mixer simple basic abstraction - added python binding

reasons:
- rapid development
- class-like code structure
- more readable code
features:
- hcontrol binding is managed from python (opportunity to create
  virtual mixer without driver or join multiple cards to behave as one)

modules/mixer/simple/python/common.py

@@ -0,0 +1,228 @@
+#!/usr/bin/python
+#  -*- coding: utf-8 -*-
+#  -*- Python -*-
+
+from pyalsa.alsahcontrol import HControl, Element as HElement, \
+                                Info as HInfo, Value as HValue, InterfaceId, \
+                                EventMask, EventMaskRemove
+
+MIXER = InterfaceId['Mixer']
+MIXERS = str(MIXER)
+
+class BaseElement(InternalMElement):
+
+  def __init__(self, mixer, name, index, weight):
+    InternalMElement.__init__(self, mixer, name, index, weight)
+    self.channels = 0
+    self.min = [0, 0]
+    self.max = [0, 0]
+
+  def opsIsChannel(self, dir, chn):
+    return chn >= 0 and chn < self.channels
+
+  def opsGetRange(self, dir):
+    return (0, self.min[dir], self.max[dir])
+
+  def opsSetRange(self, dir, min, max):
+    self.min[dir] = min
+    self.max[dir] = max
+
+  def volumeToUser(self, info, dir, value):
+    min = info.min
+    max = info.max
+    if min == max:
+      return self.min[dir]
+    n = (value - min) * (self.max[dir] - self.min[dir])
+    return self.min[dir] + (n + (max - min) / 2) / (max - min)
+
+  def volumeFromUser(self, info, dir, value):
+    min = info.min
+    max = info.max
+    if self.max[dir] == self.min[dir]:
+      return min
+    n = (value - self.min[dir]) * (max - min)
+    return min + (n + (self.max[dir] - self.min[dir]) / 2) / (self.max[dir] - self.min[dir])
+
+class StandardElement(BaseElement):
+
+  def __init__(self, mixer, name, index, weight):
+    BaseElement.__init__(self, mixer, name, index, weight)
+    self.channels = 1
+    self.volume = [None, None]
+    self.volumeinfo = [None, None]
+    self.volumetuple = [None, None]
+    self.switch = [None, None]
+    self.switchinfo = [None, None]
+    self.switchtuple = [None, None]
+
+  def decideChannels(self):
+    max = 0
+    for i in [0, 1]:
+      if self.volume[i]:
+        count = self.volumeinfo[i].count
+        if count > max:
+          max = count
+      if self.switch[i]:
+        count = self.switchinfo[i].count
+        if count > max:
+          max = count
+    self.channels = max
+
+  def attachVolume(self, helem, dir):
+    self.volume[dir] = helem
+    self.volumeinfo[dir] = HInfo(helem)
+    self.min[dir] = self.volumeinfo[dir].min
+    self.max[dir] = self.volumeinfo[dir].max
+    self.volumetuple[dir] = HValue(helem).getTuple(self.volumeinfo[dir].type, self.volumeinfo[dir].count)
+
+  def attachSwitch(self, helem, dir):
+    self.switch[dir] = helem
+    self.switchinfo[dir] = HInfo(helem)
+    self.switchtuple[dir] = HValue(helem).getTuple(self.switchinfo[dir].type, self.switchinfo[dir].count)
+
+  def attach(self, helem):
+    BaseElement.attach(self, helem)
+    if helem.name.endswith('Playback Volume'):
+      self.attachVolume(helem, 0)
+      self.caps |= self.CAP_PVOLUME
+    elif helem.name.endswith('Capture Volume'):
+      self.attachVolume(helem, 1)
+      self.caps |= self.CAP_CVOLUME
+    elif helem.name.endswith('Playback Switch'):
+      self.attachSwitch(helem, 0)
+      self.caps |= self.CAP_PSWITCH
+    elif helem.name.endswith('Capture Switch'):
+      self.attachSwitch(helem, 1)
+      self.caps |= self.CAP_CSWITCH
+    self.decideChannels()
+    self.eventInfo()
+
+  def opsGetVolume(self, dir, chn):
+    return (0, self.volumeToUser(self.volumeinfo[dir], dir, self.volumetuple[dir][chn]))
+
+  def opsSetVolume(self, dir, chn, value):
