My use-case is like this:
The user defined some tags (text like "#asdf", "#qwerty", "#let_me_think_about_it" and "#decide later"). I want to display these in a box without scrolling (and don't know, how many tags the user created until I display the box).
The box itself should not be scrollable at all but be shown in a UITableViewCell (which is being scrolled). So it must compute the proposed height and respond to Autolayout mechanisms. If a (ARM) Mac user resizes the window to be smaller than before (or an iOS user rotates the device), the box should increase/decrease its height, as necessary (within the limits of Autolayout, since I know of some issues). Each of the tags should be (de)selectable at the same time (UILabel with UITapGestureRegognizer attachted?) and be able to displayed 'selected' (via a background view).
So, the box should primary try to align all content horizontal. If There's not enough horizontal space, do a "line break" and continue on the next "line".
My current solution is a UIScrollView that the user can scroll horizontal and tap any of the (UILabel) views. The displayed views itself are being loaded from a NIB file, like a UITableView does. The issue here is that not any of the selected tags might be visible at the first glance.
If there was no Autolayout, I'd exactly know what to do. But since there it is, I want to use Autolayout in my NIB files and wonder what you would do?
(How do you compute the required width of such a view and decide when a line break is to be done (and how?))
I think I need a simple hint. But if it needs code to explain, ObjC and Swift is both acceptable. :-)
So, the box should primary try to align all content horizontal. If There's not enough horizontal space, do a "line break" and continue on the next "line".
This sounds like a job for UICollectionView with UICollectionViewFlowLayout. You can disable scrolling, and the layout object will tell you the size of the content so that you can adjust the size of the box.
(How do you compute the required width of such a view and decide when a line break is to be done (and how?))
If you're doing it yourself, you add up the widths of all the items on the first line, and if it's larger than the available space, you move the item that extends past the limit and any subsequent items to the next line. Repeat as needed. But that's exactly what a flow layout does for a collection view, so there's no need to roll your own.
Related
I am building an app about meetings where I want to show a preview of the VIP participants in each meeting cell.
These participants are not clickable nor scrollable, the only purpose it's to quickly see them at a glance.
The problem is that the view is very dynamic:
VIP's appear with image or initials
The rest of the attendees is just a number
if >5 VIP's, the circles start going together overlapping (spacing goes smaller)
if 9 VIPs, big wrapping circle “All VIPs in Attendance"
This is how it will look:
What should I do?
CollectionView (seems over-kill as I am not interested in any kind of interaction with the images)?
StackView?
Images (and change constrains programmatically)?
NOTE:
These is just one kind of Table View Cell, but we have a lot more variations, so we are building the custom cells in xib files. Xcode doesn't allow me to add a Collection View Cell in to the Collection View within the xib.
Interesting task - I'm sure there are numerous approaches, but here is one using UIStackView plus some on-the-fly calculations.
The idea is to define a maximum gap between views; a maximum width for all views; calculate the actual gap needed, and then let UIStackview handle the actual positioning.
Certainly not every feature you need, but should get you going in the right direction.
You can see/download the source for this here: https://github.com/DonMag/ScratchPad
Look at the Swift3/SpreadingViews sub-project for this example.
The problem with scrollable views (UIScrollView based views as UICollectionView), is that you will have to deal with the scroll, or pre-compute the width of your content, which is not always easy. For this reason, if you don't want to have scrollable content, I'd not use a UICollectionView, neither any UIScrollView based view.
Then you have the option to go with an UIStackView. Stack views are great to "append" multiple views and create some kind of "pile" of views in a very easy way. However, if you don't control how many items you need, you will overpass the boundaries of your container view.
Therefore, this is what I'd do:
"Fixed container view width" case: If your container view (your cell) has a fixed width (that never changes), I'd manually add as many UIImageViews I want to support in the XIB itself, and then hide/unhide them depending on the number of items I want to display.
"Variable container view width" case: If your container view (your cell) has a variable width (that changes depending on the screen size or whatever other factor), then you will have to compute in any case (do the math!) the amount of items you are able to display within the width you have available. Then, you can choose between using an UIStackView or adding your views & constraints manually to your container view.
