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>

4 files changed, 10 insertions, 3 deletions

diff --git a/ui/qt/percent_bar_delegate.cpp b/ui/qt/percent_bar_delegate.cpp
index 2a8ea0b2f2..358650ee5d 100644
--- a/ui/qt/percent_bar_delegate.cpp
+++ b/ui/qt/percent_bar_delegate.cpp
@@ -37,7 +37,7 @@ void PercentBarDelegate::paint(QPainter *painter, const QStyleOptionViewItem &op
 
     // Paint our rect with no text using the current style, then draw our
     // bar and text over it.
-    QStyledItemDelegate::paint(painter, option, QModelIndex());
+    QStyledItemDelegate::paint(painter, option, index);
 
     bool ok = false;
     double value = index.data(Qt::UserRole).toDouble(&ok);
diff --git a/ui/qt/percent_bar_delegate.h b/ui/qt/percent_bar_delegate.h
index 0a3ac9af67..2c8d47288f 100644
--- a/ui/qt/percent_bar_delegate.h
+++ b/ui/qt/percent_bar_delegate.h
@@ -51,6 +51,10 @@ class PercentBarDelegate : public QStyledItemDelegate
 
 public:
     PercentBarDelegate(QWidget *parent = 0) : QStyledItemDelegate(parent) { }
+
+    // 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;
diff --git a/ui/qt/timeline_delegate.cpp b/ui/qt/timeline_delegate.cpp
index 0cfdd73147..2162da1030 100644
--- a/ui/qt/timeline_delegate.cpp
+++ b/ui/qt/timeline_delegate.cpp
@@ -43,12 +43,11 @@ void TimelineDelegate::paint(QPainter *painter, const QStyleOptionViewItem &opti
     QStyleOptionViewItem option_vi = option;
     QStyledItemDelegate::initStyleOption(&option_vi, index);
 
-
     struct timeline_span span_px = index.data(Qt::UserRole).value<struct timeline_span>();
 
     // Paint our rect with no text using the current style, then draw our
     // bar and text over it.
-    QStyledItemDelegate::paint(painter, option, QModelIndex());
+    QStyledItemDelegate::paint(painter, option, index);
 
     if (QApplication::style()->objectName().contains("vista")) {
         // QWindowsVistaStyle::drawControl does this internally. Unfortunately there
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;