add example: stored-settings

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

1 files changed, 58 insertions, 0 deletions

diff --git a/examples/stored-settings b/examples/stored-settings
new file mode 100644
index 0000000..e3b45c0
--- /dev/null
+++ b/examples/stored-settings
@@ -0,0 +1,58 @@
+# -*- python -*-
+
+# This example demonstrates how settings can be stored
+# and be transition from later.
+
+import os
+import time
+
+
+uses_adhoc_opts = True
+'''
+:bool  `True` if the configuration script parses the ad-hoc settings
+'''
+
+
+# Get --temperature from Blueshift ad-hoc settigns
+temperature_to = int(parser.opts['--temperature'][0])
+
+# Get old temperature setting
+temperature_from = 6500
+storage_file = '/dev/shm/.blueshift-conf-%s-%s' % (os.environ['DISPLAY'], os.environ['USER'])
+if os.path.exists(storage_file):
+    with open(storage_file, 'rb') as file:
+        temperature_from = int(file.read().decode('utf-8', 'replace').split('\n')[0])
+
+# Store new temperature
+with open(storage_file, 'wb') as file:
+    file.write(str(temperature_to).encode('utf-8'))
+    file.flush()
+
+# Calculate transition time
+fadein_time = abs(temperature_to - temperature_from) * 5 / (6500 - 3700)
+fadein_steps = fadein_time * 10
+
+# Function for setting the colour temperature
+def adjust(alpha):
+    temp = temperature_to * alpha + temperature_from * (1 - alpha)
+    start_over()
+    temperature(temp, lambda t : divide_by_maximum(cmf_10deg(t)))
+    randr(0)
+
+# Perform transition
+if not (panicgate or temperature_to == temperature_from):
+    signal.signal(signal.SIGTERM, signal_SIGTERM)
+    dtime = fadein_time / fadein_steps
+    df = 1 / fadein_steps
+    trans = 0
+    while running:
+        try:
+            trans += df
+            if trans > 1:
+                break
+            adjust(trans)
+            time.sleep(dtime)
+        except KeyboardInterrupt:
+            running = False
+adjust(1)
+