I'd like different words in a UILabel to be different colors. Does this mean each word will need to be a different UILabel? I'm guessing yes, though sure would be nice to just put color codes in the label somehow, you know? I guess I'm a bit spoiled by text markup in HTML.
There is no proper UIRichTextView in iOS. It's high on my wish-list for iOS 6 (and there's some reason to believe we may get it then due to the release of Pages).
Your options are to use multiple UILabel views, NSString UIKit Additions, Core Text, UIWebView, or one of a few third-party frameworks such as:
NSAttributedString-Additions-for-HTML
CoreTextWrapper
OHAttributedLabel
OmniUI
All of the current solutions have different problems. The most common problem is that it's hard to get select and copy functionality to work with rich text unless you use a web view. Web views are incredibly annoying because they're asynchronous and you have to do a lot of your interactions in JavaScript.
I wish there were a better answer.
(Obligatory shilling: This topic is covered in depth in Chapter 18 of iOS 5 Programming Pushing the Limits.)
UILabel doesn't support segmented formatting (the entire thing can only have one format).
Have a look at OHAttributedLabel, which does what you want.
As far as I'm aware you'd need to have separate labels for each different coloured word. Depending what you're trying to do you may be able to make use of myLabel.textColor to change the colour of the periodically or on events etc.
Related
I've read in the documentation that the NSString category method drawInRect is good for small amounts of text, but is too much overhead for large amounts. The alternative in my case would be to use Core Text CTFrameDraw.
My question is, what is the "cut-off" point between using drawInRect vs Core Text? Is Core Text always faster than drawInRect? If the extra programming is not the issue, should I always just use Core Text instead of drawInRect, even for small strings?
Mostly I'll be drawing paragraphs, but sometimes they can be short lines too.
For me it comes to use core text when I have some specific requirements from the graphic designer. For instance label that need to mix colors, type, font size etc. drawRect is method that draws something in a view layer, is just a wrapper around CG functions, core text is full framework to deal on how to draw text: change fonts, spaces, interlines.
I mean is not fair as a comparison, a better question could be when it comes to use core text instead of common UI text porpoise obejects and the answer is based on your app design-UI related requirements. Hope this helps.
I would write some test code to benchmark the two methods under consideration using your expected statistical distribution of string content. Maybe a timing a few tens of millions of string renders using each. Run the benchmarks on an actual iOS device, as relative performance may be different using the ARM targeted frameworks.
I wonder if using a UIWebView would get all the performance that's possible. The iOS (and every OS) has a constantly loaded webkit ready to go. Its pretty well optimized too. It would also get work offloaded.
Interesting to compare.
I would like to implement rich format text views as are demonstrated in Instagram. Following is a screenshot.
Specifically, my goals are:
Words at different positions of the same text view may have different font sizes, font colors and font styles(bold, italic, etc).
Touch events (long press, touch down, etc) can be detected in the delegate callbacks. Information (which word is touched, whether it's a long press or a touch down, etc) can be gathered in such callback methods.
Big frameworks like Three20 are out of the question. Small, independent libraries are highly preferred. Low level Cocoa Touch APIs may also be OK if it won't take me more than a few days to wrap them up.
Any suggestions are highly appreciated.
NSAttributedString lets you do this. If you have access to the iOS 5 developers cookbook by Erica Sadun there is a recipe for a wrapper around NSMutableAttributedString which makes it simple to add text piece by piece, changing attributes as you go.
Here is the source on Erica's githuib
Finally found an ideal open source solution (supports both iOS 5.0 and iOS 6): the OHAttributedLabel, which is capable of both rich format and touch handling.
https://github.com/AliSoftware/OHAttributedLabel
I am pretty new to iPhone development and currently working on an application which includes a view that performs a simple numerical calculation. In particular, the user enters 3 or 4 values into text fields and the view displays the result. Something along the lines of http://www.moneychimp.com/calculator/compound_interest_calculator.htm
What is the nicest way to achieve this? I am currently using simple UITextFields and a UILabel for the result but it doesn't look nice or "native-like". What UI object would be best to use?
Thank you!
