recycleview.py 文件源码

def get_view(self, index):
        """Returns a view instance for the data at `index`. It looks through
        the various caches and finally creates a view if it doesn't exist.
        The returned view is synced with the data, except for the pos/size
        properties.
        """
        if index in self.views:
            return self.views[index]

        dirty_views = self.dirty_views
        viewclass = self.get_viewclass(index)
        if viewclass is None:
            return
        rv = self.recycleview
        stale = False
        view = None

        if viewclass in dirty_views:
            dirty_class = dirty_views[viewclass]
            if index in dirty_class:
                # we found ourself in the dirty list, no need to update data!
                view = dirty_class.pop(index)
            elif _cached_views[viewclass]:
                # global cache has this class, update data
                view, stale = _cached_views[viewclass].pop(), True
            elif dirty_class:
                # random any dirty view element - update data
                view, stale = dirty_class.popitem()[1], True
        elif _cached_views[viewclass]:
            # global cache has this class, update data
            view, stale = _cached_views[viewclass].pop(), True

        if view is None:
            # create a fresh one
            view = self.create_view(index, viewclass)

        if stale is True:
            item = self[index]
            if viewclass not in _view_base_cache:
                _view_base_cache[viewclass] = isinstance(view,
                                                         RecycleViewMixin)

            if _view_base_cache[viewclass]:
                view.refresh_view_attrs(rv, item)
            else:
                for key, value in item.items():
                    setattr(view, key, value)

        self.views[index] = view
        return view