First of all, there are many questions on StackOverflow, but none that fully answer this question.
The problem is mainly, but most likely not limited to, Thai and Arabic diacritics when rendered with a custom Latin-only font, using the text property of a UILabel. Which is also intrinsically sized in an auto-layout. I've already done everything Apple suggests, playing with the settings mentioned in their documentation, WWDC videos, as well as questions on StackOverflow (e.g. clipsToBounds = NO, etc.). Keep in mind, only my custom font setup clips in my scenario, not the iOS system font (.SF-UIDisplay), and not even the iOS system provided Helvetica or Helvetic Neue. The custom font has been checked and rechecked, and at this point the conclusion, iOS is the anomaly across all platforms, even macOS. To be even clearer, the same clipping behavior as the custom font can be seen with SF Pro, a font provided by Apple themselves here: https://developer.apple.com/fonts/
This question is about the most proper, least intrusive, and most complete way to do what is necessary to not clip diacritics. Meaning, how would you do this, ideally, from scratch.
All of my font research and test runs have led all those involved in this problem to believe that Apple has implemented special treatment specifically for their system fonts in UILabel, to avoid diacritic clipping. So making that an assumption, I'm also assuming the font is ok, and I'm looking for solutions that do not involve editing the font.
In my tries to use the font, the first thing to go wrong was vertical clipping of the ascender diacritics of Thai glyphs:
นื้ทั้มูHello
This means the glyphs of the font Thonburi when they cascade from the custom Latin-only font. The fix from this point, was to use a custom font only for Thai without any Latin characters, so it could be defined as the primary font, and cascade to the previously mentioned Latin-only custom font. After all this, the custom Thai font still has horizontal clipping issues on diacritics that come at the end of the text:
Worldฟล์
So now I am at a loss for anything further that font management puppetry can do (though still open to suggestions), and I am moving on to more code-centric fixes. I've seen quite a few questions and answers mentioning subclassing UILabel, but I'd like to know what this would look like that could accomplish what I've described.
I'd also like to know if just opting out of UILabel would be an option for anyone. Meaning would writing something from the ground up with TextKit be worth it to avoid all these bugs that seem to only plague iOS, and specifically UILabel.
At first I thought this was a problem with the framework but it's not, it's just a strict enforcement of a font's metrics. And in probably everything but web/app development, fonts are not rendered so strictly, which is why this problem rarely comes up. Fonts have a number of metrics that tell the program rendering it onto the screen how to render it, most importantly how to handle padding. And UILabel (and UITextField, and likely others) applies these metrics strictly. And the problem for us is that some fonts are very decorative and are often too thick or oblique to fit perfectly into the square canvas that each character must fit into (this is especially the case with accents, like umlauts). This isn't a problem outside of web/app development because when a character doesn't fit into its canvas, like a very thick, wide, and oblique W, the program just shows it anyway, and that's why a low-hanging g might spill into the line below it. But if that g was rendered in a single-line UILabel, because of how strict the font-metric enforcement is in iOS, that low-handing g is clipped.
Subclassing UILabel (in the case of UILabel) and overriding its intrinsicContentSize to add some extra padding is not a good idea, on further research. For one, it's kind of hacky, but more importantly, it produces constraint warnings in the debugger. The true fix, and the only acceptable fix AFAIK, is to edit the font's metrics.
Download a program like Glyphs (https://glyphsapp.com/), open the font, open the Font's Info, and in the Masters tab, give the font the proper ascender and descender values. To best understand how these values work, open the San Francisco font in the program and see how Apple did it (it's the font they made specifically for macOS and iOS development). As a side note, if you use this app, when you're editing the font's info, go into the Features tab as well, delete all of the features (using the minus icon in the lower left) and hit Update to let the program manage the font's features for you.
The last hurdle is clipping at the leading edge (not the top and bottom) which the ascender and descender metrics don't address. You can use the Glyphs program to edit the canvas size of individual characters to make sure they all fit but that changes the complexion of the font because it changes the character spacing too noticeably. For this problem, I think the best solution is to simply use attributed strings for your labels and text fields. And that's because attributed strings let you safely edit padding without hacking into intrinsic sizes. An example:
someLabel.attributedText = NSAttributedString(string: "Done", attributes: [NSAttributedString.Key.font: UIFont.blackItalic(size: 26), NSAttributedString.Key.foregroundColor: UIColor.black, NSAttributedString.Key.paragraphStyle: NSMutableParagraphStyle.kItalicCenter])
For convenience, I extended NSMutableParagraphStyle since I use this font all over:
extension NSMutableParagraphStyle {
static var kItalicCenter: NSMutableParagraphStyle {
let s = NSMutableParagraphStyle()
s.alignment = .center
s.firstLineHeadIndent = 2
s.headIndent = 2
return s
}
}
This label will push the font forward a couple of points to prevent clipping.
I was trying to solve similar problem with diacritics in Arabic and found workaround:
I have a UITableViewCell with UILabel with arabic text, it's diacritics were cut sometimes
I overrided - (void)drawRect:(CGRect)frame to directly draw NSAttributedString on UITableViewCell
Also I decreased alpha self.arabicLabel.alpha = 0.1; to draw manually on top of label position, I still keep it to calculate cell's height
- (void)drawRect:(CGRect)frame {
[super drawRect:frame];
if (self.viewModel == nil) return;
NSAttributedString *string = [self.viewModel arabicStringWithTajweed];
CGRect originalRect = [self convertRect:self.arabicLabel.frame fromView:self.arabicLabel];
[string drawInRect:originalRect];
}
The core problem on iOS is font substitution. You are specifying a latin font, the font does not contain glyphs for the characters that will be rendered, the system uses a different font to draw the glyphs, but it is still measuring based on the original font.
