i have this structure. Scrollview -> UICollectionview + Label
This viewcontroller has array of items (BlockItem). On scrollViewDidScroll i change current test label (description)
func scrollViewDidScroll(_ scrollView:UIScrollView)
{
let midX:CGFloat = scrollView.bounds.midX
let midY:CGFloat = scrollView.bounds.midY
let point:CGPoint = CGPoint(x:midX, y:midY)
guard
let indexPath:IndexPath = collectionView.indexPathForItem(at:point)
else
{
return
}
let currentPage:Int = indexPath.item
if let found = items.first(where: {$0.id == String(block[currentPage])}) {
description.text = found.description
}
}
The main issue that i want my description label will be moving together when i move my collectionview cell and appear from the next cell. In other words, if I scroll to the left my description should move along with the cell, i.e. go to the left and appear on the right of the screen.
How can i do this? I know i could make a big collectionview but i need that only image part should be scrollable, not the entire block.
Here is what i want to achieve
Here is video example: scroll works only if i swipe on the image area, and doesn't work when i scroll down the page
https://drive.google.com/file/d/1kl1GYgXvK4bL3toTfOvpxF2WqS56pQO9/view?usp=sharing
You exactly said this:
"The main issue that I want my description label will be moving together when I move my collection view cell and appear from the next cell."
If you want your description label moving together, just include them into your collection cell. It's very clear from your point there
I don't understand why u need to separate it, but you want it to slide from new cell.
If you insisted that you want to archive the label, not in a scroll view, then use 2 label
One label for this cell and one label will come from scroll direction, u can archive this by creating manually. This is a simple code for a swipe left to scroll
UIView.animate(withDuration: 0.5) {
//insert your label animation
//current label moved with the scroll to left
//create a new label from the outer right of the current view, scroll it to the middle of your view
}
But it will be hard work for good animation or scroll support.
Related
I have a specific design that I want to achieve, it doesn't seems to complex to me but I'm struggling a lot to make it happen.
First the design looks like this:
So, I have a table view of items which have a picture, then a title and then a collection of three items which will be ImageViews.
All of this inside a cell and inside a stackView.
I tried to make an horizontal stack view and did manage to append my items correctly but it went horribly wrong in terms of design as my imageviews were stretching all the way horizontally. I guess this is not possible to NOT stretch this items.
I also tried to add a collection view into the table view but figured out that was very complex for a thing this basic (as I guess it should be). And then, I'm here.
Here is my code and where I'm stuck at:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = debateList.dequeueReusableCell(withIdentifier: "itemsBox", for: indexPath) as! ItemBox
// Make a variable with 3 participants
let participants = tableView[indexPath.row].participants?.prefix(3)
// iterate over them and adding them to anything that can be doable
participants?.forEach { participant in
let imageView = UIImageView()
let imageUrl = URL(string: participant.imageURL)
imageView.kf.setImage(with: imageUrl)
// Here add item to something
}
return cell
}
I'm stuck and it's getting too long for something this little. Guess I'm a little bit upset with myself for not figuring out how to do it.
If you are having up to 5 participants, then I would suggest you to add by default 2 subviews in horizontal stack view:
empty view with width constraint >= 5 (call it spaceview)
fixed width for "60 % no" UILabel.
then programmatically insert image views with fixed width and aspect ratio 1:1 in horizontal stack view at index 0.
This way, if there will be only 1-2 participants, then the remaining space will be occupied by spaceview as its width will be greater than 5.
If the participants will be more than 5, then better option is to use collectionview with uilabel in horizontal stack view.
First if they are 3 static number of images then it's better to make them inside design and assign the image urls to their outlets respectively
Second for your current work you need to add a width constraint (regarding height they will fit all the stack height when it's a horizontal stack ) like
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.widthAnchor.constraint(equalToConstant: 50).isActive = true
I'm creating an app that needs to show a tableview like below image
Similar colored circles are to be matched with a line.
Which view i can add the lines?
Or need to create a new view above tableview? But still my tableview needs to be scrolled.
How can i achieve this?
Update for Bounty
I want to implement the same with incliend lines between neighbouring circles. How to achieve the same?
