nullptr);
 private:
diff --git a/src/widgets/widgets/qdial.h b/src/widgets/widgets/qdial.h
index 1db1f9bb07..9abea5bf45 100644
--- a/src/widgets/widgets/qdial.h
+++ b/src/widgets/widgets/qdial.h
@@ -90,7 +90,7 @@ protected:
     void mouseMoveEvent(QMouseEvent *me) override;
 
     void sliderChange(SliderChange change) override;
-    void initStyleOption(QStyleOptionSlider *option) const;
+    virtual void initStyleOption(QStyleOptionSlider *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qdockwidget.h b/src/widgets/widgets/qdockwidget.h
index d553407fb5..69c5a6447a 100644
--- a/src/widgets/widgets/qdockwidget.h
+++ b/src/widgets/widgets/qdockwidget.h
@@ -116,7 +116,7 @@ protected:
     void closeEvent(QCloseEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
     bool event(QEvent *event) override;
-    void initStyleOption(QStyleOptionDockWidget *option) const;
+    virtual void initStyleOption(QStyleOptionDockWidget *option) const;
 
 private:
     Q_DECLARE_PRIVATE(QDockWidget)
diff --git a/src/widgets/widgets/qfocusframe.h b/src/widgets/widgets/qfocusframe.h
index 73d5b42bd8..8f6b7dd067 100644
--- a/src/widgets/widgets/qfocusframe.h
+++ b/src/widgets/widgets/qfocusframe.h
@@ -64,7 +64,7 @@ protected:
 
     bool eventFilter(QObject *, QEvent *) override;
     void paintEvent(QPaintEvent *) override;
-    void initStyleOption(QStyleOption *option) const;
+    virtual void initStyleOption(QStyleOption *option) const;
 
 private:
     Q_DECLARE_PRIVATE(QFocusFrame)
diff --git a/src/widgets/widgets/qframe.h b/src/widgets/widgets/qframe.h
index 595dfa929d..144003bc0e 100644
--- a/src/widgets/widgets/qframe.h
+++ b/src/widgets/widgets/qframe.h
@@ -116,7 +116,7 @@ protected:
 
 protected:
     QFrame(QFramePrivate &dd, QWidget* parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags());
-    void initStyleOption(QStyleOptionFrame *option) const;
+    virtual void initStyleOption(QStyleOptionFrame *option) const;
 
 private:
     Q_DISABLE_COPY(QFrame)
diff --git a/src/widgets/widgets/qgroupbox.h b/src/widgets/widgets/qgroupbox.h
index bd8394b43b..f3ed35b7fb 100644
--- a/src/widgets/widgets/qgroupbox.h
+++ b/src/widgets/widgets/qgroupbox.h
@@ -94,7 +94,7 @@ protected:
     void mousePressEvent(QMouseEvent *event) override;
     void mouseMoveEvent(QMouseEvent *event) override;
     void mouseReleaseEvent(QMouseEvent *event) override;
-    void initStyleOption(QStyleOptionGroupBox *option) const;
+    virtual void initStyleOption(QStyleOptionGroupBox *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qlineedit.h b/src/widgets/widgets/qlineedit.h
index 41efab9229..d47f979a63 100644
--- a/src/widgets/widgets/qlineedit.h
+++ b/src/widgets/widgets/qlineedit.h
@@ -229,7 +229,7 @@ protected:
 #endif
 
     void inputMethodEvent(QInputMethodEvent *) override;
-    void initStyleOption(QStyleOptionFrame *option) const;
+    virtual void initStyleOption(QStyleOptionFrame *option) const;
 public:
     QVariant inputMethodQuery(Qt::InputMethodQuery) const override;
     Q_INVOKABLE QVariant inputMethodQuery(Qt::InputMethodQuery property, QVariant argument) const;
diff --git a/src/widgets/widgets/qmenu.h b/src/widgets/widgets/qmenu.h
index b770b27957..e8b27c3278 100644
--- a/src/widgets/widgets/qmenu.h
+++ b/src/widgets/widgets/qmenu.h
@@ -257,7 +257,7 @@ protected:
     void timerEvent(QTimerEvent *) override;
     bool event(QEvent *) override;
     bool focusNextPrevChild(bool next) override;
-    void initStyleOption(QStyleOptionMenuItem *option, const QAction *action) const;
+    virtual void initStyleOption(QStyleOptionMenuItem *option, const QAction *action) const;
 
