expose dashboardshown as readonly

remove the transparency stuff from the c++ part, beloongs to the qml part

shell/desktopview.cpp

@@ -134,10 +134,6 @@ void DesktopView::setDashboardShown(bool shown)
         KWindowSystem::raiseWindow(winId());
         KWindowSystem::forceActiveWindow(winId());
 
-        QObject *wpGraphicObject = containment()->property("wallpaperGraphicsObject").value<QObject *>();
-        if (wpGraphicObject) {
-            wpGraphicObject->setProperty("opacity", 0.3);
-        }
     } else {
         if (m_stayBehind) {
             KWindowSystem::setType(winId(), NET::Desktop);
@@ -146,13 +142,10 @@ void DesktopView::setDashboardShown(bool shown)
         lower();
         KWindowSystem::lowerWindow(winId());
 
-        QObject *wpGraphicObject = containment()->property("wallpaperGraphicsObject").value<QObject *>();
-        if (wpGraphicObject) {
-            wpGraphicObject->setProperty("opacity", 1);
-        }
     }
 
     m_dashboardShown = shown;
+    emit dashboardShownChanged();
 }
 
 bool DesktopView::event(QEvent *e)

shell/desktopview.h

@@ -31,6 +31,8 @@ class DesktopView : public PlasmaQuick::View
     Q_OBJECT
     Q_PROPERTY(bool stayBehind READ stayBehind WRITE setStayBehind NOTIFY stayBehindChanged)
     Q_PROPERTY(bool fillScreen READ fillScreen WRITE setFillScreen NOTIFY fillScreenChanged)
+    //the qml part doesn't need to be able to write it, hide for now
+    Q_PROPERTY(bool dashboardShown READ isDashboardShown NOTIFY dashboardShownChanged)
 
 public:
     explicit DesktopView(ShellCorona *corona, QScreen *screen);
@@ -59,6 +61,7 @@ protected Q_SLOTS:
 Q_SIGNALS:
     void stayBehindChanged();
     void fillScreenChanged();
+    void dashboardShownChanged();
 
 private:
     void coronaPackageChanged(const Plasma::Package &package);