1 files changed, 68 insertions, 0 deletions
diff --git a/brillo/dbus/dbus_signal.h b/brillo/dbus/dbus_signal.h
new file mode 100644
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+++ b/brillo/dbus/dbus_signal.h
@@ -0,0 +1,68 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef LIBCHROMEOS_BRILLO_DBUS_DBUS_SIGNAL_H_
+#define LIBCHROMEOS_BRILLO_DBUS_DBUS_SIGNAL_H_
+
+#include <string>
+#include <typeinfo>
+
+#include <base/bind.h>
+#include <base/macros.h>
+#include <brillo/brillo_export.h>
+#include <brillo/dbus/dbus_param_writer.h>
+#include <dbus/message.h>
+
+namespace brillo {
+namespace dbus_utils {
+
+class DBusObject;
+
+// Base class for D-Bus signal proxy classes.
+// Used mostly to store the polymorphic DBusSignal<...> in a single map
+// container inside DBusInterface object.
+class BRILLO_EXPORT DBusSignalBase {
+ public:
+  DBusSignalBase(DBusObject* dbus_object,
+                 const std::string& interface_name,
+                 const std::string& signal_name);
+  virtual ~DBusSignalBase() = default;
+
+ protected:
+  bool SendSignal(dbus::Signal* signal) const;
+
+  std::string interface_name_;
+  std::string signal_name_;
+
+ private:
+  DBusObject* dbus_object_;
+
+  DISALLOW_COPY_AND_ASSIGN(DBusSignalBase);
+};
+
+// DBusSignal<...> is a concrete signal proxy class that knows about the
+// exact number of signal arguments and their types.
+template<typename... Args>
+class DBusSignal : public DBusSignalBase {
+ public:
+  // Expose the custom constructor from DBusSignalBase.
+  using DBusSignalBase::DBusSignalBase;
+  ~DBusSignal() override = default;
+
+  // DBusSignal<...>::Send(...) dispatches the signal with the given arguments.
+  bool Send(const Args&... args) const {
+    dbus::Signal signal(interface_name_, signal_name_);
+    dbus::MessageWriter signal_writer(&signal);
+    DBusParamWriter::Append(&signal_writer, args...);
+    return SendSignal(&signal);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DBusSignal);
+};
+
+}  // namespace dbus_utils
+}  // namespace brillo
+
+#endif  // LIBCHROMEOS_BRILLO_DBUS_DBUS_SIGNAL_H_