Prevent, in apply_configuration, a xrandr call that disables all screens

[deb_pkgs/autorandr.git] / autorandr.py

diff --git a/autorandr.py b/autorandr.py
index 19f1a5e2e2242f43097f12346364413fc5441e8d..2baa1b142ff3696f1215a6379fcb1c155a2a8664 100755 (executable)
--- a/autorandr.py
+++ b/autorandr.py
@@ -328,6 +328,8 @@ def parse_xrandr_output():
 
     # Split at output boundaries and instanciate an XrandrOutput per output
     split_xrandr_output = re.split("(?m)^([^ ]+ (?:(?:dis)?connected|unknown connection).*)$", xrandr_output)
+    if len(split_xrandr_output) < 2:
+        raise RuntimeError("No output boundaries found")
     outputs = OrderedDict()
     modes = OrderedDict()
     for i in range(1, len(split_xrandr_output), 2):
@@ -349,7 +351,7 @@ def load_profiles(profile_path):
         if not os.path.isfile(config_name) or not os.path.isfile(setup_name):
             continue
 
-        edids = dict([ x.strip().split() for x in open(setup_name).readlines() ])
+        edids = dict([ x.strip().split() for x in open(setup_name).readlines() if x.strip() ])
 
         config = {}
         buffer = []
@@ -431,29 +433,46 @@ def apply_configuration(configuration, dry_run=False):
     else:
         base_argv = [ "xrandr" ]
 
-    # Disable all unused outputs
-    argv = base_argv[:]
-    disable_argv = []
+    # There are several xrandr / driver bugs we need to take care of here:
+    # - We cannot enable more than two screens at the same time
+    #   See https://github.com/phillipberndt/autorandr/pull/6
+    #   and commits f4cce4d and 8429886.
+    # - We cannot disable all screens
+    #   See https://github.com/phillipberndt/autorandr/pull/20
+    # - We should disable screens before enabling others, because there's
+    #   a limit on the number of enabled screens
+    # - We must make sure that the screen at 0x0 is activated first,
+    #   or the other (first) screen to be activated would be moved there.
+
+    disable_outputs = []
+    enable_outputs = []
     for output in outputs:
         if not configuration[output].edid or "off" in configuration[output].options:
-            disable_argv += configuration[output].option_vector
-    if disable_argv:
-        if subprocess.call(base_argv + disable_argv) != 0:
+            disable_outputs.append(configuration[output].option_vector)
+        else:
+            enable_outputs.append(configuration[output].option_vector)
+
+    # Disable all but the last of the outputs to be disabled
+    if len(disable_outputs) > 1:
+        if subprocess.call(base_argv + list(chain.from_iterable(disable_outputs[:-1]))) != 0:
             # Disabling the outputs failed. Retry with the next command:
             # Sometimes disabling of outputs fails due to an invalid RRSetScreenSize.
             # This does not occur if simultaneously the primary screen is reset.
             pass
         else:
-            disable_argv = []
-
-    # Enable remaining outputs in pairs of two
-    remaining_outputs = [ x for x in outputs if configuration[x].edid ]
-    for index in range(0, len(remaining_outputs), 2):
-        argv = base_argv[:]
-        if disable_argv:
-            argv += disable_argv
-            disable_argv = []
-        argv += configuration[remaining_outputs[index]].option_vector + (configuration[remaining_outputs[index + 1]].option_vector if index < len(remaining_outputs) - 1 else [])
+            disable_outputs = disable_outputs[-1:]
+
+    # If disable_outputs still has more than one output in it, one of the xrandr-calls below would
+    # disable the last two screens. This is a problem, so if this would happen, instead disable only
+    # one screen in the first call below.
+    if len(disable_outputs) > 0 and len(disable_outputs) % 2 == 0:
+        # In the context of a xrandr call that changes the display change, `--query' should do nothing
+        disable_outputs.insert(0, ['--query'])
+
+    # Enable the remaining outputs in pairs of two operations
+    operations = disable_outputs + enable_outputs
+    for index in range(0, len(operations), 2):
+        argv = base_argv + list(chain.from_iterable(operations[index:index+2]))
         if subprocess.call(argv) != 0:
             raise RuntimeError("Command failed: %s" % " ".join(argv))
 
@@ -463,6 +482,12 @@ def add_unused_outputs(source_configuration, target_configuration):
         if output_name not in target_configuration:
             target_configuration[output_name] = XrandrOutput(output_name, output.edid, { "off": None })
 
+def remove_irrelevant_outputs(source_configuration, target_configuration):
+    "Remove outputs from target that ought to be 'off' and already are"
+    for output_name, output in source_configuration.items():
+        if "off" in output.options and output_name in target_configuration and "off" in target_configuration[output_name].options:
+            del target_configuration[output_name]
+
 def generate_virtual_profile(configuration, modes, profile_name):
     "Generate one of the virtual profiles"
     configuration = copy.deepcopy(configuration)
@@ -613,6 +638,7 @@ def main(argv):
         if load_config == dict(config) and not "-f" in options and not "--force" in options:
             print("Config already loaded", file=sys.stderr)
             sys.exit(0)
+        remove_irrelevant_outputs(config, load_config)
 
         try:
             if "--dry-run" in options: