I have an NSAttributedString in a UITextView and would like to handle the UIContentSizeCategoryDidChangeNotification when working with Dynamic Type and specifically the text styles. All the examples I've seen (IntroToTextKitDemo) address the case where the font is the same for the whole UI element. Does anyone know how to handle this properly so all the attributes update properly?
Note: I asked this on the developer forums when iOS 7 was under NDA. I'm posting it here because I found a solution and thought others might find it useful.
I found a solution. When handling the notification you need to walk the attributes and look for the text styles and update the font:
- (void)preferredContentSizeChanged:(NSNotification *)aNotification
{
UITextView *textView = <the text view holding your attributed text>
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithAttributedString:textView.attributedText];
NSRange range = NSMakeRange(0, attributedString.length - 1);
// Walk the string's attributes
[attributedString enumerateAttributesInRange:range options:NSAttributedStringEnumerationReverse usingBlock:
^(NSDictionary *attributes, NSRange range, BOOL *stop) {
// Find the font descriptor which is based on the old font size change
NSMutableDictionary *mutableAttributes = [NSMutableDictionary dictionaryWithDictionary:attributes];
UIFont *font = mutableAttributes[#"NSFont"];
UIFontDescriptor *fontDescriptor = font.fontDescriptor;
// Get the text style and get a new font descriptor based on the style and update font size
id styleAttribute = [fontDescriptor objectForKey:UIFontDescriptorTextStyleAttribute];
UIFontDescriptor *newFontDescriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:styleAttribute];
// Get the new font from the new font descriptor and update the font attribute over the range
UIFont *newFont = [UIFont fontWithDescriptor:newFontDescriptor size:0.0];
[attributedString addAttribute:NSFontAttributeName value:newFont range:range];
}];
textView.attributedText = attributedString;
}
Related
I am trying to change text font size with using NSAttributedString. But it's size doesn't change.
NSDictionary *attrDict = #{NSFontAttributeName : [UIFont boldSystemFontOfSize:22], NSForegroundColorAttributeName : [UIColor orangeColor]};
NSAttributedString *newAttString = [[NSAttributedString alloc] initWithString:mytext attributes:attrDict];
[result appendAttributedString:newAttString];
Only text color changes. Size of result string is not 22 and also it is not bold.
Instead of applying the attributes with the alloc, init, try doing it after with something like (with a mutable NSAttributedString):
NSMutableAttributedString *newAtt = [[NSMutableAttributedString alloc] initWithString:mytext]; // Allocate a new NSMutableAttributedString with `mytext`
[newAtt addAttributes:#{NSFontAttributeName : [UIFont boldSystemFontOfSize:20],
NSForegroundColorAttributeName: [UIColor orangeColor]}
range:NSMakeRange(0, [result length])]; // add new attributes for the length of the string `mytext`
[result setAttributedText:newAtt];
This answer would vary depending on what result is, I tested it on a UITextView and it worked fine, there is also an attributedText
property on UILabels.
Hope this helps.
You didn't mention what result means at the end of your code. Are you sure you want to "append" it?
Besides, I use this code for setting fonts
[UIFont fontWithName:#"Arial-BoldMT" size:22.0f]
This can be used to set different fonts and sizes respectively.
Hope this helps:)
I am bringing in some data from a JSON file and I want to change the font to courier but when I try to do the following I get this error: "Property 'font' not found on object NSString". Is there any way around this?
NSString *timePeriod = [diction objectForKey:#"Time Period"];
UIFont *changeFont = [UIFont fontWithName:#"Courier" size:12];
timePeriod.font = changeFont;
A font is part of an attributed string.
NSMutableAttributedString timeSringWithAttr = [[NSMutableAttributedString alloc] initWithString:timeString];
[timeStringWithAttr addAttribute:NSFontAttributeName
value:changeFont
range:NSRangeFromString(timeString)];
NSString just stores strings, it has no knowledge of fonts. If you want to set the font when you draw the string use the NSString AppKit additions:
https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/ApplicationKit/Classes/NSString_AppKitAdditions/Reference/Reference.html#//apple_ref/doc/uid/20000155
Basically, you want to set the font when you draw the string to screen.
