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//-*-C++-*-
/*
* KMix -- KDE's full featured mini mixer
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1307, USA.
*/
#ifndef MIXER_BACKEND_H
#define MIXER_BACKEND_H
#include "mixer.h"
class Mixer_Backend
{
// The Mixer Backend's may only be accessed from the Mixer class.
friend class Mixer;
protected:
Mixer_Backend(int devnum);
virtual ~Mixer_Backend();
/// Derived classes MUST implement this to open the mixer. Returns a KMix error code (O=OK).
virtual int open() = 0;
virtual int close() = 0;
/** Returns, whether this Mixer object contains a valid Mixer. You should return "false", when
* the Mixer with the devnum given in the constructor is not supported by the Backend. The two
* typical cases are:
* (1) No such hardware installed
* (2) The hardware exists, but has no mixer support (e.g. external soundcard with only mechanical volume knobs)
* The default implementation calls open(), checks the return code and whether the number of
* supported channels is > 0. Then it calls close().
* You should reimplement this method in your backend, when there is a less time-consuming method than
* calling open() and close() for checking the existance of a Mixer.
*/
virtual bool isValid();
/** @return true, if the Mixer is open (and thus can be operated) */
bool isOpen();
virtual bool prepareUpdateFromHW();
/// Volume Read
virtual int readVolumeFromHW( int devnum, Volume &vol ) = 0;
/// Volume Write
virtual int writeVolumeToHW( int devnum, Volume &volume ) = 0;
/// Enums
virtual void setEnumIdHW(int mixerIdx, unsigned int);
virtual unsigned int enumIdHW(int mixerIdx);
/// Recording Switches
virtual bool setRecsrcHW( int devnum, bool on) = 0;
virtual bool isRecsrcHW( int devnum ) = 0;
/// Overwrite in the backend if the backend can see changes without polling
virtual bool needsPolling() { return true; }
/** overwrite this if you need to connect to slots in the mixer (e.g. readSetFromHW)
this called in the very beginning and only if !needsPolling
*/
virtual void prepareSignalling( Mixer * ) {}
MixDevice* recommendedMaster();
/** Return a translated error text for the given error number.
* Subclasses can override this method to produce platform
* specific error descriptions.
*/
virtual QString errorText(int mixer_error);
/// Prints out a translated error text for the given error number on stderr
void errormsg(int mixer_error);
int m_devnum;
/// User friendly name of the Mixer (e.g. "IRIX Audio Mixer"). If your mixer API
/// gives you a usable name, use that name.
QString m_mixerName;
// All mix devices of this phyisical device.
MixSet m_mixDevices;
/******************************************************************************************
* Please don't access the next vars from the Mixer class (even though Mixer is a friend).
* There are proper accesor methods for them.
******************************************************************************************/
bool m_isOpen;
// The MixDevice that would qualify best as MasterDevice (according to the taste of the Backend developer)
MixDevice* m_recommendedMaster;
};
#endif
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