Fix More Scrolling Edge Cases

Author: thecoolwinter

Sources/CodeEditSourceEditor/Controller/TextViewController.swift

@@ -339,6 +339,8 @@ public class TextViewController: NSViewController {
         styleGutterView()
 
         highlighter?.invalidate()
+        minimapView.updateContentViewHeight()
+        minimapView.updateDocumentVisibleViewPosition()
     }
 
     deinit {

Sources/CodeEditSourceEditor/Extensions/NSScrollView+percentScrolled.swift

@@ -8,11 +8,13 @@
 import AppKit
 
 extension NSScrollView {
+    /// The maximum `Y` value that can be scrolled to, as the origin of the `documentVisibleRect`.
     var documentMaxOriginY: CGFloat {
-        let totalHeight = (documentView?.frame.height ?? 0.0) + contentInsets.top
-        return totalHeight - (documentVisibleRect.height - contentInsets.top)
+        let totalHeight = (documentView?.frame.height ?? 0.0) + contentInsets.vertical
+        return totalHeight - documentVisibleRect.height
     }
 
+    /// The percent amount the scroll view has been scrolled. Measured as the available space that can be scrolled.
     var percentScrolled: CGFloat {
         let currentYPos = documentVisibleRect.origin.y + contentInsets.top
         return currentYPos / documentMaxOriginY

Sources/CodeEditSourceEditor/Minimap/MinimapView+DocumentVisibleView.swift

@@ -29,14 +29,23 @@ extension MinimapView {
         }
 
         let availableHeight = min(minimapHeight, containerHeight)
+        let editorScrollViewVisibleRect = (
+            editorScrollView.documentVisibleRect.height - editorScrollView.contentInsets.vertical
+        )
         let scrollPercentage = editorScrollView.percentScrolled
         guard scrollPercentage.isFinite else { return }
 
+        let multiplier = if minimapHeight < containerHeight {
+            editorScrollViewVisibleRect / textView.frame.height
+        } else {
+            editorToMinimapHeightRatio
+        }
+
         // Update Visible Pane, should scroll down slowly as the user scrolls the document, following a similar pace
         // as the vertical `NSScroller`.
-        // Visible pane's height   = scrollview visible height * (minimap line height / editor line height)
+        // Visible pane's height   = visible height * multiplier
         // Visible pane's position = (container height - visible pane height) * scrollPercentage
-        let visibleRectHeight = containerHeight * editorToMinimapHeightRatio
+        let visibleRectHeight = availableHeight * multiplier
         guard visibleRectHeight < 1e100 else { return }
 
         let availableContainerHeight = (availableHeight - visibleRectHeight)
@@ -54,14 +63,13 @@ extension MinimapView {
     }
 
     private func setScrollViewPosition(scrollPercentage: CGFloat) {
-        let topInsets = scrollView.contentInsets.top
-        let totalHeight = contentView.frame.height + topInsets
+        let totalHeight = contentView.frame.height + scrollView.contentInsets.vertical
+        let visibleHeight = scrollView.documentVisibleRect.height
+        let yPos = (totalHeight - visibleHeight) * scrollPercentage
         scrollView.contentView.scroll(
             to: NSPoint(
                 x: scrollView.contentView.frame.origin.x,
-                y: (
-                    scrollPercentage * (totalHeight - (scrollView.documentVisibleRect.height - topInsets))
-                ) - topInsets
+                y: yPos - scrollView.contentInsets.top
             )
         )
         scrollView.reflectScrolledClipView(scrollView.contentView)

Sources/CodeEditSourceEditor/Minimap/MinimapView+DragVisibleView.swift

@@ -29,9 +29,7 @@ extension MinimapView {
         // Minimum Y value is the top of the scroll view
         newScrollViewY = max(-editorScrollView.contentInsets.top, newScrollViewY)
         newScrollViewY = min( // Max y value needs to take into account the editor overscroll
-            editorScrollView.documentMaxOriginY
-            - editorScrollView.contentInsets.top
-            + editorScrollView.contentInsets.bottom,
+            editorScrollView.documentMaxOriginY - editorScrollView.contentInsets.top, // Relative to the content's top
             newScrollViewY
         )
 

Sources/CodeEditSourceEditor/Minimap/MinimapView.swift

@@ -85,6 +85,9 @@ public class MinimapView: FlippedNSView {
 
         self.contentView = MinimapContentView()
         contentView.translatesAutoresizingMaskIntoConstraints = false
+        contentView.wantsLayer = true
+        contentView.layer?.borderWidth = 1.0
+        contentView.layer?.borderColor = NSColor.blue.cgColor
 
         self.documentVisibleView = NSView()
         documentVisibleView.translatesAutoresizingMaskIntoConstraints = false
@@ -153,6 +156,7 @@ public class MinimapView: FlippedNSView {
             textView: textView,
             delegate: self
         )
+        selectionManager?.insertionPointColor = .clear
         contentView.textView = textView
         contentView.selectionManager = selectionManager
     }
@@ -226,9 +230,14 @@ public class MinimapView: FlippedNSView {
         fatalError("init(coder:) has not been implemented")
     }
 
+    deinit {
+        NotificationCenter.default.removeObserver(self)
+    }
+
     override public var visibleRect: NSRect {
         var rect = scrollView.documentVisibleRect
         rect.origin.y += scrollView.contentInsets.top
+        rect.size.height -= scrollView.contentInsets.vertical
         return rect.pixelAligned
     }
 
@@ -264,14 +273,15 @@ public class MinimapView: FlippedNSView {
     /// cached height.
     func updateContentViewHeight() {
         guard let estimatedContentHeight = layoutManager?.estimatedHeight(),
-              let overscrollAmount = textView?.overscrollAmount else {
+              let editorEstimatedHeight = textView?.layoutManager.estimatedHeight() else {
             return
         }
-        let overscroll = containerHeight * overscrollAmount * editorToMinimapHeightRatio
+        let overscrollAmount = textView?.overscrollAmount ?? 0.0
+        let overscroll = containerHeight * overscrollAmount * (estimatedContentHeight / editorEstimatedHeight)
         let height = estimatedContentHeight + overscroll
 
         // Only update a frame if needed
-        if contentView.frame.height != height {
+        if contentView.frame.height != height && height.isFinite && height < (textView?.frame.height ?? 0.0) {
             contentView.frame.size.height = height
         }
     }