Qt: Add hover style to packet list and proto tree

Highlight the row in packet list and proto tree when mouse hovers
above the row. This mimics the behaviour on Windows.

Change-Id: I28461f9d7740269bad39893597232fe775f77a86
Reviewed-on: https://code.wireshark.org/review/32619
Petri-Dish: Stig Bjørlykke <stig@bjorlykke.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

ui/qt/models/related_packet_delegate.cpp

@@ -73,6 +73,11 @@ void RelatedPacketDelegate::paint(QPainter *painter, const QStyleOptionViewItem
     QColor fg;
     if (cg == QPalette::Normal && !(option_vi.state & QStyle::State_Active))
         cg = QPalette::Inactive;
+#if !defined(Q_OS_WIN)
+    if (option_vi.state & QStyle::State_MouseOver) {
+        fg = QApplication::palette().text().color();
+    } else
+#endif
     if (option_vi.state & QStyle::State_Selected) {
         fg = option_vi.palette.color(cg, QPalette::HighlightedText);
     } else {

ui/qt/packet_list.cpp

@@ -297,6 +297,23 @@ void PacketList::colorsChanged()
         "  background-color: qlineargradient(x1:0, y1:0, x2:0, y2:1 stop: 0 %4, stop: 0.5 %3, stop: 1 %4);"
         "}";
 
+    QString hover_style;
+#if !defined(Q_OS_WIN)
+#if defined(Q_OS_MAC)
+    QPalette default_pal = QApplication::palette();
+    default_pal.setCurrentColorGroup(QPalette::Active);
+    QColor hover_color = default_pal.highlight().color();
+#else
+    QColor hover_color = ColorUtils::alphaBlend(palette().window(), palette().highlight(), 0.5);
+#endif
+
+    hover_style = QString(
+        "QTreeView:item:hover {"
+        "  background-color: %1;"
+        "  color: palette(text);"
+        "}").arg(hover_color.name());
+#endif
+
     QString active_style   = QString();
     QString inactive_style = QString();
 
@@ -391,7 +408,7 @@ void PacketList::colorsChanged()
     }
 
     // Set the style sheet
-    setStyleSheet(active_style + inactive_style);
+    setStyleSheet(active_style + inactive_style + hover_style);
 }
 
 void PacketList::drawRow (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const

ui/qt/proto_tree.cpp

@@ -15,6 +15,7 @@
 #include <epan/ftypes/ftypes.h>
 #include <epan/prefs.h>
 
+#include <ui/qt/utils/color_utils.h>
 #include <ui/qt/utils/variant_pointer.h>
 #include <ui/qt/utils/wireshark_mime_data.h>
 #include <ui/qt/widgets/drag_label.h>
@@ -48,6 +49,22 @@ ProtoTree::ProtoTree(QWidget *parent, epan_dissect_t *edt_fixed) :
     // similar to PacketListModel::data.
     setHeaderHidden(true);
 
+#if !defined(Q_OS_WIN)
+#if defined(Q_OS_MAC)
+    QPalette default_pal = QApplication::palette();
+    default_pal.setCurrentColorGroup(QPalette::Active);
+    QColor hover_color = default_pal.highlight().color();
+#else
+    QColor hover_color = ColorUtils::alphaBlend(palette().window(), palette().highlight(), 0.5);
+#endif
+
+    setStyleSheet(QString(
+        "QTreeView:item:hover {"
+        "  background-color: %1;"
+        "  color: palette(text);"
+        "}").arg(hover_color.name()));
+#endif
+
     // Shrink down to a small but nonzero size in the main splitter.
     int one_em = fontMetrics().height();
     setMinimumSize(one_em, one_em);