QmlProfiler: tooltips for the labels column

Due to space restrictions, the descriptive text of events
in the labels column of the timeline view are elided.  This
patch adds tooltips on mouseover with location and details.

Change-Id: I229988e114f21e4d9575dff137aa91918ad1afa3
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/plugins/qmlprofiler/qml/Label.qml

@@ -39,6 +39,7 @@ Item {
     property int typeIndex: index
 
     property variant descriptions: []
+    property variant extdescriptions: []
     property variant eventIds: []
 
     height: root.singleRowHeight
@@ -67,17 +68,21 @@ Item {
         onDataReady: {
             var desc=[];
             var ids=[];
+            var extdesc=[];
             for (var i=0; i<qmlEventList.uniqueEventsOfType(typeIndex); i++) {
                 desc[i] = qmlEventList.eventTextForType(typeIndex, i);
                 ids[i] = qmlEventList.eventIdForType(typeIndex, i);
+                extdesc[i] = qmlEventList.eventDisplayNameForType(typeIndex, i) + " : " + desc[i];
             }
             descriptions = desc;
             eventIds = ids;
+            extdescriptions = extdesc;
             updateHeight();
         }
         onDataClear: {
             descriptions = [];
             eventIds = [];
+            extdescriptions = [];
             updateHeight();
         }
     }
@@ -121,6 +126,9 @@ Item {
                 }
                 MouseArea {
                     anchors.fill: parent
+                    hoverEnabled: true
+                    onEntered: changeToolTip(extdescriptions[index]);
+                    onExited: changeToolTip("");
                     onClicked: {
                         if (mouse.modifiers & Qt.ShiftModifier)
                             view.selectPrevFromId(eventIds[index]);