Source code for simvx.core.clipboard

"""Clipboard support for the SimVX editor.

Provides node copy/paste (serialized via scene helpers) and text clipboard
with optional platform integration (e.g., GLFW ``glfwGetClipboardString``).
"""


from __future__ import annotations

import logging
from collections.abc import Callable
from typing import Any, ClassVar

log = logging.getLogger(__name__)




class Clipboard:
    """Singleton-style clipboard accessed entirely through class methods."""

    _node_data: ClassVar[dict | None] = None
    _text: ClassVar[str] = ""
    _platform_get: ClassVar[Callable[[], str] | None] = None
    _platform_set: ClassVar[Callable[[str], None] | None] = None

    # -- node operations ---------------------------------------------------



    @classmethod
    def copy_node(cls, node: Any) -> None:
        """Serialize *node* (and its subtree) onto the clipboard."""
        from .scene import _serialize_node

        cls._node_data = _serialize_node(node)




    @classmethod
    def paste_node(cls, parent: Any | None = None) -> Any | None:
        """Deserialize the stored node tree.

        If *parent* is given the new node is added as a child.
        Returns the new node, or ``None`` when the clipboard is empty.
        """
        if cls._node_data is None:
            return None

        from .scene import _deserialize_node
        node = _deserialize_node(cls._node_data)
        if parent is not None:
            parent.add_child(node)
        return node




    @classmethod
    def has_node(cls) -> bool:
        """Return whether serialized node data is available."""
        return cls._node_data is not None


    # -- text operations ---------------------------------------------------



    @classmethod
    def copy_text(cls, text: str) -> None:
        """Store *text* and push to the platform clipboard if available."""
        cls._text = text
        if cls._platform_set is not None:
            cls._platform_set(text)




    @classmethod
    def paste_text(cls) -> str:
        """Return text from the platform clipboard, falling back to internal storage."""
        if cls._platform_get is not None:
            return cls._platform_get()
        return cls._text


    # -- platform integration ----------------------------------------------



    @classmethod
    def set_platform_clipboard(
        cls,
        get_fn: Callable[[], str],
        set_fn: Callable[[str], None],
    ) -> None:
        """Register platform clipboard accessors (called by graphics backend at init)."""
        cls._platform_get = get_fn
        cls._platform_set = set_fn


    # -- housekeeping ------------------------------------------------------



    @classmethod
    def clear(cls) -> None:
        """Clear both node and text clipboard data."""
        cls._node_data = None
        cls._text = ""