I have to show the Font Preview of a font. For that I just Copied the character set from the font and then I showed as the Preview. This is my coding.
NSString *fontName=#"aFontName";
CFStringRef CFFontName = (CFStringRef)fontName;
CTFontRef fontRef = CTFontCreateWithName(CFFontName, 0.0,NULL);
NSCharacterSet *characterset = (NSCharacterSet *) CTFontCopyCharacterSet (fontRef);
unichar idx;
NSString *str=[[NSString alloc]init];
for( idx = 0; idx < 65000; idx++ )
{
if ([characterset characterIsMember: idx])
{
if ( isprint(idx) ) {
NSString *str2 = [NSString stringWithFormat:#"%c",idx];
str=[str stringByAppendingString:str2];
}
else {
NSString *str1 = [NSString stringWithFormat:#"%C",idx];
str=[str stringByAppendingString:str1];
}
}
}
Then Finally in the TextView I showed the Strings from the str as Font Preview. But str has lot of unwanted characters(For the Hindi Language Font it is showing the English character also) . I think it is not the correct way for showing the Preview of a font. Is there is any other way for showing the font preview like FontBook application in mac?
FontBook is using a private routine to get a sample string from the font. If private routines are okay for your app, then you can simply define:
CFStringRef CTFontCopySampleString(CTFontRef font, int options);
and call like:
NSString* sample = (NSString *) CTFontCopySampleString(fontRef, 0);
and you'll get the same string as FontBook shows.
Related
I am working with a Objective-C Application, specifically I am gathering the dictionary representation of NSUserDefaults with this code:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *userDefaultsDict = [defaults dictionaryRepresentation];
While enumerating keys and objects of the resulting dict, sometimes I find a kind of opaque string that you can see in the following picture:
So it seems like an encoding problem.
If I try to print description of the string, the debugger correctly prints:
Printing description of obj:
tsuqsx
However, if I try to write obj to a file, or use it in any other way, I get an unreadable output like this:
What I would like to achieve is the following:
Detect in some way that the string has the encoding problem.
Convert the string to UTF8 encoding to use it in the rest of the program.
Any help is greatly appreciated. Thanks
EDIT: Very Hacky possible Solution that helps explaining what I am trying to do.
After trying all possible solutions based on dataUsingEncoding and back, I ended up with the following solution, absolutely weird, but I post it here, in the hope that it can help somebody to guess the encoding and what to do with unprintable characters:
- (BOOL)isProblematicString:(NSString *)candidateString {
BOOL returnValue = YES;
if ([candidateString length] <= 2) {
return NO;
}
const char *temp = [candidateString UTF8String];
long length = temp[0];
char *dest = malloc(length + 1);
long ctr = 1;
long usefulCounter = 0;
for (ctr = 1;ctr <= length;ctr++) {
if ((ctr - 1) % 3 == 0) {
memcpy(&dest[ctr - usefulCounter - 1],&temp[ctr],1);
} else {
if (ctr != 1 && ctr < [candidateString length]) {
if (temp[ctr] < 0x10 || temp[ctr] > 0x1F) {
returnValue = NO;
}
}
usefulCounter += 1;
}
}
memset(&dest[length],0,1);
free(dest);
return returnValue;
}
- (NSString *)utf8StringFromUnknownEncodedString:(NSString*)originalUnknownString {
const char *temp = [originalUnknownString UTF8String];
long length = temp[0];
char *dest = malloc(length + 1);
long ctr = 1;
long usefulCounter = 0;
for (ctr = 1;ctr <= length;ctr++) {
if ((ctr - 1) % 3 == 0) {
memcpy(&dest[ctr - usefulCounter - 1],&temp[ctr],1);
} else {
usefulCounter += 1;
}
}
memset(&dest[length],0,1);
NSString *returnValue = [[NSString alloc] initWithUTF8String:dest];
free(dest);
return returnValue;
}
This returns me a string that I can use to build a full UTF8 string. I am looking for a clean solution. Any help is greatly appreciated. Thanks
We're talking about a string which comes from the /Library/Preferences/.GlobalPreferences.plist
(key com.apple.preferences.timezone.new.selected_city).
