Replace QAbstractItemView::viewOptions with initViewItemOption

viewOptions returned a QStyleOptionViewItem object. Such a method
can never support newer versions of the option structure.

Most styleable QWidget classes provide a virtual method
initStyleOption that initializes the option object passed in as a
pointer, e.g QFrame, QAbstractSpinBox, or QComboBox.

Follow that API convention, but name it initViewItemOption, as the
QStyleOptionViewItem struct contains information about the item as
well as the widget itelf.

This is a source incompatible change that will go unnoticed unless
existing subclasses mark their overrides as 'override', or call
the removed QAbstractItemView::viewOption virtual function.

[ChangeLog][QtWidgets][QAbstractItemView] The virtual viewOptions
method that previously returned a QStyleOptionViewItem object has
been renamed to initViewItemOption, and initializes a
QStyleOptionViewItem object that's passed in through a pointer.

Change-Id: Ie058702aed42d77274fa3c4abb43ba302e57e348
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

8 files changed, 93 insertions, 66 deletions

diff --git a/src/widgets/itemviews/qabstractitemview.cpp b/src/widgets/itemviews/qabstractitemview.cpp
index bd835f56cc..a6b49c05b7 100644
--- a/src/widgets/itemviews/qabstractitemview.cpp
+++ b/src/widgets/itemviews/qabstractitemview.cpp
@@ -1718,7 +1718,8 @@ bool QAbstractItemView::viewportEvent(QEvent *event)
     case QEvent::WhatsThis: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
         const QModelIndex index = indexAt(he->pos());
-        QStyleOptionViewItem option = viewOptions();
+        QStyleOptionViewItem option;
+        initViewItemOption(&option);
         option.rect = visualRect(index);
         option.state |= (index == currentIndex() ? QStyle::State_HasFocus : QStyle::State_None);
 
@@ -1931,7 +1932,8 @@ void QAbstractItemView::mouseReleaseEvent(QMouseEvent *event)
             emit clicked(index);
         if (edited)
             return;
-        QStyleOptionViewItem option = viewOptions();
+        QStyleOptionViewItem option;
+        initViewItemOption(&option);
         if (d->pressedAlreadySelected)
             option.state |= QStyle::State_Selected;
         if ((d->model->flags(index) & Qt::ItemIsEnabled)
@@ -2720,7 +2722,8 @@ void QAbstractItemView::updateEditorGeometries()
         d->executePostedLayout();
         return;
     }
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     QEditorIndexHash::iterator it = d->editorIndexHash.begin();
     QWidgetList editorsToRelease;
     QWidgetList editorsToHide;
@@ -3018,7 +3021,9 @@ QSize QAbstractItemView::sizeHintForIndex(const QModelIndex &index) const
     if (!d->isIndexValid(index))
         return QSize();
     const auto delegate = d->delegateForIndex(index);
-    return delegate ? delegate->sizeHint(viewOptions(), index) : QSize();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
+    return delegate ? delegate->sizeHint(option, index) : QSize();
 }
 
 /*!
@@ -3046,7 +3051,8 @@ int QAbstractItemView::sizeHintForRow(int row) const
 
     ensurePolished();
 
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     int height = 0;
     int colCount = d->model->columnCount(d->root);
     for (int c = 0; c < colCount; ++c) {
@@ -3076,7 +3082,8 @@ int QAbstractItemView::sizeHintForColumn(int column) const
 
     ensurePolished();
 
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     int width = 0;
     int rows = d->model->rowCount(d->root);
     for (int r = 0; r < rows; ++r) {
@@ -3098,7 +3105,8 @@ int QAbstractItemView::sizeHintForColumn(int column) const
 void QAbstractItemView::openPersistentEditor(const QModelIndex &index)
 {
     Q_D(QAbstractItemView);
-    QStyleOptionViewItem options = viewOptions();
+    QStyleOptionViewItem options;
+    initViewItemOption(&options);
     options.rect = visualRect(index);
     options.state |= (index == currentIndex() ? QStyle::State_HasFocus : QStyle::State_None);
 
@@ -3688,41 +3696,46 @@ void QAbstractItemView::startDrag(Qt::DropActions supportedActions)
 #endif // QT_CONFIG(draganddrop)
 
