volume: convert to C++

1 files changed, 141 insertions, 0 deletions

diff --git a/src/Volume.cxx b/src/Volume.cxx
new file mode 100644
index 00000000..f6643a90
--- /dev/null
+++ b/src/Volume.cxx
@@ -0,0 +1,141 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "Volume.hxx"
+
+extern "C" {
+#include "idle.h"
+#include "mixer_all.h"
+#include "event_pipe.h"
+}
+
+#include <glib.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "volume"
+
+#define SW_VOLUME_STATE                         "sw_volume: "
+
+static unsigned volume_software_set = 100;
+
+/** the cached hardware mixer value; invalid if negative */
+static int last_hardware_volume = -1;
+/** the age of #last_hardware_volume */
+static GTimer *hardware_volume_timer;
+
+/**
+ * Handler for #PIPE_EVENT_MIXER.
+ */
+static void
+mixer_event_callback(void)
+{
+	/* flush the hardware volume cache */
+	last_hardware_volume = -1;
+
+	/* notify clients */
+	idle_add(IDLE_MIXER);
+}
+
+void volume_finish(void)
+{
+	g_timer_destroy(hardware_volume_timer);
+}
+
+void volume_init(void)
+{
+	hardware_volume_timer = g_timer_new();
+
+	event_pipe_register(PIPE_EVENT_MIXER, mixer_event_callback);
+}
+
+int volume_level_get(void)
+{
+	assert(hardware_volume_timer != NULL);
+
+	if (last_hardware_volume >= 0 &&
+	    g_timer_elapsed(hardware_volume_timer, NULL) < 1.0)
+		/* throttle access to hardware mixers */
+		return last_hardware_volume;
+
+	last_hardware_volume = mixer_all_get_volume();
+	g_timer_start(hardware_volume_timer);
+	return last_hardware_volume;
+}
+
+static bool software_volume_change(unsigned volume)
+{
+	assert(volume <= 100);
+
+	volume_software_set = volume;
+	mixer_all_set_software_volume(volume);
+
+	return true;
+}
+
+static bool hardware_volume_change(unsigned volume)
+{
+	/* reset the cache */
+	last_hardware_volume = -1;
+
+	return mixer_all_set_volume(volume);
+}
+
+bool volume_level_change(unsigned volume)
+{
+	assert(volume <= 100);
+
+	volume_software_set = volume;
+
+	idle_add(IDLE_MIXER);
+
+	return hardware_volume_change(volume);
+}
+
+bool
+read_sw_volume_state(const char *line)
+{
+	char *end = NULL;
+	long int sv;
+
+	if (!g_str_has_prefix(line, SW_VOLUME_STATE))
+		return false;
+
+	line += sizeof(SW_VOLUME_STATE) - 1;
+	sv = strtol(line, &end, 10);
+	if (*end == 0 && sv >= 0 && sv <= 100)
+		software_volume_change(sv);
+	else
+		g_warning("Can't parse software volume: %s\n", line);
+	return true;
+}
+
+void save_sw_volume_state(FILE *fp)
+{
+	fprintf(fp, SW_VOLUME_STATE "%u\n", volume_software_set);
+}
+
+unsigned
+sw_volume_state_get_hash(void)
+{
+	return volume_software_set;
+}