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Update TextView
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@nicklockwood
nicklockwood committed Feb 3, 2024
1 parent 393d928 commit cfc95b2
Showing 1 changed file with 95 additions and 7 deletions.
102 changes: 95 additions & 7 deletions Viewer/iOS/TextView.swift
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@ class TextView: UIScrollView {
private let gutterView = LineNumberView()
private var lineCount = 0
private var lastSpaceIndex: Int?
private var updateLock: Int = 0
fileprivate var currentAction: TextAction?
let textView: UITextView

Expand Down Expand Up @@ -51,6 +52,16 @@ class TextView: UIScrollView {

var indentNewLines: Bool = true

var showInvisibleCharacters: Bool = false {
didSet {
layoutManager.invalidateDisplay(forCharacterRange: NSRange(
location: 0,
length: (textView.text as NSString).length
))
setNeedsLayout()
}
}

var spellCheckingType: UITextSpellCheckingType = .no {
didSet {
textView.spellCheckingType = spellCheckingType
Expand All @@ -59,6 +70,10 @@ class TextView: UIScrollView {
}
}

var disableAutocorrection: Bool = true {
didSet { updateAutocorrectOptions() }
}

var disableDoubleSpacePeriodShortcut: Bool = false

var text: String {
Expand Down Expand Up @@ -137,12 +152,10 @@ class TextView: UIScrollView {
textView.showsVerticalScrollIndicator = true
textView.alwaysBounceVertical = true
textView.alwaysBounceHorizontal = false
#if os(iOS)
#if !os(visionOS)
textView.keyboardDismissMode = .interactive
#endif
textView.autocorrectionType = .no
textView.spellCheckingType = spellCheckingType
textView.autocapitalizationType = .none
textView.smartQuotesType = .no
textView.smartDashesType = .no
textView.smartInsertDeleteType = .no
Expand All @@ -151,15 +164,25 @@ class TextView: UIScrollView {
textView.delegate = self
textView.textDragDelegate = self
textView.textDropDelegate = self
updateAutocorrectOptions()
addSubview(textView)
gutterView.font = UIFontMetrics.default.scaledFont(for: font)
gutterView.backgroundColor = .secondarySystemBackground
gutterView.backgroundColor = textView.backgroundColor
gutterView.contentMode = .right
gutterView.isHidden = true
addSubview(gutterView)
avoidKeyboard()
updateLineCount()
updateInsets()

if #available(iOS 16.0, *) {
textView.isFindInteractionEnabled = true
}
}

private func updateAutocorrectOptions() {
textView.autocorrectionType = .no // disableAutocorrection ? .no : .default
textView.autocapitalizationType = disableAutocorrection ? .none : .sentences
}

private var previousSize: CGSize = .zero
Expand Down Expand Up @@ -242,6 +265,8 @@ private extension TextView {
bottom: _contentInset.bottom + safeAreaInsets.bottom,
right: _contentInset.right + safeAreaInsets.right
)
layoutManager.font = UIFontMetrics.default.scaledFont(for: font)
layoutManager.drawInvisibleChars = showInvisibleCharacters
if showLineNumbers {
layoutManager.gutterWidth = ceil(String(lineCount).size(withAttributes: [
.font: UIFontMetrics.default.scaledFont(for: font),
Expand Down Expand Up @@ -365,9 +390,10 @@ private final class _UITextView: UITextView {
let line = textStorage.mutableString.substring(
with: NSRange(location: lineStart, length: offset - lineStart)
)
rect.origin.x = max(rect.origin.x, (line as NSString).size(
let x = max(rect.origin.x, (line as NSString).size(
withAttributes: font.map { [.font: $0] } ?? [:]
).width)
rect.origin.x = x.isFinite ? x : 0
return rect
}
}
Expand Down Expand Up @@ -469,7 +495,9 @@ extension TextView: UITextViewDelegate, UIScrollViewDelegate {
} else {
textView.textStorage.mutableString.replaceCharacters(in: range, with: text)
}
updateLock += 1
textView.selectedRange = NSRange(location: newRange.upperBound, length: 0)
updateLock -= 1
if showLineNumbers {
updateLineCount(oldText: oldText, newText: text)
}
Expand Down Expand Up @@ -515,6 +543,9 @@ extension TextView: UITextViewDelegate, UIScrollViewDelegate {
shouldChangeTextIn range: NSRange,
replacementText text: String
) -> Bool {
if updateLock > 0 {
return false
}
lastSpaceIndex = nil
guard undoManager?.isUndoing != true,
undoManager?.isRedoing != true
Expand Down Expand Up @@ -641,6 +672,18 @@ extension TextView: UITextDragDelegate, UITextDropDelegate {
}

