Nullable annotations for LinuxFramebuffer (#17489)

src/Linux/Avalonia.LinuxFramebuffer/Avalonia.LinuxFramebuffer.csproj

@@ -10,4 +10,5 @@
     <Compile Include="..\..\Shared\RawEventGrouping.cs" />
   </ItemGroup>
   <Import Project="..\..\..\build\TrimmingEnable.props" />
+  <Import Project="..\..\..\build\NullableEnable.props" />
 </Project>

src/Linux/Avalonia.LinuxFramebuffer/EpollDispatcherImpl.cs

@@ -11,7 +11,7 @@ namespace Avalonia.LinuxFramebuffer;
 internal unsafe class EpollDispatcherImpl : IControlledDispatcherImpl
 {
     private readonly ManagedDispatcherImpl.IManagedDispatcherInputProvider _inputProvider;
-    private Thread _mainThread;
+    private readonly Thread _mainThread;
 
     [StructLayout(LayoutKind.Explicit)]
     private struct epoll_data
@@ -161,6 +161,7 @@ internal unsafe class EpollDispatcherImpl : IControlledDispatcherImpl
 
                 itimerspec timer = new()
                 {
+                    it_interval = default,
                     it_value = new()
                     {
                         tv_sec = new IntPtr(Math.Min((int)waitFor.TotalSeconds, 100)),
@@ -219,8 +220,8 @@ internal unsafe class EpollDispatcherImpl : IControlledDispatcherImpl
 
     public bool CurrentThreadIsLoopThread => Thread.CurrentThread == _mainThread;
 
-    public event Action Signaled;
-    public event Action Timer;
+    public event Action? Signaled;
+    public event Action? Timer;
 
     public void UpdateTimer(long? dueTimeInMs)
     {

src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs

@@ -6,7 +6,6 @@ using Avalonia.Input.Raw;
 using Avalonia.LinuxFramebuffer.Input;
 using Avalonia.LinuxFramebuffer.Output;
 using Avalonia.Platform;
-using Avalonia.Rendering;
 using Avalonia.Rendering.Composition;
  using Avalonia.Threading;
 
@@ -18,7 +17,7 @@ using Avalonia.Rendering.Composition;
         private readonly IInputBackend _inputBackend;
         private readonly RawEventGrouper _inputQueue;
 
-        public IInputRoot InputRoot { get; private set; }
+        public IInputRoot? InputRoot { get; private set; }
 
         public FramebufferToplevelImpl(IOutputBackend outputBackend, IInputBackend inputBackend)
         {
@@ -49,28 +48,28 @@ using Avalonia.Rendering.Composition;
 
         public PixelPoint PointToScreen(Point p) => PixelPoint.FromPoint(p, 1);
 
-        public void SetCursor(ICursorImpl cursor)
+        public void SetCursor(ICursorImpl? cursor)
         {
         }
 
         public double DesktopScaling => 1;
-        public IPlatformHandle Handle { get; }
+        public IPlatformHandle? Handle => null;
         public Size ClientSize => ScaledSize;
         public Size? FrameSize => null;
-        public IMouseDevice MouseDevice => new MouseDevice();
-        public IPopupImpl CreatePopup() => null;
+        public IMouseDevice MouseDevice { get; } = new MouseDevice();
+        public IPopupImpl? CreatePopup() => null;
 
         public double RenderScaling => _outputBackend.Scaling;
         public IEnumerable<object> Surfaces { get; }
-        public Action<RawInputEventArgs> Input { get; set; }
-        public Action<Rect> Paint { get; set; }
-        public Action<Size, WindowResizeReason> Resized { get; set; }
-        public Action<double> ScalingChanged { get; set; }
+        public Action<RawInputEventArgs>? Input { get; set; }
+        public Action<Rect>? Paint { get; set; }
+        public Action<Size, WindowResizeReason>? Resized { get; set; }
+        public Action<double>? ScalingChanged { get; set; }
 
-        public Action<WindowTransparencyLevel> TransparencyLevelChanged { get; set; }
+        public Action<WindowTransparencyLevel>? TransparencyLevelChanged { get; set; }
 
-        public Action Closed { get; set; }
-        public Action LostFocus { get; set; }
+        public Action? Closed { get; set; }
+        public Action? LostFocus { get; set; }
 
         public Size ScaledSize => _outputBackend.PixelSize.ToSize(RenderScaling);
 
