QComboBox cleanup: use member initialization and nullptr

Cleanup QComboBox private classes:
 - rearrange members to avoid unneeded padding
 - use nullptr
 - remove unused functions
 - don't print warnings about own deprecated functions

Change-Id: I350d1c63602e32cf4b45549bc35cf1538dbbe8f0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

src/widgets/widgets/qcombobox.cpp

@@ -91,30 +91,11 @@ QT_BEGIN_NAMESPACE
 
 QComboBoxPrivate::QComboBoxPrivate()
     : QWidgetPrivate(),
-      model(0),
-      lineEdit(0),
-      container(0),
-      insertPolicy(QComboBox::InsertAtBottom),
-      sizeAdjustPolicy(QComboBox::AdjustToContentsOnFirstShow),
-      minimumContentsLength(0),
       shownOnce(false),
       autoCompletion(true),
       duplicatesEnabled(false),
       frame(true),
-      maxVisibleItems(10),
+      inserting(false)
-      maxCount(INT_MAX),
-      modelColumn(0),
-      inserting(false),
-      arrowState(QStyle::State_None),
-      hoverControl(QStyle::SC_None),
-      autoCompletionCaseSensitivity(Qt::CaseInsensitive),
-      indexBeforeChange(-1)
-#ifdef Q_OS_MAC
-      , m_platformMenu(0)
-#endif
-#if QT_CONFIG(completer)
-      , completer(0)
-#endif
 {
 }
 
@@ -447,12 +428,8 @@ void QComboBoxPrivateContainer::paintEvent(QPaintEvent *e)
     QFrame::paintEvent(e);
 }
 
-void QComboBoxPrivateContainer::leaveEvent(QEvent *)
-{
-}
-
 QComboBoxPrivateContainer::QComboBoxPrivateContainer(QAbstractItemView *itemView, QComboBox *parent)
-    : QFrame(parent, Qt::Popup), combo(parent), view(0), top(0), bottom(0), maybeIgnoreMouseButtonRelease(false)
+    : QFrame(parent, Qt::Popup), combo(parent)
 {
     // we need the combobox and itemview
     Q_ASSERT(parent);
@@ -557,7 +534,7 @@ void QComboBoxPrivateContainer::updateScrollers()
 */
 void QComboBoxPrivateContainer::viewDestroyed()
 {
-    view = 0;
+    view = nullptr;
     setItemView(new QComboBoxListView());
 }
 
@@ -591,7 +568,7 @@ void QComboBoxPrivateContainer::setItemView(QAbstractItemView *itemView)
 
         if (isAncestorOf(view))
             delete view;
-        view = 0;
+        view = nullptr;
     }
 
     // setup the item view
@@ -1568,7 +1545,7 @@ void QComboBox::setAutoCompletion(bool enable)
         d->lineEdit->setCompleter(d->completer);
         d->completer->setWidget(this);
     } else {
-        d->lineEdit->setCompleter(0);
+        d->lineEdit->setCompleter(nullptr);
     }
 }
 
@@ -1757,7 +1734,7 @@ QSize QComboBox::iconSize() const
     if (d->iconSize.isValid())
         return d->iconSize;
 
-    int iconWidth = style()->pixelMetric(QStyle::PM_SmallIconSize, 0, this);
+    int iconWidth = style()->pixelMetric(QStyle::PM_SmallIconSize, nullptr, this);
     return QSize(iconWidth, iconWidth);
 }
 
@@ -1827,7 +1804,7 @@ QString QComboBox::placeholderText() const
 bool QComboBox::isEditable() const
 {
     Q_D(const QComboBox);
-    return d->lineEdit != 0;
+    return d->lineEdit != nullptr;
 }
 
 /*! \internal
@@ -1883,7 +1860,7 @@ void QComboBox::setEditable(bool editable)
         setAttribute(Qt::WA_InputMethodEnabled, false);
         d->lineEdit->hide();
         d->lineEdit->deleteLater();
-        d->lineEdit = 0;
+        d->lineEdit = nullptr;
     }
 
     d->updateDelegate();
@@ -1932,6 +1909,8 @@ void QComboBox::setLineEdit(QLineEdit *edit)
     d->lineEdit->setFocusProxy(this);
     d->lineEdit->setAttribute(Qt::WA_MacShowFocusRect, false);
 #if QT_DEPRECATED_SINCE(5, 13)
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_DEPRECATED
 #if QT_CONFIG(completer)
     setAutoCompletion(d->autoCompletion);
 
