Allow GraphicsView.setCentralItem(None)

pyqtgraph/graphicsItems/ViewBox/ViewBox.py

@@ -1322,6 +1322,8 @@ class ViewBox(GraphicsWidget):
                 k.destroyed.disconnect()
             except RuntimeError:  ## signal is already disconnected.
                 pass
+            except TypeError:  ## view has already been deleted (?)
+                pass
             
     def locate(self, item, timeout=3.0, children=False):
         """

pyqtgraph/widgets/GraphicsView.py

@@ -181,8 +181,9 @@ class GraphicsView(QtGui.QGraphicsView):
         if self.centralWidget is not None:
             self.scene().removeItem(self.centralWidget)
         self.centralWidget = item
-        self.sceneObj.addItem(item)
-        self.resizeEvent(None)
+        if item is not None:
+            self.sceneObj.addItem(item)
+            self.resizeEvent(None)
         
     def addItem(self, *args):
         return self.scene().addItem(*args)
@@ -272,7 +273,8 @@ class GraphicsView(QtGui.QGraphicsView):
             scaleChanged = True
         self.range = newRect
         #print "New Range:", self.range
-        self.centralWidget.setGeometry(self.range)
+        if self.centralWidget is not None:
+            self.centralWidget.setGeometry(self.range)
         self.updateMatrix(propagate)
         if scaleChanged:
             self.sigScaleChanged.emit(self)