Shift-Click to Extend Selection

Sources/CodeEditTextView/Extensions/NSRange+/NSRange+init.swift

@@ -0,0 +1,15 @@
+//
+//  NSRange.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 8/20/24.
+//
+
+import Foundation
+
+extension NSRange {
+    @inline(__always)
+    init(start: Int, end: Int) {
+        self.init(location: start, length: end - start)
+    }
+}

Sources/CodeEditTextView/Extensions/NSTextStorage+getLine.swift

@@ -14,7 +14,7 @@ extension NSString {
         var contentsEnd: Int = NSNotFound
         self.getLineStart(nil, end: &end, contentsEnd: &contentsEnd, for: range)
         if end != NSNotFound && contentsEnd != NSNotFound && end != contentsEnd {
-            return NSRange(location: contentsEnd, length: end - contentsEnd)
+            return NSRange(start: contentsEnd, end: end)
         } else {
             return nil
         }

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager+Edits.swift

@@ -43,7 +43,7 @@ extension TextLayoutManager: NSTextStorageDelegate {
         if !string.isEmpty {
             var index = 0
             while let nextLine = (string as NSString).getNextLine(startingAt: index) {
-                let lineRange = NSRange(location: index, length: nextLine.max - index)
+                let lineRange = NSRange(start: index, end: nextLine.max)
                 applyLineInsert((string as NSString).substring(with: lineRange) as NSString, at: range.location + index)
                 index = nextLine.max
             }

Sources/CodeEditTextView/TextLayoutManager/TextLayoutManager+Public.swift

@@ -188,10 +188,7 @@ extension TextLayoutManager {
         let originalHeight = lineStorage.height
 
         for linePosition in lineStorage.linesInRange(
-            NSRange(
-                location: startingLinePosition.range.location,
-                length: linePosition.range.max - startingLinePosition.range.location
-            )
+            NSRange(start: startingLinePosition.range.location, end: linePosition.range.max)
         ) {
             let height = ensureLayoutFor(position: linePosition)
             if height != linePosition.height {

Sources/CodeEditTextView/TextLine/Typesetter.swift

@@ -79,7 +79,7 @@ final class Typesetter {
                     constrainingWidth: maxWidth
                 )
                 let lineFragment = typesetLine(
-                    range: NSRange(location: startIndex, length: lineBreak - startIndex),
+                    range: NSRange(start: startIndex, end: lineBreak),
                     lineHeightMultiplier: lineHeightMultiplier
                 )
                 lines.append(.init(

Sources/CodeEditTextView/TextSelectionManager/Destination.swift

@@ -0,0 +1,17 @@
+//
+//  Destination.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 8/20/24.
+//
+
+public extension TextSelectionManager {
+    public enum Destination {
+        case character
+        case word
+        case line
+        case visualLine
+        case page
+        case document
+    }
+}

Sources/CodeEditTextView/TextSelectionManager/Direction.swift

@@ -0,0 +1,15 @@
+//
+//  Direction.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 8/20/24.
+//
+
+public extension TextSelectionManager {
+    public enum Direction {
+        case up
+        case down
+        case forward
+        case backward
+    }
+}

Sources/CodeEditTextView/TextSelectionManager/SelectionManipulation/SelectionManipulation+Horizontal.swift

@@ -42,7 +42,7 @@ package extension TextSelectionManager {
             return extendSelectionVisualLine(string: string, from: offset, delta: delta)
         case .document:
             if delta > 0 {
-                return NSRange(location: offset, length: string.length - offset)
+                return NSRange(start: offset, end: string.length)
             } else {
                 return NSRange(location: 0, length: offset)
             }
@@ -194,8 +194,8 @@ package extension TextSelectionManager {
         delta: Int
     ) -> NSRange {
         var foundRange = NSRange(
-            location: min(lineBound, offset),
-            length: max(lineBound, offset) - min(lineBound, offset)
+            start: min(lineBound, offset),
+            end: max(lineBound, offset)
         )
         let originalFoundRange = foundRange
 

Sources/CodeEditTextView/TextSelectionManager/SelectionManipulation/SelectionManipulation+Vertical.swift