 private Q_SLOTS:
     void internalDelayedPopup();
diff --git a/src/widgets/widgets/qmenubar.h b/src/widgets/widgets/qmenubar.h
index cf6663f94a..f2170ebf5a 100644
--- a/src/widgets/widgets/qmenubar.h
+++ b/src/widgets/widgets/qmenubar.h
@@ -150,7 +150,7 @@ protected:
     void timerEvent(QTimerEvent *) override;
     bool eventFilter(QObject *, QEvent *) override;
     bool event(QEvent *) override;
-    void initStyleOption(QStyleOptionMenuItem *option, const QAction *action) const;
+    virtual void initStyleOption(QStyleOptionMenuItem *option, const QAction *action) const;
 
 private:
     Q_DECLARE_PRIVATE(QMenuBar)
diff --git a/src/widgets/widgets/qprogressbar.cpp b/src/widgets/widgets/qprogressbar.cpp
index 04241fda09..f94cbd3172 100644
--- a/src/widgets/widgets/qprogressbar.cpp
+++ b/src/widgets/widgets/qprogressbar.cpp
@@ -107,6 +107,8 @@ void QProgressBarPrivate::resetLayoutItemMargins()
 {
     Q_Q(QProgressBar);
     QStyleOptionProgressBar option;
+    // ### It seems like this can be called directly from the constructor which should be avoided
+    // ### if possible, since we will not call a possible re-implemented version
     q->initStyleOption(&option);
     setLayoutItemMargins(QStyle::SE_ProgressBarLayoutItem, &option);
 }
diff --git a/src/widgets/widgets/qprogressbar.h b/src/widgets/widgets/qprogressbar.h
index ec9686068c..e112af416b 100644
--- a/src/widgets/widgets/qprogressbar.h
+++ b/src/widgets/widgets/qprogressbar.h
@@ -111,7 +111,7 @@ Q_SIGNALS:
 protected:
     bool event(QEvent *e) override;
     void paintEvent(QPaintEvent *) override;
-    void initStyleOption(QStyleOptionProgressBar *option) const;
+    virtual void initStyleOption(QStyleOptionProgressBar *option) const;
 
 private:
     Q_DECLARE_PRIVATE(QProgressBar)
diff --git a/src/widgets/widgets/qpushbutton.h b/src/widgets/widgets/qpushbutton.h
index 283dfe2c61..5452f4227b 100644
--- a/src/widgets/widgets/qpushbutton.h
+++ b/src/widgets/widgets/qpushbutton.h
@@ -93,7 +93,7 @@ protected:
     void keyPressEvent(QKeyEvent *) override;
     void focusInEvent(QFocusEvent *) override;
     void focusOutEvent(QFocusEvent *) override;
-    void initStyleOption(QStyleOptionButton *option) const;
+    virtual void initStyleOption(QStyleOptionButton *option) const;
     bool hitButton(const QPoint &pos) const override;
     QPushButton(QPushButtonPrivate &dd, QWidget* parent = nullptr);
 
diff --git a/src/widgets/widgets/qradiobutton.h b/src/widgets/widgets/qradiobutton.h
index c6b5ddce84..009e7107c6 100644
--- a/src/widgets/widgets/qradiobutton.h
+++ b/src/widgets/widgets/qradiobutton.h
@@ -68,7 +68,7 @@ protected:
     bool hitButton(const QPoint &) const override;
     void paintEvent(QPaintEvent *) override;
     void mouseMoveEvent(QMouseEvent *) override;
-    void initStyleOption(QStyleOptionButton *button) const;
+    virtual void initStyleOption(QStyleOptionButton *button) const;
 
 
 private:
diff --git a/src/widgets/widgets/qrubberband.h b/src/widgets/widgets/qrubberband.h
index c683c24a18..9822f036f1 100644
--- a/src/widgets/widgets/qrubberband.h
+++ b/src/widgets/widgets/qrubberband.h
@@ -79,7 +79,7 @@ protected:
     void showEvent(QShowEvent *) override;
     void resizeEvent(QResizeEvent *) override;
     void moveEvent(QMoveEvent *) override;
-    void initStyleOption(QStyleOptionRubberBand *option) const;
+    virtual void initStyleOption(QStyleOptionRubberBand *option) const;
 
