codekingpro/portable-devtools

1from __future__ import annotations2 3import logging4import typing5from collections.abc import Mapping6 7from ..utils import signals8from ._api import Contentview9from ._api import Metadata10 11logger = logging.getLogger(__name__)12 13 14def _on_change(view: Contentview) -> None: ...15 16 17class ContentviewRegistry(Mapping[str, Contentview]):18    def __init__(self):19        self._by_name: dict[str, Contentview] = {}20        self.on_change = signals.SyncSignal(_on_change)21 22    def register(self, instance: Contentview | type[Contentview]) -> None:23        if isinstance(instance, type):24            instance = instance()25        name = instance.name.lower()26        if name in self._by_name:27            logger.info(f"Replacing existing {name} contentview.")28        self._by_name[name] = instance29        self.on_change.send(instance)30 31    def available_views(self) -> list[str]:32        return ["auto", *sorted(self._by_name.keys())]33 34    def get_view(35        self, data: bytes, metadata: Metadata, view_name: str = "auto"36    ) -> Contentview:37        """38        Get the best contentview for the given data and metadata.39 40        If `view_name` is "auto" or the provided view not found,41        the best matching contentview based on `render_priority` will be returned.42        """43        if view_name != "auto":44            try:45                return self[view_name.lower()]46            except KeyError:47                logger.warning(48                    f"Unknown contentview {view_name!r}, selecting best match instead."49                )50 51        max_prio: tuple[float, Contentview] | None = None52        for name, view in self._by_name.items():53            try:54                priority = view.render_priority(data, metadata)55                assert isinstance(priority, (int, float)), (56                    f"render_priority for {view.name} did not return a number."57                )58            except Exception:59                logger.exception(f"Error in {view.name}.render_priority")60            else:61                if max_prio is None or max_prio[0] < priority:62                    max_prio = (priority, view)63        assert max_prio, "At least one view needs to have a working `render_priority`."64        return max_prio[1]65 66    def __iter__(self) -> typing.Iterator[str]:67        return iter(self._by_name)68 69    def __getitem__(self, item: str) -> Contentview:70        return self._by_name[item.lower()]71 72    def __len__(self):73        return len(self._by_name)74