refactor(clipboard): use protocols instead of abstract base class

normcap/clipboard/__init__.py

@@ -1,7 +1,13 @@
-from normcap.clipboard.main import ClipboardHandlers, copy, copy_with_handler
+from normcap.clipboard.main import (
+    Handler,
+    copy,
+    copy_with_handler,
+    get_available_handlers,
+)
 
 __all__ = [
+    "Handler",
     "copy",
     "copy_with_handler",
-    "ClipboardHandlers",
+    "get_available_handlers",
 ]

normcap/clipboard/handlers/pbcopy.py

@@ -2,31 +2,31 @@
 import subprocess
 import sys
 
-from .base import ClipboardHandlerBase
-
 logger = logging.getLogger(__name__)
 
+install_instructions = ""  # pbcopy is pre-installed on macOS
+
+
+def copy(text: str) -> None:
+    subprocess.run(
+        ["pbcopy", "w"],  # noqa: S607
+        shell=False,  # noqa: S603
+        input=text.encode("utf-8"),
+        check=True,
+        timeout=30,
+        env={"LC_CTYPE": "UTF-8"},
+    )
+
+
+def is_compatible() -> bool:
+    if sys.platform != "darwin":
+        logger.debug("%s is incompatible on non-macOS systems", __name__)
+        return False
+
+    logger.debug("%s is compatible", __name__)
+    return True
+
 
-class PbCopyHandler(ClipboardHandlerBase):
-    @staticmethod
-    def _copy(text: str) -> None:
-        subprocess.run(
-            ["pbcopy", "w"],  # noqa: S607
-            shell=False,  # noqa: S603
-            input=text.encode("utf-8"),
-            check=True,
-            timeout=30,
-            env={"LC_CTYPE": "UTF-8"},
-        )
-
-    def is_compatible(self) -> bool:
-        if sys.platform != "darwin":
-            logger.debug("%s is incompatible on non-macOS systems", self.name)
-            return False
-
-        logger.debug("%s is compatible", self.name)
-        return True
-
-    def is_installed(self) -> bool:
-        logger.debug("%s requires no dependencies", self.name)
-        return True
+def is_installed() -> bool:
+    logger.debug("%s requires no dependencies", __name__)
+    return True

normcap/clipboard/handlers/qtclipboard.py

@@ -1,39 +1,44 @@
 import logging
 from typing import Any, cast
 
+from normcap.clipboard import system_info
+
 try:
     from PySide6 import QtGui
 
 except ImportError:
     QtGui = cast(Any, None)
 
-from .base import ClipboardHandlerBase
 
 logger = logging.getLogger(__name__)
 
+install_instructions = (
+    "Please install the Python package PySide6 with your preferred package manager."
+)
+
+
+def copy(text: str) -> None:
+    """Use QtWidgets.QApplication.clipboard to copy text to system clipboard."""
+    app = QtGui.QGuiApplication.instance() or QtGui.QGuiApplication()
+
+    cb = app.clipboard()  # type: ignore  # Type hint wrong in PySide6?
+    cb.setText(text)
+    app.processEvents()
 
-class QtCopyHandler(ClipboardHandlerBase):
-    @staticmethod
-    def _copy(text: str) -> None:
-        """Use QtWidgets.QApplication.clipboard to copy text to system clipboard."""
-        app = QtGui.QGuiApplication.instance() or QtGui.QGuiApplication()
 
-        cb = app.clipboard()  # type: ignore  # Type hint wrong in PySide6?
-        cb.setText(text)
-        app.processEvents()
+def is_compatible() -> bool:
+    if not QtGui:
+        logger.debug("%s is not compatible on systems w/o PySide6", __name__)
+        return False
 
-    def is_compatible(self) -> bool:
-        if not QtGui:
-            logger.debug("%s is not compatible on systems w/o PySide6", self.name)
-            return False
+    if system_info.os_has_wayland_display_manager():
+        logger.debug("%s is not compatible with Wayland", __name__)
+        return False
 
-        if self._os_has_wayland_display_manager():
-            logger.debug("%s is not compatible with Wayland", self.name)
-            return False
+    logger.debug("%s is compatible", __name__)
+    return True
 
-        logger.debug("%s is compatible", self.name)
-        return True
 
-    def is_installed(self) -> bool:
-        logger.debug("%s requires no dependencies", self.name)
-        return True
+def is_installed() -> bool:
+    logger.debug("%s requires no dependencies", __name__)
+    return True