Fixes: Use alternate row colors for sidebar

Task:     As discussed with b_lindeijer
Details:
This enables alternate row colors, with filled empty
area on the side bar for improved usability.

src/plugins/coreplugin/manhattanstyle.cpp

@@ -388,15 +388,20 @@ QPixmap ManhattanStyle::standardPixmap(StandardPixmap standardPixmap, const QSty
 int ManhattanStyle::styleHint(StyleHint hint, const QStyleOption *option, const QWidget *widget,
                               QStyleHintReturn *returnData) const
 {
-    int ret = 0;
+    int ret = d->style->styleHint(hint, option, widget, returnData);
     switch (hint) {
+    // Make project explorer alternate rows all the way
+    case QStyle::SH_ItemView_PaintAlternatingRowColorsForEmptyArea:
+        if (widget && widget->property("AlternateEmpty").toBool())
+            ret = true;
+        break;
     case QStyle::SH_EtchDisabledText:
-        ret = false; // We really should only enforce this for panel widgets
+        if (panelWidget(widget))
+            ret = false;
         break;
     default:
-        ret =  d->style->styleHint(hint, option, widget, returnData);
+        break;
     }
-
     return ret;
 }
 

src/plugins/projectexplorer/projecttreewidget.cpp

@@ -73,6 +73,8 @@ public:
         setContextMenuPolicy(Qt::CustomContextMenu);
         setUniformRowHeights(true);
         setTextElideMode(Qt::ElideNone);
+        setAlternatingRowColors(true);
+        setProperty("AlternateEmpty", true); // Let Manhattan to override style default
 //        setExpandsOnDoubleClick(false);
     }