Remove WindowsGraphics and DeviceContext

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.CreateBrushScope.cs

@@ -25,8 +25,10 @@ internal static partial class Gdi32
             /// </summary>
             public CreateBrushScope(Color color)
             {
-                HBrush = CreateSolidBrush(ColorTranslator.ToWin32(color));
-            }
+                HBrush = color.IsSystemColor
+                    ? User32.GetSysColorBrush(ColorTranslator.ToOle(color) & 0xFF)
+                    : CreateSolidBrush(ColorTranslator.ToWin32(color));
+              }
 
             public static implicit operator HBRUSH(in CreateBrushScope scope) => scope.HBrush;
             public static implicit operator HGDIOBJ(in CreateBrushScope scope) => scope.HBrush;
@@ -37,6 +39,7 @@ public void Dispose()
             {
                 if (!HBrush.IsNull)
                 {
+                    // Note that this is a no-op if the original brush was a system brush
                     DeleteObject(HBrush);
                 }
             }

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.CreateCompatibleDC.cs

@@ -11,12 +11,5 @@ internal static partial class Gdi32
     {
         [DllImport(Libraries.Gdi32, ExactSpelling = true)]
         public static extern HDC CreateCompatibleDC(HDC hDC);
-
-        public static HDC CreateCompatibleDC(HandleRef hDC)
-        {
-            HDC result = CreateCompatibleDC((HDC)hDC.Handle);
-            GC.KeepAlive(hDC.Wrapper);
-            return result;
-        }
     }
 }

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.CreatePenScope.cs

@@ -34,6 +34,7 @@ public CreatePenScope(Color color, int width = 1)
             }
 
             public static implicit operator HPEN(in CreatePenScope scope) => scope.HPen;
+            public static implicit operator HGDIOBJ(in CreatePenScope scope) => scope.HPen;
 
             public bool IsNull => HPen.IsNull;
 

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.GetClipBox.cs

@@ -0,0 +1,15 @@
+// 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;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Gdi32
+    {
+        [DllImport(Libraries.Gdi32, ExactSpelling = true)]
+        public static extern RegionType GetClipBox(HDC hdc, ref RECT lprect);
+    }
+}

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.GetDeviceCaps.cs

@@ -17,14 +17,8 @@ public enum DeviceCapability : int
             LOGPIXELSY = 90
         }
 
+        [SuppressGCTransition]
         [DllImport(Libraries.Gdi32, SetLastError = true, ExactSpelling = true)]
         public static extern int GetDeviceCaps(HDC hDC, DeviceCapability nIndex);
-
-        public static int GetDeviceCaps(IHandle hDC, DeviceCapability nIndex)
-        {
-            int caps = GetDeviceCaps((HDC)hDC.Handle, nIndex);
-            GC.KeepAlive(hDC);
-            return caps;
-        }
     }
 }

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SelectPaletteScope.cs

@@ -32,7 +32,26 @@ public SelectPaletteScope(HDC hdc, HPALETTE hpalette, bool forceBackground, bool
             }
 
             public static SelectPaletteScope HalftonePalette(HDC hdc, bool forceBackground, bool realizePalette)
-                => new SelectPaletteScope(hdc, (HPALETTE)Graphics.GetHalftonePalette(), forceBackground, realizePalette);
+            {
+                if (GetDeviceCaps(hdc, DeviceCapability.BITSPIXEL) > 8)
+                {
+                    // https://docs.microsoft.com/windows/win32/api/Gdiplusgraphics/nf-gdiplusgraphics-graphics-gethalftonepalette
+                    // The purpose of the Graphics::GetHalftonePalette method is to enable GDI+ to produce a better
+                    // quality halftone when the display uses 8 bits per pixel. This method allocates a palette of
+                    // 256 entries (each of which are 4 bytes a piece).
+                    //
+                    // Doing this is a bit pointless when the color depth is much higher (the normal scenario). As such
+                    // we'll skip doing this unless we see 8bpp or less.
+
+                    return default;
+                }
+
+                return new SelectPaletteScope(
+                    hdc,
+                    (HPALETTE)Graphics.GetHalftonePalette(),
+                    forceBackground,
+                    realizePalette);
+            }
 
             public static implicit operator HPALETTE(in SelectPaletteScope paletteScope) => paletteScope.HPalette;
 

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SelectionScope.cs

@@ -22,17 +22,30 @@ internal static partial class Gdi32
             public HGDIOBJ PreviousObject { get; }
 
