Collapse whitespace according to CSS spec after converting HTML to

attributed string

Fixes #27
This commit is contained in:
Shadowfacts 2020-01-21 21:21:23 -05:00
parent cece8825ad
commit e9db3fa0ac
Signed by untrusted user: shadowfacts
GPG Key ID: 94A5AB95422746E5
4 changed files with 125 additions and 7 deletions

View File

@ -104,6 +104,7 @@
D62D2422217AA7E1005076CC /* UserActivityManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = D62D2421217AA7E1005076CC /* UserActivityManager.swift */; };
D62D2424217ABF3F005076CC /* NSUserActivity+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = D62D2423217ABF3F005076CC /* NSUserActivity+Extensions.swift */; };
D62D2426217ABF63005076CC /* UserActivityType.swift in Sources */ = {isa = PBXBuildFile; fileRef = D62D2425217ABF63005076CC /* UserActivityType.swift */; };
D62FF04823D7CDD700909D6E /* AttributedStringHelperTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D62FF04723D7CDD700909D6E /* AttributedStringHelperTests.swift */; };
D6333B372137838300CE884A /* AttributedString+Helpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6333B362137838300CE884A /* AttributedString+Helpers.swift */; };
D6333B772138D94E00CE884A /* ComposeMediaView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6333B762138D94E00CE884A /* ComposeMediaView.swift */; };
D6333B792139AEFD00CE884A /* Date+TimeAgo.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6333B782139AEFD00CE884A /* Date+TimeAgo.swift */; };
@ -376,6 +377,7 @@
D62D2421217AA7E1005076CC /* UserActivityManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserActivityManager.swift; sourceTree = "<group>"; };
D62D2423217ABF3F005076CC /* NSUserActivity+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NSUserActivity+Extensions.swift"; sourceTree = "<group>"; };
D62D2425217ABF63005076CC /* UserActivityType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserActivityType.swift; sourceTree = "<group>"; };
D62FF04723D7CDD700909D6E /* AttributedStringHelperTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AttributedStringHelperTests.swift; sourceTree = "<group>"; };
D6333B362137838300CE884A /* AttributedString+Helpers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AttributedString+Helpers.swift"; sourceTree = "<group>"; };
D6333B762138D94E00CE884A /* ComposeMediaView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ComposeMediaView.swift; sourceTree = "<group>"; };
D6333B782139AEFD00CE884A /* Date+TimeAgo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Date+TimeAgo.swift"; sourceTree = "<group>"; };
@ -1206,6 +1208,7 @@
isa = PBXGroup;
children = (
D6D4DDE4212518A200E1C4BB /* TuskerTests.swift */,
D62FF04723D7CDD700909D6E /* AttributedStringHelperTests.swift */,
D6D4DDE6212518A200E1C4BB /* Info.plist */,
);
path = TuskerTests;
@ -1743,6 +1746,7 @@
isa = PBXSourcesBuildPhase;
buildActionMask = 2147483647;
files = (
D62FF04823D7CDD700909D6E /* AttributedStringHelperTests.swift in Sources */,
D6D4DDE5212518A200E1C4BB /* TuskerTests.swift in Sources */,
);
runOnlyForDeploymentPostprocessing = 0;

View File

@ -8,28 +8,95 @@
import Foundation
extension NSMutableAttributedString {
private let ASCII_NEWLINE: unichar = 10
private let ASCII_SPACE: unichar = 32
extension NSAttributedString {
var fullRange: NSRange {
return NSRange(location: 0, length: self.length)
}
/// Creates a new string with the whitespace collapsed according to the CSS Text Module Level 3 rules.
/// See https://www.w3.org/TR/css-text-3/#white-space-phase-1
func collapsingWhitespace() -> NSAttributedString {
let mut = NSMutableAttributedString(attributedString: self)
mut.collapseWhitespace()
return mut
}
}
extension NSMutableAttributedString {
func trimLeadingCharactersInSet(_ charSet: CharacterSet) {
var range = (string as NSString).rangeOfCharacter(from: charSet)
while range.length != 0 && range.location == 0 {
replaceCharacters(in: range, with: "")
range = (string as NSString).rangeOfCharacter(from: charSet)
}
}
func trimTrailingCharactersInSet(_ charSet: CharacterSet) {
var range = (string as NSString).rangeOfCharacter(from: charSet, options: .backwards)
while range.length != 0 && range.length + range.location == length {
replaceCharacters(in: range, with: "")
range = (string as NSString).rangeOfCharacter(from: charSet, options: .backwards)
}
}
/// Collapses whitespace in this string according to the CSS Text Module Level 3 rules.
/// See https://www.w3.org/TR/css-text-3/#white-space-phase-1
func collapseWhitespace() {
let str = self.mutableString
var i = 0
while i < str.length {
if str.character(at: i) == ASCII_NEWLINE {
var j: Int
if i > 0 {
// scan backwards to find beginning of space characters preceeding newline
j = i - 1
while j >= 0 {
if str.character(at: j) != ASCII_SPACE {
break
}
j -= 1
}
// add one after loop completes because start of range is _inclusive_
j += 1
} else {
j = 0
}
var k: Int
if i < str.length - 1 {
// scan forwards to find end of space characters following newline
k = i + 1
while k < str.length {
if str.character(at: k) != ASCII_SPACE {
break
}
k += 1
}
// don't need to subtract one before breaking out of loop, because end of range is _exclusive_
} else {
// range end is _exclusive_, so use whole string length that way last character is included
k = str.length
}
// if there's only one character to be replaced, that means we'd be replacing the newline with a newline, so don't bother
if k - j > 1 {
str.replaceCharacters(in: NSRange(location: j, length: k - j), with: "\n")
// continue scanning through the string starting after the newline we just inserted
i = j
}
}
i += 1
}
}
}

View File

@ -109,11 +109,12 @@ class ContentTextView: LinkTextView {
let attributedText = attributedTextForHTMLNode(body)
let mutAttrString = NSMutableAttributedString(attributedString: attributedText)
mutAttrString.trimTrailingCharactersInSet(.whitespacesAndNewlines)
mutAttrString.collapseWhitespace()
self.attributedText = mutAttrString
}
func attributedTextForHTMLNode(_ node: Node, usePreformattedText: Bool = false) -> NSAttributedString {
private func attributedTextForHTMLNode(_ node: Node, usePreformattedText: Bool = false) -> NSAttributedString {
switch node {
case let node as TextNode:
let text: String

View File

@ -0,0 +1,46 @@
//
// AttributedStringHelperTests.swift
// TuskerTests
//
// Created by Shadowfacts on 1/21/20.
// Copyright © 2020 Shadowfacts. All rights reserved.
//
import XCTest
@testable import Tusker
class AttributedStringHelperTests: XCTestCase {
override func setUp() {
}
override func tearDown() {
}
func testCollapsingWhitespace() {
var str = NSAttributedString(string: "test 1\n")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "test 1\n"))
str = NSAttributedString(string: "test 2 \n")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "test 2\n"))
str = NSAttributedString(string: "test 3\n ")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "test 3\n"))
str = NSAttributedString(string: "test 4 \n ")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "test 4\n"))
str = NSAttributedString(string: "test 5 \n blah")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "test 5\nblah"))
str = NSAttributedString(string: "\ntest 6")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "\ntest 6"))
str = NSAttributedString(string: " \ntest 7")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "\ntest 7"))
str = NSAttributedString(string: " \n test 8")
XCTAssertEqual(str.collapsingWhitespace(), NSAttributedString(string: "\ntest 8"))
}
}