Add script hook `predetect`, executed before invoking xrandr to detect the current config

See bug #61

README.md

@@ -117,6 +117,11 @@ about it. The same holds for `preswitch`, which is executed before the switch
 takes place, and `postsave`, which is executed after a profile was
 stored/altered.
 
+If you experience issues with xrandr being executed too early after connecting
+a new monitor, then you can create a script `predetect`, which will be executed
+before autorandr attempts to run xrandr. Place e.g. `sleep 1` into that file
+to make autorandr wait a second before running xrandr.
+
 All scripts can also be placed in any of the `$XDG_CONFIG_DIRS`. In addition to
 the script names themselves, any executables in subdirectories named
 `script_name.d` (e.g. `postswitch.d`) are executed as well. In scripts, some of
@@ -125,4 +130,5 @@ The most useful one is `$AUTORANDR_CURRENT_PROFILE`.
 
 ## Changelog
 
+* *2016-11-15* New script hook, `predetect`
 * *2016-10-03* Install a desktop file to `/etc/xdg/autostart` by default

autorandr.py

@@ -729,6 +729,8 @@ def exec_scripts(profile_path, script_name, meta_information=None):
     and system-wide configuration folders, named script_name or residing in
     subdirectories named script_name.d.
 
+    If profile_path is None, only global scripts will be invoked.
+
     meta_information is expected to be an dictionary. It will be passed to the block scripts
     in the environment, as variables called AUTORANDR_<CAPITALIZED_KEY_HERE>.
 
@@ -748,8 +750,11 @@ def exec_scripts(profile_path, script_name, meta_information=None):
     if not os.path.isdir(user_profile_path):
         user_profile_path = os.path.join(os.environ.get("XDG_CONFIG_HOME", os.path.expanduser("~/.config")), "autorandr")
 
-    for folder in chain((profile_path, os.path.dirname(profile_path), user_profile_path),
-                        (os.path.join(x, "autorandr") for x in os.environ.get("XDG_CONFIG_DIRS", "/etc/xdg").split(":"))):
+    candidate_directories = chain((user_profile_path,), (os.path.join(x, "autorandr") for x in os.environ.get("XDG_CONFIG_DIRS", "/etc/xdg").split(":")))
+    if profile_path:
+        candidate_directories = chain((profile_path,), candidate_directories)
+
+    for folder in candidate_directories:
 
         if script_name not in ran_scripts:
             script = os.path.join(folder, script_name)
@@ -879,6 +884,7 @@ def main(argv):
 
     profile_symlinks = { k: v for k, v in profile_symlinks.items() if v in (x[0] for x in virtual_profiles) or v in profiles }
 
+    exec_scripts(None, "predetect")
     config, modes = parse_xrandr_output()
 
     if "--fingerprint" in options: