Item delegates: show localized detailed tooltips and "What's this?" texts

Extract the common part from QItemDelegate and QStyledItemDelegate
which uses QLocale to convert a value for Qt::DisplayRole to a string.
Use this code to get the text for tooltips and "What's this?".

[ChangeLog][QtWidgets][QAbstractItemDelegate] Show localized detailed
tooltips and "What's this?" texts.

Task-number: QTBUG-16469
Change-Id: I8618763d45b8cfddafc2f263d658ba256be60a15
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

1 files changed, 6 insertions, 36 deletions

diff --git a/src/widgets/itemviews/qitemdelegate.cpp b/src/widgets/itemviews/qitemdelegate.cpp
index cd952737dd..2b6e1210ca 100644
--- a/src/widgets/itemviews/qitemdelegate.cpp
+++ b/src/widgets/itemviews/qitemdelegate.cpp
@@ -61,6 +61,7 @@
 
 #include <limits.h>
 
+// keep in sync with QAbstractItemDelegate::helpEvent()
 #ifndef DBL_DIG
 #  define DBL_DIG 10
 #endif
@@ -96,7 +97,7 @@ public:
             return text;
         }
 
-    static QString valueToText(const QVariant &value, const QStyleOptionViewItem &option);
+    QString valueToText(const QVariant &value, const QStyleOptionViewItem &option) const;
 
     QItemEditorFactory *f;
     bool clipPainting;
@@ -326,40 +327,9 @@ void QItemDelegate::setClipping(bool clip)
     d->clipPainting = clip;
 }
 
-QString QItemDelegatePrivate::valueToText(const QVariant &value, const QStyleOptionViewItem &option)
+QString QItemDelegatePrivate::valueToText(const QVariant &value, const QStyleOptionViewItem &option) const
 {
-    QString text;
-    switch (value.userType()) {
-        case QMetaType::Float:
-            text = option.locale.toString(value.toFloat(), 'g');
-            break;
-        case QVariant::Double:
-            text = option.locale.toString(value.toDouble(), 'g', DBL_DIG);
-            break;
-        case QVariant::Int:
-        case QVariant::LongLong:
-            text = option.locale.toString(value.toLongLong());
-            break;
-        case QVariant::UInt:
-        case QVariant::ULongLong:
-            text = option.locale.toString(value.toULongLong());
-            break;
-        case QVariant::Date:
-            text = option.locale.toString(value.toDate(), QLocale::ShortFormat);
-            break;
-        case QVariant::Time:
-            text = option.locale.toString(value.toTime(), QLocale::ShortFormat);
-            break;
-        case QVariant::DateTime:
-            text = option.locale.toString(value.toDateTime().date(), QLocale::ShortFormat);
-            text += QLatin1Char(' ');
-            text += option.locale.toString(value.toDateTime().time(), QLocale::ShortFormat);
-            break;
-        default:
-            text = replaceNewLine(value.toString());
-            break;
-    }
-    return text;
+    return textForRole(Qt::DisplayRole, value, option.locale, DBL_DIG);
 }
 
 /*!
@@ -428,7 +398,7 @@ void QItemDelegate::paint(QPainter *painter,
     QRect displayRect;
     value = index.data(Qt::DisplayRole);
     if (value.isValid() && !value.isNull()) {
-        text = QItemDelegatePrivate::valueToText(value, opt);
+        text = d->valueToText(value, opt);
         displayRect = textRectangle(painter, d->textLayoutBounds(opt), opt.font, text);
     }
 
@@ -1055,7 +1025,7 @@ QRect QItemDelegate::rect(const QStyleOptionViewItem &option,
             return QRect(QPoint(0, 0), option.decorationSize);
         case QVariant::String:
         default: {
-            QString text = QItemDelegatePrivate::valueToText(value, option);
+            const QString text = d->valueToText(value, option);
             value = index.data(Qt::FontRole);
             QFont fnt = qvariant_cast<QFont>(value).resolve(option.font);
             return textRectangle(0, d->textLayoutBounds(option), fnt, text); }