use mouse wheel to activate applets

--when the user has chosen to activate tasks
through mouse wheel and there are applets that
can be hovered, then for these applets the mouse
wheel can be also used to activate/deactivate them.

containment/package/contents/ui/applet/AppletItem.qml

@@ -385,7 +385,7 @@ Item {
     Connections{
         target: root
 
-       /* onGlobalDirectRenderChanged:{
+        /* onGlobalDirectRenderChanged:{
             if (root.globalDirectRender && restoreAnimation.running) {
                 // console.log("CLEAR APPLET SCALE !!!!");
                 //restoreAnimation.stop();
@@ -574,6 +574,7 @@ Item {
         //! plasma tooltips are disabled
         visible: !container.latteApplet && !lockZoom && canBeHovered && !(container.isSeparator && !root.editMode)  //&& (root.zoomFactor>1)
 
+        property bool blockWheel: false
         property bool fastEnteringFlag: false
         property bool pressed: false
 
@@ -711,6 +712,42 @@ Item {
         onReleased: {
             pressed = false;
         }
+
+        onWheel: {
+            if (isSeparator || !root.mouseWheelActions || blockWheel
+                    || (root.dockIsHidden || root.inSlidingIn || root.inSlidingOut)){
+                return;
+            }
+
+            var angle = wheel.angleDelta.y / 8;
+
+            blockWheel = true;
+            scrollDelayer.start();
+
+            if (angle > 12) {
+                //positive direction
+                if (!isExpanded) {
+                    dock.toggleAppletExpanded(applet.id);
+                }
+            } else if (angle < -12) {
+                //negative direction
+                if (isExpanded) {
+                    dock.toggleAppletExpanded(applet.id);
+                }
+            }
+        }
+
+        //! A timer is needed in order to handle also touchpads that probably
+        //! send too many signals very fast. This way the signals per sec are limited.
+        //! The user needs to have a steady normal scroll in order to not
+        //! notice a annoying delay
+        Timer{
+            id: scrollDelayer
+
+            interval: 700
+
+            onTriggered: appletMouseArea.blockWheel = false;
+        }
     }
 
     //BEGIN states