How i can disable drag interaction on specific sections or cells if
tableView.dragInteractionEnabled = true ?
Now all table cells draggable, but i want to drag specific rows in this table.
Is it possible?
You can natively allow/disallow moving cells with the canMoveRowAt method:
func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool {
return yourDataSource[indexPath.row] is YourMovableCellClass
}
You could do it by returning an empty array in tableView(_:itemsForBeginning:at:)
Return value
An array of UIDragItem objects representing the contents of the specified row. Return an empty array if you do not want the user to drag the specified row.
https://developer.apple.com/documentation/uikit/uitableviewdragdelegate/2897492-tableview
In my case (it's a collection view, but approach is the same) I check type of the cell and allow/forbid dragging depending on it:
func collectionView(_ collectionView: UICollectionView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
if let cell = collectionView.cellForItem(at: indexPath) as? CalendarCollectionCell {
let item = cell.calendar!
let itemProvider = NSItemProvider(object: item.name! as NSString)
let dragItem = UIDragItem(itemProvider: itemProvider)
dragItem.localObject = item
return [dragItem]
} else {
return [UIDragItem]()
}
}
Yes, this is possible. First, you need to define which cells are draggable.
In your tableView(cellForRowAt...) method set up a conditional check of some sort.
// Some code to set up your cell
// All cells are disabled by default
// Only enable the one you want to drag.
cell.userInteractionEnabled = false
// Use this conditional to determine which cells
// become dragable.
if indexPath.row % 2 = 0 {
// This is the cell you want to be able to drag.
cell.userInteractionEnabled = true
}
return cell
Related
I'm making a music app recently, and I'd like to know how to pass data from CollectionView to TableView which has several sections. Here is the home page of my project, and what I want to do is when user tap the image, it will precent another ViewController with the information about the picture. I already know how to present a ViewController by clicking CollectionViewCell inside TableView by delegate, but only if there's only one section.
The thing is that I have 5 sections in this page, and I also have 5 different models for encoding the JSON from API. So how I show the pictures is to send the image urls(from 5 models) to TableViewCell in each section like this:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: HomeTableViewCell.identifier, for: indexPath) as? HomeTableViewCell else { return UITableViewCell() }
cell.delegate = self
switch homeSections[indexPath.section] {
case .newReleases:
if let newReleases = self.newReleases?.albums.items.map({$0.images[0].url}) {
cell.getPictures = newReleases
}
return cell
case .followSingers:
if let currentlyFollowing = self.currentlyFollowing?.artists.items.map({$0.images[0].url}) {
cell.getPictures = currentlyFollowing
cell.isCircle = true
}
return cell
case .catrgories:
if let categories = self.musicCategory?.playlists.items.map({$0.images[0].url}) {
cell.getPictures = categories
}
return cell
case .artists:
if let playlist = self.relatedArtists?.artists.map({$0.images[0].url}){
cell.getPictures = playlist
}
return cell
case .recentlyPlayed:
if let recentlyPlayed = self.recentlyPlayed?.items?.map({$0.track.album.images[0].url}) {
cell.getPictures = recentlyPlayed
}
return cell
}
}
However, when I want to pass the information which the user tap, there's nothing I can pass but indexPath. I've tried to declare the 5 different model types in TableViewCell, but I still don't know which section did the user tap. Does anyone can help? Thanks a lot!
Update:
To make the question more clearly, please refer to the information below.
In this page, I have a TableView and embed a CollectionView in the TableViewCell, and there's only one ImageView in the CollectionViewCell.
The "New Releases", "Currently Following" and "Categories" are the header of TableView. The "New Releases" is the first section, and the "Currently Following" is the second section, and so on.
Here is how I set cellForItem in CollectionView Delegate. It basically converts String to URL, and display the picture on the screen.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: HomeCollectionViewCell.identifier, for: indexPath) as? HomeCollectionViewCell else { return UICollectionViewCell() }
guard let url = URL(string: getPictures[indexPath.row]) else { return UICollectionViewCell() }
cell.myImageView.getImages(url: url)
if isCircle == true {
cell.myImageView.layer.cornerRadius = cell.myImageView.frame.width/2
}
return cell
}
When the user taps the image, it will only trigger the didSelectItemAt in CollectionView. And I can only pass indexPath.row so far.