 /*!
-    Returns a QStyleOptionViewItem structure populated with the view's
-    palette, font, state, alignments etc.
+    \since 6.0
+
+    Initialize the \a option structure with the view's palette, font, state,
+    alignments etc.
+
+    \note Implementations of this methods should check the \l{QStyleOption::}
+    version of the structure received, populate all members the implementation
+    is familiar with, and set the version member to the one supported by the
+    implementation before returning.
 */
-QStyleOptionViewItem QAbstractItemView::viewOptions() const
+void QAbstractItemView::initViewItemOption(QStyleOptionViewItem *option) const
 {
     Q_D(const QAbstractItemView);
-    QStyleOptionViewItem option;
-    option.initFrom(this);
-    option.state &= ~QStyle::State_MouseOver;
-    option.font = font();
+    option->initFrom(this);
+    option->state &= ~QStyle::State_MouseOver;
+    option->font = font();
 
     // On mac the focus appearance follows window activation
     // not widget activation
     if (!hasFocus())
-        option.state &= ~QStyle::State_Active;
+        option->state &= ~QStyle::State_Active;
 
-    option.state &= ~QStyle::State_HasFocus;
+    option->state &= ~QStyle::State_HasFocus;
     if (d->iconSize.isValid()) {
-        option.decorationSize = d->iconSize;
+        option->decorationSize = d->iconSize;
     } else {
         int pm = style()->pixelMetric(QStyle::PM_SmallIconSize, nullptr, this);
-        option.decorationSize = QSize(pm, pm);
+        option->decorationSize = QSize(pm, pm);
     }
-    option.decorationPosition = QStyleOptionViewItem::Left;
-    option.decorationAlignment = Qt::AlignCenter;
-    option.displayAlignment = Qt::AlignLeft|Qt::AlignVCenter;
-    option.textElideMode = d->textElideMode;
-    option.rect = QRect();
-    option.showDecorationSelected = style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, nullptr, this);
+    option->decorationPosition = QStyleOptionViewItem::Left;
+    option->decorationAlignment = Qt::AlignCenter;
+    option->displayAlignment = Qt::AlignLeft|Qt::AlignVCenter;
+    option->textElideMode = d->textElideMode;
+    option->rect = QRect();
+    option->showDecorationSelected = style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, nullptr, this);
     if (d->wrapItemText)
-        option.features = QStyleOptionViewItem::WrapText;
-    option.locale = locale();
-    option.locale.setNumberOptions(QLocale::OmitGroupSeparator);
-    option.widget = this;
-    return option;
+        option->features = QStyleOptionViewItem::WrapText;
+    option->locale = locale();
+    option->locale.setNumberOptions(QLocale::OmitGroupSeparator);
+    option->widget = this;
 }
 
 /*!
@@ -4352,7 +4365,8 @@ bool QAbstractItemViewPrivate::sendDelegateEvent(const QModelIndex &index, QEven
 {
     Q_Q(const QAbstractItemView);
     QModelIndex buddy = model->buddy(index);
-    QStyleOptionViewItem options = q->viewOptions();
+    QStyleOptionViewItem options;
+    q->initViewItemOption(&options);
     options.rect = q->visualRect(buddy);
     options.state |= (buddy == q->currentIndex() ? QStyle::State_HasFocus : QStyle::State_None);
     QAbstractItemDelegate *delegate = delegateForIndex(index);
@@ -4364,7 +4378,8 @@ bool QAbstractItemViewPrivate::openEditor(const QModelIndex &index, QEvent *even
     Q_Q(QAbstractItemView);
 
     QModelIndex buddy = model->buddy(index);
-    QStyleOptionViewItem options = q->viewOptions();
+    QStyleOptionViewItem options;
+    q->initViewItemOption(&options);
     options.rect = q->visualRect(buddy);
     options.state |= (buddy == q->currentIndex() ? QStyle::State_HasFocus : QStyle::State_None);
 
