Add query fonction in ALC_SOFT_system_events unreleased extension (#938)

* feat(ALC_SOFT_system_events): Add alcEventIsSupportedSOFT method in ALC_SOFT_system_events unreleased extension

The purpose of this addition (to my collection) are allow to retrieve which events are supported and if events are fully supported or if some case isn't managed for some reason

For exemple only some backends provide system events:
 * pipewire -> Full support of extension
 * wasapi -> Full support of extension
 * pulseaudio -> Support of add and remove devices events only
 * coreaudio -> Support of default device change only

* feat(ALC_SOFT_system_events): Fix typo in alext.h

Cf following review : https://github.com/kcat/openal-soft/pull/938#discussion_r1404509828

* feat(ALC_SOFT_system_events): Remove ALC_EVENT_NOT_SUPPORTED_SOFT token

Cf following discussions between this comment : https://github.com/kcat/openal-soft/pull/938#issuecomment-1825876452 to this comment : https://github.com/kcat/openal-soft/pull/938#issuecomment-1826419406

13 files changed, 129 insertions, 18 deletions

diff --git a/alc/alc.cpp b/alc/alc.cpp
index 08ef0063..be41f278 100644
--- a/alc/alc.cpp
+++ b/alc/alc.cpp
@@ -69,6 +69,7 @@
 #include "al/filter.h"
 #include "al/listener.h"
 #include "al/source.h"
+#include "alc/events.h"
 #include "albit.h"
 #include "alconfig.h"
 #include "almalloc.h"
@@ -3469,3 +3470,42 @@ FORCE_ALIGN ALCboolean ALC_APIENTRY alcReopenDeviceSOFT(ALCdevice *device,
     ResetDeviceParams(dev.get(), attribs);
     return ALC_TRUE;
 }
+
+/************************************************
+ * ALC event query functions
+ ************************************************/
+
+FORCE_ALIGN ALCenum ALC_APIENTRY alcEventIsSupportedSOFT(ALCenum eventType, ALCenum deviceType) noexcept
+{
+    auto etype = alc::GetEventType(eventType);
+    if(!etype)
+    {
+        WARN("Invalid event type: 0x%04x\n", eventType);
+        alcSetError(nullptr, ALC_INVALID_ENUM);
+        return ALC_EVENT_NOT_SUPPORTED_SOFT;
+    }
+    switch(deviceType)
+    {
+        case al::to_underlying(alc::DeviceType::Playback):
+        {
+            if(!PlaybackFactory)
+            {
+                return ALC_EVENT_NOT_SUPPORTED_SOFT;
+            }
+
+            auto supported = PlaybackFactory->queryEventSupport(*etype, BackendType::Playback);
+            return al::to_underlying(supported);
+        }
+        case al::to_underlying(alc::DeviceType::Capture):
+        {
+            if(!CaptureFactory)
+            {
+                return ALC_EVENT_NOT_SUPPORTED_SOFT;
+            }
+
+            auto supported = CaptureFactory->queryEventSupport(*etype, BackendType::Capture);
+            return al::to_underlying(supported);
+        }
+    }
+    return ALC_EVENT_NOT_SUPPORTED_SOFT;
+}
\ No newline at end of file
diff --git a/alc/backends/base.h b/alc/backends/base.h
index a4079fe4..ea3b57a3 100644
--- a/alc/backends/base.h
+++ b/alc/backends/base.h
@@ -11,6 +11,7 @@
 
 #include "core/device.h"
 #include "core/except.h"
+#include "alc/events.h"
 
 
 using uint = unsigned int;
@@ -79,6 +80,10 @@ struct BackendFactory {
 
     virtual bool querySupport(BackendType type) = 0;
 
+    virtual alc::EventSupport queryEventSupport(alc::EventType eventType, BackendType type) {
+        return alc::EventSupport::NoSupport;
+    }
+
     virtual std::string probe(BackendType type) = 0;
 
     virtual BackendPtr createBackend(DeviceBase *device, BackendType type) = 0;
diff --git a/alc/backends/coreaudio.cpp b/alc/backends/coreaudio.cpp
index 1684545b..eb4e5880 100644
--- a/alc/backends/coreaudio.cpp
+++ b/alc/backends/coreaudio.cpp
@@ -39,7 +39,6 @@
 #include "core/device.h"
 #include "core/logging.h"
 #include "ringbuffer.h"
-#include "alc/events.h"
 
