Qt: Fix QStyledItemDelegate assertions.

QStyledItemDelegate::paint asserts if you pass it an empty QModelIndex.
We were doing this in PercentBarDelegate and TimelineDelegate in order to
keep it from drawing any text. Return an empty string from ::displayText
instead, which appears to be the correct way to paint without text.

Bug: 13180
Change-Id: I8064d9575e04e95a926797eec7f6ad2b0bfef1c0
Reviewed-on: https://code.wireshark.org/review/19007
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/ui/qt/timeline_delegate.h b/ui/qt/timeline_delegate.h
index face6da320..bc64c24877 100644
--- a/ui/qt/timeline_delegate.h
+++ b/ui/qt/timeline_delegate.h
@@ -58,6 +58,10 @@ class TimelineDelegate : public QStyledItemDelegate
 
 public:
     TimelineDelegate(QWidget *parent = 0);
+
+    // Make sure QStyledItemDelegate::paint doesn't draw any text.
+    virtual QString displayText(const QVariant &, const QLocale &) const { return QString(); }
+
 protected:
     void paint(QPainter *painter, const QStyleOptionViewItem &option,
                const QModelIndex &index) const;