cancel button using MBProgressView - swift

Question

I am trying to use cancel button with the MBProgressView. I am getting the error "cannot convert value of type '()' to expected argument type 'Selector'"
hud.button.addTarget(hud.progressObject, action: cancelButton(), for: .touchUpInside)
I have also tried doing this:
hud.button.addTarget(hud.progressObject, action: #selector(cancelButton), for: .touchUpInside)
and I got the error "Argument of #selector cannot refer to local function 'cancelButton()'".
Can anyone explain to me what am i doing wrong?
cancelButton should be in viewDidLoad or at least I need to find a way to access what's inside viewDidload, because I need to use hud and snapshot.progress to cancel the download:
override func viewDidLoad() {
super.viewDidLoad()
let appdelegate = UIApplication.shared.delegate as! AppDelegate
appdelegate.orintation = UIInterfaceOrientationMask.allButUpsideDown
if book?.bookPath != book?.bookPath {
print("HERE \(book?.bookPath)")
loadReader(filePaht: (book?.bookPath)!)
} else {
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
let strName = book?.id
let filePath = "\(documentsPath)/"+strName!+".pdf"
let fileManager = FileManager.default
if fileManager.fileExists(atPath: filePath) {
loadReader(filePaht: filePath)
return;
}
print("DOWNLOAD #1")
let reference = FIRStorage.storage().reference(forURL: (self.book?.bookURL)!)
let downloadTask = reference.data(withMaxSize: 50 * 1024 * 1024) { (data, error) -> Void in
if (error != nil) {
} else {
if ((try! data?.write(to: URL.init(fileURLWithPath: filePath, isDirectory: false))) != nil) {
self.db.upDate(id: (self.book?.id)!, bookPath: filePath)
self.loadReader(filePaht: filePath)
}
}
}
downloadTask.observe(.resume) { (snapshot) -> Void in
// Download resumed, also fires when the download starts
}
downloadTask.observe(.pause) { (snapshot) -> Void in
// Download paused
}
downloadTask.observe(.progress) { (snapshot) -> Void in
DispatchQueue.global(qos: .default).async(execute: {() -> Void in
self.showHUDWithCancel("Downloading")
DispatchQueue.main.async(execute: {() -> Void in
})
})
self.hud.progressObject = snapshot.progress
}
downloadTask.observe(.success) { (snapshot) -> Void in
// Download completed successfully
print("Download Success")
SwiftLoader.hide()
}
downloadTask.observe(.failure) { (snapshot) -> Void in
//Download failed
print("Download failed")
}
}
}
func showHUDWithCancel(_ aMessage: String) {
self.hud = MBProgressHUD.showAdded(to: self.view, animated: true)
self.hud.mode = MBProgressHUDMode.annularDeterminate
self.hud.label.text = aMessage
self.hud.detailsLabel.text = "Tap to cancel"
let tap = UITapGestureRecognizer(target: self, action: #selector(cancelButton))
self.hud.addGestureRecognizer(tap)
}
func cancelButton() {
self.hud.hide(animated: true)
self.hud.progressObject?.cancel()
print("cancel button is working")
}
This is the Cancel Button function
func cancelButton() {
MBProgressHUD.hide(for: view, animated: true)
snapshot.progress?.pause()
}