 #include <AudioUnit/AudioUnit.h>
 #include <AudioToolbox/AudioToolbox.h>
@@ -1013,3 +1012,13 @@ BackendPtr CoreAudioBackendFactory::createBackend(DeviceBase *device, BackendTyp
         return BackendPtr{new CoreAudioCapture{device}};
     return nullptr;
 }
+
+alc::EventSupport CoreAudioBackendFactory::queryEventSupport(alc::EventType eventType, BackendType type)
+{
+    switch(eventType) {
+        case alc::EventType::DefaultDeviceChanged: {
+            return alc::EventSupport::FullSupport;
+        }
+    }
+    return alc::EventSupport::NoSupport;
+}
diff --git a/alc/backends/coreaudio.h b/alc/backends/coreaudio.h
index 1252edde..6ea4307c 100644
--- a/alc/backends/coreaudio.h
+++ b/alc/backends/coreaudio.h
@@ -9,6 +9,8 @@ public:
 
     bool querySupport(BackendType type) override;
 
+    alc::EventSupport queryEventSupport(alc::EventType eventType, BackendType type) override;
+
     std::string probe(BackendType type) override;
 
     BackendPtr createBackend(DeviceBase *device, BackendType type) override;
diff --git a/alc/backends/pipewire.cpp b/alc/backends/pipewire.cpp
index 6cfb31a4..d1a9d095 100644
--- a/alc/backends/pipewire.cpp
+++ b/alc/backends/pipewire.cpp
@@ -40,7 +40,6 @@
 
 #include "albit.h"
 #include "alc/alconfig.h"
-#include "alc/events.h"
 #include "almalloc.h"
 #include "alnumeric.h"
 #include "alspan.h"
@@ -2266,3 +2265,19 @@ BackendFactory &PipeWireBackendFactory::getFactory()
     static PipeWireBackendFactory factory{};
     return factory;
 }
+
+alc::EventSupport PipeWireBackendFactory::queryEventSupport(alc::EventType eventType, BackendType type)
+{
+    switch(eventType) {
+        case alc::EventType::DefaultDeviceChanged: {
+            return alc::EventSupport::FullSupport;
+        }
+        case alc::EventType::DeviceAdded: {
+            return alc::EventSupport::FullSupport;
+        }
+        case alc::EventType::DeviceRemoved: {
+            return alc::EventSupport::FullSupport;
+        }
+    }
+    return alc::EventSupport::NoSupport;
+}
\ No newline at end of file
diff --git a/alc/backends/pipewire.h b/alc/backends/pipewire.h
index 5f930239..5493684f 100644
--- a/alc/backends/pipewire.h
+++ b/alc/backends/pipewire.h
@@ -13,6 +13,8 @@ public:
 
     bool querySupport(BackendType type) override;
 
+    alc::EventSupport queryEventSupport(alc::EventType eventType, BackendType type) override;
+
     std::string probe(BackendType type) override;
 
     BackendPtr createBackend(DeviceBase *device, BackendType type) override;
diff --git a/alc/backends/pulseaudio.cpp b/alc/backends/pulseaudio.cpp
index e2cea8a8..23ed1415 100644
--- a/alc/backends/pulseaudio.cpp
+++ b/alc/backends/pulseaudio.cpp
@@ -41,7 +41,6 @@
 
 #include "albit.h"
 #include "alc/alconfig.h"
-#include "alc/events.h"
 #include "almalloc.h"
 #include "alnumeric.h"
 #include "alspan.h"
@@ -1491,3 +1490,16 @@ BackendFactory &PulseBackendFactory::getFactory()
     static PulseBackendFactory factory{};
     return factory;
 }
+
+alc::EventSupport PulseBackendFactory::queryEventSupport(alc::EventType eventType, BackendType type)
+{
+    switch(eventType) {
+        case alc::EventType::DeviceAdded: {
+            return alc::EventSupport::FullSupport;
+        }
+        case alc::EventType::DeviceRemoved: {
+            return alc::EventSupport::FullSupport;
+        }
+    }
+    return alc::EventSupport::NoSupport;
+}
diff --git a/alc/backends/pulseaudio.h b/alc/backends/pulseaudio.h
index 6690fe8a..4752a891 100644
--- a/alc/backends/pulseaudio.h
+++ b/alc/backends/pulseaudio.h
@@ -9,6 +9,8 @@ public:
 
     bool querySupport(BackendType type) override;
 
+    alc::EventSupport queryEventSupport(alc::EventType eventType, BackendType type) override;
+
     std::string probe(BackendType type) override;
 
     BackendPtr createBackend(DeviceBase *device, BackendType type) override;
diff --git a/alc/backends/wasapi.cpp b/alc/backends/wasapi.cpp
index 37151ef9..a4d6ea2f 100644
--- a/alc/backends/wasapi.cpp
+++ b/alc/backends/wasapi.cpp
@@ -60,7 +60,6 @@
 
