Improve invisible character drawing on a non-opaque view

CHANGELOG.md

@@ -19,6 +19,7 @@ develop
 
 - Improve performance of closing large size document.
 - Add “.swift” extension to file types treaded as CotEditor script.
+- Improve invisible character drawing on a non-opaque view.
 - Change syntax style detection behavior to set “None” style if no appropriate style can be found on file opening.
 - [non-AppStore ver.] Update Sparkle framework to version 1.17.0.
 - And some minor improvements and fixes.

CotEditor/Sources/LayoutManager.swift

@@ -211,6 +211,11 @@ final class LayoutManager: NSLayoutManager {
             let string = self.textStorage?.string
         {
             let isVertical = (self.firstTextView?.layoutOrientation == .vertical)
+            let isOpaque = self.firstTextView?.isOpaque ?? true
+            
+            if !isOpaque {
+                context.setShouldSmoothFonts(false)
+            }
             
             // flip coordinate if needed
             if NSGraphicsContext.current()?.isFlipped ?? false {
@@ -268,6 +273,10 @@ final class LayoutManager: NSLayoutManager {
                 context.textPosition = point
                 CTLineDraw(line, context)
             }
+            
+            if !isOpaque {
+                context.setShouldSmoothFonts(true)
+            }
         }
         
         super.drawGlyphs(forGlyphRange: glyphsToShow, at: origin)