add xscreensaver 'candy' (sub process)

src/application.vala

@@ -13,6 +13,8 @@ namespace Deskcandy {
       this.add_action(toggle_enabled);
 
       this.set_up_actions();
+
+      var xss = new Candy.XScreensaver();
     }
 
     private void on_toggle_enabled() {

src/candy/xscreensaver.vala

@@ -0,0 +1,54 @@
+namespace Deskcandy.Candy {
+  class XScreensaver : Object {
+    public string config_dir { get; private set; }
+    public string path_dir { get; private set; }
+
+    public XScreensaver() {
+      this.hacky_determine_directories.begin();
+    }
+
+    private async void hacky_determine_directories() {
+      warning("HACK: launching xscreensaver-settings to figure out the configuration");
+      try {
+        var proc = new Subprocess(SubprocessFlags.STDERR_PIPE, "xscreensaver-settings", "--debug");
+        GLib.Timeout.add(250, () => {
+          proc.send_signal(15);
+          try {
+            proc.wait();
+            var dis = new DataInputStream(proc.get_stderr_pipe());
+            this.interpret_output(dis);
+          } catch (Error e) {
+            warning(e.message);
+            return false;
+          }
+
+          return false;
+        });
+
+      } catch (Error e) {
+        error("failed to initialize xscreensaver settings.");
+      }
+    }
+
+    private void interpret_output(DataInputStream dis) {
+      Regex config_dir_regex = /xscreensaver-settings: using config directory "(.*)"/;
+      Regex path_dir_regex = /.*added "(.*)" to \$PATH/;
+
+      string line;
+      try {
+        while ((line = dis.read_line_utf8()) != null) {
+          MatchInfo info;
+          if (config_dir_regex.match(line, 0, out info)) {
+            this.config_dir = info.fetch(1);
+            message(@"Found xscreensaver config dir: $(this.config_dir)");
+          } else if (path_dir_regex.match(line, 0, out info)) {
+            this.path_dir = info.fetch(1);
+            message(@"Found xscreensaver path dir: $(this.path_dir)");
+          }
+        }
+      } catch (IOError e) {
+        error(e.message);
+      }
+    }
+  }
+}

src/meson.build

@@ -3,8 +3,10 @@ deskcandy_sources = [
   'window.vala',
   'desktop_window.vala',
   'application.vala',
+  'candy/xscreensaver.vala'
 ]
 
+
 deskcandy_deps = [
   dependency('gio-2.0', version: '>= 2.50'),
   dependency('gtk+-3.0', version: '>= 3.22'),