Demonstration below:
create design like this
Based on your requirement just hide upper line and lower line of circle
You need to create collection view in tableview cell. In collection view you create one cell. Design the same user interface like your design. Show and hide the view with matching of rule. It will not affect tableview scrolling. and with this approach you can also provide scroll in collection view cell. i can provide you coded solution if you able to provide me more information. Thanks
You can use this Third Party LIb
You need to use a combination of collection view and a table view to give support for all devices.
1.Create one collection view cell with following layout
Hide upper and lower lines as per your need
Add collection view in table view cell and managed a number of cells in collection view depending upon the current device width and item's in between spacing.
You can create a vertical label without text, set the background color with black and place it behind the circle in view hierarchy and set a width of the label as per your requirement. Then you can hide unhide the label whenever you want.
P.S.: Make sure to hide your cell separator.
I have created a demo project. You can find it here. I tried to match your requirements. You can update the collection view settings to handle the hide and show of labels.
Let me know if you have any questions.
Hope this help.
Thanks!
To connect any circle with any other circle in the cell above / below, it will be easier and cleaner to create the connection lines dynamically rather than building them into the asset as before. This part is simple. The question now is where to add them.
You could have the connection lines between every two cells be contained in the top or bottom cell of each pair, since views can show content beyond their bounds.
There's a problem with this though, regardless of which cell contains the lines. For example, if the top cell contains them, then as soon as it is scrolled up off screen, the lines will disappear when didEndDisplayingCell is called, even though the bottom cell is still completely on screen. And then scrolling slightly such that cellForRow is called, the lines will suddenly appear again.
If you want to avoid that problem, then here is one approach:
One Approach
Give your table view and cells a clear background color, and have another table view underneath to display a new cell which will contain the connection lines.
So you now have a background TVC, with a back cell, and a foreground TVC with a fore cell. You add these TVC's as children in a parent view controller (of which you can set whatever background color you like), disable user interaction on the background TVC, and peg the background TVC's content offset to the foreground TVC's content offset in an observation block, so they will stay in sync when scrolling. I've done this before; it works well. Use the same row height, and give the background TVC a top inset of half the row height.
We can make the connection lines in the back cell hug the top and bottom edges of the cell. This way circles will be connected at their centre.
Perhaps define a method in your model that calculates what connections there are, and returns them, making that a model concern.
extension Array where Element == MyModel {
/**
A connection is a (Int, Int).
(0, 0) means the 0th circle in element i is connected to the 0th circle in element j
For each pair of elements i, j, there is an array of such connections, called a mesh.
Returns n - 1 meshes.
*/
func getMeshes() -> [[(Int, Int)]] {
// Your code here
}
}
Then in your parent VC, do something like this:
class Parent_VC: UIViewController {
var observation: NSKeyValueObservation!
var b: Background_TVC!
override func viewDidLoad() {
super.viewDidLoad()
let b = Background_TVC(model.getMeshes())
let f = Foreground_TVC(model)
for each in [b, f] {
self.addChild(each)
each.view.frame = self.view.bounds
self.view.addSubview(each.view)
each.didMove(toParent: self)
}
let insets = UIEdgeInsets(top: b.tableView.rowHeight / 2, left: 0, bottom: 0, right: 0)
b.tableView.isUserInteractionEnabled = false
b.tableView.contentInset = insets
self.b = b
self.observation = f.tableView.observe(\.contentOffset, options: [.new]) { (_, change) in
let y = change.newValue!.y
self.b.tableView.contentOffset.y = y // + or - half the row height
}
}
}
Then of course there's your drawing code. You could make it a method of your back cell class (a custom cell), which will take in a mesh data structure and then draw the lines that represent it. Something like this:
class Back_Cell: UITableViewCell {
/**
Returns an image with all the connection lines drawn for the given mesh.