@@ -28,7 +28,7 @@ package extension TextSelectionManager {
         if up && layoutManager?.lineStorage.first?.range.contains(offset) ?? false {
             return NSRange(location: 0, length: offset)
         } else if !up && layoutManager?.lineStorage.last?.range.contains(offset) ?? false {
-            return NSRange(location: offset, length: (textStorage?.length ?? 0) - offset)
+            return NSRange(start: offset, end: (textStorage?.length ?? offset))
         }
 
         switch destination {
@@ -42,7 +42,7 @@ package extension TextSelectionManager {
             if up {
                 return NSRange(location: 0, length: offset)
             } else {
-                return NSRange(location: offset, length: (textStorage?.length ?? 0) - offset)
+                return NSRange(start: offset, end: (textStorage?.length ?? offset))
             }
         }
     }
@@ -107,10 +107,8 @@ package extension TextSelectionManager {
                 return NSRange(location: offset, length: 0)
             }
             return NSRange(
-                location: up ? nextLine.range.location : offset,
-                length: up
-                ? offset - nextLine.range.location
-                : nextLine.range.max - offset - (layoutManager?.detectedLineEnding.length ?? 0)
+                start: up ? nextLine.range.location : offset,
+                end: up ? offset : nextLine.range.max - (layoutManager?.detectedLineEnding.length ?? 0)
             )
         }
     }
@@ -142,7 +140,7 @@ package extension TextSelectionManager {
         }
 
         if delta > 0 {
-            return NSRange(location: nextPageOffset, length: offset - nextPageOffset)
+            return NSRange(start: nextPageOffset, end: offset)
         } else {
             return NSRange(location: offset, length: nextPageOffset - offset)
         }

Sources/CodeEditTextView/TextSelectionManager/TextSelection.swift

@@ -0,0 +1,46 @@
+//
+//  TextSelection.swift
+//  CodeEditTextView
+//
+//  Created by Khan Winter on 8/20/24.
+//
+
+import Foundation
+import AppKit
+
+public extension TextSelectionManager {
+    public class TextSelection: Hashable, Equatable {
+        public var range: NSRange
+        weak var view: NSView?
+        var boundingRect: CGRect = .zero
+        var suggestedXPos: CGFloat?
+        /// The position this selection should 'rotate' around when modifying selections.
+        var pivot: Int?
+
+        init(range: NSRange, view: CursorView? = nil) {
+            self.range = range
+            self.view = view
+        }
+
+        var isCursor: Bool {
+            range.length == 0
+        }
+
+        public func hash(into hasher: inout Hasher) {
+            hasher.combine(range)
+        }
+
+        public static func == (lhs: TextSelection, rhs: TextSelection) -> Bool {
+            lhs.range == rhs.range
+        }
+    }
+}
+
+private extension TextSelectionManager.TextSelection {
+    func didInsertText(length: Int, retainLength: Bool = false) {
+        if !retainLength {
+            range.length = 0
+        }
+        range.location += length
+    }
+}

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift

@@ -19,50 +19,6 @@ public protocol TextSelectionManagerDelegate: AnyObject {
 /// Draws selections using a draw method similar to the `TextLayoutManager` class, and adds cursor views when
 /// appropriate.
 public class TextSelectionManager: NSObject {
-    // MARK: - TextSelection
-
-    public class TextSelection: Hashable, Equatable {
-        public var range: NSRange
-        weak var view: NSView?
-        var boundingRect: CGRect = .zero
-        var suggestedXPos: CGFloat?
-        /// The position this selection should 'rotate' around when modifying selections.
-        var pivot: Int?
-
-        init(range: NSRange, view: CursorView? = nil) {
-            self.range = range
-            self.view = view
-        }
-
-        var isCursor: Bool {
-            range.length == 0
-        }
-
-        public func hash(into hasher: inout Hasher) {
-            hasher.combine(range)
-        }
-
-        public static func == (lhs: TextSelection, rhs: TextSelection) -> Bool {
-            lhs.range == rhs.range
-        }
-    }
-
-    public enum Destination {
-        case character
-        case word
-        case line
-        case visualLine
-        case page
-        case document
-    }
-
-    public enum Direction {
-        case up
-        case down
-        case forward
-        case backward
-    }
-
     // MARK: - Properties
 
     // swiftlint:disable:next line_length
@@ -107,7 +63,9 @@ public class TextSelectionManager: NSObject {
     }
 
