Implement CVDisplayLink based timer on macOS

native/Avalonia.Native/src/OSX/Avalonia.Native.OSX.xcodeproj/project.pbxproj

@@ -59,6 +59,7 @@
 		BC11A5BE2608D58F0017BAD0 /* automation.h in Headers */ = {isa = PBXBuildFile; fileRef = BC11A5BC2608D58F0017BAD0 /* automation.h */; };
 		BC11A5BF2608D58F0017BAD0 /* automation.mm in Sources */ = {isa = PBXBuildFile; fileRef = BC11A5BD2608D58F0017BAD0 /* automation.mm */; };
 		ED3791C42862E1F40080BD62 /* UniformTypeIdentifiers.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = ED3791C32862E1F40080BD62 /* UniformTypeIdentifiers.framework */; };
+		ED754D262A97306B0078B4DF /* PlatformRenderTimer.mm in Sources */ = {isa = PBXBuildFile; fileRef = ED754D252A97306B0078B4DF /* PlatformRenderTimer.mm */; };
 		EDF8CDCD2964CB01001EE34F /* PlatformSettings.mm in Sources */ = {isa = PBXBuildFile; fileRef = EDF8CDCC2964CB01001EE34F /* PlatformSettings.mm */; };
 /* End PBXBuildFile section */
 
@@ -122,6 +123,7 @@
 		BC11A5BC2608D58F0017BAD0 /* automation.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = automation.h; sourceTree = "<group>"; };
 		BC11A5BD2608D58F0017BAD0 /* automation.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = automation.mm; sourceTree = "<group>"; };
 		ED3791C32862E1F40080BD62 /* UniformTypeIdentifiers.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = UniformTypeIdentifiers.framework; path = System/Library/Frameworks/UniformTypeIdentifiers.framework; sourceTree = SDKROOT; };
+		ED754D252A97306B0078B4DF /* PlatformRenderTimer.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = PlatformRenderTimer.mm; sourceTree = "<group>"; };
 		EDF8CDCC2964CB01001EE34F /* PlatformSettings.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = PlatformSettings.mm; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -162,6 +164,7 @@
 		AB7A61E62147C814003C5833 = {
 			isa = PBXGroup;
 			children = (
+				ED754D252A97306B0078B4DF /* PlatformRenderTimer.mm */,
 				855EDC9E28C6546F00807998 /* PlatformBehaviorInhibition.mm */,
 				8D2F3511292F6AAE007FCF54 /* AvnTextInputMethodDelegate.h */,
 				8D300D68292E1E5D00320C49 /* AvnTextInputMethod.mm */,
@@ -333,6 +336,7 @@
 				18391068E48EF96E3DB5FDAB /* ResizeScope.mm in Sources */,
 				18391D4EB311BC7EF8B8C0A6 /* AvnView.mm in Sources */,
 				18391AA7E0BBA74D184C5734 /* AutoFitContentView.mm in Sources */,
+				ED754D262A97306B0078B4DF /* PlatformRenderTimer.mm in Sources */,
 				1839151F32D1BB1AB51A7BB6 /* AvnPanelWindow.mm in Sources */,
 				18391AC16726CBC45856233B /* AvnWindow.mm in Sources */,
 				18391D8CD1756DC858DC1A09 /* PopupImpl.mm in Sources */,

native/Avalonia.Native/src/OSX/PlatformRenderTimer.mm

@@ -0,0 +1,84 @@
+#include "common.h"
+
+class PlatformRenderTimer : public ComSingleObject<IAvnPlatformRenderTimer, &IID_IAvnPlatformRenderTimer>
+{
+private:
+    ComPtr<IAvnActionCallback> _callback;
+    CVDisplayLinkRef _displayLink;
+
+public:
+    FORWARD_IUNKNOWN()
+    virtual HRESULT RegisterTick (
+        IAvnActionCallback* callback) override
+    {
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            if (_displayLink != nil)
+            {
+                return E_UNEXPECTED;
+            }
+
+            _callback = callback;
+            auto result = CVDisplayLinkCreateWithActiveCGDisplays(&_displayLink);
+            if (result != 0)
+            {
+                return E_FAIL;
+            }
+
+            result = CVDisplayLinkSetOutputCallback(_displayLink, OnTick, this);
+            if (result != 0)
+            {
+                return E_FAIL;
+            }
+        }
+        return S_OK;
+    }
+
+    virtual void Start () override
+    {
+        START_COM_CALL;
+
+        @autoreleasepool
+        {
+            if (CVDisplayLinkIsRunning(_displayLink) == false) {
+                CVDisplayLinkStart(_displayLink);
+            }
+        }
+    }
+
+    virtual void Stop () override
+    {
+        START_COM_CALL;
+
+        @autoreleasepool
+        {
+            if (CVDisplayLinkIsRunning(_displayLink) == true) {
+                CVDisplayLinkStop(_displayLink);
+            }
+        }
+    }
+
+    virtual bool RunsInBackground () override
+    {
+        START_COM_CALL;
+
+        @autoreleasepool
+        {
+            return true;
+        }
+    }
+    
+    static CVReturn OnTick(CVDisplayLinkRef displayLink, const CVTimeStamp *inNow, const CVTimeStamp *inOutputTime, CVOptionFlags flagsIn, CVOptionFlags *flagsOut, void *displayLinkContext)
+    {
+        PlatformRenderTimer *object = (PlatformRenderTimer *)displayLinkContext;
+        object->_callback->Run();
+        return kCVReturnSuccess;
+    }
+};
+
+extern IAvnPlatformRenderTimer* CreatePlatformRenderTimer()
+{
+    return new PlatformRenderTimer();
+}

