Fix current line highlight with line height 1.0 (fix #594)

CHANGELOG.md

@@ -20,6 +20,7 @@ develop
 
 - Fix an issue find string is not shared to other applications after quitting CotEditor.
 - Address an issue with drawing area of zoomed character view in character inspector popover.
+- [beta] Fix an issue where current line highlight was occasionally too wide when line height is 1.0.
 - [beta] Fix an issue where inputting character with unicode hex didn't work.
 - [beta] Fix some memory leaks.
 

CotEditor/Sources/EditorTextView.swift

@@ -1080,8 +1080,9 @@ final class EditorTextView: NSTextView, Themable {
         //   -> The actual line height will be calculated in LayoutManager and ATSTypesetter based on this line height multiple.
         //      Because the default Cocoa Text System calculate line height differently
         //      if the first character of the document is drawn with another font (typically by a composite font).
-        paragraphStyle.lineHeightMultiple = self.lineHeight
-        
+        //   -> Round line height for workaround to avoid expanding current line highlight when line height is 1.0. (2016-09 on macOS Sierra 10.12)
+        paragraphStyle.lineHeightMultiple = self.lineHeight.rounded(to: 5)
+        moof(self.lineHeight.rounded(to: 5))
         // calculate tab interval
         if let font = self.font, let displayFont = self.layoutManager?.substituteFont(for: font) {
             paragraphStyle.tabStops = []

CotEditor/Sources/Geometry.swift

@@ -95,3 +95,18 @@ extension CGRect {
     }
     
 }
+
+
+
+// MARK: CGFloat
+
+extension CGFloat {
+    
+    /// round to decimal places value
+    func rounded(to places: Int) -> CGFloat {
+        
+        let divisor = pow(10.0, CGFloat(places))
+        return (self * divisor).rounded() / divisor
+    }
+    
+}