@@ -4424,7 +4439,8 @@ QPixmap QAbstractItemViewPrivate::renderToPixmap(const QModelIndexList &indexes,
 
     pixmap.fill(Qt::transparent);
     QPainter painter(&pixmap);
-    QStyleOptionViewItem option = q->viewOptions();
+    QStyleOptionViewItem option;
+    q->initViewItemOption(&option);
     option.state |= QStyle::State_Selected;
     for (int j = 0; j < paintPairs.count(); ++j) {
         option.rect = paintPairs.at(j).rect.translated(-r->topLeft());
diff --git a/src/widgets/itemviews/qabstractitemview.h b/src/widgets/itemviews/qabstractitemview.h
index 7efe5e3753..4b8effb63e 100644
--- a/src/widgets/itemviews/qabstractitemview.h
+++ b/src/widgets/itemviews/qabstractitemview.h
@@ -297,7 +297,7 @@ protected:
     virtual void startDrag(Qt::DropActions supportedActions);
 #endif
 
-    virtual QStyleOptionViewItem viewOptions() const;
+    virtual void initViewItemOption(QStyleOptionViewItem *option) const;
 
     enum State {
         NoState,
diff --git a/src/widgets/itemviews/qlistview.cpp b/src/widgets/itemviews/qlistview.cpp
index 385671f4fb..141937da75 100644
--- a/src/widgets/itemviews/qlistview.cpp
+++ b/src/widgets/itemviews/qlistview.cpp
@@ -971,29 +971,27 @@ void QListView::startDrag(Qt::DropActions supportedActions)
 /*!
   \reimp
 */
-QStyleOptionViewItem QListView::viewOptions() const
+void QListView::initViewItemOption(QStyleOptionViewItem *option) const
 {
     Q_D(const QListView);
-    QStyleOptionViewItem option = QAbstractItemView::viewOptions();
+    QAbstractItemView::initViewItemOption(option);
     if (!d->iconSize.isValid()) { // otherwise it was already set in abstractitemview
         int pm = (d->viewMode == QListView::ListMode
                   ? style()->pixelMetric(QStyle::PM_ListViewIconSize, nullptr, this)
                   : style()->pixelMetric(QStyle::PM_IconViewIconSize, nullptr, this));
-        option.decorationSize = QSize(pm, pm);
+        option->decorationSize = QSize(pm, pm);
     }
     if (d->viewMode == QListView::IconMode) {
-        option.showDecorationSelected = false;
-        option.decorationPosition = QStyleOptionViewItem::Top;
-        option.displayAlignment = Qt::AlignCenter;
+        option->showDecorationSelected = false;
+        option->decorationPosition = QStyleOptionViewItem::Top;
+        option->displayAlignment = Qt::AlignCenter;
     } else {
-        option.decorationPosition = QStyleOptionViewItem::Left;
+        option->decorationPosition = QStyleOptionViewItem::Left;
     }
 
     if (d->gridSize().isValid()) {
-        option.rect.setSize(d->gridSize());
+        option->rect.setSize(d->gridSize());
     }
-
-    return option;
 }
 
 
@@ -1005,7 +1003,8 @@ void QListView::paintEvent(QPaintEvent *e)
     Q_D(QListView);
     if (!d->itemDelegate)
         return;
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     QPainter painter(d->viewport);
 
     const QList<QModelIndex> toBeRendered =
@@ -1555,7 +1554,8 @@ void QListView::updateGeometries()
         verticalScrollBar()->setRange(0, 0);
     } else {
         QModelIndex index = d->model->index(0, d->column, d->root);
-        QStyleOptionViewItem option = viewOptions();
+        QStyleOptionViewItem option;
+        initViewItemOption(&option);
         QSize step = d->itemSize(option, index);
         d->commonListView->updateHorizontalScrollBar(step);
         d->commonListView->updateVerticalScrollBar(step);
@@ -2457,7 +2457,8 @@ QListViewItem QListModeViewBase::indexToListViewItem(const QModelIndex &index) c
                                            0, segmentStartRows.count() - 1);
 