The NSString class doesn't have font property, and it shouldn't since every String object is an array of characters.
Instead, use UILabel or UITextView, depends on your needs with text in it, and set font property on them.
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 200, 50)];
label.text = #"YOUR_TEXT";
label.font = [UIFont fontWithName:#"Courier" size:12.0f];
And in convention you shouldn't name variables with verb names, those are for functions.
Like UIFont *changeFont..
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 have the below code in my app
NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:self.myDisplayTxt];
[string addAttribute:(NSString*)kCTForegroundColorAttributeName
value:(id)[[UIColor redColor] CGColor]
range:NSMakeRange(0,5)];
self.myTextView.text = string;
When assigning the NSMutableAttributedString to UITextView I get the following error:
Incompatible objective c types struct NSMutableAttributedString
expected struct nsstring
So please let me know, how can I display the NSMutableAttributedString in UITextView.
You can try to use some library to do that. As omz wrote, the UITextView does not unfortunatelly support the NSAttributedString.
Maybe this one can help you: https://github.com/enormego/EGOTextView
They say about this library the following:
UITextView replacement with additional support for NSAttributedString.
UPDATE: Based on your clarification in the comment for omz's answer, you can look here:
Underline text inside uitextview
UPDATE 2: In iOS 6 you can use the NSAttributedString out of the box. For example like this:
UIColor *_red=[UIColor redColor];
UIFont *font=[UIFont fontWithName:#"Helvetica-Bold" size:72.0f];
[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];
[attString addAttribute:NSStrokeColorAttributeName value:_red range:NSMakeRange(0, _stringLength)];
[attString addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithFloat:-3.0] range:NSMakeRange(0, _stringLength)];
You can't, UITextView doesn't support attributed strings. If you really only want to use attributed strings to set the foreground color (as in your example), you could achieve the same by setting the text view's textColor property.
You should assign attributed string via UITextView.attributedText property. UITextView.text accepts NSString or plain text only.
textView.attributedText = attributedString;
See documentation:
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UITextView_Class/index.html#//apple_ref/occ/instp/UITextView/attributedText
I've got an NSTask (with an NSPipe set up) running in the background and I want to output the contents, as they're coming in, in an NSTextView (output).
The code I'm using is :
NSMutableAttributedString* str = [[NSMutableAttributedString alloc] initWithString:s];
//[str addAttribute:NSForegroundColorAttributeName value:[NSColor whiteColor] range:NSMakeRange(0, [str length])];
[[output textStorage] appendAttributedString:str];
[output scrollRangeToVisible:NSMakeRange([[output string] length], 0)];
Issues :
When there is a lot of data appending, the view seems like "flashing"... and not working properly.
Given that the NSTextView is on a Sheet, NO CONTENTS seem to be appearing when the mouse pointer is elsewhere other than hovering above the NSTextView
Why is that, although I've set the color/insertion color/etc of the NSTextView, this doesn't seem to apply to newly inserted text?
What's the suggested way of appending (+scrolling) on an NSTextView?
Thanks!
Remember that user interface elements, and this includes NSTextView, do their magic on the main thread. If you're attempting to add information to the text view, that's where you'd best be doing it. Here's how:
[[output textStorage] performSelectorOnMainThread:#selector(appendAttributedString:)
withObject:str
waitUntilDone:YES];
I'd address your third point, but frankly, that's a thing of which I'm still very much a student.
