I'm replacing the selected text in a textView with the new one. To accomplish this, I'm using this code based on this answer of beyowulf. All works well, the replaced text becomes selected, the problem arises when in the text there is one ore more special characters (like emoji etc). In this case the selected text misses one ore more characters at the end of the selection.
mainTextField.replaceRange((theRange), withText: newStr) // replace old text with the new one
selectNewText(theRange, newStr: newStr) // select the new text
func selectNewText(theRange: UITextRange, newStr: String) {
let newStrLength = newStr.characters.count // let's see how long is the string
mainTextField.selectedTextRange = mainTextField.textRangeFromPosition(theRange.start, toPosition: mainTextField.positionFromPosition(theRange.start, offset: newStrLength)!)
mainTextField.becomeFirstResponder()
}
OK, after I read the answers and comments to this question, I fixed this problem by replacing this statement (which returns the "human-perceptible" number of characters):
let newStrLength = newStr.characters.count
With this one:
let newStrLength = newStr.utf16.count
PS
By the way, here is some test I done with different implementations:
let str = "Abc😬"
let count = str.characters.count
print(count) // 4
let count2 = str.utf16.count
print(count2) // 5
let count3 = str.utf8.count
print(count3) // 7
Related
#IBAction func generateBtn(sender: UIButton) {
let strt = UInt32(strtNum.text!)
let end = UInt32(endNum.text!)
let ttlNums = Int(amtNums.text!)
let x = RandomNum()
var z = 0
while z<ttlNums{
let y = x.rndNumGen(strt!, end: end!)
z += 1
var h = [String]()
h.append(String(y))
let display:String = h.joinWithSeparator(", ")
winningNums.text = display
print (display)
}
}
I don't know what is wrong with this code. I am trying to put the string display into the label and it prints out the last number from the random number generator. When i print it to the console it shows all of the random numbers.
The primary issue here is that your array is created fresh in every loop iteration, and your label is being set in every loop iteration. That means that the array will only ever contain the element made in that iteration, after which it's reset to a new array, and a new element is added. The array needs to be initialized once at the start, and have elements added to it repeatedly in the loop, then put into the label once at the end.
#IBAction func generateBtn(sender: UIButton) {
guard let startText = strtNum.text, let start = UInt32(startText),
let endText = endNum.text, let end = UInt32(endText),
let ttlText = amtNums.text, let ttlNums = UInt32(ttlText) else {
//one of these is nil, handle it gracefully here
return
}
let randomGenerator = RandomNum()
var h = [String]()
h.reserveCapacity(ttlNums)
for _ in 0..<ttlNums {
let randomNum = randomGenerator.rndNumGen(start, end: end)
h.append(String(RandomNum))
}
let display = h.joinWithSeparator(", ")
winningNums.text = display
print(display)
}
I've made a few other changes to bring this code in line with Swift best practices and conventions:
Don't force unwrap. Use an if let or guard let binding to safely handle nil values.
Give your variables meaningful names. Avoid single-letter names except in specific instances.
Don't put spaces beside a function/method name and the proceeding brackets.
Don't use a while loop to iterate over a known range. Instead, use a for in loop.
Dn't type in t3xtspk, it mks ur code look lik an angsty teenagr wrote it. Autocomplete will finish off words for you, so you barely end up typing anyway. Make it easy and readable.
I would suggest you make a few changes yourself:
Rename generateBtn. Functions/methods DO things, they're actions. They should be named with verbs, or verb phrases. Perhaps try something like displayRandomArray.
Refactor the random array generation into its own method.
Rename RandomNum. By the looks of it, it's not a number at all, it's a random number generator. Perhaps try RandomNumberGenerator
Rename h.
Add code to deal with what happens when the .text is nil, or what happens when it contains a string that isn't a UInt32 (thus causing the UInt32 initializer to fail and return nil)
I have a function that finds the current word a user has selected in a UITextView. However, if I call this function when an emoji is in the UITextView.text property, I see a crash. I believe this is because of the different character counts in String vs NSString.