             /// <summary>
-            ///  Selects <paramref name="object"/> into the given <paramref name="hdc"/>.
+            ///  Selects <paramref name="object"/> into the given <paramref name="hdc"/> using
+            ///  <see cref="SelectObject(HDC, HGDIOBJ)"/>.
             /// </summary>
             public SelectObjectScope(HDC hdc, HGDIOBJ @object)
             {
-                _hdc = hdc;
-                PreviousObject = SelectObject(hdc, @object);
+                // Selecting null doesn't mean anything
+
+                if (@object.IsNull)
+                {
+                    this = default;
+                }
+                else
+                {
+                    _hdc = hdc;
+                    PreviousObject = SelectObject(hdc, @object);
+                }
             }
 
             public void Dispose()
             {
-                SelectObject(_hdc, PreviousObject);
+                if (!_hdc.IsNull)
+                {
+                    SelectObject(_hdc, PreviousObject);
+                }
             }
         }
     }

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SetBackgroundColorScope.cs

@@ -0,0 +1,47 @@
+// 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;
+using System.Drawing;
+
+internal static partial class Interop
+{
+    internal static partial class Gdi32
+    {
+        /// <summary>
+        ///  Helper to scope selecting a given background color into a HDC. Restores the original background color into
+        ///  the HDC when disposed.
+        /// </summary>
+        /// <remarks>
+        ///  Use in a <see langword="using" /> statement. If you must pass this around, always pass by
+        ///  <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
+        /// </remarks>
+        internal readonly ref struct SetBackgroundColorScope
+        {
+            private readonly int _previousColor;
+            private readonly HDC _hdc;
+
+            /// <summary>
+            ///  Sets text color <paramref name="color"/> in the given <paramref name="hdc"/> using
+            ///  <see cref="SetBkColor(HDC, int)"/>.
+            /// </summary>
+            public SetBackgroundColorScope(HDC hdc, Color color)
+            {
+                int colorref = ColorTranslator.ToWin32(color);
+                _previousColor = SetBkColor(hdc, colorref);
+
+                // If we didn't actually change the color, don't keep the HDC so we skip putting back the same state.
+                _hdc = colorref == _previousColor ? default : hdc;
+            }
+
+            public void Dispose()
+            {
+                if (!_hdc.IsNull)
+                {
+                    SetBkColor(_hdc, _previousColor);
+                }
+            }
+        }
+    }
+}

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SetMapModeScope.cs

@@ -0,0 +1,46 @@
+// 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;
+using System.Drawing;
+
+internal static partial class Interop
+{
+    internal static partial class Gdi32
+    {
+        /// <summary>
+        ///  Helper to scope selecting a given mapping mode into a HDC. Restores the original mapping mode into the HDC
+        ///  when disposed.
+        /// </summary>
+        /// <remarks>
+        ///  Use in a <see langword="using" /> statement. If you must pass this around, always pass by
+        ///  <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
+        /// </remarks>
+        internal readonly ref struct SetMapModeScope
+        {
+            private readonly MM _previousMapMode;
+            private readonly HDC _hdc;
+
+            /// <summary>
+            ///  Sets the <paramref name="mapMode"/> in the given <paramref name="hdc"/> using
+            ///  <see cref="SetMapMode(HDC, MM)"/>.
+            /// </summary>
+            public SetMapModeScope(HDC hdc, MM mapMode)
+            {
+                _previousMapMode = SetMapMode(hdc, mapMode);
+
+                // If we didn't actually change the map mode, don't keep the HDC so we skip putting back the same state.
+                _hdc = mapMode == _previousMapMode ? default : hdc;
+            }
+
+            public void Dispose()
+            {
+                if (!_hdc.IsNull)
+                {
+                    SetMapMode(_hdc, _previousMapMode);
+                }
+            }
+        }
+    }
+}

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SetRop2Scope.cs

@@ -9,20 +9,20 @@ internal static partial class Interop
     internal static partial class Gdi32
     {
         /// <summary>
-        ///  Helper to scope selecting a given foreground mix mode into a HDC. Restores the original
-        ///  mix mode into the HDC when disposed.
+        ///  Helper to scope selecting a given foreground mix mode into a HDC. Restores the original mix mode into the
+        ///  HDC when disposed.
         /// </summary>
         /// <remarks>
-        ///  Use in a <see langword="using" /> statement. If you must pass this around, always pass
-        ///  by <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
+        ///  Use in a <see langword="using" /> statement. If you must pass this around, always pass by
+        ///  <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
         /// </remarks>
         internal readonly ref struct SetRop2Scope
         {
             private readonly R2 _previousRop;
             private readonly HDC _hdc;
 
             /// <summary>
-            ///  Selects <paramref name="rop2"/> into the given <paramref name="hdc"/>.
+            ///  Selects <paramref name="rop2"/> into the given <paramref name="hdc"/> using <see cref="SetROP2(HDC, R2)"/>.
             /// </summary>
             public SetRop2Scope(HDC hdc, R2 rop2)
             {