Does what I say make sense?
Thanks,
I've been doing iOS for a while now, but when it comes to dynamically hiding / showing elements, I'm a bit lost.
Coming from Android, I'm used to being able to simply set views to visibility gone, but this doesn't exist on iOS.
So let's say I have the following scenario:
Basically I want to have a table, but the table should not fill the entire view controller. Instead it should leave place for optionally either a button, a multiline label, or possibly both at the bottom (if visible, these should be fixed, not scroll).
One way to solve this would be to use auto layout and modify constraints, like adding a zero height constraint. But that would make iOS kill one of the other constraints, which would make it hard to change it again. For the label, I wouldn't always want to have a height constraint, because it could be multiline, and should take the size it needs.
Maybe it's easier to skip autolayout here and modify frames instead, I don't know.
My question is: What approach would be best here?
Is there some other way of doing this I haven't thought of, or do I have to try to do what I described above?
I'm not primarily looking for code (code can be ok), but I'm more interested in a description of how it can be done.
I'd like to support iOS 7.
This problem had a variety of solutions, and opinion based, but I'm facing such questions a lot, when I don't know what to choose and what would be the "right thing".
So, I my opinion, the best solution here is using autolayout, you need to set height of label manually, but you have a few methods for this, at least you can play with it and if you don't succeed ask question about it. Using frames, you'll face same problem of calculating height, right? But with auto layout, you only need to set height, vertical space to 0, when you need to hide message.
You can also use constrains with priority lower 1000, and remove completely constraints from message (button, label) if you don't need it at all anymore.
For example, taking your layout image, you can make UIView with subviews: button, label. Top constraint connect to the UITableView, other constraints to the sides.Label and button will calculate the view's height. The only question here is label height.
So in ios assuming that the background of both these objects is opaque only the front most view in the Heirarchy will be visible and interactable, An easy solution would be to change the different frames of these two things you need and make sure they are in the back of your view heirachy, and when you need them to appear use view.bringSubviewToFront(mySubview) and view.pushSubviewToBack(mySubview) to make it disappear again. View obviously would be referring to main view of your view controller.
I work on a app, nothing fancy, but since is my first app, there alot of stuff I never did before.
So, I'm trying to build a view like the image attached.
I've looked up on the Internet how to do something like that but I don't know what is better/cleaner way to do.
As you can see I have 3 areas: the title, the tableview in the middle and a button on the lower side.
The table will expand based on the content (3 lines or 30 lines) so the button must move down and a scroll bar should appear.
So, my idea:
Using a tableview having 3 static cells: one to put my title, second to put a tableview having prototypes cells, and a third one for the button.
That way I would have a scroll bar when the table in the middle grows, pushing the button.
Here I have a question: how to have the table view (the inner tableview) resize itself, pushing the height of the middle row, instead of having a fixed width with a scroll.
Is the the best way to achieve that?
Thanks for any idea.
C.C.
Are you sure you want to push the bottom UI down as the table grows? You say whether the table has 3 or 30 cells, but what if it has 300 cells? Your user then has to scroll to the bottom to reach the button and tab bar. I think you'll find that it would be better to use Auto Layout and let the table fill the screen space between the title and the button. The table will scroll so if you have 300 cells then you can scroll through inside the table's available area.
The advantage here is you won't be fighting with Auto Layout. If your user rotates an iPhone 4S into landscape you'll only have a few rows displayed but conversely if they run in portrait on an iPad you'll fill all of that space.
As for how to do it, the other advantage is that you don't need the nested table you describe. Use a constraint to attach the title label to the top layout guide, then attach the tab bar to the bottom layout guide. Put a vertical space constraint between the button and the tab bar. Finally, put vertical space constraints between the table and the title & the table and the button. (You'll need to implement constraints for the horizontal axis as well, but that's pretty simple.)
There's are refinements you can put into place if you want the table to shrink to fit if there are only 3 rows, but this should get you started and you may not want that anyway.
Key point: the tableView wants to scroll naturally, inside a view sized to fit the display. Don't change that behavior unless you really have to. Neither your users nor UIKit expects what you're trying to do, and the table is going to fight you all the way about it.
