Bug Report: Crash when Using STTextView Outside NSScrollView

[mredig]

In my project, I experienced a crash due to multiple constraint updates in a single pass (or something like that - it's been a couple days and I'm going off memory) when attempting to create an STTextView outside a scroll view.

In commit 639400ea6, I reproduced the issue with the following changes to ViewController.swift in the TextEdit sample:

//  Created by Marcin Krzyzanowski
//  https://github.com/krzyzanowskim/STTextView/blob/main/LICENSE.md

import AppKit
import STTextView
import SwiftUI

// import DummyPlugin

final class ViewController: NSViewController {
    private var textView: STTextView!

    private var completions: [Completion.Item] = []

    override func viewDidLoad() {
        super.viewDidLoad()

//        let scrollView = STTextView.scrollableTextView()
//        textView = scrollView.documentView as? STTextView
		textView = STTextView()
//        scrollView.translatesAutoresizingMaskIntoConstraints = false
//        scrollView.hasVerticalScroller = true
//        scrollView.drawsBackground = true

        let paragraph = NSParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
        paragraph.lineHeightMultiple = 1.2
        textView.typingAttributes[.paragraphStyle] = paragraph

//        textView.font = NSFont.monospacedSystemFont(ofSize: 0, weight: .regular)
        textView.string = try! String(contentsOf: Bundle.main.url(forResource: "content", withExtension: "txt")!)
        textView.isHorizontallyResizable = false // wrap
        textView.highlightSelectedLine = true
        textView.isIncrementalSearchingEnabled = true
        textView.showsInvisibleCharacters = false
        textView.delegate = self
		textView.isEditable = false
		textView.isSelectable = true

        // Plugins
        // textView.addPlugin(DummyPlugin())

        // Line numbers
//        let rulerView = STLineNumberRulerView(textView: textView)
//        rulerView.font = NSFont.monospacedSystemFont(ofSize: 0, weight: .regular)
//        rulerView.allowsMarkers = true
//        rulerView.highlightSelectedLine = true
//        scrollView.verticalRulerView = rulerView
//        scrollView.rulersVisible = true

//        view.addSubview(scrollView)
//        NSLayoutConstraint.activate([
//            scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
//            scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
//            scrollView.topAnchor.constraint(equalTo: view.topAnchor),
//            scrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
//        ])
		textView.translatesAutoresizingMaskIntoConstraints = false
		view.addSubview(textView)
		NSLayoutConstraint.activate([
			textView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
			textView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
			textView.topAnchor.constraint(equalTo: view.topAnchor),
			textView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
		])

        // Add attributes

        // add link to occurences of STTextView
        do {
            let str = textView.string
            var currentRange = str.startIndex..<str.endIndex
            while let ocurrenceRange = str.range(of: "STTextView", range: currentRange) {
                textView.addAttributes([.link: URL(string: "https://swift.best")! as NSURL], range: NSRange(ocurrenceRange, in: str))
                currentRange = ocurrenceRange.upperBound..<currentRange.upperBound
            }
        }

        do {
            let str = textView.string
            var currentRange = str.startIndex..<str.endIndex
            while let ocurrenceRange = str.range(of: "vim", range: currentRange) {
                textView.addAttributes([.cursor: NSCursor.operationNotAllowed], range: NSRange(ocurrenceRange, in: str))
                currentRange = ocurrenceRange.upperBound..<currentRange.upperBound
            }
        }
//  Insert attachment image using NSTextAttachmentCell
//
//         do {
//             let attachment = NSTextAttachment()
//             let img = NSImage(systemSymbolName: "figure.walk", accessibilityDescription: nil)
//             let cell = NSTextAttachmentCell(imageCell: img)
//             attachment.attachmentCell = cell
//             let attachmentString = NSAttributedString(attachment: attachment)
//             textView.insertText(attachmentString, replacementRange: NSRange(location: 20, length: 0))
//         }
//

//  Insert attachment image using NSTextAttachmentViewProvider
        do {
            let attachment = MyTextAttachment()
            let attachmentString = NSAttributedString(attachment: attachment)
            textView.insertText(attachmentString, replacementRange: NSRange(location: 30, length: 0))
        }


        // Emphasize first line
        textView.addAttributes(
            [
                .foregroundColor: NSColor.controlAccentColor,
                .font: NSFont.monospacedSystemFont(ofSize: NSFont.systemFontSize * 1.2, weight: .bold)
            ],
            range: NSRange(textView.string.linesRanges().first!, in: textView.string)
        )

        updateCompletionsInBackground()
    }

// ... the rest is unchanged

I was hoping to find time to contribute back to the project and dig into this deeper, but it's looking grim that I'll be able to do so. Hopefully someone will be able to find a fix!

[krzyzanowskim]

frankly, I did not foresee using it outside scrollview. there are features that assume enclosing scrollview exists (like gutter view, or text finder). I think the easiest way to workaround is to continue use NSScrollView as a container, but setup as not scrollable - is it possible way to use it?

[Mx-Iris]

Similarly NSTableView and NSTextView are assumed to be embedded in a scrolling view, which gives a lot of weird errors when no scrolling view exists.

[krzyzanowskim]

right. I'm not sure if it is worth to fight that battle after all. but if anyone willing to git it a shot, I'm happy look at it!