I need to design a view in which:
A lot of text is presented, with variable paragraph length
Specific paragraphs can be called into specific parts of the view (top, middle, bottom) either by the user (search, go-to) or programmatically.
Whenever a paragraph reaches a position in the view (let's say the middle) it triggers an event
Each paragraph can be tapped/selected to trigger events.
Each word in the paragraphs can be selected.
Bonus: the paragraphs are presented continuously, without breaklines (which excludes tableviews).
The text is fixed, and each paragraph is indexed (the data comes from an sqlite database).
I thought of three possible approaches, but each of them have its own problems I could not overcome:
A single textview. This would let me free to format the text the way I want, and work on the single words. On the other hand, I haven't figure out a way to act on the individual paragraphs. I wouldn't mind adding the index number for each paragraph on the side of the paragraph, but I don't know the best way to tag it (HTML?). Moreover i don't think there is something similar to scrolltoposition for anything other than a tableview.
Textviews for the individual paragraphs. I could use the index in the database to label each of them. Yet, as above, I don't think there is something similar to scrolltoposition...
Resizable textviews inside each cell in a tableview. This would let me work easily with the paragraphs and formats, but I don't think the text within the cell is selectable.
Any advice on how to solve those specific problems?
Any suggestion of an alternative way to achieve this?
The best approach, by far, is the UITableView. Everything you have listed is easily accomplished with the delegate methods of UITableViewDelegate, and UIScrollViewDelegate (of which a table view calls). The only issue with the tableview is the fact that UILabels cannot be selected within them. This is easily solved by not using a UILabel, but a UITextView. Simply disable scrolling on the text view, and disable editing (I'm not sure if disabling editing removes the selectability. If it does, override the UITextView and block edits from there).
1. Use UITableView
2. Create UITableViewCell with UIScrollView inside it
3. Override UIScrollView to disable editing
4. Add logic to UITableViewDelegate and UIScrollViewDelegate (of the table view) for the taps and position events
good luck,
ZR
Related
New to Swift. I am trying to write a recipe-sharing app for fun. One of the features is to let users create a new recipe. On this page, users should be able to give an intro to the recipe to be created, upload an image THEN add a LIST of ingredients dynamically (as we have no idea how many ingredients in total beforehand).
I have created a UIViewController, which includes a UIViewTable, an image view and a "add another ingredient" button. I have created a class for the ingredient. And when the "add" button is pressed, a new "Ingredient" cell will be added to the table. However, I found that adjusting the UIViewTable height dynamically is quite hard.
I want my table to adjust its height according to the number of cells (rows). I haven't found much useful info online.
Or maybe I should've not even used this structure. Instead, just use UITableController (The entire page is a table)? But I got confused that some of the elements (image view, submit a recipe button, recipe-intro textfield etc) will be only created once. Why do I bother making them as prototype cells and add them to my view programmatically?
Thanks in advance!
First of all, welcome to Swift!
You put a few questions together, I will try to answer them one by one. Let's start with the simple stuff.
Don't try to change the height of UITableView based on the number of items. If you want to achieve similar functionality, take a look at UIStackView. Set fixed size for the tableView, ideally with constraints using auto layout.
UITableView is supposed to fill specified space and scroll items inside or show cell on top if there are not enough cells to cover all space.
UITableView is highly optimized to scroll over huge amount of cells as the cells are reused on the background. If you are new to the iOS world, take a look at this function https://developer.apple.com/documentation/uikit/uitableviewcell/1623223-prepareforreuse it can save you hours of debugging (I have been there)
UITableView vs UITableController
UITableController can save you a few lines of code, but using UITableView inside of UIViewController can give you more freedom and save you refactoring if your app is likely to change in the future. There is no specific advantage of UITableController
If you want to provide the extra elements (image view, submit button, text field etc), you can use several methods and this is where the UIViewController with your own UITableView comes in handy.
You can put some buttons, like a plus icon or "Done" button into the navigation bar, as the native Calendar app does.
You can put the static content (intro text field, image view) above the table view (visible always). Use constraints to place the static content on the viewController.view and constraint the table view under your static content. The table view will take less space on the view keeping the space for your content.
Insert your static content as a table view header (will scroll out with the content). Search "HeaderView" here on stack overflow to see how to achieve that.
Place your content over the tableView. If your button is small (rounded), you can place it over the tableView, eg. Twitter uses this for a new tween button.
Hope this answer your questions. Cheers!
My goal is to have a Swift implementation of a UICollectionView with dynamic content where each cell hold parts of a sentence. Each part of the sentence can be edited by the user. The problem is that some parts of a sentence might be longer than the container itself. Using sizeToFit is not an alternative because all content should have the same font size to maintain readability throughout the collection view.
Right now the behaviour I get, when I have a part of a sentence longer than the container is the following:
As you can see the third row has leading ellipsis.
