util.py: implemented rofi wrapper

util.py

@@ -0,0 +1,58 @@
+import subprocess
+from dataclasses import dataclass
+from typing import Optional
+
+@dataclass
+class RofiResult:
+    """Data returned from Rofi.
+
+    Attributes
+    ----------
+    index
+        Index within entries of the selected entry.
+        `None` if nothing was selected.
+    value
+        Selected entry's string value.
+        `None` if the value is not in the list or nothing was selected.
+    custom_bind
+        ID of custom bind used to select entry. None if no custom bind was used.
+    """
+    index: Optional[int]
+    value: str
+    custom_bind: Optional[int]
+
+
+def rofi(entries: list[str], prompt: str="> ", fuzzy=True, extra_args=[]) -> Optional[RofiResult]:
+    """Start a Rofi prompt.
+
+    Returns
+    -------
+    None if the prompt was cancelled, or a `RofiResult`.
+    """
+    args = ["rofi", "-dmenu", "-sep", "\\0"]
+    args += ["-p", prompt]
+
+    if fuzzy:
+        args += ["-matching", "fuzzy"]
+
+    args += extra_args
+
+    ret = RofiResult(None, "", None)
+    
+    res = subprocess.run(args, input="\0".join(entries), stdout=subprocess.PIPE, text=True)
+    match res.returncode:
+        case 0:
+            pass
+        case 1:
+            return None
+        case x if x >= 10 and x <= 28:
+            ret.custom_bind = x - 9
+        case _ as retc:
+            raise RuntimeError(f"Rofi returned an unexpected return code `{retc}`.")
+    ret.value = res.stdout.strip()
+    try:
+        ret.index = entries.index(ret.value)
+    except ValueError:
+        pass
+
+    return ret