Battery: Split operating system specific code

This removes all operating system specific code from the main
battery file into their own source files. CMake will add the
correct implementation automatically.

src/battery/freebsd.c

@@ -0,0 +1,79 @@
+/**************************************************************************
+*
+* Tint2 : FreeBSD battery
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License version 2
+* or any later version as published by the Free Software Foundation.
+*
+* 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.
+**************************************************************************/
+
+#if defined(__FreeBSD__)
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <string.h>
+
+#include "common.h"
+#include "battery.h"
+
+gboolean battery_os_init() {
+	int sysctl_out = 0;
+	size_t len = sizeof(sysctl_out);
+
+	return (sysctlbyname("hw.acpi.battery.state", &sysctl_out, &len, NULL, 0) == 0) ||
+			(sysctlbyname("hw.acpi.battery.time", &sysctl_out, &len, NULL, 0) == 0) ||
+			(sysctlbyname("hw.acpi.battery.life", &sysctl_out, &len, NULL, 0) == 0);
+}
+
+void battery_os_free() {
+	return;
+}
+
+int battery_os_update(struct batstate *state) {
+	int sysctl_out = 0;
+	size_t len = sizeof(sysctl_out);
+	gboolean err = 0;
+
+	if (sysctlbyname("hw.acpi.battery.state", &sysctl_out, &len, NULL, 0) == 0) {
+		switch(sysctl_out) {
+		case 1:
+			state->state = BATTERY_DISCHARGING;
+			break;
+		case 2:
+			state->state = BATTERY_CHARGING;
+			break;
+		default:
+			state->state = BATTERY_FULL;
+			break;
+		}
+	} else {
+		fprintf(stderr, "power update: no such sysctl");
+		err = -1;
+	}
+
+	if (sysctlbyname("hw.acpi.battery.time", &sysctl_out, &len, NULL, 0) == 0)
+		batstate_set_time(state, sysctl_out * 60);
+	else
+		err = -1;
+
+	if (sysctlbyname("hw.acpi.battery.life", &sysctl_out, &len, NULL, 0) == 0)
+		state->percentage = sysctl_out;
+	else
+		err = -1;
+	
+	return err;
+}
+
+char* battery_os_tooltip() {
+	return strdup("Operating System not supported");
+}
+
+#endif