[modules] re-enable caffeine

modules/contrib/caffeine.py

@@ -0,0 +1,102 @@
+#pylint: disable=C0111,R0903,W0212
+
+"""Enable/disable automatic screen locking.
+
+Requires the following executables:
+    * xdg-screensaver
+    * xdotool
+    * xprop (as dependency for xdotool)
+    * notify-send
+"""
+
+import logging
+import os
+import psutil
+import bumblebee.input
+import bumblebee.output
+import bumblebee.engine
+
+class Module(bumblebee.engine.Module):
+    def __init__(self, engine, config):
+        super(Module, self).__init__(engine, config,
+            bumblebee.output.Widget(full_text="")
+        )
+        self._active = False
+        self._xid = None
+
+        engine.input.register_callback(self, button=bumblebee.input.LEFT_MOUSE,
+            cmd=self._toggle
+        )
+
+    def _check_requirements(self):
+        requirements = ['xdotool', 'xprop', 'xdg-screensaver']
+        missing = []
+        for tool in requirements:
+            if not bumblebee.util.which(tool):
+                missing.append(tool)
+        return missing
+
+    def _get_i3bar_xid(self):
+        xid = bumblebee.util.execute("xdotool search --class \"i3bar\"").partition('\n')[0].strip()
+        if xid.isdigit():
+            return xid
+        logging.warning("Module caffeine: xdotool couldn't get X window ID of \"i3bar\".")
+        return None
+
+    def _notify(self):
+        if not bumblebee.util.which('notify-send'):
+            return
+
+        if self._active:
+            bumblebee.util.execute("notify-send \"Consuming caffeine\"")
+        else:
+            bumblebee.util.execute("notify-send \"Out of coffee\"")
+
+    def _suspend_screensaver(self):
+        self._xid = self._get_i3bar_xid()
+        if self._xid is None:
+            return False
+
+        pid = os.fork()
+        if pid == 0:
+            os.setsid()
+            bumblebee.util.execute("xdg-screensaver suspend {}".format(self._xid))
+            os._exit(0)
+        else:
+            os.waitpid(pid, 0)
+        return True
+
+    def _resume_screensaver(self):
+        success = True
+        xprop_path = bumblebee.util.which('xprop')
+        pids = [ p.pid for p in psutil.process_iter() if p.cmdline() == [xprop_path, '-id', str(self._xid), '-spy'] ]
+        for pid in pids:
+            try:
+                os.kill(pid, 9)
+            except OSError:
+                success = False
+        return success
+
+    def state(self, _):
+        if self._active:
+            return "activated"
+        return "deactivated"
+
+    def _toggle(self, _):
+        missing = self._check_requirements()
+        if missing:
+            logging.warning('Could not run caffeine - missing %s!', ", ".join(missing))
+            return
+
+        self._active = not self._active
+        if self._active:
+            success = self._suspend_screensaver()
+        else:
+            success = self._resume_screensaver()
+
+        if success:
+            self._notify()
+        else:
+            self._active = not self._active
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4