NSString *city = [[NSUserDefaults standardUserDefaults]
stringForKey:#"com.apple.preferences.timezone.new.selected_city"];
NSLog(#"%#", city); // \^Zt\^\\^]s\^]\^\u\^V\^_q\^]\^[s\^W\^Zx\^P
(lldb) p [city description]
(__NSCFString *) $1 = 0x0000600003f6c240 #"\x1at\x1c\x1ds\x1d\x1cu\x16\x1fq\x1d\x1bs\x17\x1ax\x10"
What I would like to achieve is the following:
Detect in some way that the string has the encoding problem.
Convert the string to UTF8 encoding to use it in the rest of the program.
&
After trying all possible solutions based on dataUsingEncoding and back.
This string has no encoding problem and characters like \x1a, \x1c, ... are valid characters.
You can call dataUsingEncoding: with ASCII, UTF-8, ... but all these characters will still be
present. They're called control characters (or non-printing characters). The linked Wikipedia page explains what these characters are and how they're defined in ASCII, extended ASCII and unicode.
What you're looking for is a way how to remove control characters from a string.
Remove control characters
We can create a category for our new method:
#interface NSString (ControlCharacters)
- (NSString *)stringByRemovingControlCharacters;
#end
#implementation NSString (ControlCharacters)
- (NSString *)stringByRemovingControlCharacters {
// TODO Remove control characters
return self;
}
#end
In all examples below, the city variable is created in this way ...
NSString *city = [[NSUserDefaults standardUserDefaults]
stringForKey:#"com.apple.preferences.timezone.new.selected_city"];
... and contains #"\x1at\x1c\x1ds\x1d\x1cu\x16\x1fq\x1d\x1bs\x17\x1ax\x10". Also all
examples below were tested with the following code:
NSString *cityWithoutCC = [city stringByRemovingControlCharacters];
// tsuqsx
NSLog(#"%#", cityWithoutCC);
// {length = 6, bytes = 0x747375717378}
NSLog(#"%#", [cityWithoutCC dataUsingEncoding:NSUTF8StringEncoding]);
Split & join
One way is to utilize the NSCharacterSet.controlCharacterSet.
There's a stringByTrimmingCharactersInSet:
method (NSString), but it removes these characters from the beginning/end only,
which is not what you're looking for. There's a trick you can use:
- (NSString *)stringByRemovingControlCharacters {
NSArray<NSString *> *components = [self componentsSeparatedByCharactersInSet:NSCharacterSet.controlCharacterSet];
return [components componentsJoinedByString:#""];
}
It splits the string by control characters and then joins these components back. Not a very efficient way, but it works.
ICU transform
Another way is to use ICU transform (see ICU User Guide).
There's a stringByApplyingTransform:reverse:
method (NSString), but it only accepts predefined constants. Documentation says:
The constants defined by the NSStringTransform type offer a subset of the functionality provided by the underlying ICU transform functionality. To apply an ICU transform defined in the ICU User Guide that doesn't have a corresponding NSStringTransform constant, create an instance of NSMutableString and call the applyTransform:reverse:range:updatedRange: method instead.
Let's update our implementation:
- (NSString *)stringByRemovingControlCharacters {
NSMutableString *result = [self mutableCopy];
[result applyTransform:#"[[:Cc:] [:Cf:]] Remove"
reverse:NO
range:NSMakeRange(0, self.length)
updatedRange:nil];
return result;
}
[:Cc:] represents control characters, [:Cf:] represents format characters. Both represents the same character set as the already mentioned NSCharacterSet.controlCharacterSet. Documentation:
A character set containing the characters in Unicode General Category Cc and Cf.
Iterate over characters
NSCharacterSet also offers the characterIsMember: method. Here we need to iterate over characters (unichar) and check if it's a control character or not.
Let's update our implementation:
- (NSString *)stringByRemovingControlCharacters {
if (self.length == 0) {
return self;
}
NSUInteger length = self.length;
unichar characters[length];
[self getCharacters:characters];
NSUInteger resultLength = 0;
unichar result[length];
NSCharacterSet *controlCharacterSet = NSCharacterSet.controlCharacterSet;
for (NSUInteger i = 0 ; i < length ; i++) {
if ([controlCharacterSet characterIsMember:characters[i]] == NO) {
result[resultLength++] = characters[i];
}
}
return [NSString stringWithCharacters:result length:resultLength];
}
Here we filter out all characters (unichar) which belong to the controlCharacterSet.
Other ways
There're other ways how to iterate over characters - for example - Most efficient way to iterate over all the chars in an NSString.
