implemented getting metadata from focused zathura

.gitignore

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+.venv/
+__pycache__

copy_ref.py

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+#!/usr/bin/env python3

datatypes.py

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+from typing import NewType
+from os import PathLike
+from dataclasses import dataclass
+
+# X11 window id
+WindowId = NewType("WindowId", int)
+# PID int
+ProcessId = NewType("ProcessId", int)
+# page number
+PageNumber = NewType("PageNumber", int)
+
+
+# reference to a specific page in a specific pdf
+@dataclass
+class Reference:
+    filename: PathLike
+    page: PageNumber

pdf_data.py

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+from pathlib import Path
+from datatypes import *
+import pydbus
+import subprocess
+
+
+def get_metadata_pdf() -> Reference:
+    """Find current page of focused PDF reader window.
+
+    Returns
+    -------
+    `Reference` to the current page, or None if not found.
+    """
+    try:
+        res = subprocess.run(
+            ["xdotool", "getactivewindow"], capture_output=True, text=True
+        )
+        window_id: WindowId = WindowId(int(res.stdout))
+        res = subprocess.run(
+            ["xdotool", "getactivewindow", "getwindowpid"],
+            capture_output=True,
+            text=True,
+        )
+        pid: ProcessId = ProcessId(int(res.stdout))
+    except subprocess.CalledProcessError as e:
+        raise Exception(
+            "Could not get currently focused window. Check that `xdotool` is installed."
+        ) from e
+
+    try:
+        res = subprocess.run(
+            ["xprop", "-id", str(window_id), "WM_CLASS"], capture_output=True, text=True
+        )
+        # WM_CLASS(STRING) = "org.pwmt.zathura", "Zathura"
+        wm_class: list[str] = [
+            i.strip('"') for i in res.stdout.split(" = ")[-1].split(", ")
+        ]
+    except subprocess.CalledProcessError as e:
+        raise Exception(
+            "Could not get focused window class. Check that `xprop` is installed."
+        ) from e
+
+    match wm_class[0]:
+        case "Zathura":
+            return get_metadata_zathura(pid)
+        case "org.pwmt.zathura":
+            return get_metadata_zathura(pid)
+        case _:
+            raise NotImplemented("Can not retrieve pdf data from this type of window.")
+
+
+def get_metadata_zathura(pid: ProcessId) -> Reference:
+    """Given the PID of a Zathura instance, find which page of which file it's on.
+
+    Parameters
+    ----------
+    pid
+        Process ID of the Zathura instance to retrieve the reference from.
+
+    Returns
+    -------
+    `Reference` that the Zathura instance is currently on
+    """
+
+    bus = pydbus.SessionBus()
+    obj = bus.get(f"org.pwmt.zathura.PID-{pid}", "/org/pwmt/zathura")
+
+    filename: str = obj.filename
+    pagenumber: PageNumber = obj.pagenumber
+
+    return Reference(filename=Path(filename), page=pagenumber)

requirements.txt

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+pycairo==1.24.0
+pydbus==0.6.0
+PyGObject==3.44.1