How do I properly convert this?
func currentWord() -> String {
let cursorPosition = selectedRange.location
let separationCharacters = NSCharacterSet(charactersInString: " ")
// crash occurs here
let beginRange = Range(text.startIndex.advancedBy(0) ..< text.startIndex.advancedBy(cursorPosition))
let endRange = Range(text.startIndex.advancedBy(cursorPosition) ..< text.startIndex.advancedBy(text.characters.count))
let beginPhrase = text.substringWithRange(beginRange)
let endPhrase = text.substringWithRange(endRange)
let beginWords = beginPhrase.componentsSeparatedByCharactersInSet(separationCharacters)
let endWords = endPhrase.componentsSeparatedByCharactersInSet(separationCharacters)
return beginWords.last! + endWords.first!
}
I believe this is because of the different character counts in String vs NSString
You're right about that. You are shifting back and forth between using NSRange (Cocoa) and Range (Swift) — and they work differently. And NSString (Cocoa) and String (Swift) have different ideas of where the character boundaries are. You need to be consistent.
Once you've used selectedRange in the first line, you are in the Cocoa world of NSRange. You need to stay consistently in the Cocoa world. Don't use any Swift Ranges! Don't use any Swift characters!
Form your beginRange entirely using NSRange — for example, call NSMakeRange. Don't use characters.count; stay in the NSString world and use the string's length (in Swift, that is its utf16.count). Then all will be well.
I am developing a IOS custom keyboard. I was wondering if there was a way to fetch the current text inside of the text field and how it would work.
For example, we can use textDocumentProxy.hasText() to see if the textfield has text inside but I want to know the exact string that is inside the textfield.
The closest things would be textDocumentProxy.documentContextBeforeInput and textDocumentProxy.documentContextAfterInput. These will respect sentences and such, which means if the value is a paragraph, you will only get the current sentence. Users have been known to retrieve the entire string by repositioning the cursor multiple times until everything is retrieved.
Of course, you generally do not have to worry about this if the field expects a single value like a username, email, id number, etc. Combining the values of both before and after input contexts should suffice.
Sample Code
For the single phrase value, you would do:
let value = (textDocumentProxy.documentContextBeforeInput ?? "") + (textDocumentProxy.documentContextAfterInput ?? "")
For values that might contain sentence ending punctuation, it will be a little more complicated as you need to run it on a separate thread. Because of this, and the fact that you have to move the input cursor to get the full text, the cursor will visibly move. It is also unknown whether this will be accepted into the AppStore (after all, Apple probably did not add an easy way to get the full text on purpose in order to prevent official custom keyboards from invading a user's privacy).
Note: the below code is based off of this Stack Overflow answer except modified for Swift, removed unnecessary sleeps, uses strings with no custom categories, and uses a more efficient movement process.
func foo() {
dispatch_async(dispatch_queue_create("com.example.test", DISPATCH_QUEUE_SERIAL)) { () -> Void in
let string = self.fullDocumentContext()
}
}
func fullDocumentContext() {
let textDocumentProxy = self.textDocumentProxy
var before = textDocumentProxy.documentContextBeforeInput
var completePriorString = "";
// Grab everything before the cursor
while (before != nil && !before!.isEmpty) {
completePriorString = before! + completePriorString
let length = before!.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)
textDocumentProxy.adjustTextPositionByCharacterOffset(-length)
NSThread.sleepForTimeInterval(0.01)
before = textDocumentProxy.documentContextBeforeInput
}
// Move the cursor back to the original position
self.textDocumentProxy.adjustTextPositionByCharacterOffset(completePriorString.characters.count)
NSThread.sleepForTimeInterval(0.01)
var after = textDocumentProxy.documentContextAfterInput
var completeAfterString = "";
// Grab everything after the cursor
while (after != nil && !after!.isEmpty) {
completeAfterString += after!
