Improve code quality

Author: VahidN

src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/PatternColor.cs

@@ -14,15 +14,16 @@ public class PatternColor : ExtendedColor
     ///     Creates a color representing a pattern.
     /// </summary>
     /// <param name="painter">the actual pattern</param>
-    public PatternColor(PdfPatternPainter painter) : base(TYPE_PATTERN, .5f, .5f, .5f) => _painter = painter;
+    public PatternColor(PdfPatternPainter painter) : base(TYPE_PATTERN, red: .5f, green: .5f, blue: .5f)
+        => _painter = painter;
 
     /// <summary>
     ///     Gets the pattern.
     /// </summary>
     /// <returns>the pattern</returns>
     public PdfPatternPainter Painter => _painter;
 
-    public override bool Equals(object obj) => this == obj;
+    public override bool Equals(object obj) => obj is PatternColor color && color.Painter.Equals(Painter);
 
     public override int GetHashCode() => _painter.GetHashCode();
 }

src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/PdfName.cs

@@ -3460,19 +3460,7 @@ public int CompareTo(object obj)
     /// <param name="obj">the reference object with which to compare.</param>
     /// <returns> true  if this object is the same as the obj</returns>
     public override bool Equals(object obj)
-    {
-        if (this == obj)
-        {
-            return true;
-        }
-
-        if (obj is PdfName)
-        {
-            return CompareTo(obj) == 0;
-        }
-
-        return false;
-    }
+        => !ReferenceEquals(objA: null, obj) && (ReferenceEquals(this, obj) || (obj is PdfName && CompareTo(obj) == 0));
 
     /// <summary>
     ///     Returns a hash code value for the object. This method is

src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/PdfPKCS7.cs

@@ -1137,7 +1137,7 @@ public byte[] GetEncodedPkcs7(byte[] secondDigest, DateTime signingTime, ITsaCli
         //                }
 
         // Only allow one signerInfo
-        body.Add(new DerSet(new DerSequence(signerinfo)));
+        body.Add(DerSet.FromElement(new DerSequence(signerinfo)));
 
         // Now we have the body, wrap it in it's PKCS7Signed shell
         // and return it
@@ -1391,7 +1391,7 @@ private static Asn1EncodableVector buildUnauthenticatedAttributes(byte[] timeSta
         var v = new Asn1EncodableVector();
         v.Add(new DerObjectIdentifier(idTimeStampToken)); // id-aa-timeStampToken
         var seq = (Asn1Sequence)tempstream.ReadObject();
-        v.Add(new DerSet(seq));
+        v.Add(DerSet.FromElement(seq));
 
         unauthAttributes.Add(new DerSequence(v));
 
@@ -1524,7 +1524,7 @@ private static DerSet getAuthenticatedAttributeSet(byte[] secondDigest, DateTime
             v3.Add(den);
             v3.Add(new DerTaggedObject(isExplicit: true, tagNo: 0, new DerSequence(v2)));
             vo1.Add(new DerSequence(v3));
-            v.Add(new DerSet(new DerSequence(new DerTaggedObject(isExplicit: true, tagNo: 1, new DerSequence(vo1)))));
+            v.Add(DerSet.FromElement(new DerSequence(new DerTaggedObject(isExplicit: true, tagNo: 1, new DerSequence(vo1)))));
             attribute.Add(new DerSequence(v));
         }
 

src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/ShadingColor.cs

@@ -6,12 +6,13 @@ namespace iTextSharp.text.pdf;
 /// </summary>
 public class ShadingColor : ExtendedColor
 {
-    public ShadingColor(PdfShadingPattern shadingPattern) : base(TYPE_SHADING, .5f, .5f, .5f) =>
-        PdfShadingPattern = shadingPattern;
+    public ShadingColor(PdfShadingPattern shadingPattern) : base(TYPE_SHADING, red: .5f, green: .5f, blue: .5f)
+        => PdfShadingPattern = shadingPattern;
 
     public PdfShadingPattern PdfShadingPattern { get; }
 
-    public override bool Equals(object obj) => this == obj;
+    public override bool Equals(object obj)
+        => obj is ShadingColor color && color.PdfShadingPattern.Equals(PdfShadingPattern);
 
     public override int GetHashCode() => PdfShadingPattern.GetHashCode();
 }

src/iTextSharp.LGPLv2.Core/iTextSharp/text/pdf/SpotColor.cs

@@ -1,15 +1,15 @@
+using System.util;
+
 namespace iTextSharp.text.pdf;
 
 /// <summary>
 ///     @author  psoares
 /// </summary>
 public class SpotColor : ExtendedColor
 {
-    public SpotColor(PdfSpotColor spot, float tint) :
-        base(TYPE_SEPARATION,
-             ((spot?.AlternativeCs.R ?? throw new ArgumentNullException(nameof(spot))) / 255f - 1f) * tint + 1,
-             (spot.AlternativeCs.G / 255f - 1f) * tint + 1,
-             (spot.AlternativeCs.B / 255f - 1f) * tint + 1)
+    public SpotColor(PdfSpotColor spot, float tint) : base(TYPE_SEPARATION,
+        ((spot?.AlternativeCs.R ?? throw new ArgumentNullException(nameof(spot))) / 255f - 1f) * tint + 1,
+        (spot.AlternativeCs.G / 255f - 1f) * tint + 1, (spot.AlternativeCs.B / 255f - 1f) * tint + 1)
     {
         PdfSpotColor = spot;
         Tint = tint;
@@ -23,7 +23,8 @@ public SpotColor(PdfSpotColor spot, float tint) :
 
     public float Tint { get; }
 
-    public override bool Equals(object obj) => this == obj;
+    public override bool Equals(object obj)
+        => obj is SpotColor color && color.PdfSpotColor.Equals(PdfSpotColor) && color.Tint.ApproxEquals(Tint);
 
     public override int GetHashCode() => PdfSpotColor.GetHashCode() ^ Tint.GetHashCode();
 }