gui/ocarina: Add basic command line options

These options are mostly used to communicate with a running Ocarina
instance to control playback.

Implements #37: Ocarina Command Line Commands
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

TODO

@@ -38,4 +38,3 @@ Future work:
 		- OSX
 		- Windows
 		- Android
-	- Command line tools for web interface development?

gui/ocarina.c

@@ -2,6 +2,7 @@
  * Copyright 2014 (c) Anna Schumaker.
  */
 #include <core/core.h>
+#include <core/audio.h>
 #include <gui/audio.h>
 #include <gui/builder.h>
 #include <gui/collection.h>
@@ -13,7 +14,17 @@
 #include <gui/view.h>
 #include <gui/window.h>
 
-#define OCARINA_FLAGS (G_APPLICATION_FLAGS_NONE)
+#define OCARINA_FLAGS (G_APPLICATION_HANDLES_COMMAND_LINE)
+
+static const GOptionEntry ocarina_options[] = {
+	{ "next",     'n', 0, G_OPTION_ARG_NONE, NULL, "Play next track",        NULL },
+	{ "pause",    'P', 0, G_OPTION_ARG_NONE, NULL, "Pause playback",         NULL },
+	{ "play",     'p', 0, G_OPTION_ARG_NONE, NULL, "Start playback",         NULL },
+	{ "previous", 'N', 0, G_OPTION_ARG_NONE, NULL, "Play previous track",    NULL },
+	{ "toggle",   't', 0, G_OPTION_ARG_NONE, NULL, "Toggle playback state",  NULL },
+	{ "version",  'v', 0, G_OPTION_ARG_NONE, NULL, "Print version and exit", NULL },
+	{ NULL },
+};
 
 #ifndef CONFIG_DEBUG
 const static gchar *OCARINA_APP = "org.gtk.ocarina";
@@ -46,6 +57,44 @@ static void __ocarina_activate(GApplication *application, gpointer data)
 				   GTK_WINDOW(gui_builder_widget("o_window")));
 }
 
+static int __ocarina_local_options(GApplication *application,
+				   GVariantDict *options, gpointer data)
+{
+	if (!g_variant_dict_contains(options, "version"))
+		return -1;
+	g_printf("Ocarina %s\n", get_version());
+	g_printf("GTK+ %u.%u.%u\n", GTK_MAJOR_VERSION, GTK_MINOR_VERSION, GTK_MICRO_VERSION);
+	g_printf("%s\n", gst_version_string());
+	g_printf("%s, %s\n", __DATE__, __TIME__);
+	return 0;
+}
+
+static int __ocarina_command_line(GApplication            *application,
+				  GApplicationCommandLine *command,
+				  gpointer                 data)
+{
+	GVariantDict *options;
+
+	g_application_activate(application);
+
+	options = g_application_command_line_get_options_dict(command);
+	if (g_variant_dict_contains(options, "next"))
+		audio_next();
+	else if (g_variant_dict_contains(options, "pause"))
+		audio_pause();
+	else if (g_variant_dict_contains(options, "play"))
+		audio_play();
+	else if (g_variant_dict_contains(options, "previous"))
+		audio_prev();
+	else if (g_variant_dict_contains(options, "toggle")) {
+		if (audio_cur_state() == GST_STATE_PLAYING)
+			audio_pause();
+		else
+			audio_play();
+	}
+	return 0;
+}
+
 static void __ocarina_startup(GApplication *application, gpointer data)
 {
 	gchar *ui   = find_file_path("ocarina.ui");
@@ -81,12 +130,17 @@ static void __ocarina_shutdown(GApplication *application, gpointer data)
 int main(int argc, char **argv)
 {
 	GtkApplication *ocarina = gtk_application_new(OCARINA_APP, OCARINA_FLAGS);
-
 	startup_argc = argc;
 	startup_argv = argv;
 
-	g_signal_connect(G_APPLICATION(ocarina), "activate", (GCallback)__ocarina_activate, NULL);
-	g_signal_connect(G_APPLICATION(ocarina), "startup",  (GCallback)__ocarina_startup,  NULL);
-	g_signal_connect(G_APPLICATION(ocarina), "shutdown", (GCallback)__ocarina_shutdown, NULL);
+	g_application_add_main_option_entries(G_APPLICATION(ocarina), ocarina_options);
+	g_application_add_option_group(G_APPLICATION(ocarina), gst_init_get_option_group());
+
+	g_signal_connect(G_APPLICATION(ocarina), "activate",     (GCallback)__ocarina_activate,      NULL);
+	g_signal_connect(G_APPLICATION(ocarina), "handle-local-options",
+								 (GCallback)__ocarina_local_options, NULL);
+	g_signal_connect(G_APPLICATION(ocarina), "command-line", (GCallback)__ocarina_command_line,  NULL);
+	g_signal_connect(G_APPLICATION(ocarina), "startup",      (GCallback)__ocarina_startup,       NULL);
+	g_signal_connect(G_APPLICATION(ocarina), "shutdown",     (GCallback)__ocarina_shutdown,      NULL);
 	return g_application_run(G_APPLICATION(ocarina), argc, argv);
 }