Convert IFont and IFontDisp to CSWin32 (#8322)

Converts IFont / IFontDisp to CSWin32. IFontDisp wasn't properly defined (wrong DISPIDs). I attemped to run my VB tests against the correct code to see if that fixed the test run problem, but alas, it did not. Including the VB tests (Skipped) to allow manual testing and allow investigating and vetting against further fixes that come as part of the modernization effort here.

This adds some tests for the other IFont usages. Additionally:

- Adds the interface definition for IDispatch (which CsWin32 omits) and a CCW
- Adds DynamicAxHost for testing AxHost with controls direct from assemblies
- Adds ComClasses/ComClassFactory for creating COM classes direct from assemblies
- Adds explicit converters to VARIANT and CY (currency format)
- Adds ToStringAndFree to BSTR
- Adds another overload for prop getting from IDispatch
- Moves code from ControlPaint to it's only usage in COM2FontConverter

src/System.Windows.Forms.Primitives/src/Interop/Ole32/Interop.QACONTAINER.cs

@@ -22,7 +22,7 @@ public sealed class QACONTAINER
             public QACONTAINERFLAGS dwAmbientFlags;
             public uint colorFore;
             public uint colorBack;
-            public IFont? pFont;
+            public IFont.Interface? pFont;
             public IntPtr pUndoMgr;
             public uint dwAppearance;
             public PInvoke.LCID lcid;

src/System.Windows.Forms.Primitives/src/Interop/OleAut32/Interop.VARIANT.cs

@@ -39,8 +39,11 @@ public void Clear()
         //
         // If the VARTYPE is a VT_VECTOR, the contents are cleared as above and CoTaskMemFree is also called on
         // cabstr.pElems.
-
+        //
         // https://learn.microsoft.com/windows/win32/api/oleauto/nf-oleauto-variantclear#remarks
+        //
+        //     - VT_BSTR (SysFreeString)
+        //     - VT_DISPATCH / VT_UNKOWN (->Release(), if not VT_BYREF)
 
         fixed (void* t = &this)
         {
@@ -841,6 +844,32 @@ private static object ToVector(in CA ca, VARENUM vectorType)
     private static Span<T> GetSpan<T>(Array arr)
         => MemoryMarshal.CreateSpan(ref Unsafe.AsRef<T>(Marshal.UnsafeAddrOfPinnedArrayElement(arr, 0).ToPointer()), arr.Length);
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static explicit operator bool(VARIANT variant)
+        => variant.vt == VT_BOOL ? variant.data.boolVal != VARIANT_BOOL.VARIANT_FALSE : ThrowInvalidCast<bool>();
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static explicit operator short(VARIANT variant)
+        => variant.vt == VT_I2 ? variant.data.iVal : ThrowInvalidCast<short>();
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static explicit operator BSTR(VARIANT variant)
+        => variant.vt == VT_BSTR ? variant.data.bstrVal : ThrowInvalidCast<BSTR>();
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static explicit operator CY(VARIANT variant)
+        => variant.vt == VT_CY ? variant.data.cyVal : ThrowInvalidCast<CY>();
+
+    public static explicit operator decimal(VARIANT variant) => variant.vt switch
+    {
+        VT_DECIMAL => variant.Anonymous.decVal.ToDecimal(),
+        VT_CY => decimal.FromOACurrency(variant.data.cyVal.int64),
+        _ => ThrowInvalidCast<decimal>(),
+    };
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static T ThrowInvalidCast<T>() => throw new InvalidCastException();
+
     internal partial struct _Anonymous_e__Union
     {
         internal partial struct _Anonymous_e__Struct

src/System.Windows.Forms.Primitives/src/NativeMethods.json

@@ -5,6 +5,7 @@
   "comInterop": {
     "preserveSigMethods": [
       "IAutoComplete2.SetOptions",
+      "IClassFactory.CreateInstance",
       "IDispatch.Invoke",
       "IFileDialog.Show",
       "IFileDialog.GetResult",

src/System.Windows.Forms.Primitives/src/NativeMethods.txt

@@ -69,11 +69,23 @@ DestroyCursor
 DestroyIcon
 DestroyMenu
 DestroyWindow
-DestroyWindow
+DISP_E_ARRAYISLOCKED
+DISP_E_BADINDEX
+DISP_E_BADPARAMCOUNT
+DISP_E_BADVARTYPE
+DISP_E_BADCALLEE
+DISP_E_BUFFERTOOSMALL
 DISP_E_DIVBYZERO
 DISP_E_EXCEPTION
 DISP_E_MEMBERNOTFOUND
+DISP_E_NONAMEDARGS
+DISP_E_NOTACOLLECTION
+DISP_E_OVERFLOW
 DISP_E_PARAMNOTFOUND
+DISP_E_PARAMNOTOPTIONAL
+DISP_E_TYPEMISMATCH
+DISP_E_UNKNOWNINTERFACE
+DISP_E_UNKNOWNLCID
 DISP_E_UNKNOWNNAME
 DISPATCH_FLAGS
 DispatchMessage
@@ -128,6 +140,7 @@ ExtTextOut
 FDAP
 FILETIME
 FillRect
+FONTDESC
 FormatMessage
 FUNCDESC
 FUNCFLAGS
@@ -267,6 +280,7 @@ HitTestThemeBackground
 HWND_*
 IAccessible
 IAutoComplete2
+IClassFactory
 IClassFactory2
 ICM_MODE
 ICON_*
@@ -416,6 +430,7 @@ OLE_E_ADVISENOTSUPPORTED
 OLE_E_INVALIDRECT
 OLE_E_NOCONNECTION
 OLE_E_PROMPTSAVECANCELLED
+OleCreateFontIndirect
 OleCreatePictureIndirect
 OleFlushClipboard
 OleInitialize

