use percentage based brightness steps

1 files changed, 29 insertions, 8 deletions

diff --git a/tp-key-handler b/tp-key-handler
index a47f8f8..259210f 100755
--- a/tp-key-handler
+++ b/tp-key-handler
@@ -130,21 +130,42 @@ class KeyhandlerDBUSService(dbus.service.Object):
         popen.wait()
         self._showMicState()
 
-    @dbus.service.method('org.elektranox.keyhandler')
-    def backlightDec(self):
-        brightness = self._getBacklight() - 5
+    def _backlightChg(self, decrease):
+        brightness = self._getBacklight()
+        maximum = self._getMaxBacklight()
+        current = self._getBacklight() / maximum * 100
+        step = 1
+
+        # probably should implement something using a logarithmic scale
+        if current <= 2:
+            step = int(0.5 * maximum/100)
+        elif current <= 10:
+            step = int(1 * maximum/100)
+        elif current <= 50:
+            step = int(5 * maximum/100)
+        else:
+            step = int(10 * maximum/100)
+
+        if decrease:
+            brightness -= step
+        else:
+            brightness += step
+
         if brightness < 0:
             brightness = 0
+        if brightness > maximum:
+            brightness = maximum
         self._setBacklight(brightness)
         self._showBacklightState()
 
+
+    @dbus.service.method('org.elektranox.keyhandler')
+    def backlightDec(self):
+        self._backlightChg(True)
+
     @dbus.service.method('org.elektranox.keyhandler')
     def backlightInc(self):
-        brightness = self._getBacklight() + 5
-        if brightness > self._getMaxBacklight():
-            brightness = self._getMaxBacklight()
-        self._setBacklight(brightness)
-        self._showBacklightState()
+        self._backlightChg(False)
 
     @dbus.service.method('org.elektranox.keyhandler')
     def XF86Display(self):