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
delegate?.sendIndexPath(index: indexPath.row)
}
How do I make an UITableView which allows sections to either have single or multiple selection?
I have a single UITableView with multiple sections. I want some sections to allow multiple selections and some to only allow a single selection. This is what I currently have:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let cell = tableView.cellForRow(at: indexPath)
// Get the current question
if var question = self.questions[indexPath.section] as? MultipleChoiceQuestion {
// If question allows multiple selection set a checkmark and update question with selected answer
if question.hasMultiValue {
cell?.accessoryType = .checkmark
question.givenAnswer = question.answers[indexPath.row]
} else {
// Question is single selection only. This entire part goes wrong.
if let givenAnswerIsEmpty = question.givenAnswer {
cell?.accessoryType = .none
} else {
self.questions[indexPath.section].givenAnswer = question.answers[indexPath.row]
cell?.accessoryType = .checkmark
}
}
}
}
My objects all have the property hasMultiValue which indicates if a section should allow multiple selections or not. They also have the property givenAnswer which could be seen as a "isSelected" flag. The code above only works for multi selection.
I've been searching around for a solution. There are a few questions like this one but the solution involves using the delegate method didDeselectRowAt. This method won't get called unless I physically deselect the current cell which is not what I want.
What I do want is for example:
If you select row1 and change your mind to row2, you should be able to select row2 which automatically deselects row1.
You didn't try willSelectRowAt?
You can try this code, this is tested on a table view controller
var selectedItemInSection1: Int?
override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
// Just return the same index path if the section was not the second one
guard indexPath.section == 1 else { return indexPath }
// Get the previously selected item, and deselect it
if let prev = selectedItemInSection1 {
tableView.deselectRow(at: IndexPath.init(row: prev, section: 1), animated: true)
}
// Save the newly selected item index, to be deselected when other is selected in the same section
selectedItemInSection1 = indexPath.row
// Select the item
return indexPath
}
override func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
guard indexPath.section == 1 else { return }
// If it is in the second section, indicate that no item is selected now
selectedItemInSection1 = nil
}
I am fetching previously selected categorylist from the server. say for an example.cateogrylist i fetched from the server was in following formate
categoryid : 2,6,12,17
now what i need to do is want to enable checkmark in my tableview based on this categorylist,for that purpose i converted this list into an [Int] array like this :
func get_numbers(stringtext:String) -> [Int] {
let StringRecordedArr = stringtext.components(separatedBy: ",")
return StringRecordedArr.map { Int($0)!}
}
in viewDidLoad() :
selectedCells = self.get_numbers(stringtext: UpdateMedicalReportDetailsViewController.catId)
print(myselection)
while printing it's giving me results like this : [12,17,6,8,10]
i want to enable checkimage based on this array.I tried some code while printing its giving me the right result like whatever the categories i selected at the time of posting ,i am able to fetch it but failed to place back this selection in tableview.Requirement : while i open this page it should show me the selection based on the categorylist i fetched from the server.
var selectedCells : [Int] = []
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell1 = table.dequeueReusableCell(withIdentifier: "mycell") as! catcell
cell1.mytext.text = categoriesName[indexPath.row]
if UpdateMedicalReportDetailsViewController.flag == 1
{
selectedCells = self.get_numbers(stringtext: UpdateMedicalReportDetailsViewController.catId)
cell1.checkimage.image = another
print(selectedCells)
}
else
{
selectedCells = []
cell1.checkimage.image = myimage
}
return cell1
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let cell = table.cellForRow(at: indexPath) as! catcell
cell.checkimage.image = myimage
if cell.isSelected == true
{
self.selectedCells.append(indexPath.row)
cell.checkimage.image = another
}
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
let cell = table.cellForRow(at: indexPath) as! catcell
if cell.isSelected == false
{
self.selectedCells.remove(at: self.selectedCells.index(of: indexPath.row)!)
cell.checkimage.image = myimage
}
}
output :
This is a very common use case in most apps. I'm assuming you have an array of all categories, and then an array of selected categories. What you need to do is in cellForRowAtIndexPath, check to see if the current index path row's corresponding category in the "all categories" array is also present in the "selected categories" array. You can do this by comparing id's etc.