What I would like to achieve is the following, the overflowing part of the cell should wrap as analogous to a span tag in HTML, like so:
Is this possible? How can I achieve such a thing?
As far as I can tell, it's possible but complex - here are a few pointers of what I'd say you're going to need:
2 additional collection view cell types: in the first, only the left edges are rounded, in the second only the right
Use Core Text API to measure where your text needs to be wrapped
In your datasource, you're going to have to then recognize the situation before you create the cells and then instead of creating a single cell, you create two, using those new types you have.
I've got a few custom UITableViewCells that I'm making accessible. I'm trying to get VoiceOver to read all the subviews when the cell is tapped. From my understanding, this is something you get for free when using or sublcassing UITableViewCell (Correct me if I'm wrong on that.)
The issue is in a few of my cells. In most of my cells, everything reads correctly. However, when I tap on a cell that contains a UITextField (or subclass of UITextField) it does not read the UITextField. It will read all the other elements (except the UIButton on one cell as well,) but will skip the text fields.
Does anyone know any reasons it would not read the UITextFields? And the one UIButton? Is there something special that needs to be done for those to be read? Or something special to be done to a UITableViewCell subclass that I haven't done?
Sorry for posting no code, I'm not really sure what code would be relevant to post since I don't see anything related to accessibility at all in the code. In the storyboard, it is selected as accessible for all elements I want read, however the UITextFields seem to ignore this setting.
What you want to do is create a custom cell class, and override the accessibilityLabel property of that class. Collecting all subviews accessibility labels. I'm on a windows machine now, so pardon if this doesn't quite compile, but you should get the idea.
#implementation MyCustomCellViewClass
-(NSString*)accessibilityLabel {
NSMutableString* result = [NSMutableString new];
for (subview in [view accessibilityElementViews]) {
[result append:subview.accessibilityLabel];
}
return result;
}
By including this as a property override, rather than setting accessibility labels at all potential points that it changes, you remove the concern of future devs overriding this behavior. You also gain automatic handling of dynamic elements within these cells, as the accessibility label will simply stay in sync with the accessibility information of the subviews. You can then include this class as a parent class of any future subclasses to trivially maintain this behavior. If any of your devs are dumb enough to remove this sub class from the inheritance tree you have bigger problems to deal with!
Make sure with this approach that your cell has the correct role. Whatever the active element of the cell is (be it a tab, link, button, etc) should be the role of your super view. The other elements are just informative.
Let's say your table cell has 4 elements a label, a button, a text field, a image view. All these elements are in the contentView of your tablecell.
To make sure the voice over reads all the 4 elements in your table cell, you need to tell the voice over that your contentview contains 4 elements.You can do this by adding all the elements in your contentView to the contentView's accessibilityElements Array.
contentView.accessibilityElements=#[label,button,textField,imageView];
Then the voice over will not skip any of these 4 elements.
I need to create a dialog, similar to the one that is used to write functions in Numbers from APple, for example.
User can select range in the table, which is then represented as any kind of UIView inside text input line. When long-tapped, the content can be edited like normal text, but what is most important is that whole subView, containing text with range description is treated as one character.
Does anybody know or have idea how to achieve this?
I would appreciate any hints...
I had to deal with something similar, to have custom UIView(s) in a search field.
I'm not aware of a "simple" way (ie, API) to achieve your goal. You need to create a custom component that looks like a classic field, but isn't one.
To be a little more specific:
Subclass an UIView (or directly an UIScrollView)
Have inside a TextField (or UITextView depending if it needs more than one line) to handle the "keyboard".
Put some custom UIView/UILabel before the textField/textView and adjust the textField/textView origin depending these views/labels
If you want to have a label/view IN the text, then it's a little more complex and you'll need something even more custom:
Handling the keyboard events without a textField/textView (there is a way but I forgot how exactly)
Drawing the text and adding views/labels in specific locations.
Of course all depends on the component you want to create ^^ there is no one simple answer.
One of the views of my iOS app contains a quite long text inside a UIScrollView, with an user guide. The text is localized in three languages and splitted in chapters with titles.
I'm using multiple UITextView. At the end of each view constructor I'm adding it to the main view and I call:
[self autoSizeTextView:myuitexview];
to make it resize accordingly to the length of the text for the language in use.
The next UITextView is positioned calculating the position and the height of the previous one, to have them presented in order and not overlapped.
This is a tedious job! Considering that I don't want to use a web view (to keep good performances), is there an another way to display a long and not mono-block text (with chapters and a not so simple layout) on iOS?
Posting from my comment:
Is there a reason for not using UITableView? I'd suggest, instead of doing this in a UIScrollView, do it in a UITableView. It'd save your app some resources to do your positioning calculations, and the lazy loading of paragraphs will be taken care of by the cellForRowAtIndexPath, which will keep the app very responsive
#flip79: glad it helped!