1 files changed, 125 insertions, 44 deletions

diff --git a/src/widgets/widgets/qcombobox.cpp b/src/widgets/widgets/qcombobox.cpp
index 9a0e969e1c..d786c7ff83 100644
--- a/src/widgets/widgets/qcombobox.cpp
+++ b/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),
-      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
+      inserting(false)
 {
 }
 
@@ -148,7 +129,15 @@ QStyleOptionMenuItem QComboMenuDelegate::getStyleOption(const QStyleOptionViewIt
     if (option.state & QStyle::State_Selected)
         menuOption.state |= QStyle::State_Selected;
     menuOption.checkType = QStyleOptionMenuItem::NonExclusive;
-    menuOption.checked = mCombo->currentIndex() == index.row();
+    // a valid checkstate means that the model has checkable items
+    const QVariant checkState = index.data(Qt::CheckStateRole);
+    if (!checkState.isValid()) {
+        menuOption.checked = mCombo->currentIndex() == index.row();
+    } else {
+        menuOption.checked = qvariant_cast<int>(checkState) == Qt::Checked;
+        menuOption.state |= qvariant_cast<int>(checkState) == Qt::Checked
+                          ? QStyle::State_On : QStyle::State_Off;
+    }
     if (QComboBoxDelegate::isSeparator(index))
         menuOption.menuItemType = QStyleOptionMenuItem::Separator;
     else
@@ -183,7 +172,7 @@ QStyleOptionMenuItem QComboMenuDelegate::getStyleOption(const QStyleOptionViewIt
     // that order, also override the font for the popup menu.
     QVariant fontRoleData = index.data(Qt::FontRole);
     if (fontRoleData.isValid()) {
-        menuOption.font = fontRoleData.value<QFont>();
+        menuOption.font = qvariant_cast<QFont>(fontRoleData);
     } else if (mCombo->testAttribute(Qt::WA_SetFont)
             || mCombo->testAttribute(Qt::WA_MacSmallSize)
             || mCombo->testAttribute(Qt::WA_MacMiniSize)
@@ -198,6 +187,55 @@ QStyleOptionMenuItem QComboMenuDelegate::getStyleOption(const QStyleOptionViewIt
     return menuOption;
 }
 
+bool QComboMenuDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
+                                     const QStyleOptionViewItem &option, const QModelIndex &index)
+{
+    Q_ASSERT(event);
+    Q_ASSERT(model);
+
+    // make sure that the item is checkable
+    Qt::ItemFlags flags = model->flags(index);
+    if (!(flags & Qt::ItemIsUserCheckable) || !(option.state & QStyle::State_Enabled)
+        || !(flags & Qt::ItemIsEnabled))
+        return false;
+
+    // make sure that we have a check state
+    const QVariant checkState = index.data(Qt::CheckStateRole);
+    if (!checkState.isValid())
+        return false;
+
+    // make sure that we have the right event type
+    if ((event->type() == QEvent::MouseButtonRelease)
+        || (event->type() == QEvent::MouseButtonDblClick)
+        || (event->type() == QEvent::MouseButtonPress)) {
+        QMouseEvent *me = static_cast<QMouseEvent*>(event);
+        if (me->button() != Qt::LeftButton)
+            return false;
+
+        if ((event->type() == QEvent::MouseButtonPress)
+            || (event->type() == QEvent::MouseButtonDblClick)) {
+            pressedIndex = index.row();
+            return false;
+        }
+
+        if (index.row() != pressedIndex)
+            return false;
+        pressedIndex = -1;
+
+    } else if (event->type() == QEvent::KeyPress) {
+        if (static_cast<QKeyEvent*>(event)->key() != Qt::Key_Space
+         && static_cast<QKeyEvent*>(event)->key() != Qt::Key_Select)
+            return false;
+    } else {
+        return false;
+    }
+
+    // we don't support user-tristate items in QComboBox (not implemented in any style)
+    Qt::CheckState newState = (static_cast<Qt::CheckState>(checkState.toInt()) == Qt::Checked)
+                            ? Qt::Unchecked : Qt::Checked;
+    return model->setData(index, newState, Qt::CheckStateRole);
+}
+
 #if QT_CONFIG(completer)
 void QComboBoxPrivate::_q_completerActivated(const QModelIndex &index)
 {
@@ -368,6 +406,8 @@ QSize QComboBoxPrivate::recomputeSizeHint(QSize &sh) const
         }
         if (minimumContentsLength > 0)
             sh.setWidth(qMax(sh.width(), minimumContentsLength * fm.horizontalAdvance(QLatin1Char('X')) + (hasIcon ? iconSize.width() + 4 : 0)));
+        if (!placeholderText.isEmpty())
+            sh.setWidth(qMax(sh.width(), fm.boundingRect(placeholderText).width()));
 
 
         // height
@@ -445,12 +485,8 @@ 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);
@@ -555,7 +591,7 @@ void QComboBoxPrivateContainer::updateScrollers()
 */
 void QComboBoxPrivateContainer::viewDestroyed()
 {
-    view = 0;
+    view = nullptr;
     setItemView(new QComboBoxListView());
 }
 
@@ -589,7 +625,7 @@ void QComboBoxPrivateContainer::setItemView(QAbstractItemView *itemView)
 
         if (isAncestorOf(view))
             delete view;
-        view = 0;
+        view = nullptr;
     }
 