If you have a match, then you know that the cell needs to be selected/checked. A clean way to do this is give your cell subclass a custom load method and you can pass a flag for selected/checked.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = table.dequeueReusableCell(withIdentifier: "mycell") as! catcell
let category = self.categories[indexPath.row] // Let's say category is a string "hello"
Bool selected = self.selectedCategories.contains(category)
cell.load(category, selected)
return cell
}
So with the code above, let's say that categories is just an array of category strings like hello, world, and stackoverflow. We check to see if the selectedCategories array contains the current cell/row's category word.
Let's say that the cell we're setting up has a category of hello, and selectedCategories does contain it. That means the selected bool gets set to true.
We then pass the category and selected values into the cell subclass' load method, and inside that load method you can set the cell's title text to the category and you can check if selected is true or false and if it's true you can display the checked box UI.
I have a table with 3 rows each with check button.What I am doing is when I select all the three buttons I want to click my cancel button which is on view not table on same controller to reload all 3 rows the call goes to custom cell class where uncheck is set to true and rows are reloaded.For the first attempt it works fine I can see correct index to be reloaded.On the second time again when I select all 3 check buttons and click cancel again I can see correct index to be reloaded but the call is not going to custom cell class again the check box still remains checked.Any idea why?
I am always getting correct index in my array.
Cancel button code-:
#IBAction func cancelDataItemSelected(_ sender: UIButton) {
for index in selectedButtonIndex{
let indexPath = IndexPath(item: index, section: 0)
print(selectedButtonIndex)
filterTableViewController.reloadRows(at: [indexPath], with: UITableViewRowAnimation.none)
}
selectedButtonIndex .removeAll()
print(selectedButtonIndex)
}
Table code-:
extension filterControllerViewController:UITableViewDataSource,UITableViewDelegate
{
// NUMBER OF ROWS IN SECTION
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return ControllerData.count
}
// CELL FOR ROW IN INDEX PATH
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
let Cell = tableView.dequeueReusableCell(withIdentifier: "filterCell", for: indexPath) as! ControllerCellTableViewCell
Cell.filterTableMenu.text = ControllerData[indexPath.item]
Cell.radioButtonTapAction = {
(cell,checked) in
if let radioButtonTappedIndex = tableView.indexPath(for: cell)?.row{
if checked == true {
self.selectedButtonIndex.append(radioButtonTappedIndex)
}
else{
while self.selectedButtonIndex.contains(radioButtonTappedIndex) {
if let itemToRemoveIndex = self.selectedButtonIndex.index(of: radioButtonTappedIndex) {
self.selectedButtonIndex.remove(at: itemToRemoveIndex)
}
}
}
}
}
return filterCell
}
Custom Class-:
var radioButtonTapAction : ((UITableViewCell,Bool)->Void)?
//MARK-:awakeFromNib()
override func awakeFromNib() {
super.awakeFromNib()
filterTableSelectionStyle()
self.isChecked = false
}
// CHECKED RADIO BUTTON IMAGE
let checkedImage = (UIImage(named: "CheckButton")?.withRenderingMode(UIImageRenderingMode.alwaysOriginal))! as UIImage
// UNCHECKED RADIO BUTTON IMAGE
let uncheckedImage = (UIImage(named: "CheckButton__Deselect")?.withRenderingMode(UIImageRenderingMode.alwaysOriginal))! as UIImage
// Bool STORED property
var isChecked: Bool = false {
didSet{
// IF TRUE SET TO CHECKED IMAGE ELSE UNCHECKED IMAGE
if isChecked == true {
TableRadioButton.setImage(checkedImage, for: UIControlState.normal)
} else {
TableRadioButton.setImage(uncheckedImage, for: UIControlState.normal)
}
}
}
// FILTER CONTROLLER RADIO BUTTON ACTION
#IBAction func RadioButtonTapped(_ sender: Any) {
isChecked = !isChecked
radioButtonTapAction?(self,isChecked)
}
Fundamental misunderstanding of how "reusable" table cells work.