src/System.Windows.Forms.Primitives/src/Windows/Win32/Foundation/BSTR.cs

@@ -21,5 +21,15 @@ public void Dispose()
         }
     }
 
+    /// <summary>
+    ///  Converts the <see cref="BSTR"/> to string and frees it.
+    /// </summary>
+    public readonly string ToStringAndFree()
+    {
+        string result = ToString();
+        Dispose();
+        return result;
+    }
+
     public bool IsNull => Value is null;
 }

src/System.Windows.Forms.Primitives/src/Windows/Win32/System/Com/CY.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Windows.Win32.System.Com;
+
+internal partial struct CY
+{
+    // https://learn.microsoft.com/openspecs/windows_protocols/ms-oaut/5a2b34c4-d109-438e-9ec8-84816d8de40d
+
+    public static explicit operator decimal(CY value) => decimal.FromOACurrency(value.int64);
+    public static explicit operator CY(decimal value) => new() { int64 = decimal.ToOACurrency(value) };
+
+    public static explicit operator float(CY value) => (float)(value.int64 / 10000f);
+    public static explicit operator CY(float value) => new() { int64 = (long)(value * 10000) };
+}

src/System.Windows.Forms.Primitives/src/Windows/Win32/System/Com/IDispatch.Interface.cs

@@ -0,0 +1,82 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using ComWrappers = Interop.WinFormsComWrappers;
+
+namespace Windows.Win32.System.Com;
+
+internal unsafe partial struct IDispatch : IVTable<IDispatch, IDispatch.Vtbl>
+{
+    static void IVTable<IDispatch, Vtbl>.PopulateComInterfaceVTable(Vtbl* vtable)
+    {
+        vtable->GetTypeInfoCount_4 = &GetTypeInfoCount;
+        vtable->GetTypeInfo_5 = &GetTypeInfo;
+        vtable->GetIDsOfNames_6 = &GetIDsOfNames;
+        vtable->Invoke_7 = &Invoke;
+    }
+
+    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvStdcall) })]
+    private static HRESULT GetTypeInfoCount(IDispatch* @this, uint* pctinfo)
+        => ComWrappers.UnwrapAndInvoke<IDispatch, Interface>(@this, o => o.GetTypeInfoCount(pctinfo));
+
+    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvStdcall) })]
+    private static HRESULT GetTypeInfo(IDispatch* @this, uint iTInfo, uint lcid, ITypeInfo** ppTInfo)
+        => ComWrappers.UnwrapAndInvoke<IDispatch, Interface>(@this, o => o.GetTypeInfo(iTInfo, lcid, ppTInfo));
+
+    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvStdcall) })]
+    private static HRESULT GetIDsOfNames(IDispatch* @this, Guid* riid, PWSTR* rgszNames, uint cNames, uint lcid, int* rgDispId)
+        => ComWrappers.UnwrapAndInvoke<IDispatch, Interface>(@this, o => o.GetIDsOfNames(riid, rgszNames, cNames, lcid, rgDispId));
+
+    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvStdcall) })]
+    private static HRESULT Invoke(
+        IDispatch* @this,
+        int dispIdMember,
+        Guid* riid,
+        uint lcid,
+        DISPATCH_FLAGS dwFlags,
+        DISPPARAMS* pDispParams,
+        VARIANT* pVarResult,
+        EXCEPINFO* pExcepInfo,
+        uint* pArgErr)
+        => ComWrappers.UnwrapAndInvoke<IDispatch, Interface>(
+            @this,
+            o => o.Invoke(dispIdMember, riid, lcid, dwFlags, pDispParams, pVarResult, pExcepInfo, pArgErr));
+
+    [ComImport]
+    [Guid("00020400-0000-0000-C000-000000000046")]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    public unsafe interface Interface
+    {
+        [PreserveSig]
+        HRESULT GetTypeInfoCount(
+            uint* pctinfo);
+
+        [PreserveSig]
+        HRESULT GetTypeInfo(
+            uint iTInfo,
+            uint lcid,
+            ITypeInfo** ppTInfo);
+
+        [PreserveSig]
+        HRESULT GetIDsOfNames(
+            Guid* riid,
+            PWSTR* rgszNames,
+            uint cNames,
+            uint lcid,
+            int* rgDispId);
+
+        [PreserveSig]
+        HRESULT Invoke(
+            int dispIdMember,
+            Guid* riid,
+            uint lcid,
+            DISPATCH_FLAGS dwFlags,
+            DISPPARAMS* pDispParams,
+            VARIANT* pVarResult,
+            EXCEPINFO* pExcepInfo,
+            uint* pArgErr);
+    }
+}

src/System.Windows.Forms.Primitives/src/Windows/Win32/System/Com/IDispatch.cs

@@ -29,5 +29,17 @@ internal HRESULT GetProperty(
                     puArgErr: null);
             }
         }
+
+        /// <summary>
+        ///  Get the specified <paramref name="dispId"/> property.
+        /// </summary>
+        internal VARIANT GetProperty(
+            uint dispId,
+            uint lcid = 0)
+        {
+            VARIANT variant = default;
+            GetProperty(dispId, &variant, lcid).ThrowOnFailure();
+            return variant;
+        }
     }
 }