BBEdit & others
Let's write this string to a file:
NSString *city = [[NSUserDefaults standardUserDefaults]
stringForKey:#"com.apple.preferences.timezone.new.selected_city"];
[city writeToFile:#"/Users/zrzka/city.txt"
atomically:YES
encoding:NSUTF8StringEncoding
error:nil];
It's up to the editor how all these controls characters are handled/displayed. Here's en example - Visual Studio Code.
View - Render Control Characters off:
View - Render Control Characters on:
BBEdit displays question marks (upside down), but I'm sure there's a way how to
toggle control characters rendering. Don't have BBEdit installed to verify it.
How do I make the following script repeat the text input into it?
self.textView.text = self.userTextInput
The above script was written as a text input from a ViewController but I want it to loop 10 times in its text viewer, how do I write that?
thanks.
Use following code to get your desired result.
NSMutableString *teststring = [NSMutableString string];
for(int i = 0; i<10;i++)
{
[teststring appendString:self.userTextInput];
}
self.textView.text = teststring;
I want to get the most recent word entered by the user from the UITextView.
The user can enter a word anywhere in the UITextView, in the middle or in the end or in the beginning. I would consider it a word when the user finishes typing it and presses a space and does any corrections using the "Suggestions from the UIMenuController".
Example: User types in "kimd" in the UITextView somewhere in the middle of text, he gets a popup for autocorrection "kind" which he does. After he does that, I want to capture "kind" and use it in my application.
I searched a lot on the internet but found solutions that talk about when the user enters text in the end. I also tried detecting a space and then doing a backward search until another space after some text is found, so that i can qualify it as a word. But I think there may be better ways to do this.
I have read somewhere that iOS caches the recent text that we enter in a text field or text view. If I can pop off the top one , that's all I want. I just need handle to that object.
I would really appreciate the help.
Note: The user can enter text anywhere in UItextview. I need the most recent entered word
Thanks.
//This method looks for the recent string entered by user and then takes appropriate action.
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
//Look for Space or any specific string such as a space
if ([text isEqualToString:#" "]) {
NSMutableCharacterSet *workingSet = [[NSCharacterSet whitespaceAndNewlineCharacterSet] mutableCopy];
NSRange newRange = [self.myTextView.text rangeOfCharacterFromSet:workingSet
options:NSBackwardsSearch
range:NSMakeRange(0, (currentLocation - 1))];
//The below code could be done in a better way...
UITextPosition *beginning = myTextView.beginningOfDocument;
UITextPosition *start = [myTextView positionFromPosition:beginning offset:currentLocation];
UITextPosition *end = [myTextView positionFromPosition:beginning offset:newRangeLocation+1];
UITextRange *textRange = [myTextView textRangeFromPosition:end toPosition:start];
NSString* str = [self.myTextView textInRange:textRange];
}
}
Here is what I would suggest doing, might seem a little hacky but it would work just fine:
First in .h conform to the UITextViewDelegate and set your text view's delegate to self like this:
myTextView.delegate = self;
and use this code:
- (void)textViewDidChange:(UITextView *)textView { // Delegate method called when any text is modified
if ([textView.text substringFromIndex: [textView.text length] - 1]) { // Gets last character of the text view's text
NSArray *allWords = [[textView text] componentsSeparatedByString: #" "]; // Gets the text view's text and fills an array with all strings seperated by a space in text view's text, basically all the words
NSString *mostRecentWord = [allWords lastObject]; // The most recent word!
