Added scroll past end behavior

Author: FastestMolasses

Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager.swift

@@ -221,7 +221,6 @@ public class TextSelectionManager: NSObject {
             .getLine(atOffset: range.location - (selectedLine.range.location))?
             .height
         ?? layoutManager?.estimateLineHeight()
-
     }
 
     /// Removes all cursor views and stops the cursor blink timer.

Sources/CodeEditTextView/TextView/TextView+Insert.swift

@@ -6,6 +6,7 @@
 //
 
 import AppKit
+import TextStory
 
 extension TextView {
     override public func insertNewline(_ sender: Any?) {

Sources/CodeEditTextView/TextView/TextView+Layout.swift

@@ -64,7 +64,9 @@ extension TextView {
     public func updateFrameIfNeeded() -> Bool {
         var availableSize = scrollView?.contentSize ?? .zero
         availableSize.height -= (scrollView?.contentInsets.top ?? 0) + (scrollView?.contentInsets.bottom ?? 0)
-        let newHeight = max(layoutManager.estimatedHeight(), availableSize.height)
+
+        let extraHeight = scrollPastEnd ? availableSize.height * scrollPastEndAmount : 0
+        let newHeight = max(layoutManager.estimatedHeight() + extraHeight, availableSize.height)
         let newWidth = layoutManager.estimatedWidth()
 
         var didUpdate = false

Sources/CodeEditTextView/TextView/TextView.swift

@@ -107,6 +107,22 @@ public class TextView: NSView, NSTextContent {
         }
     }
 
+    /// Determines if the text view should allow scrolling past the end of the document
+    public var scrollPastEnd: Bool = true {
+        didSet {
+            updateFrameIfNeeded()
+        }
+    }
+
+    /// The amount of extra space to add when scrolling past end is enabled, as a percentage of the viewport height
+    public var scrollPastEndAmount: CGFloat = 0.5 {
+        didSet {
+            if scrollPastEnd {
+                updateFrameIfNeeded()
+            }
+        }
+    }
+
     /// Whether or not the editor should wrap lines
     public var wrapLines: Bool {
         get {