import importlib.util
import typing
import attr
import qts
[docs]@attr.frozen
class Wrapper:
"""A representation of a specific wrapper that can be used to access a specific
version of Qt.
"""
family: str
"""The wrapper family. ``"PyQt"`` or ``"PySide"``."""
name: str
"""The name of the specific wrapper, including the version number. Such as ``"PySide6"``."""
major_version: int
"""The major version of the wrapped Qt library. Such as ``6``."""
module_name: str
"""The name used to import the module. Such as ``"PySide6"``."""
pyqt_5_wrapper = Wrapper(
family="PyQt", name="PyQt5", major_version=5, module_name="PyQt5"
)
"""The PyQt/Qt5 wrapper object."""
pyqt_6_wrapper = Wrapper(
family="PyQt", name="PyQt6", major_version=6, module_name="PyQt6"
)
"""The PyQt/Qt6 wrapper object."""
pyside_5_wrapper = Wrapper(
family="PySide", name="PySide2", major_version=5, module_name="PySide2"
)
"""The PySide/Qt5 wrapper object."""
pyside_6_wrapper = Wrapper(
family="PySide", name="PySide6", major_version=6, module_name="PySide6"
)
"""The PySide/Qt6 wrapper object."""
supported_wrappers = [
pyqt_5_wrapper,
pyqt_6_wrapper,
pyside_5_wrapper,
pyside_6_wrapper,
]
"""A list of all the supported wrapper objects."""
_wrappers_by_name = {wrapper.name.casefold(): wrapper for wrapper in supported_wrappers}
[docs]def set_wrapper(wrapper: Wrapper) -> None:
"""Set the wrapper you want to back the Qt modules accessed through qts.
:raises qts.WrapperAlreadySelectedError: When called and a wrapper has already
been set.
:raises qts.InvalidWrapperError: When called with an invalid wrapper.
"""
# This could accept the new wrapper if it matches the existing selection, but this
# seems like it would mostly just encourage coding that hazards setting to a
# different wrapper in some other case. May as well complain early so that
# developers get early warning and can adjust their design.
if qts.wrapper is not None:
raise qts.WrapperAlreadySelectedError(
existing_wrapper=qts.wrapper,
requested_wrapper=wrapper,
)
if wrapper not in supported_wrappers:
raise qts.InvalidWrapperError(wrapper=wrapper)
qts.wrapper = wrapper
qts.is_pyqt_5_wrapper = wrapper == pyqt_5_wrapper
qts.is_pyqt_6_wrapper = wrapper == pyqt_6_wrapper
qts.is_pyside_5_wrapper = wrapper == pyside_5_wrapper
qts.is_pyside_6_wrapper = wrapper == pyside_6_wrapper
[docs]def available_wrappers(
wrappers: typing.Optional[typing.Iterable[Wrapper]] = None,
) -> typing.Sequence[Wrapper]:
"""Get a sequence of the wrappers that are available for use. If ``wrappers`` is
passed, only wrappers that are both available and in the passed iterable will be
returned.
:returns: The wrappers that are installed and available for use.
"""
if wrappers is None:
wrappers = supported_wrappers
available = [
wrapper for wrapper in wrappers if importlib.util.find_spec(wrapper.module_name)
]
return available
[docs]def available_wrapper(
wrappers: typing.Optional[typing.Iterable[Wrapper]] = None,
) -> Wrapper:
"""Get the available wrapper when there is only one.
:return: The wrapper object for the single available wrapper.
:raises qts.NoWrapperAvailableError: When no wrappers are available.
:raises qts.MultipleWrappersAvailableError: If more than one wrapper is available.
"""
if wrappers is None:
wrappers = supported_wrappers
all_available = available_wrappers(wrappers=wrappers)
if len(all_available) == 0:
raise qts.NoWrapperAvailableError(wrappers=wrappers)
elif len(all_available) > 1:
raise qts.MultipleWrappersAvailableError(searched=wrappers, found=all_available)
[the_one] = all_available
return the_one
[docs]def wrapper_by_name(name: str) -> Wrapper:
"""Get a wrapper object by its name. The name is checked case insensitively.
:returns: The wrapper that goes by the passed name.
"""
return _wrappers_by_name[name.casefold()]