}
}
I use this code to get the word behind the #-sign:
- (void)textViewDidChange:(UITextView *)textView {
NSRange rangeOfLastInsertedCharacter = textView.selectedRange;
rangeOfLastInsertedCharacter.location = MAX(rangeOfLastInsertedCharacter.location - 1,0);
rangeOfLastInsertedCharacter.length = 1;
NSString *lastInsertedSubstring;
NSString *mentionSubString;
if (![textView.text isEqualToString:#""]) {
lastInsertedSubstring = [textView.text substringWithRange:rangeOfLastInsertedCharacter];
if (self.startOfMention > 0 || self.startOfHashtag > 0) {
if ([lastInsertedSubstring isEqualToString:#" "] || (self.startOfMention > textView.selectedRange.location || self.startOfHashtag > textView.selectedRange.location)) {
self.startOfMention = 0;
self.lenthOfMentionSubstring = 0;
}
}
if (self.startOfMention > 0) {
self.lenthOfMentionSubstring = textView.selectedRange.location - self.startOfMention;
NSRange rangeOfMentionSubstring = {self.startOfMention, textView.selectedRange.location - self.startOfMention};
mentionSubString = [textView.text substringWithRange:rangeOfMentionSubstring];
dhDebug(#"mentionSubString: %#", mentionSubString);
UIAccessibilityPostNotification(UIAccessibilityLayoutChangedNotification, nil);
}
}
}
Simple extension for UITextView:
extension UITextView {
func editedWord() -> String {
let cursorPosition = selectedRange.location
let separationCharacters = NSCharacterSet(charactersInString: " ")
let beginRange = Range(start: text.startIndex.advancedBy(0), end: text.startIndex.advancedBy(cursorPosition))
let endRange = Range(start: text.startIndex.advancedBy(cursorPosition), end: 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'm trying to save the content of a UITextView which contains lines of text formatted both RTL and LTR.
The problem is that UITextView checks only the first character to format direction. Let's assume I'm in "edit" mode and write this text (__ means spaces):
text1_______________________________________
____________________________________________אקסא
text2_______________________________________
and after saving we lost RTL for אקסא. Now I'd like to edit this text once again which now looks like:
text1_______________________________________
אקסא
text2_______________________________________
I'm not able to mix \u200F with \u200E directional characters in one UITextView.
How to manage this and save correctly bidirectional text from UITextView?
Here is a quick proof of concept using NSAttributedString :
- Split the text in paragraphs
- For each paragraph, detect the main language
- Create an attributed text with the correct alignmenent for the corresponding range
// In a subclass of `UITextView`
+ (UITextAlignment)alignmentForString:(NSString *)astring {
NSArray *rightToLeftLanguages = #[#"ar",#"fa",#"he",#"ur",#"ps",#"sd",#"arc",#"bcc",#"bqi",#"ckb",#"dv",#"glk",#"ku",#"pnb",#"mzn"];
NSString *lang = CFBridgingRelease(CFStringTokenizerCopyBestStringLanguage((CFStringRef)astring,CFRangeMake(0,[astring length])));
if (astring.length) {
if ([rightToLeftLanguages containsObject:lang]) {
return NSTextAlignmentRight;
}
}
return NSTextAlignmentLeft;
}
- (void)setText:(NSString *)str { // Override
[super setText:str];
// Split in paragraph
NSArray *paragraphs = [self.text componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
// Attributed string for the whole string
NSMutableAttributedString *attribString = [[NSMutableAttributedString alloc]initWithString:self.text];
NSUInteger loc = 0;
for(NSString *paragraph in paragraphs) {
// Find the correct alignment for this paragraph
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
[paragraphStyle setAlignment:[WGTextView alignmentForString:paragraph]];
// Find its corresponding range in the string
NSRange range = NSMakeRange(loc, [paragraph length]);
// Add it to the attributed string
[attribString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:range];
loc += [paragraph length];
}
[super setAttributedText:attribString];
}
Also, I recommend reading the Unicode BiDi Algorithm to manage more complex use cases.
I'm trying to get the name of the connected external display with Cocoa or CoreFoundation. With "name" I mean that string that appears in the title bar of the System Preferences window when editing Display preferences.
I couldn't find any API for that in NSScreen or in the Quartz Display Services.
But there has to be a way, because if I access the color space of the display like this:
CGColorSpaceRef colorSpace = CGDisplayCopyColorSpace(displayID);
and I log the color space's description I get:
<CGColorSpace 0x100113c20>
(kCGColorSpaceICCBased; kCGColorSpaceModelRGB; DELL 2408WFP)
I found a solution in an other thread (I wonder why I didn't find that before...).
I updated it to be ARC compatible:
- (NSString *)screenNameForDisplay:(CGDirectDisplayID)displayID {
NSString *screenName = #"";
NSDictionary *deviceInfo = (__bridge NSDictionary *)IODisplayCreateInfoDictionary(CGDisplayIOServicePort(displayID), kIODisplayOnlyPreferredName);
NSDictionary *localizedNames = [deviceInfo objectForKey:[NSString stringWithUTF8String:kDisplayProductName]];
if ([localizedNames count] > 0) {
screenName = [localizedNames objectForKey:[[localizedNames allKeys] objectAtIndex:0]];
}
return screenName;
}