Answer 1

Try this -
Call below showHUDWithCancel from where you want to add hud with Cancel.
class ViewController: UIViewController {
var hud = MBProgressHUD()
override func viewDidLoad() {
super.viewDidLoad()
}
func showHUDWithCancel(_ aMessage: String) {
self.hud = MBProgressHUD.showAdded(to: self.view, animated: true)
self.hud.label.text = aMessage
self.hud.detailsLabel.text = "Tap to cancel"
let tap = UITapGestureRecognizer(target: self, action: #selector(cancelButton))
self.hud.addGestureRecognizer(tap)
}
func cancelButton() {
self.hud.hide(animated: true)
// do your other stuff here.
}
}
Add this code within your viewDidLoad it will work.
override func viewDidLoad() {
super.viewDidLoad()
let appdelegate = UIApplication.shared.delegate as! AppDelegate
appdelegate.orintation = UIInterfaceOrientationMask.allButUpsideDown
if book?.bookPath != book?.bookPath {
print("HERE \(book?.bookPath)")
loadReader(filePaht: (book?.bookPath)!)
} else {
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
let strName = book?.id
let filePath = "\(documentsPath)/"+strName!+".pdf"
let fileManager = FileManager.default
if fileManager.fileExists(atPath: filePath) {
loadReader(filePaht: filePath)
return;
}
print("DOWNLOAD #1")
let reference = FIRStorage.storage().reference(forURL: (self.book?.bookURL)!)
downloadTask = reference.data(withMaxSize: 50 * 1024 * 1024) { (data, error) -> Void in
if (error != nil) {
} else {
if ((try! data?.write(to: URL.init(fileURLWithPath: filePath, isDirectory: false))) != nil) {
self.db.upDate(id: (self.book?.id)!, bookPath: filePath)
self.loadReader(filePaht: filePath)
}
}
}
downloadTask.observe(.resume) { (snapshot) -> Void in
// Download resumed, also fires when the download starts
}
downloadTask.observe(.pause) { (snapshot) -> Void in
// Download paused
}
downloadTask.observe(.progress) { (snapshot) -> Void in OperationQueue.main.addOperation {
OperationQueue.main.addOperation {
self.hud.progressObject = snapshot.progress
self.showHUDWithCancel("Downloading")
}
}
}
downloadTask.observe(.success) { (snapshot) -> Void in OperationQueue.main.addOperation {
// Download completed successfully
print("Download Success")
OperationQueue.main.addOperation {
SwiftLoader.hide()
}
}
}
downloadTask.observe(.failure) { (snapshot) -> Void in OperationQueue.main.addOperation {
//Download failed
print("Download failed")
OperationQueue.main.addOperation {
_ = self.navigationController?.popViewController(animated: false)
}
}
}
}
}

Answer 2

Move definition of downloadTask outside of the viewDidLoad method scope into the class itself. This way you'll be able to access task directly, not via snapshot passed in observers, or progress attached to either downloadTask or progressHUD. Doing so you could access task from any method of your view controller including cancelButton():
task.pause()
instead of
snapshot.progress?.pause()
Final code could look like:
class ViewController: UIViewController {
var downloadTask: FIRStorageDownloadTask!
...
override func viewDidLoad() {
super.viewDidLoad()
...
let reference = FIRStorage.storage().reference(forURL: (self.book?.bookURL)!)
downloadTask = reference...
...
}
}

Answer 3

NOTICE: For those of you who use the latest version of MBProgressView, the button documentation has been changed:
/**
* A button that is placed below the labels. Visible only if a target / action is added and a title is assigned..
*/
So, the creation should look something like the following:
class Tools {
static func popLoadingDialog(viewParent: UIView,
label: String,
cancelTarget: Any? = nil,
cancelSelector: Selector? = nil) -> MBProgressHUD {
let loadingNotification = MBProgressHUD.showAdded(to: viewParent, animated: true)
loadingNotification.mode = MBProgressHUDMode.indeterminate
loadingNotification.label.text = label
if(cancelSelector != nil) {
loadingNotification.button.setTitle("Cancel", for: .normal)
loadingNotification.button.addTarget(cancelTarget, action: cancelSelector!, for: .touchUpInside)
}
return loadingNotification
}
}
and call it:
loadingIndicator = Tools.createLoadingDialog(viewParent: view,
label: "Please wait...",
cancelTarget: self,
cancelSelector: #selector(onCancelClick))
loadingIndicator?.show(animated: true)
}
#objc func onCancelClick(){
// do something when the user click on cancel...
}