     // MARK: - Selected Ranges
-
+
+    /// Set the selected ranges to a single range. Overrides any existing selections.
+    /// - Parameter range: The range to set.
     public func setSelectedRange(_ range: NSRange) {
         textSelections.forEach { $0.view?.removeFromSuperview() }
         let selection = TextSelection(range: range)
@@ -119,6 +77,8 @@ public class TextSelectionManager: NSObject {
         }
     }
 
+    /// Set the selected ranges to new ranges. Overrides any existing selections.
+    /// - Parameter range: The selected ranges to set.
     public func setSelectedRanges(_ ranges: [NSRange]) {
         textSelections.forEach { $0.view?.removeFromSuperview() }
         // Remove duplicates, invalid ranges, update suggested X position.
@@ -137,7 +97,9 @@ public class TextSelectionManager: NSObject {
             NotificationCenter.default.post(Notification(name: Self.selectionChangedNotification, object: self))
         }
     }
-
+
+    /// Append a new selected range to the existing ones.
+    /// - Parameter range: The new range to add.
     public func addSelectedRange(_ range: NSRange) {
         let newTextSelection = TextSelection(range: range)
         var didHandle = false
@@ -336,14 +298,3 @@ public class TextSelectionManager: NSObject {
         context.restoreGState()
     }
 }
-
-// MARK: - Private TextSelection
-
-private extension TextSelectionManager.TextSelection {
-    func didInsertText(length: Int, retainLength: Bool = false) {
-        if !retainLength {
-            range.length = 0
-        }
-        range.location += length
-    }
-}

Sources/CodeEditTextView/TextView/TextView+Mouse.swift

@@ -19,21 +19,35 @@ extension TextView {
 
         switch event.clickCount {
         case 1:
+            // Single click, if control-shift we add a cursor
+            // if shift, we extend the selection to the click location
+            // else we set the cursor
             guard isEditable else {
                 super.mouseDown(with: event)
                 return
             }
             if event.modifierFlags.intersection(.deviceIndependentFlagsMask).isSuperset(of: [.control, .shift]) {
                 unmarkText()
                 selectionManager.addSelectedRange(NSRange(location: offset, length: 0))
+            } else if event.modifierFlags.intersection(.deviceIndependentFlagsMask).contains(.shift) {
+                unmarkText()
+                shiftClickExtendSelection(to: offset)
             } else {
                 selectionManager.setSelectedRange(NSRange(location: offset, length: 0))
                 unmarkTextIfNeeded()
             }
         case 2:
+            guard !event.modifierFlags.contains(.shift) else {
+                super.mouseDown(with: event)
+                return
+            }
             unmarkText()
             selectWord(nil)
         case 3:
+            guard !event.modifierFlags.contains(.shift) else {
+                super.mouseDown(with: event)
+                return
+            }
             unmarkText()
             selectLine(nil)
         default:
@@ -81,4 +95,31 @@ extension TextView {
             self.autoscroll(with: event)
         }
     }
+
+    /// Extends the current selection to the offset. Only used when the user shift-clicks a location in the document.
+    ///
+    /// If the offset is within the selection, trims the selection from the nearest edge (start or end) towards the
+    /// clicked offset.
+    /// Otherwise, extends the selection to the clicked offset.
+    ///
+    /// - Parameter offset: The offset clicked on.
+    fileprivate func shiftClickExtendSelection(to offset: Int) {
+        // Use the last added selection, this is behavior copied from Xcode.
+        guard var selectedRange = selectionManager.textSelections.last?.range else { return }
+        if selectedRange.contains(offset) {
+            if offset - selectedRange.location <= selectedRange.max - offset {
+                selectedRange.length -= offset - selectedRange.location
+                selectedRange.location = offset
+            } else {
+                selectedRange.length -= selectedRange.max - offset
+            }
+        } else {
+            selectedRange.formUnion(NSRange(
+                start: min(offset, selectedRange.location),
+                end: max(offset, selectedRange.max)
+            ))
+        }
+        selectionManager.setSelectedRange(selectedRange)
+        setNeedsDisplay()
+    }
 }

Sources/CodeEditTextView/TextView/TextView+Select.swift

@@ -54,10 +54,7 @@ extension TextView {
                 .findNextOccurrenceOfCharacter(in: characterSet.inverted, from: textSelection.range.max) else {
                 return nil
             }
-            return NSRange(
-                location: start,
-                length: end - start
-            )
+            return NSRange(start: start, end: end)
         }
         selectionManager.setSelectedRanges(newSelections)
         unmarkTextIfNeeded()