Nesting UIScrollViews (which your nested table would do) works, but it opens up a lot of bad UI flow problems. In my experience every time somebody wants nested scrollViews there's some other approach which is more "natural" to iOS interface paradigms.
If you're dead set on the UI you described I wouldn't use a table for the outer structure. Just make it a UIScrollView and calculate your content size based on the number of rows the table will display. You can actually do that, and then use Auto Layout as I described.
This is the most complicated UI related problem I've come across yet. I've been trying to find a solution for literally weeks but no avail. Let em explain.
In this app I'm working on, I need to display a certain list. It's actually a schedule. Here's how it should look like,
The fields circled by red circles don't change. To explain what change means I have to show you this.
Its a set of filters which the user can show/hide certain fields and the ones that are circled in the first image are static ones. They can't be toggled on and off.
Now the problem arises with the ones that can be toggled. Here's what it looks like if you turn off the Show Actions flag.
A new label with a blue background replaces the bottom one you can see in the first image.
Here's another one where you disable Show Time option and the time labels are gone (yes it affects only for some. Its expected).
If this filter list were an option list, it would have been easy. Just create a custom cell for each option and you're good to go. But unfortunately the user is able to toggle multiple filters! For example the user can turn off both Show Actions and Show Time and it'd look like the last image but the bottom label would have the blue label in the third image.
To top it all off, the cells' height is dynamic. In iOS 8 creating self resizing cells are easy enough from the IB when you could just add auto layout constraints and done.
But it seems to me that creating these cells from the IB isn't an available option to me. Simply because there are way too many filter combinations a user can make. So the cell's subviews need to adjust to it.
My question is how can I create a dynamic cell like that? My best guess is through code, right? I haven't written my UI in code before so I tried creating a test project to familiarize myself with it. But the problems I'm facing is setting fixed frame sizes makes the dynamic nature obsolete. And how can I move a view to fill up a removed view's space (Last image. Time labels are gone so the name and the id labels move to the left to fill that space).
I know this question is a little too broad. I'm not asking for a straight answer either. I'd really appreciate some pointers, or even a better suggestion on how to approach this because I'm truly at the rock bottom on this issue.
Thank you.
It's hard to give you any precise help since your question is so broad. First, I would recommend watching the 3 videos on Auto Layout from the WWDC 2012 (sessions 202, 228, and 232).
To answer your one example, how to move a view to replace a view that's removed. You would need to make two left edge constraints from the view with the text (Kund Alof...). One with a constant of 0 to the time label with a priority of 1000 (that's the default), and another to the left edge of the cell, also with a constant of 0, but with a lower priority, say 900. As long as the time label is present, the constraint to it will determine the position of the text label, but when it's removed, the lower priority constraint to the left edge will take over and move the label over to the left edge.
(please forgive my english)
I'm new at IOS developing but I've a good skill on other programming languages (mainly c#).
I'm trying to develop a test app with a main window.
Inside that window there is a scrollview with fixed size. inside that scrollviewer there is a view containing some stacked couples of one TextField and one Label: I can't know - ad design time - how many "rows" of them I have to put into.
My problems is:
I can put on the view the first couple (a textfield and, next, a label). Label size can be one or several rows high ,so I've to set multiline and sizeToFit
How can I put the second couple (and so on) without overlap the existing labels..? I can't use a table because between rows there are other labels (title of section).
Do I have to calculate the height of each label and programmatically calculate where to draw the next? Is there a more efficient way?
I don't need code, please just some hints or some keyword to googling on.
Many thanks.
I don't see why you can't use a UITableView, you can set up cells with all the controls you need in it. Either way, using a UITableview won't make the job any easier (just more memory efficient if you have many rows).
The only way that I see is, as you said, to calculate where the next 'row' should be placed (depending on the height of your previous rows). You'll also need to calculate the entire height, in order to set it to the contentSize of the UIScrollView.
Instead of UILabel you can also use a non editable UITextView, since it'll be easier to get its size (after you set the text, you can set the size of a UITextView to be equal to its contentSize)