1 files changed, 75 insertions, 0 deletions
diff --git a/indra/llcommon/commoncontrol.h b/indra/llcommon/commoncontrol.h
new file mode 100644
index 0000000000..07d4a45ac5
--- /dev/null
+++ b/indra/llcommon/commoncontrol.h
@@ -0,0 +1,75 @@
+/**
+ * @file   commoncontrol.h
+ * @author Nat Goodspeed
+ * @date   2022-06-08
+ * @brief  Access LLViewerControl LLEventAPI, if process has one.
+ * 
+ * $LicenseInfo:firstyear=2022&license=viewerlgpl$
+ * Copyright (c) 2022, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_COMMONCONTROL_H)
+#define LL_COMMONCONTROL_H
+
+#include <vector>
+#include "llexception.h"
+#include "llsd.h"
+
+namespace LL
+{
+    class CommonControl
+    {
+    public:
+        struct Error: public LLException
+        {
+            Error(const std::string& what): LLException(what) {}
+        };
+
+        /// Exception thrown if there's no LLViewerControl LLEventAPI
+        struct NoListener: public Error
+        {
+            NoListener(const std::string& what): Error(what) {}
+        };
+
+        struct ParamError: public Error
+        {
+            ParamError(const std::string& what): Error(what) {}
+        };
+
+        /// set control group.key to defined default value
+        static
+        LLSD set_default(const std::string& group, const std::string& key);
+
+        /// set control group.key to specified value
+        static
+        LLSD set(const std::string& group, const std::string& key, const LLSD& value);
+
+        /// toggle boolean control group.key
+        static
+        LLSD toggle(const std::string& group, const std::string& key);
+
+        /// get the definition for control group.key, (! isDefined()) if bad
+        /// ["name"], ["type"], ["value"], ["comment"]
+        static
+        LLSD get_def(const std::string& group, const std::string& key);
+
+        /// get the value of control group.key
+        static
+        LLSD get(const std::string& group, const std::string& key);
+
+        /// get defined groups
+        static
+        std::vector<std::string> get_groups();
+
+        /// get definitions for all variables in group
+        static
+        LLSD get_vars(const std::string& group);
+
+    private:
+        static
+        LLSD access(const LLSD& params);
+    };
+} // namespace LL
+
+#endif /* ! defined(LL_COMMONCONTROL_H) */