Support snippet insertion in multi-cursor editing

CHANGELOG.md

@@ -5,6 +5,11 @@ Change Log
 3.7.0-beta.4 (unreleased)
 --------------------------
 
+### Improvements
+
+- [beta] Support snippet insertion in multi-cursor editing.
+
+
 ### Fixes
 
 - [beta] Suppress blinking Edit menu when perform `^⇧↑` or `^⇧↓` shortcut.

CotEditor/Sources/NSTextView+Snippet.swift

@@ -8,7 +8,7 @@
 //
 //  ---------------------------------------------------------------------------
 //
-//  © 2017 1024jp
+//  © 2017-2019 1024jp
 //
 //  Licensed under the Apache License, Version 2.0 (the "License");
 //  you may not use this file except in compliance with the License.
@@ -29,16 +29,21 @@ extension NSTextView {
     
     func insert(snippet: Snippet) {
         
-        let range = self.rangeForUserTextChange
+        let ranges = (self.rangesForUserTextChange ?? self.selectedRanges).map { $0.rangeValue }
+        let strings = [String](repeating: snippet.string, count: ranges.count)
         
-        guard self.shouldChangeText(in: range, replacementString: snippet.string) else { return }
+        let selectedRanges: [NSRange]? = {
+            guard let selection = snippet.selection else { return nil }
+            
+            let snippetLength = snippet.string.utf16.count
+            return ranges.map { range in
+                let location = ranges.prefix { $0 != range }.map { snippetLength - $0.length }.reduce(range.location, +)
+                return NSRange(location: location + selection.location, length: selection.length)
+            }
+        }()
+        
+        self.replace(with: strings, ranges: ranges, selectedRanges: selectedRanges, actionName: "Insert Snippet".localized)
         
-        self.replaceCharacters(in: range, with: snippet.string)
-        self.didChangeText()
-        if let selection = snippet.selection {
-            self.selectedRange = NSRange(location: range.location + selection.location, length: selection.length)
-        }
-        self.undoManager?.setActionName("Insert Snippet".localized)
     }
     
 }