@@ -81,6 +80,6 @@ using Avalonia.Rendering.Composition;
         public void SetFrameThemeVariant(PlatformThemeVariant themeVariant) { }
 
         public AcrylicPlatformCompensationLevels AcrylicCompensationLevels { get; } = new AcrylicPlatformCompensationLevels(1, 1, 1);
-        public object TryGetFeature(Type featureType) => null;
+        public object? TryGetFeature(Type featureType) => null;
     }
 }

src/Linux/Avalonia.LinuxFramebuffer/Input/EvDev/EvDevBackend.cs

@@ -12,8 +12,8 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
         private readonly EvDevDeviceDescription[] _deviceDescriptions;
         private readonly List<EvDevDeviceHandler> _handlers = new List<EvDevDeviceHandler>();
         private int _epoll;
-        private Action<RawInputEventArgs> _onInput;
-        private IInputRoot _inputRoot;
+        private Action<RawInputEventArgs>? _onInput;
+        private IInputRoot? _inputRoot;
 
         public EvDevBackend(EvDevDeviceDescription[] devices)
         {
@@ -53,7 +53,7 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
             for (var c = 0; c < _deviceDescriptions.Length; c++)
             {
                 var description = _deviceDescriptions[c];
-                var dev = EvDevDevice.Open(description.Path);
+                var dev = EvDevDevice.Open(description.Path ?? string.Empty);
                 EvDevDeviceHandler handler;
                 if (description is EvDevTouchScreenDeviceDescription touch)
                     handler = new EvDevSingleTouchScreen(dev, touch, info) { InputRoot = _inputRoot };
@@ -86,7 +86,7 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
             {
                 if (key.StartsWith("AVALONIA_EVDEV_DEVICE_"))
                 {
-                    var value = (string)env[key];
+                    var value = (string)env[key]!;
                     deviceDescriptions.Add(EvDevDeviceDescription.ParseFromEnv(value));
                 }
             }

src/Linux/Avalonia.LinuxFramebuffer/Input/EvDev/EvDevDevice.cs

@@ -1,7 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
-using System.Linq;
 using System.Runtime.InteropServices;
 
 namespace Avalonia.LinuxFramebuffer.Input.EvDev
@@ -10,7 +8,7 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
     {
         public int Fd { get; }
         private IntPtr _dev;
-        public string Name { get; }
+        public string? Name { get; }
         public List<EvType> EventTypes { get; private set; } = new List<EvType>();
         public input_absinfo? AbsX { get; }
         public input_absinfo? AbsY { get; }

src/Linux/Avalonia.LinuxFramebuffer/Input/EvDev/EvDevDeviceDescription.cs

@@ -10,7 +10,7 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
             
         }
         
-        public string Path { get; set; }
+        public string? Path { get; set; }
 
         internal static EvDevDeviceDescription ParseFromEnv(string env)
         {

src/Linux/Avalonia.LinuxFramebuffer/Input/EvDev/EvDevTouchScreen.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using Avalonia.Input;
 using Avalonia.Input.Raw;
 
@@ -90,14 +91,23 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
 
     internal abstract class EvDevDeviceHandler
     {
-        public event Action<RawInputEventArgs> OnEvent;
+        private IInputRoot? _inputRoot;
+
+        public event Action<RawInputEventArgs>? OnEvent;
+
         public EvDevDeviceHandler(EvDevDevice device)
         {
             Device = device;
         }
 
         public EvDevDevice Device { get; }
-        public IInputRoot InputRoot { get; set; }
+
+        [AllowNull]
+        public IInputRoot InputRoot
+        {
+            get => _inputRoot ?? throw new InvalidOperationException($"{nameof(InputRoot)} hasn't been set");
+            set => _inputRoot = value;
+        }
 