extension TextView: NSLayoutManagerDelegate {
func layoutManager(
_ layoutManager: NSLayoutManager,
shouldUse action: NSLayoutManager.ControlCharacterAction,
forControlCharacterAt characterIndex: Int
) -> NSLayoutManager.ControlCharacterAction {
if action.contains(.lineBreak) {
let glyphIndex = layoutManager.glyphIndexForCharacter(at: characterIndex)
layoutManager.setNotShownAttribute(false, forGlyphAt: glyphIndex)
}
return action
}

func layoutManager(_: NSLayoutManager, didCompleteLayoutFor _: NSTextContainer?,
atEnd _: Bool)
{
Expand Down Expand Up @@ -712,9 +755,11 @@ private class LayoutManager: NSLayoutManager {
private var lastParaLocation: Int = 0
private var lastParaNumber: Int = 0

var font: UIFont?
var gutterWidth: CGFloat = 0
private(set) var indexRects: [Int: CGRect] = [:]
private var indexRectsNeedUpdate: Bool = false
var drawInvisibleChars = false

func invalidateIndexRects() {
indexRectsNeedUpdate = true
Expand Down Expand Up @@ -751,6 +796,10 @@ private class LayoutManager: NSLayoutManager {
var gutterRect: CGRect = .zero
var paraNumber = 0
let text = textStorage?.mutableString ?? ""
let atts: [NSAttributedString.Key: Any] = [
.font: font ?? .preferredFont(forTextStyle: .body),
.foregroundColor: UIColor.tertiaryLabel,
]

if indexRectsNeedUpdate {
indexRects.removeAll()
Expand All @@ -759,13 +808,14 @@ private class LayoutManager: NSLayoutManager {

enumerateLineFragments(
forGlyphRange: glyphsToShow
) { rect, _, _, glyphRange, _ in
) { rect, _, textContainer, glyphRange, _ in
let charRange = self.characterRange(
forGlyphRange: glyphRange,
actualGlyphRange: nil
)
let paraRange = text.paragraphRange(for: charRange)

// Calculate line number offsets
let paraRange = text.paragraphRange(for: charRange)
if charRange.location == paraRange.location {
paraNumber = self.paraNumber(for: charRange, in: text)
gutterRect = CGRect(
Expand All @@ -776,6 +826,44 @@ private class LayoutManager: NSLayoutManager {
)
self.indexRects[paraNumber + 1] = gutterRect
}

// Draw invisible characters
if self.drawInvisibleChars {
text.enumerateSubstrings(
in: charRange,
options: .byComposedCharacterSequences
) { string, range, _, _ in
let symbol: String
switch string {
case "\t":
symbol = "\u{21E5}"
case " ":
symbol = "\u{00B7}" // "\u{2423}"
case let char? where char.first?.isNewline == true:
symbol = "\u{00B6}"
case let string:
guard let char = string?.unicodeScalars.first,
CharacterSet.controlCharacters.contains(char) ||
CharacterSet.whitespaces.contains(char)
else {
return
}
symbol = "█" // "\u{00B7}"
}
let characterRect = self.boundingRect(
forGlyphRange: range,
in: textContainer
)
guard characterRect.origin.x > 0 else {
// Workaround for spurious \n on last line
return
}
symbol.draw(
in: characterRect.offsetBy(dx: origin.x, dy: origin.y),
withAttributes: atts
)
}
}
}

// TODO: can this ever happen?
Expand Down

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