How to make UITableView appear from bottom to top when scroll? - ios

I'm looking just for general scenario.The idea is when app launches user can see only first cell of UITableView at the bottom of UIViewController. When user scrolls up full table appears and when scrolls down only first cell is displayed again. Something similar like keyboard in Facebook messenger app, but with tableView. For now I added tableView as subview to scrollView, but problem is tableView appears from top to bottom, and I'm looking for solution how to make this work upside down.. So, tableView have to appear from bottom to top of UIViewController.

My idea would be:
Give your UITableView the desired frame at viewDiDLoad (probably the height of 1 cell, at the bottom of your UIView)
Let your UIViewController implement UIScrollViewDelegate
At - (void)scrollViewDidScroll:(UIScrollView *)scrollView of UIScrollViewDelegate check which element is scrolling (if its your UITableView) and also check which direction user is scrolling
Change the frame of the UITableView as you wish, you will also have to come up with some logic to block further changing of the UITableView's frame (a BOOL would do good here I guess)

Not sure I understand your correctly but, maybe, this will be helpful
I believe you can try to add zero cell (or first section header view of your UITableView) with transparent background. So that your first cell will be placed on the bottom of screen and UITableView height will be equal to screen height.
In this case, you will have only one scrolling view (UITableView, in particularly). Following method can be used to perform expandable animation and scroll table to top to hide zero cell when user taps on first cell:
[UITableView scrollRectToVisible:animated:]
After that you can leave UITableView as it is and "constrict" your table whenever you need in the same way as it was expanded before.

I understand what you want to do.
In general, UITableView shows cells from top to bottom.
You can add transform in tableview:
tableView.transform = CGAffineTransform(scaleX: 1, y: -1)
Then your tableview will show the cells from bottom to top and you can scroll tableview from bottom to top.
But cells will be transformed as tableview, so you have to add same transform to cells also.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "cell")
**cell.transform = tableView.transform**
return cell
}
All done. Hope to helpful!

Related

Animation in UITableViewCell breaks after cell deallocation

I have an expanding view in the cell. After i press show more button it works fine. But when i scroll down and that cell deallocates from memory and then i tap on show more button again animation breaks. How can i fix it?
Project repo on Github
Collapsed view:
Expanded view:
Debugger view, before scroll:
After cell deallocation (after scroll) breaks like this, expands behind second cell:
Based on your code and comment...
Instead of expanding your cell, you're setting clipsToBounds = false and expanding the cell's contents, allowing them to extend outside the bounds of the cell.
As you scroll a UITableView, cells are - of course - added / removed as needed. But when they are re-added, the "z-order" changes (because, with "standard" table view usage, it doesn't matter).
So, after scrolling down and then back up, and then tapping the "Show more" button, that cell may be (and usually is) at a lower z-order ... and thus its expanded "out-of-bounds" content is hidden behind the cell(s) below it.
If you want to stick with that approach (as opposed to expanding the cell itself), you can try implementing scrollViewDidScroll to make sure that cell is "on the top":
func scrollViewDidScroll(_ scrollView: UIScrollView) {
// make sure the first row is visible (not scrolled off the top of the view)
let pth = IndexPath(row: 0, section: 0)
if let a = tableView.indexPathsForVisibleRows,
a.contains(pth),
let c = tableView.cellForRow(at: pth) {
// bring it to the front -- i.e. the top of the z-order
tableView.bringSubviewToFront(c)
}
}

Tableview cell does not cover the whole area as expected

I've been googling an answer for this for hours but cannot find anything that actually works in my case and I've no idea why.
I'm creating a tableview which should be from the top of the tableview to the bottom of the tableview, but in this case it doesn't.
img here
In this image you can see how it looks like in the storyboard (Which is also the way I want it to look like), you can see it almost cover the whole tableview.
And this is the result:
result of tableview
I'm trying to make the tableview cell start from the top and contain all the way to the bottom of the tableview (Well, like the storyboard image)
I've added this...
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat
{
return 410
}
You dont need to use UITableView
You add vertical scrollview and add one contianer UIView in it then you can add mutiple UILable and UITextField one bellow another.

How to resize UITableViewCell height by showing and hiding components using auto layout

I have 4 components in my cell.
UIView
UITextView
UIImageView
Another UIView on top of the UIImageView
UIView
UIView
These content can be changed according the data that comes from the server(Sometimes it needs to hide the 3rd image view, sometimes 5th UIView). I'm using auto layout and with the auto layout what is the way to change height of the cell?
You can achieve this easily by using UIStackView. Stack views are a powerful tool for quickly and easily designing your user interfaces. Their attributes allow a high degree of control over how they lay out their arranged views.
Here is link for tutorial - Tutorial
If you hide a view from stackview it conveniently disappears from the layout, but it's still a subview of the stack view. So you don't have to do anything special if you want to bring it back later on. And by using self sizing cells, cells will automatically expand or collapse based on stack view height.
Do following steps:
When you hide any component give that component frame height as 0 and reload tableview. If you giving any component constant height then take outlet of height constraint and make it zero and specify its constant height again when you unhide.
When you unhide give him specific frame height and reload tableView.
heightForRow must returnUITableViewAutomaticDimension
As you already taken components from the storyboard so compiler understands the height of cell and work accordingly.
If you still facing issue you can ask.
this two methods are use for dynamic cell height
func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat
{
return UITableViewAutomaticDimension
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
I post this for other man meet my issue.
Do not apply any change that will change the cell height in layoutSubviews, like hidden view or change any view's height.

UITableViewCell height from initial size to full screen

how i can swipe down (scroll) one cell from my tableviewcell (static cells) and make this cell fullscreen?
I know how make the cell full height:
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return tableView.frame.size.height;
}
But how i can start this cell with a fixed height and after swipe down (scroll) the cell, make the cell fullscreen?
Thank you
The way I do this sort of thing is actually to treat this as a master-detail interface. The gesture does not really expand the cell; it does a "push" of another view controller containing the full-screen version. And it does it with a custom transition animation, so that it looks like the cell is expanding to form the full-screen version.
And the same thing when returning (popping), in reverse.
This is an example; it isn't 100% identical to what you're doing, but it shows how the push-plus-custom-animation can give the sort of effect you're after:
You can also monitor frame changes in your cell class and expand when the cell is pressed, (not scroll if that's what you really want) and by monitoring frame change you can expand the cells height. Let me know if you want more information because this is on selection, not on scroll.

Dynamically updating cell height without having to scroll Swift

By default the height of my cell is set to 140.
But if expanded, it should be set to 265.
This is what I have:
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat
{
if(expanded){
return 265.0
}else{
return 140.0
}
}
The problem is, I need to scroll down, and scroll back up for the cell to change height. How do I fix this?
Secondary question (more interested in the above question, just if anyone happens to know)
Is it possible to have the cell animate from height 140 to 165?
Thanks
You need to reload the table view after you change anything in it like so:
tableView.reloadData()
When you scroll away from the cell, if it goes off the screen it is unloaded. When you scroll back up, it reloads it. You are basically just reloading the data as scrolling would do.
This code should work here:
tableView.reloadData()
It will reload the table everytime you changes something.
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