         public void HandleEvents()
         {

src/Linux/Avalonia.LinuxFramebuffer/Input/LibInput/LibInputBackend.Pointer.cs

@@ -16,14 +16,14 @@ public partial class LibInputBackend
     {
         var modifiers = RawInputModifiers.None; //TODO: support input modifiers
         var pev = libinput_event_get_pointer_event(ev);
-        var info = _screen.ScaledSize;
+        var info = _screen!.ScaledSize;
         var ts = libinput_event_pointer_get_time_usec(pev) / 1000;
         switch (type)
         {
             case LibInputEventType.LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE:
                 _mousePosition = new Point(libinput_event_pointer_get_absolute_x_transformed(pev, (int)info.Width),
                     libinput_event_pointer_get_absolute_y_transformed(pev, (int)info.Height));
-                ScheduleInput(new RawPointerEventArgs(_mouse, ts, _inputRoot, RawPointerEventType.Move, _mousePosition,
+                ScheduleInput(new RawPointerEventArgs(_mouse, ts, InputRoot, RawPointerEventType.Move, _mousePosition,
                     modifiers));
                 break;
             case LibInputEventType.LIBINPUT_EVENT_POINTER_BUTTON:
@@ -31,20 +31,20 @@ public partial class LibInputBackend
                     var button = (EvKey)libinput_event_pointer_get_button(pev);
                     var buttonState = libinput_event_pointer_get_button_state(pev);
 
-                    RawPointerEventArgs evnt = button switch
+                    RawPointerEventArgs? evnt = button switch
                     {
                         EvKey.BTN_LEFT when buttonState == 1
-                            => new(_mouse, ts, _inputRoot, RawPointerEventType.LeftButtonDown, _mousePosition, modifiers),
+                            => new(_mouse, ts, InputRoot, RawPointerEventType.LeftButtonDown, _mousePosition, modifiers),
                         EvKey.BTN_LEFT when buttonState == 0
-                            => new(_mouse, ts, _inputRoot, RawPointerEventType.LeftButtonUp, _mousePosition, modifiers),
+                            => new(_mouse, ts, InputRoot, RawPointerEventType.LeftButtonUp, _mousePosition, modifiers),
                         EvKey.BTN_RIGHT when buttonState == 1
-                            => new(_mouse, ts, _inputRoot, RawPointerEventType.RightButtonUp, _mousePosition, modifiers),
+                            => new(_mouse, ts, InputRoot, RawPointerEventType.RightButtonUp, _mousePosition, modifiers),
                         EvKey.BTN_RIGHT when buttonState == 2
-                            => new(_mouse, ts, _inputRoot, RawPointerEventType.RightButtonDown, _mousePosition, modifiers),
+                            => new(_mouse, ts, InputRoot, RawPointerEventType.RightButtonDown, _mousePosition, modifiers),
                         EvKey.BTN_MIDDLE when buttonState == 1
-                            => new(_mouse, ts, _inputRoot, RawPointerEventType.MiddleButtonDown, _mousePosition, modifiers),
+                            => new(_mouse, ts, InputRoot, RawPointerEventType.MiddleButtonDown, _mousePosition, modifiers),
                         EvKey.BTN_MIDDLE when buttonState == 2
-                            => new(_mouse, ts, _inputRoot, RawPointerEventType.MiddleButtonUp, _mousePosition, modifiers),
+                            => new(_mouse, ts, InputRoot, RawPointerEventType.MiddleButtonUp, _mousePosition, modifiers),
                         _ => default,
                     };
                     if (evnt is not null)
@@ -70,7 +70,7 @@ public partial class LibInputBackend
                                     LibInputPointerAxis.LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL);
                                 ScheduleInput(new RawMouseWheelEventArgs(_mouse
                                     , ts
-                                    , _inputRoot
+                                    , InputRoot
                                     , _mousePosition
                                     , new Vector(0, -value)
                                     , modifiers));
@@ -94,7 +94,7 @@ public partial class LibInputBackend
                             LibInputPointerAxis.LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL) / 120);
                     ScheduleInput(new RawMouseWheelEventArgs(_mouse
                         , ts
-                        , _inputRoot
+                        , InputRoot
                         , _mousePosition
                         , value
                         , modifiers));

src/Linux/Avalonia.LinuxFramebuffer/Input/LibInput/LibInputBackend.Touch.cs

@@ -18,7 +18,7 @@ public partial class LibInputBackend
             return;
         if (type < LibInputEventType.LIBINPUT_EVENT_TOUCH_FRAME)
         {
-            var info = _screen.ScaledSize;
+            var info = _screen!.ScaledSize;
             var slot = libinput_event_touch_get_slot(tev);
             Point pt;
 

src/Linux/Avalonia.LinuxFramebuffer/Input/LibInput/LibInputBackend.cs

@@ -1,4 +1,3 @@
-#nullable enable
 using System;
 using System.IO;
 using System.Threading;
@@ -25,6 +24,9 @@ namespace Avalonia.LinuxFramebuffer.Input.LibInput
             _options = options;
         }
 
