Refactor StepPanel and WelcomeDialog

resources/qml/WelcomePages/WelcomeDialog.qml

@@ -4,6 +4,7 @@
 import QtQuick 2.10
 import QtQuick.Controls 2.3
 import QtQuick.Window 2.2
+import QtGraphicalEffects 1.0  // For the DropShadow
 
 import UM 1.3 as UM
 import Cura 1.1 as Cura
@@ -21,15 +22,31 @@ Window
     height: 600  // TODO
     color: "transparent"
 
+    property int shadowOffset: 1 * screenScaleFactor
+
     property alias currentStep: stepPanel.currentStep
 
     StepPanel
     {
         id: stepPanel
+        anchors.fill: parent
         currentStep: 0
         model: CuraApplication.getWelcomePagesModel()
     }
 
+    // Drop shadow around the panel
+    DropShadow
+    {
+        id: shadow
+        radius: UM.Theme.getSize("monitor_shadow_radius").width
+        anchors.fill: stepPanel
+        source: stepPanel
+        horizontalOffset: shadowOffset
+        verticalOffset: shadowOffset
+        color: UM.Theme.getColor("monitor_shadow")
+        transparentBorder: true
+    }
+
     // Close this dialog when there's no more page to show
     Connections
     {