add battery example

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 111 insertions, 0 deletions

diff --git a/examples/battery b/examples/battery
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+++ b/examples/battery
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+# -*- python -*-
+
+# This is a small example that inverts the colours when the
+# batteries capacity is low.
+
+
+# Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+
+# Invert the colours when the battery capacity is below this threshold.
+threshold = 5 # percent
+
+
+# Current status.
+inverted = False
+
+def get_capacity():
+    '''
+    Get the current capacity and charging status
+    
+    @return  (:bool, :float)  Whether the battery is discharging and the capacity (in percents)
+    '''
+    capacity, discharging = None, None
+    
+    # Get capacity.
+    #with open('/sys/class/power_supply/BAT1/capacity', 'r') as file:
+    #    capacity = int(file.read().split('\n')[0])
+    
+    # More accurate capacity.
+    charge_full, charge_now = None, None
+    with open('/sys/class/power_supply/BAT1/charge_full', 'r') as file:
+        charge_full = int(file.read().split('\n')[0])
+    with open('/sys/class/power_supply/BAT1/charge_now', 'r') as file:
+        charge_now = int(file.read().split('\n')[0])
+    capacity = charge_now * 100 / charge_full
+    
+    # Is the battery discharging?
+    with open('/sys/class/power_supply/BAT1/status', 'r') as file:
+        discharging = file.read().split('\n')[0] == 'Discharging'
+    
+    return (discharging, capacity)
+
+
+# Lets wait only 30 seconds, instead of a minute before running again.
+wait_period = 30
+
+# Do not fade in or out.
+fadeout_time = None
+fadein_time = None
+
+
+def periodically(year, month, day, hour, minute, second, weekday, fade):
+    '''
+    :(int, int, int, int, int, int, int, float?)?→void  Place holder for periodically invoked function
+    
+    Invoked periodically
+    
+    If you want to control at what to invoke this function next time
+    you can set the value of the global variable `wait_period` to the
+    number of seconds to wait before invoking this function again.
+    The value does not need to be an integer.
+    
+    @param   year:int     The year
+    @param   month:int    The month, 1 = January, 12 = December
+    @param   day:int      The day, minimum value is 1, probable maximum value is 31 (*)
+    @param   hour:int     The hour, minimum value is 0, maximum value is 23
+    @param   minute:int   The minute, minimum value is 0, maximum value is 59
+    @param   second:int   The second, minimum value is 0, probable maximum value is 60 (**)
+    @param   weekday:int  The weekday, 1 = Monday, 7 = Sunday
+    @param   fade:float?  Blueshift can use this function to fade into a state when it start
+                          or exits. `fade` can either be negative, zero or positive or `None`,
+                          but the magnitude of value cannot exceed 1. When Blueshift starts,
+                          this function will be invoked multiple with the time parameters
+                          of the time it is invoked and each time `fade` will increase towards
+                          1, starting at 0, when the value is 1, the settings should be applied
+                          to 100 %. After this this function will be invoked once again with
+                          `fade` being `None`. When Blueshift exits the same behaviour is used
+                          except, `fade` decrease towards -1 but start slightly below 0, when
+                          -1 is reached all settings should be normal. Then Blueshift will NOT
+                          invoke this function with `fade` being `None`, instead it will by
+                          itself revert all settings and quit.
+    
+    (*)  Can be exceeded if the calendar system is changed, like in 1712-(02)Feb-30
+    (**) See https://en.wikipedia.org/wiki/Leap_second
+    '''
+    global inverted
+    
+    (discharging, capacity) = get_capacity()
+    should_invert = discharging and (capacity <= threshold)
+    
+    if should_invert ^ inverted:
+        inverted = should_invert
+        start_over()
+        if should_invert:
+            negative()
+        monitor_controller()
+