+        private IInputRoot InputRoot
+            => _inputRoot ?? throw new InvalidOperationException($"{nameof(InputRoot)} hasn't been set");
+
         private unsafe void InputThread(IntPtr ctx, LibInputBackendOptions options)
         {
             var fd = libinput_get_fd(ctx);

src/Linux/Avalonia.LinuxFramebuffer/Input/LibInput/LibInputNativeUnsafeMethods.cs

@@ -13,7 +13,7 @@ namespace Avalonia.LinuxFramebuffer.Input.LibInput
 
         static int OpenRestricted(IntPtr path, int flags, IntPtr userData)
         {
-            var fd = NativeUnsafeMethods.open(Marshal.PtrToStringAnsi(path), flags, 0);
+            var fd = NativeUnsafeMethods.open(Marshal.PtrToStringAnsi(path) ?? string.Empty, flags, 0);
             if (fd == -1)
                 return -Marshal.GetLastWin32Error();
 
@@ -31,7 +31,7 @@ namespace Avalonia.LinuxFramebuffer.Input.LibInput
         {
             s_Interface = (IntPtr*)Marshal.AllocHGlobal(IntPtr.Size * 2);
 
-            IntPtr Convert<TDelegate>(TDelegate del)
+            IntPtr Convert<TDelegate>(TDelegate del) where TDelegate : notnull
             {
                 GCHandle.Alloc(del);
                 return Marshal.GetFunctionPointerForDelegate(del);

src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Threading;
@@ -8,7 +7,6 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Controls.Embedding;
-using Avalonia.Controls.Platform;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.LinuxFramebuffer;
@@ -21,8 +19,6 @@ using Avalonia.Rendering;
 using Avalonia.Rendering.Composition;
 using Avalonia.Threading;
 
-#nullable enable
-
 namespace Avalonia.LinuxFramebuffer
 {
     internal class LinuxFramebufferIconLoaderStub : IPlatformIconLoader

src/Linux/Avalonia.LinuxFramebuffer/Output/DrmBindings.cs

@@ -63,7 +63,7 @@ namespace Avalonia.LinuxFramebuffer.Output
         public PixelSize Resolution => new PixelSize(Mode.hdisplay, Mode.vdisplay);
         public bool IsPreferred => Mode.type.HasAllFlags(DrmModeType.DRM_MODE_TYPE_PREFERRED);
 
-        public string Name { get; }
+        public string? Name { get; }
     }
 
     unsafe class DrmEncoder
@@ -141,7 +141,7 @@ namespace Avalonia.LinuxFramebuffer.Output
     public unsafe class DrmCard : IDisposable
     {
         public int Fd { get; private set; }
-        public DrmCard(string path = null)
+        public DrmCard(string? path = null)
         {
             if (path == null)
             {

src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Runtime.InteropServices;
 using Avalonia.OpenGL;
@@ -41,19 +42,19 @@ namespace Avalonia.LinuxFramebuffer.Output
         public IPlatformGraphics PlatformGraphics { get; private set; }
 
         public DrmOutput(DrmCard card, DrmResources resources, DrmConnector connector, DrmModeInfo modeInfo,
-            DrmOutputOptions options = null)
+            DrmOutputOptions? options = null)
         {
             if (options != null)
                 _outputOptions = options;
             Init(card, resources, connector, modeInfo);
         }
 
-        public DrmOutput(string path = null, bool connectorsForceProbe = false, DrmOutputOptions options = null)
+        public DrmOutput(string? path = null, bool connectorsForceProbe = false, DrmOutputOptions? options = null)
             :this(new DrmCard(path), connectorsForceProbe, options)
         {
         }
 
-        public DrmOutput(DrmCard card, bool connectorsForceProbe = false, DrmOutputOptions options = null)
+        public DrmOutput(DrmCard card, bool connectorsForceProbe = false, DrmOutputOptions? options = null)
         {
             if (options != null)
                 _outputOptions = options;
@@ -78,7 +79,7 @@ namespace Avalonia.LinuxFramebuffer.Output
             if (connector == null)
                 throw new InvalidOperationException("Unable to find connected DRM connector");
 
