QItemViews: hide ToolTip/What's this when cell has no data for it

A QToolTip/QWhatsThis was not hidden when the cursor moved to a cell
which does not return valid data for Qt::ToolTip/WhatsThisRole or when
the index is not valid. Therefore a wrong information was shown e.g.
when the cursor moved from a cell with a tooltip to one without.
Fix it by passing an empty string to QToolTip/QWhatsThis::showText().
This syncs the behavior with QGraphicsScene::helpEvent().

Fixes: QTBUG-78722
Change-Id: Ie99fe3b1d35d2f5be41dd65e2fe3173b0cc551b2
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 22 insertions, 20 deletions

diff --git a/src/widgets/itemviews/qabstractitemdelegate.cpp b/src/widgets/itemviews/qabstractitemdelegate.cpp
index 31dde8832b..eecc18e5c7 100644
--- a/src/widgets/itemviews/qabstractitemdelegate.cpp
+++ b/src/widgets/itemviews/qabstractitemdelegate.cpp
@@ -387,44 +387,46 @@ bool QAbstractItemDelegate::helpEvent(QHelpEvent *event,
                                       const QStyleOptionViewItem &option,
                                       const QModelIndex &index)
 {
-    Q_D(QAbstractItemDelegate);
-    Q_UNUSED(d);
-    Q_UNUSED(index);
-    Q_UNUSED(option);
-
     if (!event || !view)
         return false;
+    Q_D(QAbstractItemDelegate);
     switch (event->type()) {
 #ifndef QT_NO_TOOLTIP
     case QEvent::ToolTip: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
         const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
-        const QString tooltip = d->textForRole(Qt::ToolTipRole, index.data(Qt::ToolTipRole), option.locale, precision);
-        if (!tooltip.isEmpty()) {
-            QToolTip::showText(he->globalPos(), tooltip, view);
-            return true;
+        const QString tooltip = index.isValid() ?
+              d->textForRole(Qt::ToolTipRole, index.data(Qt::ToolTipRole), option.locale, precision) :
+              QString();
+        QRect rect;
+        if (index.isValid()) {
+            const QRect r = view->visualRect(index);
+            rect = QRect(view->mapToGlobal(r.topLeft()), r.size());
+        }
+        QToolTip::showText(he->globalPos(), tooltip, view, rect);
+        event->setAccepted(!tooltip.isEmpty());
+        break;
         }
-        break;}
 #endif
 #if QT_CONFIG(whatsthis)
-    case QEvent::QueryWhatsThis: {
-        if (index.data(Qt::WhatsThisRole).isValid())
-            return true;
-        break; }
+    case QEvent::QueryWhatsThis:
+        event->setAccepted(index.data(Qt::WhatsThisRole).isValid());
+        break;
     case QEvent::WhatsThis: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
         const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
-        const QString whatsthis = d->textForRole(Qt::WhatsThisRole, index.data(Qt::WhatsThisRole), option.locale, precision);
-        if (!whatsthis.isEmpty()) {
-            QWhatsThis::showText(he->globalPos(), whatsthis, view);
-            return true;
+        const QString whatsthis = index.isValid() ?
+              d->textForRole(Qt::WhatsThisRole, index.data(Qt::WhatsThisRole), option.locale, precision) :
+              QString();
+        QWhatsThis::showText(he->globalPos(), whatsthis, view);
+        event->setAccepted(!whatsthis.isEmpty());
+        break;
         }
-        break ; }
 #endif
     default:
         break;
     }
-    return false;
+    return event->isAccepted();
 }
 
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