+    val = self.volumeFromUser(self.volumeinfo[dir], dir, value)
+    if self.volumetuple[dir][chn] == val:
+      return
+    a = list(self.volumetuple[dir])
+    a[chn] = val
+    self.volumetuple[dir] = tuple(a)
+    hv = HValue(self.volume)
+    hv.setTuple(self.volumeinfo[dir].type, self.volumetuple[dir])
+    hv.write()
+
+  def opsGetSwitch(self, dir, chn):
+    return (0, self.switchtuple[dir][chn])
+
+  def opsSetSwitch(self, dir, chn, value):
+    if self.switchtuple[dir][chn] and value:
+      return
+    if not self.switchtuple[dir][chn] and not value:
+      return
+    a = list(self.switchtuple[dir])
+    a[chn] = int(value)
+    self.switchtuple[dir] = tuple(a)
+    hv = HValue(self.switch[dir])
+    hv.setTuple(self.switchinfo[dir].type, self.switchtuple[dir])
+    hv.write()
+
+  def update(self, helem):
+    for i in [0, 1]:
+      if helem == self.volume[i]:
+        self.volumetuple[i] = HValue(helem).getTuple(self.volumeinfo[i].type, self.volumeinfo[i].count)
+      elif helem == self.switch[i]:
+        self.switchtuple[i] = HValue(helem).getTuple(self.switchinfo[i].type, self.switchinfo[i].count)
+    self.eventValue()
+
+class EnumElement(BaseElement):
+
+  def __init__(self, mixer, name, index, weight):
+    BaseElement.__init__(self, mixer, name, index, weight)
+    self.mycaps = 0
+  
+  def attach(self, helem):
+    BaseElement.attach(self, helem)
+    self.enum = helem
+    self.enuminfo = HInfo(helem)
+    self.enumtuple = HValue(helem).getTuple(self.enuminfo.type, self.enuminfo.count)
+    self.channels = self.enuminfo.count
+    self.texts = self.enuminfo.itemNames
+    self.caps |= self.mycaps
+
+  def opsIsEnumerated(self, dir=-1):
+    if dir < 0:
+      return 1
+    if dir == 0 and self.mycaps & self.CAP_PENUM:
+      return 1
+    if dir == 1 and self.mycaps & self.CAP_CENUM:
+      return 1
+
+  def opsIsEnumCnt(self, dir):
+    return self.enuminfo.items
+
+  def opsGetEnumItemName(self, item):
+    return (0, self.texts[item])
+
+  def opsGetEnumItem(self, chn):
+    if chn >= self.channels:
+      return -1
+    return (0, self.enumtuple[chn])
+    
+  def opsSetEnumItem(self, chn, value):
+    if chn >= self.channels:
+      return -1
+    if self.enumtuple[chn] == value:
+      return
+    a = list(self.enumtuple)
+    a[chn] = int(value)
+    self.enumtuple = tuple(a)
+    hv = HValue(self.enum)
+    hv.setTuple(self.enuminfo.type, self.enumtuple)
+    hv.write()
+
+  def update(self, helem):
+    self.enumtuple = HValue(helem).getTuple(self.enuminfo.type, self.enuminfo.count)
+    self.eventValue()
+
+class EnumElementPlayback(EnumElement):
+
+  def __init__(self, mixer, name, index, weight):
+    EnumElement.__init__(self, mixer, name, index, weight)
+    self.mycaps = self.CAP_PENUM
+  
+class EnumElementCapture(EnumElement):
+
+  def __init__(self, mixer, name, index, weight):
+    EnumElement.__init__(self, mixer, name, index, weight)
+    self.mycaps = self.CAP_CENUM
+  
+ELEMS = []
+
+def element_add(helem):
+  key = helem.name+'//'+str(helem.index)+'//'+str(helem.interface)
+  if not CONTROLS.has_key(key):
+    return
+  val = CONTROLS[key]
+  felem = None
+  for elem in ELEMS:
+    if elem.name == val[0] and elem.index == val[1]:
+      felem = elem
+      break
+  if not felem:
+    felem = mixer.newMElement(val[3], val[0], val[1], val[2])
+    mixer.addMElement(felem)
+    ELEMS.append(felem)
+  felem.attach(helem)
+
+def eventHandler(evmask, helem, melem):
+  if evmask == EventMaskRemove:
+    return
+  if evmask & EventMask['Add']:
+    element_add(helem)
+  if evmask & EventMask['Value']:
+    melem.update(helem)
+
+def init():
+  hctl = HControl(device, load=False)
+  mixer.attachHCtl(hctl)
+  mixer.register()