 
-    QStyleOptionViewItem options = viewOptions();
+    QStyleOptionViewItem options;
+    initViewItemOption(&options);
     options.rect.setSize(contentsSize);
     QSize size = (uniformItemSizes() && cachedItemSize().isValid())
                  ? cachedItemSize() : itemSize(options, index);
@@ -2533,7 +2534,8 @@ void QListModeViewBase::doStaticLayout(const QListViewLayoutInfo &info)
 {
     const bool useItemSize = !info.grid.isValid();
     const QPoint topLeft = initStaticLayout(info);
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     option.rect = info.bounds;
     option.rect.adjust(info.spacing, info.spacing, -info.spacing, -info.spacing);
 
@@ -3007,7 +3009,8 @@ void QIconModeViewBase::scrollContentsBy(int dx, int dy, bool scrollElasticBand)
 void QIconModeViewBase::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
 {
     if (column() >= topLeft.column() && column() <= bottomRight.column())  {
-        const QStyleOptionViewItem option = viewOptions();
+        QStyleOptionViewItem option;
+        initViewItemOption(&option);
         const int bottom = qMin(items.count(), bottomRight.row() + 1);
         const bool useItemSize = !dd->grid.isValid();
         for (int row = topLeft.row(); row < bottom; ++row)
@@ -3027,7 +3030,8 @@ bool QIconModeViewBase::doBatchedItemLayout(const QListViewLayoutInfo &info, int
 {
     if (info.last >= items.count()) {
         //first we create the items
-        QStyleOptionViewItem option = viewOptions();
+        QStyleOptionViewItem option;
+        initViewItemOption(&option);
         for (int row = items.count(); row <= info.last; ++row) {
             QSize size = itemSize(option, modelIndex(row));
             QListViewItem item(QRect(0, 0, size.width(), size.height()), row); // default pos
diff --git a/src/widgets/itemviews/qlistview.h b/src/widgets/itemviews/qlistview.h
index a096029073..31b9958770 100644
--- a/src/widgets/itemviews/qlistview.h
+++ b/src/widgets/itemviews/qlistview.h
@@ -170,7 +170,7 @@ protected:
     void startDrag(Qt::DropActions supportedActions) override;
 #endif // QT_CONFIG(draganddrop)
 
-    QStyleOptionViewItem viewOptions() const override;
+    void initViewItemOption(QStyleOptionViewItem *option) const override;
     void paintEvent(QPaintEvent *e) override;
 
     int horizontalOffset() const override;
diff --git a/src/widgets/itemviews/qlistview_p.h b/src/widgets/itemviews/qlistview_p.h
index 78a8fa1c38..0701bc8c71 100644
--- a/src/widgets/itemviews/qlistview_p.h
+++ b/src/widgets/itemviews/qlistview_p.h
@@ -172,7 +172,7 @@ public:
     inline QModelIndex modelIndex(int row) const;
     inline int rowCount() const;
 
-    inline QStyleOptionViewItem viewOptions() const;
+    inline void initViewItemOption(QStyleOptionViewItem *option) const;
     inline QWidget *viewport() const;
     inline QRect clipRect() const;
 
@@ -483,7 +483,7 @@ inline QModelIndex QCommonListViewBase::modelIndex(int row) const
     { return dd->model->index(row, dd->column, dd->root); }
 inline int QCommonListViewBase::rowCount() const { return dd->model->rowCount(dd->root); }
 
-inline QStyleOptionViewItem QCommonListViewBase::viewOptions() const { return qq->viewOptions(); }
+inline void QCommonListViewBase::initViewItemOption(QStyleOptionViewItem *option) const { qq->initViewItemOption(option); }
 inline QWidget *QCommonListViewBase::viewport() const { return dd->viewport; }
 inline QRect QCommonListViewBase::clipRect() const { return dd->clipRect(); }
 
diff --git a/src/widgets/itemviews/qtableview.cpp b/src/widgets/itemviews/qtableview.cpp
index 115413cfaf..30f2eba912 100644
--- a/src/widgets/itemviews/qtableview.cpp
+++ b/src/widgets/itemviews/qtableview.cpp
@@ -1459,11 +1459,10 @@ void QTableView::scrollContentsBy(int dx, int dy)
 /*!
   \reimp
 */
-QStyleOptionViewItem QTableView::viewOptions() const
+void QTableView::initViewItemOption(QStyleOptionViewItem *option) const
 {
-    QStyleOptionViewItem option = QAbstractItemView::viewOptions();
-    option.showDecorationSelected = true;
-    return option;
+    QAbstractItemView::initViewItemOption(option);
+    option->showDecorationSelected = true;
 }
 
