Adds layer count

Brings back the layer count, the min & max. And it does not display these untill Cura is done slicing.

Fixes #117

plugins/LayerView/LayerView.py

@@ -27,9 +27,13 @@ class LayerView(View):
         self._max_layers = 10
         self._current_layer_num = 10
         self._current_layer_mesh = None
+        self._activity = False
 
         self._solid_layers = 5
 
+    def getActivity(self):
+        return self._activity
+
     def getCurrentLayer(self):
         return self._current_layer_num
     
@@ -114,13 +118,14 @@ class LayerView(View):
 
             self._current_layer_mesh = None
             self.currentLayerNumChanged.emit()
-    
+
     currentLayerNumChanged = Signal()
-    
+
     def calculateMaxLayers(self):
         scene = self.getController().getScene()
         renderer = self.getRenderer()
         if renderer and self._material:
+            self._activity = True
             renderer.setRenderSelection(False)
             self._old_max_layers = self._max_layers
             ## Recalculate num max layers
@@ -138,10 +143,11 @@ class LayerView(View):
             if new_max_layers > 0 and new_max_layers != self._old_max_layers:
                 self._max_layers = new_max_layers
                 self.maxLayersChanged.emit()
+                self._current_layer_num = self._max_layers
 
                 # This makes sure we update the current layer
                 self.setLayer(int(self._max_layers * (self._current_layer_num / self._old_max_layers)))
-    
+
     maxLayersChanged = Signal()
     
     ##  Hackish way to ensure the proxy is already created, which ensures that the layerview.qml is already created

plugins/LayerView/LayerView.qml

@@ -18,6 +18,7 @@ Item
         width: 10
         height: 250
         anchors.right : parent.right
+        anchors.rightMargin: UM.Theme.sizes.default_margin.width * 2
         orientation: Qt.Vertical
         minimumValue: 0;
         maximumValue: UM.LayerView.numLayers;
@@ -26,6 +27,6 @@ Item
         value: UM.LayerView.currentLayer
         onValueChanged: UM.LayerView.setCurrentLayer(value)
 
-        style: UM.Theme.styles.slider;
+        style: UM.LayerView.getLayerActivity ? UM.Theme.styles.layerViewSlider : UM.Theme.styles.slider
     }
 }

plugins/LayerView/LayerViewProxy.py

@@ -11,7 +11,13 @@ class LayerViewProxy(QObject):
     
     currentLayerChanged = pyqtSignal()
     maxLayersChanged = pyqtSignal()
-    
+    activityChanged = pyqtSignal()
+
+    @pyqtProperty(bool, notify = activityChanged)
+    def getLayerActivity(self):
+        active_view = self._controller.getActiveView()
+        return active_view.getActivity()
+
     @pyqtProperty(int, notify = maxLayersChanged)
     def numLayers(self):
         active_view = self._controller.getActiveView()
@@ -30,9 +36,13 @@ class LayerViewProxy(QObject):
         active_view = self._controller.getActiveView()
         if type(active_view) == LayerView.LayerView.LayerView:
             active_view.setLayer(layer_num)
+
+    def _layerActivityChanged(self):
+        self.activityChanged.emit()
             
     def _onLayerChanged(self):
         self.currentLayerChanged.emit()
+        self._layerActivityChanged()
         
     def _onMaxLayersChanged(self):
         self.maxLayersChanged.emit()