*/
func createMeshImage(for mesh: [(Int, Int)]) -> UIImage {
let canvasSize = self.contentView.bounds.size
// Create a new canvas
UIGraphicsBeginImageContextWithOptions(canvasSize, false, 0)
// Grab that canvas
let canvas = UIGraphicsGetCurrentContext()!
let spacing: CGFloat = 10.0 // whatever the spacing between your circles is
// Draw the lines
for each in mesh {
canvas.move(to: CGPoint(x: CGFloat(each.0) * spacing, y: 0))
canvas.addLine(to: CGPoint(x: CGFloat(each.1) * spacing, y: self.contentView.bounds.height))
}
canvas.setStrokeColor(UIColor.black.cgColor)
canvas.setLineWidth(3)
canvas.strokePath()
let image = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return image
}
}
You'd probably want to create a Mesh class and store the images in that model, to avoid redrawing.
So heres my issue, the 4 orange rectangles you see on the gif are a single vertical UICollectionView = orangeCollectionView.
The Green and Purple "card" views are part of another UICollectionView = overlayCollectionView.
overlayCollectionView has 3 cells, one of which is just a blank UICollectionViewCell, the other 2 are the cards.
When the overlayCollectionView is showing the blank UICollectionViewCell, I want to be able to scroll the orangeCollectionView.
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
guard let superr = superview else { return true}
for view in superr.subviews {
if view.isKind(of: OrangeCollectionView.self) {
view.point(inside: point, with: event)
return false
}
}
return true
}
This allows me to scroll the orangeCollectionView HOWEVER this doesn't actually work to fix my issue. I need to be able to scroll left and right to show the cards, however this blocks all touches becuase the point always falls on the OrangeCollectionView.
How can I check to see if they are scrolling left/right to show the cards? Otherwise if they are on the blank cell, scroll the orangeViewController up and down.
Had this issue as well... Didn't find a nice way to do it, but this works.
First, you need to access the scroll view delegate method scrollViewDidScroll(). There you call:
if scrollView == overlayScrollView {
if scrollView.contentOffset.x == self.view.frame.width { // don't know which coordinate you need
self.overlayScrollView.alpa = 0
}
}
After that, you add a blank view onto of the orange collection view. The view's alpha is 0 (I think, maybe the color is just clear; try it out if it works).
In the code, you then add a UISwipeGestureRecognizer to the view you just created and and detect whether there's a swipe to the left or to the right.
By detecting the direction of that swipe, you can simply change the contentOffset.x axis of your overlayScrollView to 0 or self.view.frame.width * 2.
Sorry I can't provide my working sample code, I'm answering from my mobile. It's not the proper solution, but when I made a food app for a big client it worked perfectly and no one ever complained :)
Say you have a table view T which shows messages,
T[ message d
T[ message c
T[ message b
T[ most recent message down bottom
Say there are 100 messages, with the bottom 4 visible in the example.
So the table view height is 700 say. You have a typical text entry underneath...
T[ message d
T[ message c
T[ message b
T[ most recent message down bottom
[enter snapped chat message!] [send]
When the keyboard appears, the new height of the visible table view is 400 say.
Of course, that will "cut off the bottom" of the messages - the most recent two will no longer be visible.
T[ message d
T[ message c
[enter snapped chat message!] [send]
[ iOS keyboard ]
[ iOS keyboard ]
(So, messages A and B are now "under" the keyboard.)
Naturally what you do is just scroll the table after the keyboard appears, for example. No problem doing it in an ad-hoc manner.
However, it would be really natural if one could subclass UITableView in such a way that, as the size of the visible area changed, the table view knew to keep the "bottom point" identical.
So, as the bottom of the table moves up and down (due to keyboard appearing - or whatever cause), the table would scroll actually based on the movement of the "base" of the table.
(Apart from anything else this would solve the "match the animation timing" nuisance.)
Could this be achieved elegantly and if so how - indeed this would seem so natural these days, perhaps it's built-in to UITableView as a flag and I just don't know?
once again the question here is
How to modify UITableView so that it moves its own scroll position, as, the view size changes...
(so as to keep the "bottom point the same")
Note that it's trivial to just scroll the table "manually" as it were from the outside.
Section headers stick to the top, so maybe something like this:
1. Make the most recent message a section header view instead of a table cell
2. Mirror the table view vertically:
tableView.transform = CGAffineTransformMakeScale(1, -1);
3. Mirror vertically the section header and table cells
4. Reverse the order of your messages
Is that what you were looking for?
This is a way late answer, but I just solved the problem a bit more elegantly than the very ingenious accepted solution.