     // setup the item view
@@ -929,7 +965,7 @@ QStyleOptionComboBox QComboBoxPrivateContainer::comboStyleOption() const
     model QStandardItemModel.
 */
 QComboBox::QComboBox(QWidget *parent)
-    : QWidget(*new QComboBoxPrivate(), parent, 0)
+    : QWidget(*new QComboBoxPrivate(), parent, { })
 {
     Q_D(QComboBox);
     d->init();
@@ -939,7 +975,7 @@ QComboBox::QComboBox(QWidget *parent)
   \internal
 */
 QComboBox::QComboBox(QComboBoxPrivate &dd, QWidget *parent)
-    : QWidget(dd, parent, 0)
+    : QWidget(dd, parent, { })
 {
     Q_D(QComboBox);
     d->init();
@@ -1110,8 +1146,9 @@ void QComboBoxPrivate::_q_rowsInserted(const QModelIndex &parent, int start, int
         q->updateGeometry();
     }
 
-    // set current index if combo was previously empty
-    if (start == 0 && (end - start + 1) == q->count() && !currentIndex.isValid()) {
+    // set current index if combo was previously empty and there is no placeholderText
+    if (start == 0 && (end - start + 1) == q->count() && !currentIndex.isValid() &&
+        placeholderText.isEmpty()) {
         q->setCurrentIndex(0);
         // need to emit changed if model updated index "silently"
     } else if (currentIndex.row() != indexBeforeChange) {
@@ -1214,10 +1251,9 @@ void QComboBox::initStyleOption(QStyleOptionComboBox *option) const
     } else {
         option->activeSubControls = d->hoverControl;
     }
-    if (d->currentIndex.isValid()) {
-        option->currentText = currentText();
+    option->currentText = currentText();
+    if (d->currentIndex.isValid())
         option->currentIcon = d->itemIcon(d->currentIndex);
-    }
     option->iconSize = iconSize();
     if (d->container && d->container->isVisible())
         option->state |= QStyle::State_On;
@@ -1566,7 +1602,7 @@ void QComboBox::setAutoCompletion(bool enable)
         d->lineEdit->setCompleter(d->completer);
         d->completer->setWidget(this);
     } else {
-        d->lineEdit->setCompleter(0);
+        d->lineEdit->setCompleter(nullptr);
     }
 }
 
@@ -1755,7 +1791,7 @@ 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);
 }
 
@@ -1772,6 +1808,45 @@ void QComboBox::setIconSize(const QSize &size)
 }
 
 /*!
+    \property QComboBox::placeholderText
+    \brief Sets a \a placeholderText text shown when no valid index is set
+
+    The \a placeholderText will be shown when an invalid index is set. The
+    text is not accessible in the dropdown list. When this function is called
+    before items are added the placeholder text will be shown, otherwise you
+    have to call setCurrentIndex(-1) programmatically if you want to show the
+    placeholder text.
+    Set an empty placeholder text to reset the setting.
+
+    When the QComboBox is editable, use QLineEdit::setPlaceholderText()
+    instead.
+
+    \since 5.15
+*/
+void QComboBox::setPlaceholderText(const QString &placeholderText)
+{
+    Q_D(QComboBox);
+    if (placeholderText == d->placeholderText)
+        return;
+
+    d->placeholderText = placeholderText;
+    if (currentIndex() == -1) {
+      if (d->placeholderText.isEmpty() && currentIndex() == -1)
+        setCurrentIndex(0);
+      else
+        update();
+    } else {
+      updateGeometry();
+    }
+}
+
+QString QComboBox::placeholderText() const
+{
+    Q_D(const QComboBox);
+    return d->placeholderText;
+}
+
+/*!
     \property QComboBox::editable
     \brief whether the combo box can be edited by the user
 
@@ -1786,7 +1861,7 @@ void QComboBox::setIconSize(const QSize &size)
 bool QComboBox::isEditable() const
 {
     Q_D(const QComboBox);
-    return d->lineEdit != 0;
+    return d->lineEdit != nullptr;
 }
 
 /*! \internal
@@ -1842,7 +1917,7 @@ void QComboBox::setEditable(bool editable)
         setAttribute(Qt::WA_InputMethodEnabled, false);
         d->lineEdit->hide();
         d->lineEdit->deleteLater();
-        d->lineEdit = 0;
+        d->lineEdit = nullptr;
     }
 
     d->updateDelegate();
@@ -1891,6 +1966,8 @@ 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);
 
@@ -1907,6 +1984,7 @@ void QComboBox::setLineEdit(QLineEdit *edit)
     }
 #endif
 #endif
+QT_WARNING_POP
 #endif
 
     setAttribute(Qt::WA_InputMethodEnabled);
@@ -1955,7 +2033,7 @@ 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
 
@@ -1999,7 +2077,7 @@ 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)
@@ -2249,7 +2327,7 @@ QString QComboBox::currentText() const
     else if (d->currentIndex.isValid())
         return d->itemText(d->currentIndex);
     else
-        return QString();
+        return d->placeholderText;
 }
 
 /*!
@@ -2886,7 +2964,7 @@ 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();
@@ -3079,6 +3157,9 @@ void QComboBox::paintEvent(QPaintEvent *)
     initStyleOption(&opt);
     painter.drawComplexControl(QStyle::CC_ComboBox, opt);
 
+    if (currentIndex() < 0)
+        opt.palette.setBrush(QPalette::ButtonText, opt.palette.brush(QPalette::ButtonText).color().lighter());
+
     // draw the icon and text
     painter.drawControl(QStyle::CE_ComboBoxLabel, opt);
 }