Setting different colours to the same character of a label - ios

How to set two different colours to the same character of a label (like NBC APP's schedule date selection. in centre selected box, the text colour has been changed regardless of character range of the label).
Sample image:
Thanks in advance.

Not exactly an answer to your question, but you can probably achieve this by:
Create two views, each containing a label, both with the full text.
Change the color accordingly.
Put the second view (with the blue text) below the first one (grey text).
Change the frame size of your first view so only half of the text is displayed.
If no truncating happens to the text, you should end up with the above effect.

Related

How to align two UILabels on the Y axis of the center of the first line of text

please see the image below for two examples of what is to be achived
the alignment should be on the Center Y of the first lines of each UILabels and should work regardless of font size or font. currently we have implemented this with different constraints to the top of the super view for different font and font size combinations.
the constraint to align the center of the two UILabels does not work since the text of the second UILabel is not fixed and can have several lines.
also the text is dynamic, so it is not known where the text will wrap to create the first line, thus it cannot be shown in an one line UILabel with the rest of the text in another one below.
currently this is implemented using UIKit, but if there is an easy solution in SwiftUI we can put these two labels in a SwiftUI component. so a SwiftUI solution would also be welcomed.
Your comments said "it should be on the glyphs" ... but, without additional information, my guess is that "real world" usage would not really need that level of precision.
For example:
While the glyphs are not perfectly center-Y aligned, it seems unlikely you'd run into a case where the first line of the "rightLabel" is " ' " ' " or . , . , ..
This layout can be easily done with only a few constraints - no need to do any calculations:
The "Positioning" label would, of course, be set .hidden = true so it would never be seen.
If you really, really want glyph-precision, you'll need to calculate
the Glyph bounding box for the left-label
the Glyph bounding box for first line of the right-label
calculate the "character box" offsets to align the Glyph Y-centers
and then position the two labels accordingly, or use Core Text to draw the text (instead of using UILabel).
Probably more work than necessary -- unless your actual use-case demands it.
That's an interesting problem! You can try using the centerYAnchor for the label on the left, and the firstBaselineAnchor for the label on the right... that will align the center Y with the text baseline, which isn't quite what you want.
To find the correct offset to apply, you can use the information from UIFont about the size of the characters. I'd probably start with capHeight * 0.5 and see if that looks or feels right. Something like:
leftLabel.centerYAnchor.constraint(equalTo: rightLabel.firstBaseLineAnchor, constant: rightFont.capHeight * 0.5)
This is a more difficult problem in SwiftUI, I think, because resolved font metrics aren't directly available to you.

treemap can't render box when containing text that is too large

When creating a treemap structure with boxes, boxes with a text that is larger than the box itself are not drawn.
Below the same treemap is show twice: once with text, once without text.
treemap with text
image without text
How do I prevent this from happening?
I'm pretty sure this can't be prevented. The reason is that the box sizes have hard constraints on their sizes (the size is as meaningful as the height of a bar in a bar chart), so they can't grow with the size of the enclosed text.
To fix this you could generate shorter labels (removing all the vowls and truncating them) and showing the full label as a tooltip? Or you could have a box with a label in it on the side which contains the currently hovered box?

Find substring that would fit inside UILabel of certain area

For a UILabel of certain width, with certain font and font size, i want to calculate amount of characters that would make 7 lines worth of text inside it + ... (three dots showing continuation). Is there a fancier way to achieve this? Currently what i'm trying is counting up to X amount of characters or 7 new line characters, which ever comes first and i cut on the text right there.
More Detail:
Trying to make an expandable row Cell which contains the UILabel, i'm achieving this with auto layout... So to control the cell expansion, i change the text to be full text or a substring of that, with a button below which toggles between the string vs substring. All of that is working. The problem i'm getting is my method of finding the substring isnt very neat. Its not consistent on how it handles text of different combination of characters or newlines. I get variations of how it looks and sometimes it just ends with three dots on a new line rather than finishing on the 7th line.
Even using auto layout you can still use the lines property of UILabel to limit the number of lines displayed by the label.
So set it 7 and you'll get 7 or less rows. Just assign the complete text.

How can I add the three dots of a UIlabel when the text is too long, at the middle of the text instead of at the end?

For example, I have the following two string: "How Munched is That Birdie in the Window?" and "S22 - E7". I want to present in the label the following: "How Munched is That Birdie in ... S22 - E7" If the string is too large according to the label's size and doesn't fit it". How you can see, the three dots are placed always in the first string, the second string is always shown full.
How can I achieve this?
Here is how to do it.
yourlabel.adjustsFontSizeToFitWidth = false
yourlabel.lineBreakMode = .byTruncatingMiddle
You can set the UILabel's ParagraphStyle LineBreakMode to byTruncatingMiddle, which will probably work in most cases with carefully planned label size. From the docs:
The line is displayed so that the beginning and end fit in the container and the missing text in the middle is indicated by an ellipsis glyph. This mode is used for single-line layout
If you want to guarantee none of the "S22 - E7" string is truncated, you would have more control using two labels and setting layout constraints such that the width of the protected label is preserved so that it can display the full string whenever possible, but that is probably overkill in most cases.
You may also find this answer helpful if decide to go a different route by manually manipulating the displayed string based on detecting how many characters will be visible given the width and font.

Align two UILabel texts

I would like to align the start of the text of two UILabels. I aligned the two UILabels (with the yellow and grey background) and used sizeToFit: to shrink the UILabels to the content but the text is not perfectly left aligned. There is a gap on the left. The gap is bigger or smaller depending on the first character. I would like to align the red lines in the following picture. There is even a small gap with the small font in the grey UILabel but it's barely visible.
With the Z character the gap is smaller but still visible by the yellow area left to the Z
A simple UILabel alignment does not help for my specific problem, because the text content is dynamic and not static. So there could be any combination depending on the data I get from the backend. Therefore I was hoping for a UIFont or UILabel attribute that could return the size of the gap based on the current rendering of the text.
I know that there are great UIFont related attributes like baseline, capHeight and ascender one can access to align text but there seems to be no attribute that would return the value of this gap on the left.
If this doesn’t need to be two UILabels, you could have one with attributed text. Then both lines would be subject to the same layout.
I haven't tried the GUI which people have been posting Screen Shots of, however... the behaviour is consistent with the very nature of typography.
The font sizes are completely different, therefore the width of an em is different, subsequently the letter-spacing is also different.
See this: http://www.w3.org/WAI/GL/css2em.htm for more information.
I know this answer doesn't give you what you have asked for, however it should explain why this is happening.
For customisation such as this (if HTML and CSS) I would use a negative / positive margin on the sub text, however seeing as you are using backgrounds use padding (or the equivalent in your GUI).
Use attributed text of UILabel
set indentation as per your requirement
ref screen shot
Select both the labels and add a constraint called align leading edges.

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