InfiniteLine caching calls merged (fixes #1450) (#1452)

pyqtgraph/graphicsItems/InfiniteLine.py

@@ -249,7 +249,7 @@ class InfiniteLine(GraphicsObject):
 
         if self.p != newPos:
             self.p = newPos
-            self._invalidateCache()
+            self.viewTransformChanged()
             GraphicsObject.setPos(self, Point(self.p))
             self.sigPositionChanged.emit(self)
 
@@ -293,9 +293,6 @@ class InfiniteLine(GraphicsObject):
             self.span = (mn, mx)
             self.update()
 
-    def _invalidateCache(self):
-        self._boundingRect = None
-
     def _computeBoundingRect(self):
         #br = UIGraphicsItem.boundingRect(self)
         vr = self.viewRect()  # bounds of containing ViewBox mapped to local coords.
@@ -432,8 +429,8 @@ class InfiniteLine(GraphicsObject):
         Called whenever the transformation matrix of the view has changed.
         (eg, the view range has changed or the view was resized)
         """
+        self._boundingRect = None
         GraphicsItem.viewTransformChanged(self)
-        self._invalidateCache()
         
     def setName(self, name):
         self._name = name