#5: Ability to scream out loud if battery is low :-)

i3pystatus/battery.py

@@ -3,6 +3,7 @@
 
 from . import IntervalModule
 from .core.util import PrefixedKeyDict
+from .core.desktop import display_notification
 
 class Battery:
     @staticmethod
@@ -47,12 +48,31 @@ class BatteryChecker(IntervalModule):
     """ 
     This class uses the /sys/class/power_supply/…/uevent interface to check for the
     battery status
+
+    Available formatters for format and alert_format_\*:
+
+    * remaining_str
+    * remaining_hm
+    * percentage
+    * percentage_design
+    * consumption (Watts)
+    * status
+    * battery_ident
     """
     
-    settings = ("battery_ident", "format")
+    settings = (
+        "battery_ident", "format",
+        ("alert", "Display a libnotify-notification on low battery"),
+        "alert_percentage", "alert_format_title", "alert_format_body", "alert_percentage",
+    )
     battery_ident = "BAT0"
     format = "{status} {remaining}"
     
+    alert = False
+    alert_percentage = 10
+    alert_format_title = "Low battery"
+    alert_format_body = "Battery {battery_ident} has only {percentage} % ({remaining_hm}) remaining!"
+
     def init(self):
         self.base_path = "/sys/class/power_supply/{0}/uevent".format(self.battery_ident)
 
@@ -61,18 +81,22 @@ class BatteryChecker(IntervalModule):
         color = "#ffffff"
 
         battery = Battery(self.base_path)
-        fdict = dict.fromkeys(("remaining_str", "remaining_hm"), "")
 
         status = battery.STATUS
         energy_now = battery.ENERGY_NOW
         energy_full = battery.ENERGY_FULL
         power_now = battery.POWER_NOW
 
-        fdict["percentage"] = (energy_now / energy_full) * 100
-        fdict["percentage_design"] = (energy_now / battery.ENERGY_FULL_DESIGN) * 100
-        fdict["consumption"] = power_now / 1000000
+        fdict = {
+            "battery_ident": self.battery_ident,
+            "remaining_str": "",
+            "remaining_hm": "",
+            "percentage": (energy_now / energy_full) * 100,
+            "percentage_design": (energy_now / battery.ENERGY_FULL_DESIGN) * 100,
+            "consumption": power_now / 1000000,
+        }
 
-        if status == "Full":
+        if status == "Full" or fdict["percentage"] > 99:
             fdict["status"] = "FULL"
         elif power_now:
             if status == "Discharging":
@@ -86,6 +110,14 @@ class BatteryChecker(IntervalModule):
                 remaining = RemainingCalculator(energy_full-energy_now, power_now)
             fdict.update(remaining.get_dict("remaining_"))
 
+        if self.alert and fdict["percentage"] <= self.alert_percentage:
+            display_notification(
+                title=self.alert_format_title.format(**fdict),
+                body=self.alert_format_body.format(**fdict),
+                icon="battery-caution",
+                urgency=2,
+            )
+
         self.output = {
             "full_text": self.format.format(**fdict).strip(),
             "instance": self.battery_ident,