It's entirely up to you. You're using the right classes for actual input- it comes down to how you choose to style those classes. I'd suggest looking at the documentation for UIView and CALayer (youView.layer, and include QuartzCore framework in your project).
A good start might be to choose a color scheme, a background for your app, and the look and feel you're shooting for- this will inform your styling. Try looking for apps that you think are elegant and attractive, and boil down what they do and what you like about them.
I'd say;
use a grouped table style (with the white tables with round corners on a blueish striped background)
embed settings values directly in the cell (aligned to the right) as much as possible
you can show a relevant keyboard (text, numbers) or picker view to let the user pick values, directly when they tap the cell. Use sliders and switches where relevant.
You may want to take a look at http://www.inappsettingskit.com/, we are currently investigating it for the same purpose and it seems to do the job
You can use either a UISlider or a UIPickerView if some of your values have limits.
You can use UISwitch for toggles.
You can also switch the default keyboard for your textfields to be numeric.
Other than that you seem to be on the right track.
Also, sometimes putting a view inside a scrollview makes things seem cooler even if its only one page. The auto bounce on scrollviews is kind of cool.
I'm new to iPhone development, and I have a question on how to create a view for my application.
The view should display a problem (using formatted/syntax highlighted text), and multiple possible answers. The user should be able to click on an answer to validate it.
Currently, I am trying to use a UITableView embedding UIWebView as contentView. That allows me to display formatted text easily.
The problem is that it is a real pain to compute and adjust the height of the cells. I have to preload the webview, call sizeToFit, get its height, and update the cell accordingly. This process should be done for the problem and the answers (as they are HTML formatted text too).
It's such a pain that I am planning to switch to something else. I thought using only a big UIWebView and design everything in HTML. But I looked at some articles describing how to communicate between the HTML page and the ObjectiveC code. This seems to involve some awful tricks too...
So... that's it, I don't really know what I should do.
I guess some of you dealt with such things before, and would provide some greatly appreciated tips :)
The catch here is that the iPhone API does not yet support NSAttributedString so you can't just set the text to appear as you would like in a textview.
I saw one work around which essentially used individual UILabels to represent each attribute run. (Can't find the link now.) They used NSString UIKit extensions to calculate the position of the strings on the view and then used that to position the labels.
Another work around would be to draw the strings with their attributes to a UIImage and then just display the image. That would be the easiest solution I think.
In either case your going to have to basically recreate the data structure of an attributed string.
NSAttributedString does a lot of work for us. We really miss it when it is gone.
I want to implement a view in an iPhone application that is essentially like a rich text document. I need it to be click-editable, and I'd like to be able to embed graphic objects (either an overlaid view object, or manually drawn in graphic) with the text wrapping around. much like you would expect in a word processor. That's about the minimum functionality needed. Changing font for certain text would be a bonus (bold, size, etc).
UITextView would be a great start for me if it supported media like graphics embedded.
I'm still very new to Cocoa and Obj-C. Where should I start?
UITextView will not be nearly sufficient -- it has a very well-defined and simple functionality. That is an extremely complicated thing you're trying to do, wrapping text around an image -- you'll have to use to manually render the text in your drawRect method and do some very complex collision detection and calculate the string sizes etc. It's do-able, but extremely complicated.
Now, if you don't want the text to hug the image, but rather have the two appear on distinct lines, then you could fake this with a UITextView, then a UIImageView, then a UITextView, manually changing size and offset of each as the text changes...but this is a cheap hack and not exactly extensible. It could be sufficient for your needs, however.
UITextView does not allow rich formatting (bold, italics, different sizes, colors...), so that too would require a custom sort of text view.
Basically, it's a pretty big undertaking. If you're really committed, I recommend what Alex said -- get very, very comfortable with UIKit and Objective-C and iPhone coding in general. Then research how to make a rich text editor in other languages more suited to the functionality, and try porting that to the iPhone.
Hope this doesn't sound too discouraging. It's possible, but it won't be easy. And always bear in mind that the iPhone is a phone. Is it really the best platform for your application?
You might start with a much smaller, unrelated project. A viewer is no problem — start with UIWebView, which can render a RTF document for viewing. Creating a document editor, however, is no small task.