 #include "albit.h"
 #include "alc/alconfig.h"
-#include "alc/events.h"
 #include "alnumeric.h"
 #include "alspan.h"
 #include "althrd_setname.h"
@@ -2741,3 +2740,19 @@ BackendFactory &WasapiBackendFactory::getFactory()
     static WasapiBackendFactory factory{};
     return factory;
 }
+
+alc::EventSupport WasapiBackendFactory::queryEventSupport(alc::EventType eventType, BackendType type)
+{
+    switch(eventType) {
+        case alc::EventType::DefaultDeviceChanged: {
+            return alc::EventSupport::FullSupport;
+        }
+        case alc::EventType::DeviceAdded: {
+            return alc::EventSupport::FullSupport;
+        }
+        case alc::EventType::DeviceRemoved: {
+            return alc::EventSupport::FullSupport;
+        }
+    }
+    return alc::EventSupport::NoSupport;
+}
diff --git a/alc/backends/wasapi.h b/alc/backends/wasapi.h
index bb2671ee..12fd95ef 100644
--- a/alc/backends/wasapi.h
+++ b/alc/backends/wasapi.h
@@ -9,6 +9,8 @@ public:
 
     bool querySupport(BackendType type) override;
 
+    alc::EventSupport queryEventSupport(alc::EventType eventType, BackendType type) override;
+
     std::string probe(BackendType type) override;
 
     BackendPtr createBackend(DeviceBase *device, BackendType type) override;
diff --git a/alc/events.cpp b/alc/events.cpp
index a80faf8a..1010a338 100644
--- a/alc/events.cpp
+++ b/alc/events.cpp
@@ -3,8 +3,6 @@
 
 #include "events.h"
 
-#include <optional>
-
 #include "alspan.h"
 #include "core/logging.h"
 #include "device.h"
@@ -12,17 +10,6 @@
 
 namespace {
 
-std::optional<alc::EventType> GetEventType(ALCenum type)
-{
-    switch(type)
-    {
-    case ALC_EVENT_TYPE_DEFAULT_DEVICE_CHANGED_SOFT: return alc::EventType::DefaultDeviceChanged;
-    case ALC_EVENT_TYPE_DEVICE_ADDED_SOFT: return alc::EventType::DeviceAdded;
-    case ALC_EVENT_TYPE_DEVICE_REMOVED_SOFT: return alc::EventType::DeviceRemoved;
-    }
-    return std::nullopt;
-}
-
 ALCenum EnumFromEventType(const alc::EventType type)
 {
     switch(type)
@@ -39,6 +26,17 @@ ALCenum EnumFromEventType(const alc::EventType type)
 
 namespace alc {
 
+std::optional<alc::EventType> GetEventType(ALCenum type)
+{
+    switch(type)
+    {
+    case ALC_EVENT_TYPE_DEFAULT_DEVICE_CHANGED_SOFT: return alc::EventType::DefaultDeviceChanged;
+    case ALC_EVENT_TYPE_DEVICE_ADDED_SOFT: return alc::EventType::DeviceAdded;
+    case ALC_EVENT_TYPE_DEVICE_REMOVED_SOFT: return alc::EventType::DeviceRemoved;
+    }
+    return std::nullopt;
+}
+
 void Event(EventType eventType, DeviceType deviceType, ALCdevice *device, std::string_view message) noexcept
 {
     auto eventlock = std::unique_lock{EventMutex};
@@ -73,7 +71,7 @@ FORCE_ALIGN ALCboolean ALC_APIENTRY alcEventControlSOFT(ALCsizei count, const AL
     alc::EventBitSet eventSet{0};
     for(ALCenum type : al::span{events, static_cast<ALCuint>(count)})
     {
-        auto etype = GetEventType(type);
+        auto etype = alc::GetEventType(type);
         if(!etype)
         {
             WARN("Invalid event type: 0x%04x\n", type);
diff --git a/alc/events.h b/alc/events.h
index 4acc505d..3f53ec76 100644
--- a/alc/events.h
+++ b/alc/events.h
@@ -6,6 +6,7 @@
 
 #include <bitset>
 #include <mutex>
+#include <optional>
 #include <string_view>
 
 
@@ -19,6 +20,13 @@ enum class EventType : uint8_t {
     Count
 };
 
+std::optional<alc::EventType> GetEventType(ALCenum type);
+
+enum class EventSupport : ALCenum {
+    FullSupport = ALC_EVENT_SUPPORTED_SOFT,
+    NoSupport = ALC_EVENT_NOT_SUPPORTED_SOFT,
+};
+
 enum class DeviceType : ALCenum {
     Playback = ALC_PLAYBACK_DEVICE_SOFT,
     Capture = ALC_CAPTURE_DEVICE_SOFT,
diff --git a/alc/export_list.h b/alc/export_list.h
index 47b04a08..c5af1ab0 100644
--- a/alc/export_list.h
+++ b/alc/export_list.h
@@ -56,6 +56,7 @@ inline const FuncExport alcFunctions[]{
 
     DECL(alcReopenDeviceSOFT),
 
+    DECL(alcEventIsSupportedSOFT),
     DECL(alcEventControlSOFT),
     DECL(alcEventCallbackSOFT),