How do I get this QGraphicsView to fit gfx item contents in view so that scroll bars possibly disappear?

enjoysmath

There is a video showing what's up. In the Logical Rule Widget there is a vertical layout of ListingWidgets, each containing various QGraphicsViews that point to an existing scene somewhere in a tab in a main window of the app.

The listing is not scaling to fit the QGraphicsItem contents.

Here is my relevant code:

def fit_contents_in_view(self):
        rect = self.scene().itemsBoundingRect()
     if rect != QRectF():
         self.setSceneRect(rect)

which is in my gfx.language_gfx_view.LanguageGfxView class. Any idea how best to fit the scene's complete content into a QGraphicView viewing area?

The complete code:
https://github.com/enjoysmath/abstract-spacecraft

Also tried:

def fit_contents_in_view(self):
        self.fitInView(self.scene().itemsBoundingRect(), Qt.IgnoreAspectRatio)