You'll need to have the following AutoLayout constraints (I'll omit the horizontal constraints):
UITableView.top = Safe Area.top
UITableView.bottom = MessageContainerView.top
MessageContainerView.bottom = Safe Area.bottom
MessageContainerView is where I keep the message text view and button. Now, in your ViewController add an IBOutlet for the bottom constraint of MessageContainerView:
#IBOutlet weak var messageContainerBottomConstraint: NSLayoutConstraint!
Next step is animating the bottom constraint's constant to be equal to the keyboard height + the safe area at the bottom and scrolling the table to the bottom when the keyboard is shown (add an observer for the notification as well):
#objc func showKeyboard(_ notification: NSNotification) {
guard let userInfo = notification.userInfo,
let targetFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue,
let animationTime = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double
else {
return
}
let safeAreaBottom = view.safeAreaInsets.bottom
messageContainerBottomConstraint.constant = -targetFrame.cgRectValue.height + safeAreaBottom
UIView.animate(withDuration: animationTime) {
self.view.layoutIfNeeded()
self.tableView.scrollToBottom()
}
}
Note that we use UIResponder.keyboardAnimationDurationUserInfoKey for the animation timing, so everything will be smooth.
Lastly, tableView.scrollToBottom() is an Extension for UITableView:
import UIKit
extension UITableView {
func scrollToBottom() {
let numberOfSections = self.numberOfSections
let numberOfRowsInSection = self.numberOfRows(inSection: numberOfSections - 1)
let indexPathForLastRow = IndexPath(row: numberOfRowsInSection - 1, section: numberOfSections - 1)
self.scrollToRow(at: indexPathForLastRow, at: .bottom, animated: false)
}
}
Let me know if you can try it, and if I missed anything.
(I did notice you asked for a way to modify the native UITableView behavior instead of "manually" scrolling, but I think this is a valid way of solving the problem)
As far as I know, you have a few choices for doing this:
If you have the indexPath of the row you want to be visible:
tableView.ScrollToRow(indexPath, UITableViewScrollPosition.Top, true);
This will scroll to the cell given by the indexPath. In this case you are selecting the option to show it on the .Top of the screen.
If you don't have the indexPath, you can use:
tableView.ScrollRectToVisible(new RectangleF(0, Ydisplacement, tableView.Width, tableView.Height), true);
Let's say that if you press the button from the bottom of the screen after typing something in the account text field, you would be required to also enter the password like in the second image.
How should I do this? I don't think that creating a new view controller would be good. So, should I somehow modify the same view controller?
How could I add the new password text field under the account text field?
Keep in mind that they are still centered. Hiding and unhiding wouldn't work in this case and I also need to modify more things than only adding that text field.
First, create a UIView with everything you need on them. in this example I will have only two text fields and they are all color coded.
The view needs to be centered both horizontally and vertically, with width and height. Set identifiler for the height constraint to be updated later. Set the clip to board to true so that when we redeuce the height of the view, text fields below will hide. The settings for the view will be like this
For your text fields, they must have a constant padding to top. In my example, they are set to be in center horizontally, having a constant height, width and padding to opp.
Now, all you need to do is to get the height of the view from code and set the height to show or hide the text fields.
var flag = true
#IBAction func click(_ sender: Any) {
if flag {
flag = false
let filteredConstraints = theView.constraints.filter { $0.identifier == "viewHeight" }
if let heightConstraint = filteredConstraints.first {
heightConstraint.constant = 60
}
} else {
flag = true
let filteredConstraints = theView.constraints.filter { $0.identifier == "viewHeight" }
if let heightConstraint = filteredConstraints.first {
heightConstraint.constant = 128
}
}
}
Here is the code running in simulater.
another option is you can make tableView at Center, you need to create tableview height constraint outlet,
then you can maintain a counter how many time you want to add View, the counter should be return in tableView numberOfRowsInSection,
and you can make this view in Prototype Cell or using NIB, then just adjust header label text, textField placeholder and text on specific cell index,
when you increase or decrease counter update tableView Constraint, example you have a cell height as 50, in first case when you have on cell in tableView, you can set your tableView height constraint's constant as 50, when cells are two the 100 and so on.....
I think it's a simple logic