[M] Rename osc -> termenv

hyfetch/termenv.py

@@ -0,0 +1,77 @@
+from __future__ import annotations
+
+import os
+import signal
+import sys
+import termios
+import tty
+
+from hyfetch.color_util import RGB
+
+
+class OSCException(Exception):
+    pass
+
+
+def unix_read_osc(seq: int) -> str:
+    # screen/tmux can't support OSC, because they can be connected to multiple
+    # terminals concurrently.
+    term = os.environ.get('TERM')
+    if term.startswith("screen") or term.startswith("tmux"):
+        raise OSCException("Screen/tmux not supported")
+
+    t = sys.stdout
+    if not t.isatty():
+        raise OSCException("Not a tty")
+
+    fd = sys.stdin.fileno()
+
+    # Set raw mode
+    settings = termios.tcgetattr(fd)
+    tty.setraw(sys.stdin.fileno())
+
+    # first, send OSC query, which is ignored by terminal which do not support it
+    t.write(f"\x1b]{seq};?\x1b\\")
+    t.flush()
+
+    # Since python's select.select is behaving differently than Unix.select, we can't use it to
+    # monitor if input is available (https://stackoverflow.com/q/74160774/7346633).
+    # My temporary solution is to set a timeout of 0.01s and read as much as possible until the timeout.
+    def handler(signum, frame):
+        raise IOError()
+    signal.signal(signal.SIGALRM, handler)
+    signal.setitimer(signal.ITIMER_REAL, 0.01, 0.0)
+    code = ""
+    try:
+        while 1:
+            code += sys.stdin.read(1)
+    except IOError:
+        pass
+
+    # Reset terminal back to normal mode (previously set to raw mode)
+    termios.tcsetattr(fd, termios.TCSADRAIN, settings)
+
+    # Validate output
+    if not code:
+        raise OSCException("No response received")
+
+    start = f"\x1b]{seq};"
+    if not code.startswith(start):
+        raise OSCException("Received response is not an OSC response")
+    code = code.lstrip(start).rstrip("\x1b\\")
+
+    return code
+
+
+def get_background_color() -> RGB | None:
+    try:
+        osc = unix_read_osc(11).lstrip("rgb:")
+        return RGB.from_hex(''.join([v[:2] for v in osc.split('/')]))
+    except Exception:
+        return None
+
+
+if __name__ == '__main__':
+    print(get_background_color())
+
+