Do not hardcode black as the text color when the cursor is over it, but instead

use caretTextColor.

Also, made caretTextColor optional and default when not set to the
foregroundColor.   The reason for this choice is that there is no escape
sequence defined for setting this attribute, but it can be set via the API that
we expose, and some color themes support this.

Author: migueldeicaza

Sources/SwiftTerm/Apple/CaretView.swift

@@ -44,6 +44,7 @@ extension CaretView {
         guard style == .steadyBlock || style  == .blinkBlock else {
             return
         }
+        let caretFG = caretTextColor ?? terminal.nativeForegroundColor
         context.setFillColor(TTColor.black.cgColor)
         for run in CTLineGetGlyphRuns(ctline) as? [CTRun] ?? [] {
             let runGlyphsCount = CTRunGetGlyphCount(run)

Sources/SwiftTerm/Mac/MacCaretView.swift

@@ -38,7 +38,7 @@ class CaretView: NSView, CALayerDelegate {
     func setText (ch: CharData) {
         let res = NSAttributedString (
             string: String (ch.getCharacter()),
-            attributes: terminal?.getAttributedValue(ch.attribute, usingFg: caretColor, andBg: caretTextColor))
+            attributes: terminal?.getAttributedValue(ch.attribute, usingFg: caretColor, andBg: caretTextColor ?? terminal?.nativeForegroundColor ?? NSColor.black))
         ctline = CTLineCreateWithAttributedString(res)
 
         setNeedsDisplay(bounds)
@@ -88,8 +88,8 @@ class CaretView: NSView, CALayerDelegate {
         }
     }
 
-    public var defaultCaretTextColor = NSColor.black
-    public var caretTextColor: NSColor = NSColor.black {
+    public var defaultCaretTextColor: NSColor? = nil
+    public var caretTextColor: NSColor? = nil {
         didSet {
             updateView()
         }

Sources/SwiftTerm/Mac/MacTerminalView.swift

@@ -235,8 +235,9 @@ open class TerminalView: NSView, NSTextInputClient, NSUserInterfaceValidations,
         set { caretView.caretColor = newValue }
     }
 
-    /// Controls the color for the text in the caret when using a block cursor
-    public var caretTextColor: NSColor {
+    /// Controls the color for the text in the caret when using a block cursor, if not set
+    /// the cursor will render with the foreground color
+    public var caretTextColor: NSColor? {
         get { caretView.caretTextColor }
         set { caretView.caretTextColor = newValue }
     }

Sources/SwiftTerm/iOS/iOSCaretView.swift

@@ -79,7 +79,7 @@ class CaretView: UIView {
     func setText (ch: CharData) {
         let res = NSAttributedString (
             string: String (ch.getCharacter()),
-            attributes: terminal?.getAttributedValue(ch.attribute, usingFg: caretColor, andBg: caretTextColor))
+            attributes: terminal?.getAttributedValue(ch.attribute, usingFg: caretColor, andBg: caretTextColor ?? terminal?.nativeForegroundColor ?? TTColor.black))
         ctline = CTLineCreateWithAttributedString(res)
         setNeedsDisplay(bounds)
     }
@@ -107,8 +107,8 @@ class CaretView: UIView {
         }
     }
 
-    public var defaultCaretTextColor = UIColor.black
-    public var caretTextColor: UIColor = UIColor.black {
+    public var defaultCaretTextColor: UIColor? = nil
+    public var caretTextColor: UIColor? = nil {
         didSet {
             updateView()
         }

Sources/SwiftTerm/iOS/iOSTerminalView.swift

@@ -817,13 +817,13 @@ open class TerminalView: UIScrollView, UITextInputTraits, UIKeyInput, UIScrollVi
         set { caretView.caretColor = newValue }
     }
 
-    /// Controls the color for the caret
-    public var caretTextColor: UIColor {
+    /// Controls the color for the text in the caret when using a block cursor, if not set
+    /// the cursor will render with the foreground color
+    public var caretTextColor: UIColor? {
         get { caretView.caretTextColor }
         set { caretView.caretTextColor = newValue }
     }
 
-    
     var _selectedTextBackgroundColor = UIColor (red: 204.0/255.0, green: 221.0/255.0, blue: 237.0/255.0, alpha: 1.0)
     /// The color used to render the selection
     public var selectedTextBackgroundColor: UIColor {