UIKit: Fix scroll view resizing behavior

Fixes the sizing logic in UIKit implementation of STTextView to correctly handle
text layout based on content size. Removes commented code in the AppKit version,
and improves the resizing logic in the UIKit version by properly calculating
content dimensions based on text layout manager's usage bounds, gutter width,
and scroll insets.

Author: krzyzanowskim

Sources/STTextViewAppKit/STTextView.swift

@@ -1220,36 +1220,6 @@ import AVFoundation
         }
 
         _configureTextContainerSize()
-
-        // add textContainerInset at some point
-        // size.width += textContainerInset.width * 2;
-        // size.height += textContainerInset.height * 2;
-
-        // if isVerticallyResizable {
-        //     // we should at least be the visible size if we're not in a clip view
-        //     // however the `size` may be bananas (estimated) and enlarge too much
-        //     // that going never going to shrink later.
-        //     // It is expected that vertically height going to grow and shring (that does not apply to horizontally)
-        //     //
-        //     // size.height = max(frame.size.height - verticalInsets, size.height)
-        // } else {
-        //     size.height = frame.size.height - verticalInsets
-        // }
-
-        // if we're in a clip view we should at be at least as big as the clip view
-        // if let clipView = scrollView?.contentView as? NSClipView {
-        //     let horizontalInsets = clipView.contentInsets.horizontalInsets
-        //     let verticalInsets = clipView.contentInsets.verticalInsets
-        //
-        //     if size.width < clipView.bounds.size.width - horizontalInsets {
-        //         size.width = clipView.bounds.size.width - horizontalInsets
-        //     }
-        //
-        //     if size.height < clipView.bounds.size.height - verticalInsets {
-        //         size.height = clipView.bounds.size.height - verticalInsets
-        //     }
-        //
-        // }
     }
 
     internal func layoutViewport() {

Sources/STTextViewUIKit/STTextView.swift

@@ -640,16 +640,6 @@ import STTextViewCommon
     }
 
     open override func sizeToFit() {
-        let gutterWidth = gutterView?.frame.width ?? 0
-        contentView.frame.origin.x = gutterWidth
-        contentView.frame.size.width = max(textLayoutManager.usageBoundsForTextContainer.size.width + textContainer.lineFragmentPadding, frame.width - gutterWidth)
-        contentView.frame.size.height = max(textLayoutManager.usageBoundsForTextContainer.size.height, frame.height)
-        contentSize = contentView.frame.size
-
-        super.sizeToFit()
-
-        _configureTextContainerSize()
-
         // Estimate `usageBoundsForTextContainer` size is based on performed layout.
         // If layout didn't happen for the whole document, it only cover
         // the fragment that is known. And even after ensureLayout for the whole document
@@ -668,7 +658,41 @@ import STTextViewCommon
         // Asking for the end location result in estimated `usageBoundsForTextContainer`
         // that eventually get right as more and more layout happen (when scrolling)
 
+        // Estimated text container size to layout document
         textLayoutManager.ensureLayout(for: NSTextRange(location: textLayoutManager.documentRange.endLocation))
+
+        super.sizeToFit()
+
+        let usageBoundsForTextContainer = textLayoutManager.usageBoundsForTextContainer
+        logger.debug("usageBoundsForTextContainer \(usageBoundsForTextContainer.debugDescription) \(#function)")
+
+        let gutterWidth = gutterView?.frame.width ?? 0
+        let verticalScrollInset = contentInset.top + contentInset.bottom
+        let visibleRectSize = self.bounds.size
+
+        let frameSize: CGSize
+        if isHorizontallyResizable {
+            // no-wrapping
+            frameSize = CGSize(
+                width: max(usageBoundsForTextContainer.size.width + gutterWidth + textContainer.lineFragmentPadding, visibleRectSize.width),
+                height: max(usageBoundsForTextContainer.size.height, visibleRectSize.height - verticalScrollInset)
+            )
+        } else {
+            // wrapping
+            frameSize = CGSize(
+                width: visibleRectSize.width - gutterWidth,
+                height: max(usageBoundsForTextContainer.size.height, visibleRectSize.height - verticalScrollInset)
+            )
+        }
+
+        if !frame.size.isAlmostEqual(to: frameSize) {
+            logger.debug("contentView.frame.size (\(frameSize.width), \(frameSize.height)) \(#function)")
+            self.contentView.frame.origin.x = gutterWidth
+            self.contentView.frame.size = frameSize
+            self.contentSize = frameSize
+        }
+
+        _configureTextContainerSize()
     }
 
     // Update textContainer width to match textview width if track textview width