To address your fourth point, it would appear you've got that figured out; just combine your append and scroll actions. But just like changing the contents of textStorage, you want to be sure you're doing this on the main thread. Since -scrollRangeToVisible: doesn't take an object for its argument, you have to do this a bit differently:
dispatch_async(dispatch_get_main_queue(), ^{
[output scrollRangeToVisible:NSMakeRange([[output string] length], 0)];
});
My first example notwithstanding, you could place your call to -appendAttributedString: inside that block as well:
dispatch_async(dispatch_get_main_queue(), ^{
[[output textStorage] appendAttributedString:str];
[output scrollRangeToVisible:NSMakeRange([[output string] length], 0)];
});
Regarding the recommended way of appending to the NSTextView: You're doing quite well with appendAttributedString:, but it's recommended to shield it inside shouldChangeTextInRange, then a beginEditing, appendAttributedString, and finally endEditing:
textStorage = [textView textStorage];
if([textView shouldChangeTextInRange:range replacementString:string])
{
[textStorage beginEditing];
[textStorage replaceCharactersInRange:range withAttributedString:attrStr];
// or if you've already set up the attributes (see below)...
// [textStorage replaceCharactersInRange:range withString:str];
[textStorage endEditing];
}
I'd strongly suggest replacing scrollRangeToVisible: by scrollToPoint:, as scrollRangeToVisible: will cause a lot of flickering and it will also gradually become slower as you move 'down the range'.
A quick-and-dirty way could be something like this:
- (void)scrollToBottom
{
NSPoint pt;
id scrollView;
id clipView;
pt.x = 0;
pt.y = 100000000000.0;
scrollView = [self enclosingScrollView];
clipView = [scrollView contentView];
pt = [clipView constrainScrollPoint:pt];
[clipView scrollToPoint:pt];
[scrollView reflectScrolledClipView:clipView];
}
I let constrainScrollPoint do all the calculation work.
I do this, because my calculations failed anyway (those suggested by Apple and others, that used visRect/docRect coordinates, produced unreliable results).
reflectScrolledClipView is also important; it updates the scroll bar so it has the correct proportion and position.
You might also find it interesting to know when scrolling has occurred. If so, subscribe to both NSViewBoundsDidChangeNotification and NSViewFrameDidChangeNotification. When one of them occurs, the scroll bar position most likely changed (investigate [textView visibleRect] and [textView bounds]).
I see you also have trouble with the text-attributes. So did I for a long time.
I found that appending an attributed string would help quite a lot, but it still wasn't enough for the text being typed.
..Then I found out about typingAttributes.
When setting up your NSTextView, for instance in an -awakeFromNib, you can pick what you like from the following...
NSMutableParagraphStyle *paragraphStyle;
float characterWidth;
NSFont *font;
uint32_t tabWidth;
NSMutableDictionary *typingAttributes;
tabWidth = 4;
font = [NSFont fontWithName:#"Monaco" size:9.0];
paragraphStyle = [[textView defaultParagraphStyle] mutableCopy];
if(NULL == paragraphStyle)
{
paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
// or maybe:
// paragraphStyle = [NSParagraphStyle new];
}
characterWidth = [[font screenFontWithRenderingMode:NSFontDefaultRenderingMode] advancementForGlyph:(NSGlyph)' '].width;
[paragraphStyle setDefaultTabInterval:(characterWidth * (float) tabWidth];
[paragraphStyle setTabStops:[NSArray array]];
typingAttributes = [[textView typingAttributes] mutableCopy];
if(NULL == typingAttributes)
{
typingAttributes = [NSMutableDictionary new];
}
[typingAttributes setObject:paragraphStyle forKey:NSParagraphStyleAttributeName];
[typingAttributes setObject:font forKey:NSFontAttributeName];
[textView setTypingAttributes:attributes];
...It's way more than you probably need, but it shows how you can set the font, the tab width and the typing attributes.
NSForegroundColorAttributeName might also be interesting for you (as well as some other attributes, type NSForegroundColorAttributeName in Xcode and option-double-click on it, then you'll see some more attributes (you can command-double-click as well; this takes you to the definition in the header file).