Let's say your table view is tall enough that only 8 cells are ever visible. It seems obvious that 8 cells will need to be created, and they will be reused when you scroll.
What may not be obvious is that the cells also are reused when they are reloaded. In other words, every time .reloadData is called - even if you are only reloading one cell that is currently visible - that cell is reused. It is not re-created.
So, the key takeaway point is: Any initialization tasks happen only when the cell is first created. After that, the cells are reused, and if you want "state" conditions - such as a checked or unchecked button - it is up to you to "reset" the cell to its original state.
As written, your cellForRowAt function only sets the .filterTableMenu.text ... it ignores the .isChecked state.
You can mostly fix things just by setting the cell's .isChecked value, but you're also tracking the on/off states in a much more complicated manner than need be. Instead of using an Array to append / remove row indexes, use an Array of Booleans, and just use array[row] to get / set the values.
Then your cellForRowAt function will look about like this:
// CELL FOR ROW IN INDEX PATH
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let filterCell = tableView.dequeueReusableCell(withIdentifier: "filterCell", for: indexPath) as! ControllerCellTableViewCell
// set the label in filterCell
filterCell.filterTableMenu.text = ControllerData[indexPath.item]
// set current state of checkbox, using Bool value from out "Tracking Array"
filterCell.isChecked = self.selectedButtonIndex[indexPath.row]
// set a "Callback Closure" in filterCell
filterCell.radioButtonTapAction = {
(checked) in
// set the slot in our "Tracking Array" to the new state of the checkbox button in filterCell
self.selectedButtonIndex[indexPath.row] = checked
}
return filterCell
}
You can see a working example here: https://github.com/DonMag/CheckBoxCells
Remember that the cells are reused and that reloadRows just tells the rows to redraw. When a checkbox in a cell is checked by the user, the new checked state should be saved in the underlying data source, and the state marked in the cell in cellForRowAtIndexPath. Otherwise the cell checkbox shows the state for the last time it was set by the user for all indices and not the state for the underlying data source.
I'm using a unclickable tableView to display different information of one object.
For this informations I have different custom cell types one where I placed a map, if my object have locations, one have a list with links, and another a multiple line label for a little description...for example.
I manage this cells with:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let cell: mapCell = tableView.dequeueReusableCellWithIdentifier("mapCell") as! MapCell
return cell
} else if indexPath.row == 1 {
let cell: textCell = tableView.dequeueReusableCellWithIdentifier("textCell") as! TextCell
return cell
} else if indexPath.row == 2 {
let cell: listCell = tableView.dequeueReusableCellWithIdentifier("listCell") as! ListCell
return cell
}
}
So far so good, everything working fine. My problem is, not every object needs a map, some of them just need some text and a list, other objects need a map and a list, other all of them. I want my tableView to skip some cells if there is a condition.
I know, I can make an symbolic array for changing the number of cells of my tableView, but that deleting just from the end of my tableView, not specific cells.
One of my ideas is to generate a empty cell, maybe with a height of 0 or 1 so that I can do something like this:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.row == 0 {
if mapCellNeeded {
let cell: mapCell = tableView.dequeueReusableCellWithIdentifier("mapCell") as! mapCell
} else {
let cell: emptyCell = tableView.dequeueReusableCellWithIdentifier("emptyCell") as! EmptyCell
}
return cell
} else if indexPath.row == 1 {
...
}...
}
put I don't know if there isn't an efficient way. Hope you guys can help me.
Your solution would work. Another approach (very nice and swifty) would be not to hardcode row numbers, but rather use enum instead:
enum InfoCellType {
case Map
case Text
case Links
}
...
var rows = [InfoCellType]()
...
// when you know what should be there or not
func constructRows() {
if (mapCellNeeded) {
rows.append(InfoCellType.Map)
}
rows.append(InfoCellType.Text)
... etc
}
Then in the table view methods just see what's the type for current indexPath:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellType: InfoCellType = self.rows[indexPath.row]
switch cellType {
case .Map:
let cell: mapCell = tableView.dequeueReusableCellWithIdentifier("mapCell") as! mapCell
return cell
case .Text:
...
case.Links:
...
}
}
This solution also allows to easily change order of rows - just change the order of items in rows array.