Add a ReadOnlyControl parameter abstraction

This allows to pass a sperici Controllable alike instance around without
relying on directly exposing the Plugin instance and parameter-id.

1 files changed, 50 insertions, 0 deletions

diff --git a/libs/ardour/readonly_control.cc b/libs/ardour/readonly_control.cc
new file mode 100644
index 0000000000..3b72ac5e1b
--- /dev/null
+++ b/libs/ardour/readonly_control.cc
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2017 Robin Gareus <robin@gareus.org>
+ * Copyright (C) 2000, 2007 Paul Davis
+ *
+ * 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 "pbd/destructible.h"
+
+#include "ardour/plugin.h"
+#include "ardour/readonly_control.h"
+
+using namespace ARDOUR;
+
+ReadOnlyControl::ReadOnlyControl (boost::shared_ptr<Plugin> p, uint32_t pnum)
+		: _plugin (boost::weak_ptr<Plugin> (p))
+		, _parameter_num (pnum)
+{ }
+
+double
+ReadOnlyControl::get_parameter () const
+{
+	boost::shared_ptr<Plugin> p = _plugin.lock();
+	if (p) {
+		return p->get_parameter (_parameter_num);
+	}
+	return 0;
+}
+
+std::string
+ReadOnlyControl::describe_parameter ()
+{
+	boost::shared_ptr<Plugin> p = _plugin.lock();
+	if (p) {
+		return p->describe_parameter (Evoral::Parameter (ARDOUR::PluginAutomation, 0, _parameter_num));
+	}
+	return "";
+}