Add scroll to visible range

- Scrolls to the specified range and centers it

Author: tom-ludwig

Sources/CodeEditTextView/EmphasizeAPI/EmphasizeAPI.swift

@@ -11,8 +11,8 @@ import AppKit
 public class EmphasizeAPI {
     // MARK: - Properties
 
-    private var highlightedRanges: [EmphasizedRange] = []
-    private var emphasizedRangeIndex: Int?
+    public private(set) var emphasizedRanges: [EmphasizedRange] = []
+    public private(set) var emphasizedRangeIndex: Int?
     private let activeColor: NSColor = NSColor(hex: 0xFFFB00, alpha: 1)
     private let inactiveColor: NSColor = NSColor.lightGray.withAlphaComponent(0.4)
 
@@ -23,8 +23,8 @@ public class EmphasizeAPI {
     }
 
     // MARK: - Structs
-    private struct EmphasizedRange {
-        var range: NSRange
+    public struct EmphasizedRange {
+        public var range: NSRange
         var layer: CAShapeLayer
     }
 
@@ -61,18 +61,18 @@ public class EmphasizeAPI {
         let layer = createEmphasizeLayer(shapePath: shapePath, active: active)
         textView?.layer?.insertSublayer(layer, at: 1)
 
-        highlightedRanges.append(EmphasizedRange(range: range, layer: layer))
+        emphasizedRanges.append(EmphasizedRange(range: range, layer: layer))
     }
 
     /// Removes the highlight for a specific range.
     /// - Parameter range: The range to remove.
     public func removeHighlightForRange(_ range: NSRange) {
-        guard let index = highlightedRanges.firstIndex(where: { $0.range == range }) else { return }
+        guard let index = emphasizedRanges.firstIndex(where: { $0.range == range }) else { return }
 
-        let removedLayer = highlightedRanges[index].layer
+        let removedLayer = emphasizedRanges[index].layer
         removedLayer.removeFromSuperlayer()
 
-        highlightedRanges.remove(at: index)
+        emphasizedRanges.remove(at: index)
 
         // Adjust the active highlight index
         if let currentIndex = emphasizedRangeIndex {
@@ -105,8 +105,8 @@ public class EmphasizeAPI {
 
     /// Removes all emphasised ranges.
     public func removeEmphasizeLayers() {
-        highlightedRanges.forEach { $0.layer.removeFromSuperlayer() }
-        highlightedRanges.removeAll()
+        emphasizedRanges.forEach { $0.layer.removeFromSuperlayer() }
+        emphasizedRanges.removeAll()
         emphasizedRangeIndex = nil
     }
 
@@ -147,29 +147,29 @@ public class EmphasizeAPI {
     /// - Returns: An optional `NSRange` representing the newly active highlight, colored in the active color.
     ///            Returns `nil` if no change occurred (e.g., if there are no highlighted ranges).
     private func shiftActiveHighlight(amount: Int) -> NSRange? {
-        guard !highlightedRanges.isEmpty else { return nil }
+        guard !emphasizedRanges.isEmpty else { return nil }
 
         var currentIndex = emphasizedRangeIndex ?? -1
-        currentIndex = (currentIndex + amount + highlightedRanges.count) % highlightedRanges.count
+        currentIndex = (currentIndex + amount + emphasizedRanges.count) % emphasizedRanges.count
 
-        guard currentIndex < highlightedRanges.count else { return nil }
+        guard currentIndex < emphasizedRanges.count else { return nil }
 
         // Reset the previously active layer
         if let currentIndex = emphasizedRangeIndex {
-            let previousLayer = highlightedRanges[currentIndex].layer
+            let previousLayer = emphasizedRanges[currentIndex].layer
             previousLayer.fillColor = inactiveColor.cgColor
             previousLayer.shadowOpacity = 0.0
         }
 
         // Set the new active layer
-        let newLayer = highlightedRanges[currentIndex].layer
+        let newLayer = emphasizedRanges[currentIndex].layer
         newLayer.fillColor = activeColor.cgColor
         newLayer.shadowOpacity = 0.3
 
         applyPopAnimation(to: newLayer)
         emphasizedRangeIndex = currentIndex
 
-        return highlightedRanges[currentIndex].range
+        return emphasizedRanges[currentIndex].range
     }
 
     private func applyPopAnimation(to layer: CALayer) {

Sources/CodeEditTextView/TextView/TextView+ScrollToVisible.swift

@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import AppKit
 
 extension TextView {
     fileprivate typealias Direction = TextSelectionManager.Direction
@@ -36,6 +37,53 @@ extension TextView {
         }
     }
 
+    public func scrollToRange(_ range: NSRange) {
+        guard let scrollView else { return }
+
+        guard let boundingRect = layoutManager.rectForOffset(range.location) else { return }
+
+        // Check if the range is already visible
+        if visibleRect.contains(boundingRect) {
+            return // No scrolling needed
+        }
+
+        // Calculate the target offset to center the range in the view
+        let targetOffset = CGPoint(
+            x: max(boundingRect.midX - visibleRect.width / 2, 0),
+            y: max(boundingRect.midY - visibleRect.height / 2, 0)
+        )
+
+        var lastFrame: CGRect = .zero
+
+        // Set a timeout to avoid a infinite loop
+        let timeout: TimeInterval = 0.5
+        let startTime = Date()
+
+        // Adjust layout until stable
+        while let newRect = layoutManager.rectForOffset(range.location),
+              lastFrame != newRect,
+              Date().timeIntervalSince(startTime) < timeout {
+            lastFrame = newRect
+            layoutManager.layoutLines()
+            selectionManager.updateSelectionViews()
+            selectionManager.drawSelections(in: visibleRect)
+        }
+
+        // Scroll to make the range appear in the middle of the screen
+        if lastFrame != .zero {
+            let animated = false // feature flag
+            if animated {
+                NSAnimationContext.runAnimationGroup { context in
+                    context.duration = 0.15 // Adjust duration as needed
+                    context.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
+                    scrollView.contentView.animator().setBoundsOrigin(targetOffset)
+                }
+            } else {
+                scrollView.contentView.scroll(to: targetOffset)
+            }
+        }
+    }
+
     /// Get the selection that should be scrolled to visible for the current text selection.
     /// - Returns: The the selection to scroll to.
     private func getSelection() -> TextSelection? {