mpd/src/output/OutputCommand.cxx

/*
 * Copyright 2003-2021 The Music Player Daemon Project
 * http://www.musicpd.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 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/*
 * Glue functions for controlling the audio outputs over the MPD
 * protocol.  These functions perform extra validation on all
 * parameters, because they might be from an untrusted source.
 *
 */

#include "OutputCommand.hxx"
#include "MultipleOutputs.hxx"
#include "Client.hxx"
#include "mixer/MixerControl.hxx"
#include "mixer/Volume.hxx"
#include "Idle.hxx"

extern unsigned audio_output_state_version;

bool
audio_output_enable_index(MultipleOutputs &outputs, unsigned idx)
{
	if (idx >= outputs.Size())
		return false;

	auto &ao = outputs.Get(idx);
	if (!ao.LockSetEnabled(true))
		return true;

	idle_add(IDLE_OUTPUT);

	if (ao.GetMixer() != nullptr) {
		InvalidateHardwareVolume();
		idle_add(IDLE_MIXER);
	}

	ao.GetClient().ApplyEnabled();

	++audio_output_state_version;

	return true;
}

bool
audio_output_disable_index(MultipleOutputs &outputs, unsigned idx)
{
	if (idx >= outputs.Size())
		return false;

	auto &ao = outputs.Get(idx);
	if (!ao.LockSetEnabled(false))
		return true;

	idle_add(IDLE_OUTPUT);

	auto *mixer = ao.GetMixer();
	if (mixer != nullptr) {
		mixer_close(mixer);
		InvalidateHardwareVolume();
		idle_add(IDLE_MIXER);
	}

	ao.GetClient().ApplyEnabled();

	++audio_output_state_version;

	return true;
}

bool
audio_output_toggle_index(MultipleOutputs &outputs, unsigned idx)
{
	if (idx >= outputs.Size())
		return false;

	auto &ao = outputs.Get(idx);
	const bool enabled = ao.LockToggleEnabled();
	idle_add(IDLE_OUTPUT);

	if (!enabled) {
		auto *mixer = ao.GetMixer();
		if (mixer != nullptr) {
			mixer_close(mixer);
			InvalidateHardwareVolume();
			idle_add(IDLE_MIXER);
		}
	}

	ao.GetClient().ApplyEnabled();

	++audio_output_state_version;

	return true;
}