1 files changed, 107 insertions, 0 deletions
diff --git a/display-manager.py b/display-manager.py
new file mode 100755
index 0000000..9213107
--- /dev/null
+++ b/display-manager.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+import subprocess, re
+
+def xrandr(args):
+    return subprocess.check_output(["xrandr"] + args).decode("utf-8")
+
+def zenity_list(text, options, height):
+    args = ["zenity", "--list", "--hide-header", "--text", text, "--height", str(height), "--column", ""] + list(options)
+    res = subprocess.run(args, stdout = subprocess.PIPE)
+    if res.returncode == 0:
+        output = res.stdout.decode("utf-8")
+        if output[-1] == "\n": output = output[:-1]
+        return output
+    else:
+        return None
+
+def current_setup():
+    displays = dict()
+    walk_display = None
+
+    for line in xrandr(["-q"]).split("\n"):
+        if len(line) == 0: continue
+        indent = len(re.match(r" *", line)[0])
+
+        if indent == 0:
+            if re.match(r"Screen [0-9]+:", line) is not None:
+                continue
+            else:
+                walk_display = line[:line.index(" ")]
+                displays[walk_display] = {
+                    "current": None,
+                    "preferred": None
+                }
+        elif indent == 2:
+            continue
+        elif indent == 3:
+            words = re.split(r" {2,}", line.strip())
+            if len(words) == 0:
+                continue
+
+            m = re.match(r"([0-9]+)x([0-9]+)$", words[0])
+            resolution = (int(m[1]), int(m[2]))
+            freq_current = None  # *
+            freq_preferred = None  # +
+            for word in words[1:]:
+                m = re.match(r"([0-9.]+)([\* ]?)([\+ ]?)$", word)
+                if m[2] == "*": freq_current = float(m[1])
+                if m[3] == "+": freq_preferred = float(m[1])
+
+            if freq_current is not None:
+                displays[walk_display]["current"] = (resolution, freq_current)
+            if freq_preferred is not None:
+                displays[walk_display]["preferred"] = (resolution, freq_preferred)
+
+    return displays
+
+def iter_find(l, predicate):
+    for x in l:
+        if predicate(x): return x
+    return None
+
+def is_internal_display(name):
+    return name.startswith("eDP")
+
+def is_external_display(name):
+    return name.startswith("HDMI")
+
+def main():
+    setup = current_setup()
+
+    def props_for_name(name):
+        nonlocal setup
+        current = False if name is None else setup[name]["current"] is not None
+        formatted = "<none>" if name is None else name + (" (enabled)" if current else "")
+        return {
+            "name": name,
+            "formatted": formatted,
+            "current": current
+        }
+
+    internal = props_for_name(iter_find(setup.keys(), is_internal_display))
+    external = props_for_name(iter_find(setup.keys(), is_external_display))
+    assert internal["name"] is not None
+    assert internal["name"] != external["name"]
+
+    other_displays = [setup[name]["formatted"] for name in setup.keys()
+                      if name not in [internal["name"], external["name"]]]
+
+    message = "{} displays connected:\n- internal: {}\n- external: {}".format(
+                    len(setup.keys()), internal["formatted"], external["formatted"])
+    if len(other_displays) > 0:
+        message += "\n- unknown: {}".format(other_displays.join(", "))
+
+    options = {
+        "Only internal": ["--output", external["name"], "--off"],
+        "External left": ["--output", external["name"], "--auto", "--left-of", internal["name"]],
+        "External right": ["--output", external["name"], "--auto", "--right-of", internal["name"]],
+        "Mirror": ["--output", external["name"], "--auto", "--same-as", internal["name"]]
+    }
+
+    response = zenity_list(message, options.keys(), 225)
+    if response is not None:
+        flags = options[response]
+        xrandr(flags)
+
+if __name__ == "__main__":
+    main()