 private:
     Q_DECLARE_PRIVATE(QRubberBand)
diff --git a/src/widgets/widgets/qscrollbar.h b/src/widgets/widgets/qscrollbar.h
index 171195fd24..de4e0c14c7 100644
--- a/src/widgets/widgets/qscrollbar.h
+++ b/src/widgets/widgets/qscrollbar.h
@@ -76,7 +76,7 @@ protected:
 #ifndef QT_NO_CONTEXTMENU
     void contextMenuEvent(QContextMenuEvent *) override;
 #endif
-    void initStyleOption(QStyleOptionSlider *option) const;
+    virtual void initStyleOption(QStyleOptionSlider *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qslider.cpp b/src/widgets/widgets/qslider.cpp
index c344d496a7..5accb9c92f 100644
--- a/src/widgets/widgets/qslider.cpp
+++ b/src/widgets/widgets/qslider.cpp
@@ -91,6 +91,8 @@ void QSliderPrivate::resetLayoutItemMargins()
 {
     Q_Q(QSlider);
     QStyleOptionSlider opt;
+    // ### This is (also) reached from the ctor which is unfortunate since a possible
+    // ### re-implementation of initStyleOption is then not called.
     q->initStyleOption(&opt);
     setLayoutItemMargins(QStyle::SE_SliderLayoutItem, &opt);
 }
diff --git a/src/widgets/widgets/qslider.h b/src/widgets/widgets/qslider.h
index f74f9c8576..a4f05c3c12 100644
--- a/src/widgets/widgets/qslider.h
+++ b/src/widgets/widgets/qslider.h
@@ -89,7 +89,7 @@ protected:
     void mousePressEvent(QMouseEvent *ev) override;
     void mouseReleaseEvent(QMouseEvent *ev) override;
     void mouseMoveEvent(QMouseEvent *ev) override;
-    void initStyleOption(QStyleOptionSlider *option) const;
+    virtual void initStyleOption(QStyleOptionSlider *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qtabbar.h b/src/widgets/widgets/qtabbar.h
index cf98834853..7feea6d2a0 100644
--- a/src/widgets/widgets/qtabbar.h
+++ b/src/widgets/widgets/qtabbar.h
@@ -212,7 +212,7 @@ protected:
     void keyPressEvent(QKeyEvent *) override;
     void changeEvent(QEvent *) override;
     void timerEvent(QTimerEvent *event) override;
-    void initStyleOption(QStyleOptionTab *option, int tabIndex) const;
+    virtual void initStyleOption(QStyleOptionTab *option, int tabIndex) const;
 
 #ifndef QT_NO_ACCESSIBILITY
     friend class QAccessibleTabBar;
diff --git a/src/widgets/widgets/qtabwidget.h b/src/widgets/widgets/qtabwidget.h
index b61a02bdc6..0b91f077e0 100644
--- a/src/widgets/widgets/qtabwidget.h
+++ b/src/widgets/widgets/qtabwidget.h
@@ -171,7 +171,7 @@ protected:
     void setTabBar(QTabBar *);
     void changeEvent(QEvent *) override;
     bool event(QEvent *) override;
-    void initStyleOption(QStyleOptionTabWidgetFrame *option) const;
+    virtual void initStyleOption(QStyleOptionTabWidgetFrame *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qtoolbar.h b/src/widgets/widgets/qtoolbar.h
index 220b30abbe..26cad77b64 100644
--- a/src/widgets/widgets/qtoolbar.h
+++ b/src/widgets/widgets/qtoolbar.h
@@ -181,7 +181,7 @@ protected:
     void changeEvent(QEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
     bool event(QEvent *event) override;
-    void initStyleOption(QStyleOptionToolBar *option) const;
+    virtual void initStyleOption(QStyleOptionToolBar *option) const;
 
 
 private:
diff --git a/src/widgets/widgets/qtoolbutton.h b/src/widgets/widgets/qtoolbutton.h
index 52bd2d5f7a..5d522c62bb 100644
--- a/src/widgets/widgets/qtoolbutton.h
+++ b/src/widgets/widgets/qtoolbutton.h
@@ -119,7 +119,7 @@ protected:
 
     bool hitButton(const QPoint &pos) const override;
     void nextCheckState() override;
-    void initStyleOption(QStyleOptionToolButton *option) const;
+    virtual void initStyleOption(QStyleOptionToolButton *option) const;
 
 private:
     Q_DISABLE_COPY(QToolButton)