@@ -1948,6 +1927,7 @@ void QComboBox::setLineEdit(QLineEdit *edit)
     }
 #endif
 #endif
+QT_WARNING_POP
 #endif
 
     setAttribute(Qt::WA_InputMethodEnabled);
@@ -1996,7 +1976,7 @@ void QComboBox::setValidator(const QValidator *v)
 const QValidator *QComboBox::validator() const
 {
     Q_D(const QComboBox);
-    return d->lineEdit ? d->lineEdit->validator() : 0;
+    return d->lineEdit ? d->lineEdit->validator() : nullptr;
 }
 #endif // QT_NO_VALIDATOR
 
@@ -2040,7 +2020,7 @@ void QComboBox::setCompleter(QCompleter *c)
 QCompleter *QComboBox::completer() const
 {
     Q_D(const QComboBox);
-    return d->lineEdit ? d->lineEdit->completer() : 0;
+    return d->lineEdit ? d->lineEdit->completer() : nullptr;
 }
 
 #endif // QT_CONFIG(completer)
@@ -2927,7 +2907,7 @@ void QComboBox::hidePopup()
         QSignalBlocker containerBlocker(d->container);
         // Flash selected/triggered item (if any).
         if (style()->styleHint(QStyle::SH_Menu_FlashTriggeredItem)) {
-            QItemSelectionModel *selectionModel = view() ? view()->selectionModel() : 0;
+            QItemSelectionModel *selectionModel = view() ? view()->selectionModel() : nullptr;
             if (selectionModel && selectionModel->hasSelection()) {
                 QEventLoop eventLoop;
                 const QItemSelection selection = selectionModel->selection();

src/widgets/widgets/qcombobox_p.h

@@ -79,7 +79,6 @@ QT_REQUIRE_CONFIG(combobox);
 
 QT_BEGIN_NAMESPACE
 
-class QAction;
 class QPlatformMenu;
 
 class QComboBoxListView : public QListView
@@ -131,9 +130,6 @@ private:
     QComboBox *combo;
 };
 
-
-class QStandardItemModel;
-
 class Q_AUTOTEST_EXPORT QComboBoxPrivateScroller : public QWidget
 {
     Q_OBJECT
@@ -212,7 +208,7 @@ Q_SIGNALS:
 private:
     QAbstractSlider::SliderAction sliderAction;
     QBasicTimer timer;
-    bool fast;
+    bool fast = false;
 };
 
 class Q_WIDGETS_EXPORT QComboBoxPrivateContainer : public QFrame
@@ -246,7 +242,6 @@ protected:
     void showEvent(QShowEvent *e) override;
     void hideEvent(QHideEvent *e) override;
     void timerEvent(QTimerEvent *timerEvent) override;
-    void leaveEvent(QEvent *e) override;
     void resizeEvent(QResizeEvent *e) override;
     void paintEvent(QPaintEvent *e) override;
     QStyleOptionComboBox comboStyleOption() const;
@@ -257,18 +252,19 @@ Q_SIGNALS:
 
 private:
     QComboBox *combo;
-    QAbstractItemView *view;
+    QAbstractItemView *view = nullptr;
-    QComboBoxPrivateScroller *top;
+    QComboBoxPrivateScroller *top = nullptr;
-    QComboBoxPrivateScroller *bottom;
+    QComboBoxPrivateScroller *bottom = nullptr;
-    bool maybeIgnoreMouseButtonRelease;
     QElapsedTimer popupTimer;
+    bool maybeIgnoreMouseButtonRelease = false;
 
     friend class QComboBox;
     friend class QComboBoxPrivate;
 };
 
 class Q_AUTOTEST_EXPORT QComboMenuDelegate : public QAbstractItemDelegate
-{ Q_OBJECT
+{
+    Q_OBJECT
 public:
     QComboMenuDelegate(QObject *parent, QComboBox *cmb) : QAbstractItemDelegate(parent), mCombo(cmb) {}
 
