From cf4ee3b2b5a4939548912aeb0f7de885127bc967 Mon Sep 17 00:00:00 2001
From: Khan Winter <35942988+thecoolwinter@users.noreply.github.com>
Date: Mon, 5 Feb 2024 08:39:19 -0600
Subject: [PATCH] (fix: #9) Grayscale Selection When Not Focused (#16)

---
 .../Extensions/NSColor+Greyscale.swift          | 17 +++++++++++++++++
 .../TextSelectionManager.swift                  |  7 ++++++-
 .../CodeEditTextView/TextView/TextView.swift    |  2 ++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 Sources/CodeEditTextView/Extensions/NSColor+Greyscale.swift

diff --git a/Sources/CodeEditTextView/Extensions/NSColor+Greyscale.swift b/Sources/CodeEditTextView/Extensions/NSColor+Greyscale.swift
new file mode 100644
index 00000000..4afd858a
--- /dev/null
+++ b/Sources/CodeEditTextView/Extensions/NSColor+Greyscale.swift
@@ -0,0 +1,17 @@
+//
+//  NSColor+Greyscale.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 2/2/24.
+//
+
+import AppKit
+
+extension NSColor {
+    var grayscale: NSColor {
+        guard let color = self.usingColorSpace(.deviceRGB) else { return self }
+        // linear relative weights for grayscale: https://en.wikipedia.org/wiki/Grayscale
+        let gray = 0.299 * color.redComponent + 0.587 * color.greenComponent + 0.114 * color.blueComponent
+        return NSColor(white: gray, alpha: color.alphaComponent)
+    }
+}
diff --git a/Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift b/Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift
index fb7cb4b0..c26b0e20 100644
--- a/Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift
+++ b/Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift
@@ -269,7 +269,12 @@ public class TextSelectionManager: NSObject {
     ///   - context: The context to draw in.
     private func drawSelectedRange(in rect: NSRect, for textSelection: TextSelection, context: CGContext) {
         context.saveGState()
-        context.setFillColor(selectionBackgroundColor.cgColor)
+
+        let fillColor = (textView?.isFirstResponder ?? false)
+        ? selectionBackgroundColor.cgColor
+        : selectionBackgroundColor.grayscale.cgColor
+
+        context.setFillColor(fillColor)
 
         let fillRects = getFillRects(in: rect, for: textSelection)
 
diff --git a/Sources/CodeEditTextView/TextView/TextView.swift b/Sources/CodeEditTextView/TextView/TextView.swift
index c55ac58c..90285fd3 100644
--- a/Sources/CodeEditTextView/TextView/TextView.swift
+++ b/Sources/CodeEditTextView/TextView/TextView.swift
@@ -314,12 +314,14 @@ public class TextView: NSView, NSTextContent {
     open override func becomeFirstResponder() -> Bool {
         isFirstResponder = true
         selectionManager.cursorTimer.resetTimer()
+        needsDisplay = true
         return super.becomeFirstResponder()
     }
 
     open override func resignFirstResponder() -> Bool {
         isFirstResponder = false
         selectionManager.removeCursors()
+        needsDisplay = true
         return super.resignFirstResponder()
     }