Add a callback to report system device changes

Devices being added or removed, or the default device changing. Not all
backends report this (none do currently), but it'll be supported where it can.

1 files changed, 36 insertions, 0 deletions

diff --git a/alc/events.h b/alc/events.h
new file mode 100644
index 00000000..51f32e57
--- /dev/null
+++ b/alc/events.h
@@ -0,0 +1,36 @@
+#ifndef ALC_EVENTS_H
+#define ALC_EVENTS_H
+
+#include "inprogext.h"
+#include "opthelpers.h"
+
+#include <bitset>
+#include <mutex>
+#include <string_view>
+
+
+namespace alc {
+
+enum class EventType : uint8_t {
+    DefaultDeviceChanged,
+    DeviceAdded,
+    DeviceRemoved,
+
+    Count
+};
+
+inline std::bitset<al::to_underlying(EventType::Count)> EventsEnabled{0};
+
+inline std::mutex EventMutex;
+
+inline ALCEVENTPROCTYPESOFT EventCallback{};
+inline void *EventUserPtr{};
+
+void Event(ALCenum eventType, ALCdevice *device, std::string_view message) noexcept;
+
+inline void Event(ALCenum eventType, std::string_view message) noexcept
+{ Event(eventType, nullptr, message); }
+
+} // namespace alc
+
+#endif /* ALC_EVENTS_H */