-            DrmModeInfo mode = null;
+            DrmModeInfo? mode = null;
 
             if (options?.VideoMode != null)
             {
@@ -157,6 +158,12 @@ namespace Avalonia.LinuxFramebuffer.Output
         }
 
 
+        [MemberNotNull(nameof(_card))]
+        [MemberNotNull(nameof(PlatformGraphics))]
+        [MemberNotNull(nameof(FbDestroyDelegate))]
+        [MemberNotNull(nameof(_eglDisplay))]
+        [MemberNotNull(nameof(_eglSurface))]
+        [MemberNotNull(nameof(_deferredContext))]
         void Init(DrmCard card, DrmResources resources, DrmConnector connector, DrmModeInfo modeInfo)
         {
             FbDestroyDelegate = FbDestroyCallback;
@@ -232,7 +239,7 @@ namespace Avalonia.LinuxFramebuffer.Output
 
             if (_outputOptions.EnableInitialBufferSwapping)
             {
-                //Go trough two cycles of buffer swapping (there are render artifacts otherwise)
+                //Go through two cycles of buffer swapping (there are render artifacts otherwise)
                 for (var c = 0; c < 2; c++)
                     using (CreateGlRenderTarget().BeginDraw())
                     {
@@ -330,7 +337,7 @@ namespace Avalonia.LinuxFramebuffer.Output
 
                 public double Scaling => _parent.Scaling;
 
-                public bool IsYFlipped { get; }
+                public bool IsYFlipped => false;
             }
 
             public IGlPlatformSurfaceRenderingSession BeginDraw()

src/Linux/Avalonia.LinuxFramebuffer/Output/FbDevBackBuffer.cs

@@ -1,6 +1,4 @@
-#nullable enable
-
-using System;
+using System;
 using System.Runtime.InteropServices;
 using System.Threading;
 using Avalonia.Logging;

src/Linux/Avalonia.LinuxFramebuffer/Output/FbDevOutputOptions.cs

@@ -1,5 +1,3 @@
-#nullable enable
-
 using Avalonia.Platform;
 
 namespace Avalonia.LinuxFramebuffer.Output;

src/Linux/Avalonia.LinuxFramebuffer/Output/FbdevOutput.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
 using System.Text;
 using Avalonia.Controls.Platform.Surfaces;
@@ -14,7 +15,7 @@ namespace Avalonia.LinuxFramebuffer
         private fb_var_screeninfo _varInfo;
         private IntPtr _mappedLength;
         private IntPtr _mappedAddress;
-        private FbDevBackBuffer _backBuffer;
+        private FbDevBackBuffer? _backBuffer;
         private readonly FbDevOutputOptions _options;
         private bool _lockedAtLeastOnce;
         public double Scaling { get; set; }
@@ -24,7 +25,7 @@ namespace Avalonia.LinuxFramebuffer
         /// </summary>
         /// <param name="fileName">The frame buffer device name.
         /// Defaults to the value in environment variable FRAMEBUFFER or /dev/fb0 when FRAMEBUFFER is not set</param>
-        public FbdevOutput(string fileName = null) : this(fileName, null)
+        public FbdevOutput(string? fileName = null) : this(fileName, null)
         {
         }
 
@@ -36,7 +37,7 @@ namespace Avalonia.LinuxFramebuffer
         /// <param name="format">The required pixel format for the frame buffer.
         /// A null value will leave the frame buffer in the current pixel format.
         /// Otherwise sets the frame buffer to the required format</param>
-        public FbdevOutput(string fileName, PixelFormat? format) : this(new FbDevOutputOptions()
+        public FbdevOutput(string? fileName, PixelFormat? format) : this(new FbDevOutputOptions()
         {
             FileName = fileName,
             PixelFormat = format
@@ -68,6 +69,7 @@ namespace Avalonia.LinuxFramebuffer
             }
         }
 
+        [MemberNotNull(nameof(Id))]
         void Init(PixelFormat? format)
         {
             fixed (void* pnfo = &_varInfo)

src/Linux/Avalonia.LinuxFramebuffer/Output/IGlOutputBackend.cs

@@ -1,4 +1,3 @@
-using Avalonia.OpenGL;
 using Avalonia.Platform;
 
 namespace Avalonia.LinuxFramebuffer.Output