native/Avalonia.Native/src/OSX/common.h

@@ -32,6 +32,7 @@ extern IAvnApplicationCommands* CreateApplicationCommands();
 extern IAvnPlatformBehaviorInhibition* CreatePlatformBehaviorInhibition();
 extern IAvnNativeControlHost* CreateNativeControlHost(NSView* parent);
 extern IAvnPlatformSettings* CreatePlatformSettings();
+extern IAvnPlatformRenderTimer* CreatePlatformRenderTimer();
 extern void SetAppMenu(IAvnMenu *menu);
 extern void SetServicesMenu (IAvnMenu* menu);
 extern IAvnMenu* GetAppMenu ();

native/Avalonia.Native/src/OSX/main.mm

@@ -446,6 +446,17 @@ public:
             return S_OK;
         }
     }
+    
+    virtual HRESULT CreatePlatformRenderTimer(IAvnPlatformRenderTimer** ppv) override
+    {
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreatePlatformRenderTimer();
+            return S_OK;
+        }
+    }
 };
 
 extern "C" IAvaloniaNativeFactory* CreateAvaloniaNative()

src/Avalonia.Native/AvaloniaNativePlatform.cs

@@ -108,7 +108,7 @@ namespace Avalonia.Native
                 .Bind<IPlatformSettings>().ToConstant(new NativePlatformSettings(_factory.CreatePlatformSettings()))
                 .Bind<IWindowingPlatform>().ToConstant(this)
                 .Bind<IClipboard>().ToConstant(new ClipboardImpl(_factory.CreateClipboard()))
-                .Bind<IRenderTimer>().ToConstant(new DefaultRenderTimer(60))
+                .Bind<IRenderTimer>().ToConstant(new AvaloniaNativeRenderTimer(_factory.CreatePlatformRenderTimer()))
                 .Bind<IMountedVolumeInfoProvider>().ToConstant(new MacOSMountedVolumeInfoProvider())
                 .Bind<IPlatformDragSource>().ToConstant(new AvaloniaNativeDragSource(_factory))
                 .Bind<IPlatformLifetimeEventsImpl>().ToConstant(applicationPlatform)

src/Avalonia.Native/AvaloniaNativeRenderTimer.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Diagnostics;
+using Avalonia.Native.Interop;
+using Avalonia.Rendering;
+#nullable enable
+
+namespace Avalonia.Native;
+
+internal sealed class AvaloniaNativeRenderTimer : NativeCallbackBase, IRenderTimer, IAvnActionCallback
+{
+    private readonly IAvnPlatformRenderTimer _platformRenderTimer;
+    private readonly Stopwatch _stopwatch;
+    private Action<TimeSpan>? _tick;
+    private int _subscriberCount;
+    private bool registered;
+
+    public AvaloniaNativeRenderTimer(IAvnPlatformRenderTimer platformRenderTimer)
+    {
+        _platformRenderTimer = platformRenderTimer;
+        _stopwatch = Stopwatch.StartNew();
+    }
+
+    public event Action<TimeSpan> Tick
+    {
+        add
+        {
+            _tick += value;
+
+            if (!registered)
+            {
+                registered = true;
+                _platformRenderTimer.RegisterTick(this);
+            }
+
+            if (_subscriberCount++ == 0)
+            {
+                _platformRenderTimer.Start();
+            }
+        }
+
+        remove
+        {
+            if (--_subscriberCount == 0)
+            {
+                _platformRenderTimer.Stop();
+            }
+
+            _tick -= value;
+        }
+    }
+
+    public bool RunsInBackground => _platformRenderTimer.RunsInBackground().FromComBool();
+
+    public void Run()
+    {
+        _tick?.Invoke(_stopwatch.Elapsed);
+    }
+}

src/Avalonia.Native/avn.idl

@@ -507,6 +507,7 @@ interface IAvaloniaNativeFactory : IUnknown
      HRESULT CreateApplicationCommands(IAvnApplicationCommands** ppv);
      HRESULT CreatePlatformSettings(IAvnPlatformSettings** ppv);
      HRESULT CreatePlatformBehaviorInhibition(IAvnPlatformBehaviorInhibition** ppv);
+     HRESULT CreatePlatformRenderTimer(IAvnPlatformRenderTimer** ppv);
 }
 
 [uuid(233e094f-9b9f-44a3-9a6e-6948bbdd9fb1)]
@@ -999,3 +1000,12 @@ interface IAvnPlatformBehaviorInhibition : IUnknown
 {
     void SetInhibitAppSleep(bool inhibitAppSleep, char* reason);
 }
+
+[uuid(22edf20d-5803-2d3f-9247-b4842e5e9322)]
+interface IAvnPlatformRenderTimer : IUnknown
+{
+    HRESULT RegisterTick(IAvnActionCallback* callback);
+    void Start();
+    void Stop();
+    bool RunsInBackground();
+}