Option 1, the most robust option, is to manually choose fonts that include glyphs for the characters you will render. When the font assigned to UILabel, or the attributed string it is rendering, contains all the glyphs that will be rendered, and that font has good metrics as most system fonts do, then nothing will be clipped.
Option 2, manually measure the string using glyph bounds. Make a subclass of UILabel and override textRectForBounds and possibly drawText. Measure the string with .usesDeviceMetrics. This is slower that measuring by font metrics and produces different results. For example, the strings "a" and "A" will measure differently.
Option 3, use baseline offset and line height multiple to make room for the diacritics that are being clipped. Choose or compute constant values for each font for each language, and apply those to the attributed string of the UILabel. This can compensate for the different in font metrics between the font you chose and the font that is actually rendering glyphs. We had localized strings with the worst case clipped characters for each language, and used those to compute the offset and height. Different fonts have different worst case clipping characters.
The text below the app icon isn't fully showing, you can see 9 characters out of the 12, is there any way to alter this making it all fit or maybe have two lines instead of one?
No
You can neither change the font size, the letter spacing or number of lines. They all are pretty much fixed.
It is your annoying job to find a app name that fits on all devices in the little space that is available.
Note that the font is not mono-spaced, meaning that all character take up different amount of space - you are going to be able to fit a lot more Is on the screen than Ws or Ms
I am trying to place an overarrow over a piece of text in MathJax.
I am using a custom font that I declare in the code-
\(\overrightarrow{\style{font-family: mysans, TeX, Arial, sans-serif;}{\text{" + tString + "}}}\)"
It works ok for most letters- for capital W or M , using a couple in a row like "WWW" the overbar is too short.
For lowercase i , using a couple in a row, ie "iii" it is too long. My hunch is that MathJax is using a standard character width size to figure out the length of the overarrow and when the character is much longer or shorter than that size, it calculates the overarrow incorrectly. Is there any way around this?
Thanks!
First off, you generally cannot use custom fonts with MathJax. As the documentation says
Since browsers do not provide APIs to access font metrics, MathJax has to ship with the necessary font data; this font data is generated during development and cannot be generated on the fly. In addition, most fonts do not cover the relevant characters for mathematical layout. Finally, some fonts (e.g. Cambria Math) store important glyphs outside the Unicode range, making them inaccessible to JavaScript.
However, if you are only looking to use custom fonts in text elements, then there is a way to work around this: style the surrounding context and set mtextFontInherit:true for the output jax, cf. e.g. here for HTML-CSS.
Unfortunately, this won't actually help you right now. There's a minor regression in MathJax 2.5 (see this discussion leading to the result you describe). This will be fixed in 2.5.1 and in the mean time you could set noReflows:false for the HTML-CSS output.
I'm trying to add text to an image in PSP X6 and I know how to do it but how can I make it look clearer/thinner?
I've created this using Arial (9 pixels) and the default stroke width (1) and not sure what else to do to make the text look less thick...
As a long-time fellow user of Corel's PaintShop Pro (including several versions by JASC before that), I have experienced the "Text" tool fluctuate (in effectiveness) over the years. This can be quite frustrating - as the quality (crispness in particular) of the text seems to vary from version-to-version.. - and sadly X6 (recently superseded by X7) is no exception.
In answer to your question, I would recommend one of the following solutions:
To get the best result with small text:
1) Ensure that the "Anti-alias" option is set to either "Sharp" or "Off".
2) Double-check that the text is not set to Bold (obvious, I know - but easily missed)
3) If possible, try dark greys (rather than pure black) as this can sometimes seem "softer" around the edges.
If you have already checked and/or tried the above, then another option is to use the technique I have adopted many times over the years - as follows:
1) Create your text (e.g. "Previous") but in a separate document - and purposefully set the text size MUCH larger than you need (e.g. 100 Point - the bigger, the better).
2) "Flatten" that image (ensuring you preserve transparency if you plan to overlay your text on a background other than pure white).
3) Resize the image down to the approximate width you require (e.g. 100 Pixels wide) by using the "Image Resize" option and ensuring that "Resample Using" is ticked/checked - and that "Smart Size" is the option used (the others: Bicubic, Bilinear and Weighted Average can also sometimes deliver better results - a little trial and error might be the order of the day until you get the hang of the technique).
Providing the desired end size is not too small, you should find the end results MUCH better than simple typing in at (say..) 9 Point to begin with.
Worth noting that this technique works particularly well for "mid-size" text - but you should also see an improvement for smaller sizes too. So something of a workaround for sure, but it definitely can and does work.
In Delphi 7 IDE, do the lines need to be a given length? I see a gray line in some Delphi code I'm working with, and it looks like ever line ends right before it.
It's called the right margin. It is intended as a guide to help you avoid writing lines that are too long and exceed your coding standards. You can switch it off from the Editor Options, as I have done here:
It's just a guide to line length. Some people don't like long lines because they can be hard to read on different resolutions or when doing comparisons.
That gray line is called the margin.
You can set its visibility and position in the Editor Properties at the Display tab in the Margin and gutter groupbox.
The margin is a visual assistent. The standard position is 80 characters, which defaults to the maximum unscrolled size of many source formatting output media, such as the one used here at Stack Overflow. Originally, it had something to do with the paper width on (matrix) printers. Maybe it still does.