Prevent battery module spamming notifications. (#581)

* Prevent battery module spamming notifications.

Raised in #578.

* Fix pep8 issues.

i3pystatus/battery.py

@@ -1,11 +1,11 @@
+import configparser
 import os
 import re
-import configparser
 
 from i3pystatus import IntervalModule, formatp
-from i3pystatus.core.util import lchop, TimeWrapper, make_bar
-from i3pystatus.core.desktop import DesktopNotification
 from i3pystatus.core.command import run_through_shell
+from i3pystatus.core.desktop import DesktopNotification
+from i3pystatus.core.util import lchop, TimeWrapper, make_bar
 
 
 class UEventParser(configparser.ConfigParser):
@@ -192,7 +192,8 @@ class BatteryChecker(IntervalModule):
         ("charging_color", "The charging color"),
         ("critical_color", "The critical color"),
         ("not_present_color", "The not present color."),
-        ("not_present_text", "The text to display when the battery is not present. Provides {battery_ident} as formatting option"),
+        ("not_present_text",
+         "The text to display when the battery is not present. Provides {battery_ident} as formatting option"),
         ("no_text_full", "Don't display text when battery is full - 100%"),
     )
 
@@ -225,6 +226,8 @@ class BatteryChecker(IntervalModule):
     path = None
     paths = []
 
+    notification = None
+
     def percentage(self, batteries, design=False):
         total_now = [battery.wh_remaining() for battery in batteries]
         total_full = [battery.wh_total() for battery in batteries]
@@ -341,13 +344,19 @@ class BatteryChecker(IntervalModule):
             run_through_shell(self.critical_level_command, enable_shell=True)
 
         if self.alert and fdict["status"] == "DIS" and fdict["percentage"] <= self.alert_percentage:
-            DesktopNotification(
-                title=formatp(self.alert_format_title, **fdict),
-                body=formatp(self.alert_format_body, **fdict),
-                icon="battery-caution",
-                urgency=2,
-                timeout=self.alert_timeout,
-            ).display()
+            title, body = formatp(self.alert_format_title, **fdict), formatp(self.alert_format_body, **fdict)
+            if not self.notification:
+                self.notification = DesktopNotification(
+                    title=title,
+                    body=body,
+                    icon="battery-caution",
+                    urgency=2,
+                    timeout=self.alert_timeout,
+                )
+                self.notification.display()
+            else:
+                self.notification.update(title=title,
+                                         body=body)
 
         fdict["status"] = self.status[fdict["status"]]
 

i3pystatus/core/desktop.py

@@ -35,6 +35,18 @@ class BaseDesktopNotification:
         """
         return False
 
+    def update(self, title=None, body=None, icon=None):
+        """
+        Update this notification.
+
+        :param title: Title of the notification
+        :param body: Body text of the notification, depending on the users system configuration HTML may be used, but is not recommended
+        :param icon: A XDG icon name, see http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
+
+        :return boolean indicating success
+        """
+        return False
+
 
 class DesktopNotification(BaseDesktopNotification):
     pass
@@ -42,6 +54,7 @@ class DesktopNotification(BaseDesktopNotification):
 
 try:
     import gi
+
     gi.require_version('Notify', '0.7')
     from gi.repository import Notify
 except (ImportError, ValueError):
@@ -61,16 +74,23 @@ else:
             Notify.Urgency.CRITICAL,
         )
 
+        def __init__(self, **kwargs):
+            super().__init__(**kwargs)
+            self.notification = Notify.Notification.new(self.title, self.body, self.icon)
+
         def display(self):
-            notification = Notify.Notification.new(self.title, self.body, self.icon)
             if self.timeout:
-                notification.set_timeout(self.timeout)
-            notification.set_urgency(self.URGENCY_LUT[self.urgency])
+                self.notification.set_timeout(self.timeout)
+            self.notification.set_urgency(self.URGENCY_LUT[self.urgency])
             try:
-                return notification.show()
+                return self.notification.show()
             except Exception:
                 self.logger.exception(
                     'Failed to display desktop notification (is a '
                     'notification daemon running?)'
                 )
                 return False
+
+        def update(self, title=None, body=None, icon=None):
+            self.notification.update(title or self.title, body or self.body, icon or self.icon)
+            return self.notification.show()