let length = after!.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)
textDocumentProxy.adjustTextPositionByCharacterOffset(length)
NSThread.sleepForTimeInterval(0.01)
after = textDocumentProxy.documentContextAfterInput
}
// Go back to the original cursor position
self.textDocumentProxy.adjustTextPositionByCharacterOffset(-(completeAfterString.characters.count))
let completeString = completePriorString + completeAfterString
print(completeString)
return completeString
}
I am making a custom keyboard extension for iOS 8 and am unsuccessful at trying to reflect the current word being typed on a UILabel sitting on top of the keyboard (think autocorrect). So far the code I wrote reflects the sentence before the cursor and not as it's being written, but as the cursor is moved from one position to another. What I am trying to achieve is exactly like the first autocorrect box in the native keyboard. Would anyone mind telling me what I am doing wrong?
Code:
override func textWillChange(textInput: UITextInput) {
var tokens = (self.textDocumentProxy as! UITextDocumentProxy).documentContextBeforeInput .componentsSeparatedByString(" ") as NSArray
var lastWord = tokens.lastObject as! String
println(lastWord)
bannerView?.btn1.setTitle(lastWord, forState: .Normal)
}
I've tried setting a condition whereby if beforeCursor contained either a space/period/comma to set the button title as "" but that is not efficient in the long run as I need to obtain words in order to be able to make an autocorrect feature.
Edit:
I've figured out how to get the word before the cursor (updated the code above), but not how to update the label as each letter is being added. func textWillChange(textInput: UITextInput)isn't working out. It's not me it's her.
Thanks!
You should use the textDocumentProxy property of your UIInputViewController:
let proxy = self.textDocumentProxy as! UITextDocumentProxy
To get the word being typed, I would suggest something like this:
var lastWordTyped: String? {
if let documentContext = proxy.documentContextBeforeInput as NSString? {
let length = documentContext.length
if length > 0 && NSCharacterSet.letterCharacterSet().characterIsMember(documentContext.characterAtIndex(length - 1)) {
let components = documentContext.componentsSeparatedByCharactersInSet(NSCharacterSet.alphanumericCharacterSet().invertedSet) as! [String]
return components[components.endIndex - 1]
}
}
return nil
}
In a UITableView, I'm listing a bunch of languages to be selected. And to put a section index view to the right like in Contacts app, I'm getting all first letters of languages in the list and then use it to generate the section index view.
It works almost perfect, Just I encountered with a problem in getting first letter of some strings in Hebrew. Here a screenshot from playground, one of the language name that I couldn't get the first letter:
Problem is, the first letter of the name of the language that has "ina" language code, isn't "א", it's an empty character; it's not a space, it's just an empty character. As you can see, it's actually 12 characters in total, but when I get count of it, it says 13 characters because there is an non-space empty character in index 0.
It works perfectly if I use "eng" or "ara" languages with putting these values in value: parameter. So maybe the problem is cause of system that returns a language name with an empty character in some cases, I don't know.
I tried some different methods of getting first letter, but any of it didn't work.
Here "א" isn't the first letter, it's the second letter. So I thought maybe I can find a simple hack with that, but I want to try solving it before trying workarounds.
Here is the code:
let locale = NSLocale(localeIdentifier: "he")
let languageName = locale.displayNameForKey(NSLocaleIdentifier, value: "ina")!
let firstLetter = first(languageName)!
println(countElements(languageName))
for character in languageName {
println(character)
}
You could use an NSCharacterSet.controlCharacterSet() to test each character. I can't figure out how to stay in Swift-native strings, but here's a function that uses NSString to return the first non-control character:
func firstNonControlCharacter(str: NSString) -> String? {
let controlChars = NSCharacterSet.controlCharacterSet()
for i in 0..<str.length {
if !controlChars.characterIsMember(str.characterAtIndex(i)) {
return str.substringWithRange(NSRange(location: i, length: 1))
}
}
return nil
}
let locale = NSLocale(localeIdentifier: "he")
let languageName = locale.displayNameForKey(NSLocaleIdentifier, value: "ina")!
let firstChar = firstNonControlCharacter(languageName) // Optional("א")