 /*!
@@ -1473,7 +1472,8 @@ void QTableView::paintEvent(QPaintEvent *event)
 {
     Q_D(QTableView);
     // setup temp variables for the painting
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     const QPoint offset = d->scrollDelayOffset;
     const bool showGrid = d->showGrid;
     const int gridSize = showGrid ? 1 : 0;
@@ -2352,7 +2352,8 @@ int QTableView::sizeHintForRow(int row) const
     if (right == -1) // the table don't have enough columns to fill the viewport
         right = d->model->columnCount(d->root) - 1;
 
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
 
     int hint = 0;
     QModelIndex index;
@@ -2440,7 +2441,8 @@ int QTableView::sizeHintForColumn(int column) const
     if (!isVisible() || bottom == -1) // the table don't have enough rows to fill the viewport
         bottom = d->model->rowCount(d->root) - 1;
 
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
 
     int hint = 0;
     int rowsProcessed = 0;
diff --git a/src/widgets/itemviews/qtableview.h b/src/widgets/itemviews/qtableview.h
index c71402014d..71caa37872 100644
--- a/src/widgets/itemviews/qtableview.h
+++ b/src/widgets/itemviews/qtableview.h
@@ -145,7 +145,7 @@ protected:
     QTableView(QTableViewPrivate &, QWidget *parent);
     void scrollContentsBy(int dx, int dy) override;
 
-    QStyleOptionViewItem viewOptions() const override;
+    void initViewItemOption(QStyleOptionViewItem *option) const override;
     void paintEvent(QPaintEvent *e) override;
 
     void timerEvent(QTimerEvent *event) override;
diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index abbdf13941..7f469a34d2 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -1472,7 +1472,8 @@ void QTreeView::drawTree(QPainter *painter, const QRegion &region) const
     Q_D(const QTreeView);
     const QList<QTreeViewItem> viewItems = d->viewItems;
 
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     const QStyle::State state = option.state;
     d->current = 0;
 
@@ -1834,7 +1835,8 @@ void QTreeView::drawBranches(QPainter *painter, const QRect &rect,
     QModelIndex current = parent;
     QModelIndex ancestor = current.parent();
 
-    QStyleOptionViewItem opt = viewOptions();
+    QStyleOptionViewItem opt;
+    initViewItemOption(&opt);
     QStyle::State extraFlags = QStyle::State_None;
     if (isEnabled())
         extraFlags |= QStyle::State_Enabled;
@@ -2868,7 +2870,8 @@ int QTreeView::sizeHintForColumn(int column) const
         return -1;
     ensurePolished();
     int w = 0;
-    QStyleOptionViewItem option = viewOptions();
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
     const QList<QTreeViewItem> viewItems = d->viewItems;
 
     const int maximumProcessRows = d->header->resizeContentsPrecision(); // To avoid this to take forever.
@@ -2980,8 +2983,9 @@ int QTreeView::indexRowSizeHint(const QModelIndex &index) const
         qSwap(end, start);
 
     int height = -1;
-    QStyleOptionViewItem option = viewOptions();
-    // ### If we want word wrapping in the items,
+    QStyleOptionViewItem option;
+    initViewItemOption(&option);
+   // ### If we want word wrapping in the items,
     // ### we need to go through all the columns
     // ### and set the width of the column
 
@@ -3252,7 +3256,8 @@ QPixmap QTreeViewPrivate::renderTreeToPixmapForAnimation(const QRect &rect) cons
     painter.end();
 
     //and now let's render the editors the editors
-    QStyleOptionViewItem option = q->viewOptions();
+    QStyleOptionViewItem option;
+    q->initViewItemOption(&option);
     for (QEditorIndexHash::const_iterator it = editorIndexHash.constBegin(); it != editorIndexHash.constEnd(); ++it) {
         QWidget *editor = it.key();
         const QModelIndex &index = it.value();