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SetTextAlign.cs

@@ -11,11 +11,11 @@ internal static partial class Interop
     internal static partial class Gdi32
     {
         [DllImport(Libraries.Gdi32, ExactSpelling = true)]
-        public static extern TA SetTextAlign(IntPtr hdc, TA align);
+        public static extern TA SetTextAlign(Gdi32.HDC hdc, TA align);
 
         public static TA SetTextAlign(IHandle hdc, TA align)
         {
-            TA result = SetTextAlign(hdc.Handle, align);
+            TA result = SetTextAlign((Gdi32.HDC)hdc.Handle, align);
             GC.KeepAlive(hdc);
             return result;
         }

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SetTextAlignmentScope.cs

@@ -0,0 +1,44 @@
+// 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;
+
+internal static partial class Interop
+{
+    internal static partial class Gdi32
+    {
+        /// <summary>
+        ///  Helper to scope selecting a given text alignment mode into a HDC. Restores the original text alignment
+        ///  mode into the HDC when disposed.
+        /// </summary>
+        /// <remarks>
+        ///  Use in a <see langword="using" /> statement. If you must pass this around, always pass by
+        ///  <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
+        /// </remarks>
+        internal readonly ref struct SetTextAlignmentScope
+        {
+            private readonly TA _previousTa;
+            private readonly HDC _hdc;
+
+            /// <summary>
+            ///  Sets <paramref name="ta"/> in the given <paramref name="hdc"/> using <see cref="SetTextAlign(HDC, TA)"/>.
+            /// </summary>
+            public SetTextAlignmentScope(HDC hdc, TA ta)
+            {
+                _previousTa = SetTextAlign(hdc, ta);
+
+                // If we didn't actually change the TA, don't keep the HDC so we skip putting back the same state.
+                _hdc = _previousTa == ta ? default : hdc;
+            }
+
+            public void Dispose()
+            {
+                if (!_hdc.IsNull)
+                {
+                    SetTextAlign(_hdc, _previousTa);
+                }
+            }
+        }
+    }
+}

src/System.Windows.Forms.Primitives/src/Interop/Gdi32/Interop.SetTextColorScope.cs

@@ -0,0 +1,47 @@
+// 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;
+using System.Drawing;
+
+internal static partial class Interop
+{
+    internal static partial class Gdi32
+    {
+        /// <summary>
+        ///  Helper to scope selecting a given foreground text color into a HDC. Restores the original text color into
+        ///  into the HDC when disposed.
+        /// </summary>
+        /// <remarks>
+        ///  Use in a <see langword="using" /> statement. If you must pass this around, always pass by
+        ///  <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
+        /// </remarks>
+        internal readonly ref struct SetTextColorScope
+        {
+            private readonly int _previousColor;
+            private readonly HDC _hdc;
+
+            /// <summary>
+            ///  Sets text color <paramref name="color"/> in the given <paramref name="hdc"/> using
+            ///  <see cref="SetTextColor(HDC, int)"/>.
+            /// </summary>
+            public SetTextColorScope(HDC hdc, Color color)
+            {
+                int colorref = ColorTranslator.ToWin32(color);
+                _previousColor = SetTextColor(hdc, colorref);
+
+                // If we didn't actually change the color, don't keep the HDC so we skip putting back the same state.
+                _hdc = colorref == _previousColor ? default : hdc;
+            }
+
+            public void Dispose()
+            {
+                if (!_hdc.IsNull)
+                {
+                    SetTextColor(_hdc, _previousColor);
+                }
+            }
+        }
+    }
+}

src/System.Windows.Forms.Primitives/src/Interop/User32/Interop.DrawIconEx.cs

@@ -4,15 +4,14 @@
 
 using System;
 using System.Runtime.InteropServices;
-using System.Windows.Forms;
 
 internal static partial class Interop
 {
     internal static partial class User32
     {
         [DllImport(Libraries.User32, ExactSpelling = true)]
         public static extern BOOL DrawIconEx(
-            IntPtr hDC,
+            Gdi32.HDC hDC,
             int xLeft,
             int yTop,
             IntPtr hIcon,
@@ -23,7 +22,7 @@ internal static partial class User32
             DI diFlags);
 
         public static BOOL DrawIconEx(
-            IntPtr hDC,
+            Gdi32.HDC hDC,
             int xLeft,
             int yTop,
             IHandle hIcon,
@@ -43,7 +42,7 @@ internal static partial class User32
             int cxWidth,
             int cyWidth)
         {
-            BOOL result = DrawIconEx(hDC.Handle, xLeft, yTop, hIcon.Handle, cxWidth, cyWidth, 0, IntPtr.Zero, DI.NORMAL);
+            BOOL result = DrawIconEx((Gdi32.HDC)hDC.Handle, xLeft, yTop, hIcon.Handle, cxWidth, cyWidth, 0, IntPtr.Zero, DI.NORMAL);
             GC.KeepAlive(hIcon);
             GC.KeepAlive(hDC);
             return result;