mixer_all: convert to C++

src/MixerAll.hxx

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2003-2013 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.
+ */
+
+/** \file
+ *
+ * Functions which affect the mixers of all audio outputs.
+ */
+
+#ifndef MPD_MIXER_ALL_HXX
+#define MPD_MIXER_ALL_HXX
+
+/**
+ * Returns the average volume of all available mixers (range 0..100).
+ * Returns -1 if no mixer can be queried.
+ */
+int
+mixer_all_get_volume(void);
+
+/**
+ * Sets the volume on all available mixers.
+ *
+ * @param volume the volume (range 0..100)
+ * @return true on success, false on failure
+ */
+bool
+mixer_all_set_volume(unsigned volume);
+
+/**
+ * Similar to mixer_all_get_volume(), but gets the volume only for
+ * software mixers.  See #software_mixer_plugin.  This function fails
+ * if no software mixer is configured.
+ */
+int
+mixer_all_get_software_volume(void);
+
+/**
+ * Similar to mixer_all_set_volume(), but sets the volume only for
+ * software mixers.  See #software_mixer_plugin.  This function cannot
+ * fail, because the underlying software mixers cannot fail either.
+ */
+void
+mixer_all_set_software_volume(unsigned volume);
+
+#endif