def _compute_max_zoom(self):
# The max zoom is the one that fits one item into the view
# We don't allow to zoom any further than this
item = QGraphicsRectItem(0, 0, ProjectItemIcon.ITEM_EXTENT, 0)
self.scene().addItem(item)
self.scene().removeItem(item)
item_scene_rect = item.boundingRegion(
item.sceneTransform()).boundingRect()
item_view_rect = self.mapFromScene(item_scene_rect).boundingRect()
viewport_extent = min(self.viewport().width(),
self.viewport().height())
return viewport_extent / item_view_rect.width()