@@ -355,8 +351,8 @@ public:
     void _q_complete();
     void _q_itemSelected(const QModelIndex &item);
     bool contains(const QString &text, int role);
-    void emitActivated(const QModelIndex&);
+    void emitActivated(const QModelIndex &index);
-    void _q_emitHighlighted(const QModelIndex&);
+    void _q_emitHighlighted(const QModelIndex &index);
     void _q_emitCurrentIndexChanged(const QModelIndex &index);
     void _q_modelDestroyed();
     void _q_modelReset();
@@ -366,8 +362,8 @@ public:
     void _q_resetButton();
     void _q_dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight);
     void _q_updateIndexBeforeChange();
-    void _q_rowsInserted(const QModelIndex & parent, int start, int end);
+    void _q_rowsInserted(const QModelIndex &parent, int start, int end);
-    void _q_rowsRemoved(const QModelIndex & parent, int start, int end);
+    void _q_rowsRemoved(const QModelIndex &parent, int start, int end);
     void updateArrow(QStyle::StateFlag state);
     bool updateHoverControl(const QPoint &pos);
     QRect popupGeometry(int screen = -1) const;
@@ -402,40 +398,38 @@ public:
     };
 #endif
 
-    QAbstractItemModel *model;
+    QAbstractItemModel *model = nullptr;
-    QLineEdit *lineEdit;
+    QLineEdit *lineEdit = nullptr;
-    QComboBoxPrivateContainer *container;
+    QComboBoxPrivateContainer *container = nullptr;
-    QComboBox::InsertPolicy insertPolicy;
-    QComboBox::SizeAdjustPolicy sizeAdjustPolicy;
-    int minimumContentsLength;
-    QSize iconSize;
-    uint shownOnce : 1;
-    uint autoCompletion : 1;
-    uint duplicatesEnabled : 1;
-    uint frame : 1;
-    uint padding : 26;
-    int maxVisibleItems;
-    int maxCount;
-    int modelColumn;
-    QString placeholderText;
-    bool inserting;
-    mutable QSize minimumSizeHint;
-    mutable QSize sizeHint;
-    QStyle::StateFlag arrowState;
-    QStyle::SubControl hoverControl;
-    QRect hoverRect;
-    QPersistentModelIndex currentIndex;
-    QPersistentModelIndex root;
-    Qt::CaseSensitivity autoCompletionCaseSensitivity;
-    int indexBeforeChange;
 #ifdef Q_OS_MAC
-    QPlatformMenu *m_platformMenu;
+    QPlatformMenu *m_platformMenu = nullptr;
 #endif
 #if QT_CONFIG(completer)
     QPointer<QCompleter> completer;
 #endif
-    static QPalette viewContainerPalette(QComboBox *cmb)
+    QPersistentModelIndex currentIndex;
-    { return cmb->d_func()->viewContainer()->palette(); }
+    QPersistentModelIndex root;
+    QString placeholderText;
+    QRect hoverRect;
+    QSize iconSize;
+    mutable QSize minimumSizeHint;
+    mutable QSize sizeHint;
+    QComboBox::InsertPolicy insertPolicy = QComboBox::InsertAtBottom;
+    QComboBox::SizeAdjustPolicy sizeAdjustPolicy = QComboBox::AdjustToContentsOnFirstShow;
+    QStyle::StateFlag arrowState = QStyle::State_None;
+    QStyle::SubControl hoverControl = QStyle::SC_None;
+    Qt::CaseSensitivity autoCompletionCaseSensitivity = Qt::CaseInsensitive;
+    int minimumContentsLength = 0;
+    int indexBeforeChange = -1;
+    int maxVisibleItems = 10;
+    int maxCount = std::numeric_limits<int>::max();
+    int modelColumn = 0;
+    int placeholderIndex = -1;
+    bool shownOnce : 1;
+    bool autoCompletion : 1;
+    bool duplicatesEnabled : 1;
+    bool frame : 1;
+    bool inserting : 1;
 };
 
 QT_END_NAMESPACE