Improve appearance of lists when converting from HTML

Closes #434
This commit is contained in:
Shadowfacts 2023-09-27 17:35:36 -04:00
parent 3ba1a00257
commit 0948371f83
1 changed files with 42 additions and 20 deletions

View File

@ -37,7 +37,12 @@ struct HTMLConverter {
mutAttrString.trimTrailingCharactersInSet(.whitespacesAndNewlines) mutAttrString.trimTrailingCharactersInSet(.whitespacesAndNewlines)
mutAttrString.collapseWhitespace() mutAttrString.collapseWhitespace()
mutAttrString.addAttribute(.paragraphStyle, value: paragraphStyle, range: mutAttrString.fullRange) // Wait until the end and then fill in the unset paragraph styles, to avoid clobbering the list style.
mutAttrString.enumerateAttribute(.paragraphStyle, in: mutAttrString.fullRange, options: .longestEffectiveRangeNotRequired) { value, range, stop in
if value == nil {
mutAttrString.addAttribute(.paragraphStyle, value: paragraphStyle, range: range)
}
}
return mutAttrString return mutAttrString
} else { } else {
@ -56,6 +61,10 @@ struct HTMLConverter {
} }
return NSAttributedString(string: text, attributes: [.font: font, .foregroundColor: color]) return NSAttributedString(string: text, attributes: [.font: font, .foregroundColor: color])
case let node as Element: case let node as Element:
if node.tagName() == "ol" || node.tagName() == "ul" {
return attributedTextForList(node, usePreformattedText: usePreformattedText)
}
let attributed = NSMutableAttributedString(string: "", attributes: [.font: font, .foregroundColor: color]) let attributed = NSMutableAttributedString(string: "", attributes: [.font: font, .foregroundColor: color])
for child in node.getChildNodes() { for child in node.getChildNodes() {
var appendEllipsis = false var appendEllipsis = false
@ -115,25 +124,6 @@ struct HTMLConverter {
case "pre": case "pre":
attributed.append(NSAttributedString(string: "\n\n")) attributed.append(NSAttributedString(string: "\n\n"))
attributed.addAttribute(.font, value: monospaceFont, range: attributed.fullRange) attributed.addAttribute(.font, value: monospaceFont, range: attributed.fullRange)
case "ol", "ul":
attributed.append(NSAttributedString(string: "\n\n"))
attributed.trimLeadingCharactersInSet(.whitespacesAndNewlines)
case "li":
let parentEl = node.parent()!
let parentTag = parentEl.tagName()
let bullet: NSAttributedString
if parentTag == "ol" {
let index = (try? node.elementSiblingIndex()) ?? 0
// we use the monospace digit font so that the periods of all the list items line up
// TODO: this probably breaks with dynamic type
bullet = NSAttributedString(string: "\(index + 1).\t", attributes: [.font: monospaceFont, .foregroundColor: color])
} else if parentTag == "ul" {
bullet = NSAttributedString(string: "\u{2022}\t", attributes: [.font: font, .foregroundColor: color])
} else {
bullet = NSAttributedString()
}
attributed.insert(bullet, at: 0)
attributed.append(NSAttributedString(string: "\n", attributes: [.font: font]))
default: default:
break break
} }
@ -144,5 +134,37 @@ struct HTMLConverter {
} }
} }
private func attributedTextForList(_ element: Element, usePreformattedText: Bool) -> NSAttributedString {
let list = element.tagName() == "ol" ? OrderedNumberTextList(markerFormat: .decimal, options: 0) : NSTextList(markerFormat: .disc, options: 0)
let paragraphStyle = paragraphStyle.mutableCopy() as! NSMutableParagraphStyle
// I don't like that I can't just use paragraphStyle.textLists, because it makes the list markers
// not use the monospace digit font (it seems to just use whatever font attribute is set for the whole thing),
// and it doesn't right align the list markers.
// Unfortunately, doing it manually means the list markers are incldued in the selectable text.
paragraphStyle.headIndent = 32
paragraphStyle.firstLineHeadIndent = 0
// Use 2 tab stops, one for the list marker, the second for the content.
paragraphStyle.tabStops = [NSTextTab(textAlignment: .right, location: 28), NSTextTab(textAlignment: .natural, location: 32)]
let str = NSMutableAttributedString(string: "")
var item = 1
for child in element.children() where child.tagName() == "li" {
if let childStr = attributedTextForHTMLNode(child, usePreformattedText: usePreformattedText) {
str.append(NSAttributedString(string: "\t\(list.marker(forItemNumber: item))\t", attributes: [
.font: UIFontMetrics(forTextStyle: .body).scaledFont(for: .monospacedDigitSystemFont(ofSize: 17, weight: .regular)),
]))
str.append(childStr)
str.append(NSAttributedString(string: "\n"))
item += 1
}
}
str.addAttribute(.paragraphStyle, value: paragraphStyle, range: str.fullRange)
return str
}
} }
private class OrderedNumberTextList: NSTextList {
override func marker(forItemNumber itemNumber: Int) -> String {
"\(super.marker(forItemNumber: itemNumber))."
}
}