Dynamically update height of collection view cells - swift

I have a collection view with many different cells in it. Each cell takes up half the width of a page, and contains an image and a label under the image.
I am starting with all of the labels being truncated, along with a "Read More" button that is supposed to expand the label.
The code to do the expanding is working, but the problem is that if I click the button on a cell in the top row, and the 2nd row also has 2 cells in it, I need those 2 cells to move down the page when I click the button as well. Right now, the text is technically "expanding" but then just being truncated due to having no height left.
I believe I need some sort of invalideLayout combination with something else to make this happen, but I can't seem to piece together how I would force all of the cells to move downwards as well.
The "Read More" button is attached to a function call that updates the number of lines for that text from "3" to "0" and reloads that cell.
Thanks in advance!

Related

Letting big shadows bleed between UITableView cells

I've created a UITableViewCell with a textfield in it, which has a large diffused shadow underneath it. I've also set it up so that these big shadows can blend under its surrounding cells.
NB. Shadow has been HEAVILY emphasised here to show the problem.
The problem is that I want the shadow from my EMAIL textfield to blend underneath the password cell. i.e. I want both textfields to have a white background, but underneath them both I have the shadow. Something like this:
The reason this is a problem is because the UITableView is being rendered with upper cells "above" the lower ones. So any shadow from the cell at row 1 will bleed on top of the cells in rows 2, 3, 4 etc.
I was wondering if perhaps there is a way to change this rendering, and instead reverse the rendering so that a cell in row 4 is actually ABOVE rows 3, 2 and 1.
Or perhaps there is a way of setting the Password textfield so that no shadows are rendered on top of it?
Any help, very much appreciated!
Thanks to #Amr for pointing me in the direction of the cell.layer.zPosition.
The higher the value this is, the "closer" to the viewer the layer sits, so as long as each row has a higher value, it will appear "above" the shadows from any cells around it.
Since I use multiple sections in my code, I used this line to assign each cell above the previous one.
cell.layer.zPosition = CGFloat(indexPath.section) * 1000 + CGFloat(indexPath.row)

dynamic button width in collection view cell

my collection view cell is full size..i have collection view cell and it contains button..i successfully display all button with it's title in collection view cell. but i am having one issue that some button title is too large..i want to change it's widht based on text...how to set button width based on text..i have vertical collection view
my array is
var arr = ["butto1 butto1 butto1","butto1 butto1butto1butto1","butto1","butto1 butto1butto1butto1"]
I have searched so many time but still i haven't point out
...any on help me..Thank you
You haven't given much information that would help in diagnosing your problem.
The button should automatically resize to fit the text unless you have set constraints that stop it from growing.
If you have set a left and a right constraint to equal a constant then it will not be able to grow.
As far as I can tell, you have two options.
Only set 3 out of 4 constraints. For example the following image has 3 constraints set which allow the button to grow downwards.
Set the right constraint to "Greater than or equal to" instead of "equal" in the interface builder. This will allow the button to grow to a maximum size which is specified by the constraints.
Also make sure to set your button to word wrap so that text continues on the next line.

AutoLayout of Custom Accordion/Collapsible UITableViewCell

I would like to build a TableView where when the user clicks on a cell it expands to show more information. My question is how do I use Autolayout to arrange the multiple items in each cell.
Each cell will always be the same size, whether it is collapsed or not, so the sizing isn't dynamic.
The first problem I have is how to use Autolayout to arrange all the items in the cell. Before Xcode 7 I was successfully using Autolayout where I would pick a label-button-view to arrange, click Editor > Align > Trailing/Leading/Top Space, to.. etc. This is now greyed out and I don't know how to replace my old strategy.
Each cell has two rows of items. The first row shows all the time, the second only shows on collapse. Below is a picture of how the cell will look when it is collapsed:
The first row is a bit trickier because outlet1 and outlet 2 will have variable sizes. I would like 'label' to come right after label1, no matter how long or short that outlet happens to be. As arranged currently, there is a variable amount of space between the two.
What I'm looking to achieve in row 1 is basically exactly like Venmo:
Notice how 'paid' conforms to the size of the two names in the first row.
The second row has two buttons and an outlet which will always be the same size.
To sum up - how can I layout these elements in the UITableView for iphones4 thru 6S - and then how do I make this cell a collapsible cell? The construction of these cells seem to work as a system, not isolated from the whole - which is why this is a 2-part question.
is this what you want to achieve?

Show a label over the limits of a UITableViewCell

I'd like to use a UItableView to show a day Calendar. Each row corresponds to one hour. I need to show the hour between 2 cell of my tableview.
Like this :
(source: free.fr)
And this is my UITableViewCell :
(source: free.fr)
In the first screenshot, it works perfectly but if I scroll down then scroll up, my time label is cut like this :
(source: free.fr)
Have you any tips to figure out this problem using a tableView ?
The way you lay out your cell now is fragile, because the order of painting the cells on screen matters a lot. Try moving the content up so that your buttons are flush with the top of the cell, and the time label fits into the cell entirely. Add a thin header view to your table to make the top cell appear normal. Keeping the content of a cell entirely within its bounds should help you maintain reasonable scrolling speeds.
EDIT : You could also put a second clipped label at the top of your cell, and make its content identical to that of the label in the prior row. You would need to take special care to hide that label in the top row, but otherwise this should make your table immune to changes in the rendering order of its cells.
Make the background color of your cell clear. As you scroll up the z ordering of your cells get reversed and the lower cells overlap the higher ones causing this clipping.

Select one table cell and have multiple cells momentarily highlight

I have related items in adjacent table cells. When either of the related items is selected, before going to the detail view, I would like the momentary cell selection highlight to show both (or in some cases 3) cells highlighted to alert the user of the relationshp.
This a purely a "nice to have" cosmetic feature.
Any help appreciated.
In the method called when the user selects a row you can use:
[cell setSelected:YES];
One way to get the cell would be using tableView:cellForRowAtIndexPath method (correct me if I'm wrong).
* FOLLOW-UP TO Shaggy Frog *
I appreciate your comments.
For some reason, I can't add a comment to or edit my own original question so I am editing my follow-up.
May I have an opinion on the following. Since the 2 highlightd cells would always be adjacent and the data related, it makes sense that the detail view contain details for both cells. However your point is valid and I don't want to get rejected.
Instead of 2 cells, if for the "related cells" I were to double the height of those cells, draw a horizontal line half way between (to make the 2 "subcells" of 44 pixels in height looking just like 2 cells) and place the data in subviews so the result looks exactly the same as 2 cells but it would actually be 1 cell. Selection of one of my "subcells" would then highlight 2 "subcells" which is the entire cell - same effect but 1 cell.
Do you think that would pass?
And of course the biggest advantage is that I know how to do this versus the multi-cell highlighting which doesn't seem possible.