Using same UIActivityIndicatorView in many view controllers - ios

Question

I have a simple iOS app with various view controllers.
Each view controller has different functionality but each view controller has 'load' button, that when triggered, sending a request and getting a result to delegate method.
I want to use an UIActivityIndicatorView that will start when the user will click the button and will stop on the delegate method.
Obviously, I want the indicator to look the same on each VC, so I've made property of it, and on each viewDidLoad method I am using this code:
self.indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
self.indicator.backgroundColor = [UIColor colorWithWhite:0.0f alpha:0.6f];
self.indicator.frame = CGRectMake(40.0, 20.0, 100.0, 100.0);
self.indicator.center = self.view.center;
The problem is, I am using the same parameters, on the same object, copping and pasting these lines on every view controller.
Let's say I want to change the style in the next version, I need to change it 10 times.
What would be the best way to use some kind of static indicator that would be set with these parameters and would be set on and off by demand?

Answer 1

Here is the one i use in swift 4.1
import UIKit
class ProgressView {
// MARK: - Variables
private var containerView = UIView()
private var progressView = UIView()
private var activityIndicator = UIActivityIndicatorView()
static var shared = ProgressView()
// To close for instantiation
private init() {}
// MARK: - Functions
func startAnimating(view: UIView = (UIApplication.shared.keyWindow?.rootViewController?.view)!) {
containerView.center = view.center
containerView.frame = view.frame
containerView.backgroundColor = UIColor(hex: 0xffffff, alpha: 0.5)
progressView.frame = CGRect(x: 0, y: 0, width: 80, height: 80)
progressView.center = containerView.center
progressView.backgroundColor = UIColor(hex: 0x444444, alpha: 0.7)
progressView.clipsToBounds = true
progressView.cornerRadius = 10
activityIndicator.frame = CGRect(x: 0, y: 0, width: 60, height: 60)
activityIndicator.center = CGPoint(x: progressView.bounds.width/2, y: progressView.bounds.height/2)
activityIndicator.style = .whiteLarge
view.addSubview(containerView)
containerView.addSubview(progressView)
progressView.addSubview(activityIndicator)
activityIndicator.startAnimating()
}
/// animate UIActivityIndicationView without blocking UI
func startSmoothAnimation(view: UIView = (UIApplication.shared.keyWindow?.rootViewController?.view)!) {
activityIndicator.frame = CGRect(x: 0, y: 0, width: 60, height: 60)
activityIndicator.center = view.center
activityIndicator.style = .whiteLarge
activityIndicator.color = UIColor.gray
view.addSubview(activityIndicator)
activityIndicator.startAnimating()
}
func stopAnimatimating() {
activityIndicator.stopAnimating()
containerView.removeFromSuperview()
}
}
extension UIColor {
convenience init(hex: UInt32, alpha: CGFloat) {
let red = CGFloat((hex & 0xFF0000) >> 16)/256.0
let green = CGFloat((hex & 0xFF00) >> 8)/256.0
let blue = CGFloat(hex & 0xFF)/256.0
self.init(red: red, green: green, blue: blue, alpha: alpha)
}
}
// usage
ProgressView.shared.startAnimating()
// to stop
ProgressView.shared.stopAnimatimating()
Hope it helps

Answer 2

I would suggest that you create a superclass to your view controllers and add the spinner functionality there, and let your view controllers inherit from it.
The superclass view controller would look something like this:
// .h-file
#interface SuperclassViewController : UIViewController
- (void)showIndicator;
- (void)hideIndicator;
#end
// .m file
#import "SuperclassViewController.h"
#interface SuperclassViewController ()
#property (nonatomic, strong) UIActivityIndicatorView *indicator;
#end
#implementation SuperclassViewController
- (void)viewDidLoad {
[super viewDidLoad];
_indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
self.indicator.backgroundColor = [UIColor colorWithWhite:0.0f alpha:0.6f];
self.indicator.frame = CGRectMake(40.0, 20.0, 100.0, 100.0);
self.indicator.layer.cornerRadius = 6;
self.indicator.center = self.view.center;
[self.indicator startAnimating];
}
- (void)showIndicator {
[self.view addSubview:self.indicator];
}
- (void)hideIndicator {
[self.indicator removeFromSuperview];
}
#end
Now, to inherit it do the following in your view controllers .h file:
#import "SuperclassViewController.h"
#interface YourViewController : SuperclassViewController;
/** properties and methods */
#end
Then you can call [self showIndicator] and [self hideIndicator] in your view controllers whenever needed without any extra coding.

Answer 3

You can create single view controller to display loading indicator in all view controller. You need to write code once, put following code in AppDelegate file.
Note: I'm not working in Objective-C, following code in Swift. So you need to transform code in objective C.
First add following code in ProgressVC:
ProgressVC.swift:
class func viewController() -> ProgressVC {
return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ProgressVC") as! ProgressVC
}
Add following code in your AppDelegate.
AppDelegate.swift:
var progressVC : ProgressVC?
static let shared = UIApplication.shared.delegate as! AppDelegate
func showLoading(isShow: Bool) {
if isShow {
// Remove progress view if already exist
if progressVC != nil {
progressVC?.view.removeFromSuperview()
progressVC = nil
}
progressVC = ProgressVC.viewController()
AppDelegate.shared.window?.addSubview((progressVC?.view)!)
} else {
if progressVC != nil {
progressVC?.view.removeFromSuperview()
}
}
}
Now, you need to call just above method with AppDelegate's shared instance. Enable animated property of UIActivityIndicatorView from storyboard.
Show:
AppDelegate.shared.showLoading(isShow: true)
Hide:
AppDelegate.shared.showLoading(isShow: false)
Screenshot:

Answer 4

You could create the activity indicator in the UIWindow and then you could show/hide it from any UIViewController.
To get the window use:
UIApplication.shared.keyWindow

Answer 5

Thank you all for your assistance,
I decided to make a singleton class that has a variable of UIActivityIndicatorView.
This is the declaration of the class:
#import "ProgressView.h"
#interface ProgressView()
#property (nonatomic) UIActivityIndicatorView *indicator;
+(ProgressView *)shared;
#end
#implementation ProgressView
+ (ProgressView *)shared {
static ProgressView* sharedVC = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedVC = [[self alloc] init];
});
return sharedVC;
}
- (instancetype)init {
self = [super init];
if (self) {
self.indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
self.indicator.backgroundColor = [UIColor colorWithWhite:0.0f alpha:0.6f];
self.indicator.frame = CGRectMake(40.0, 20.0, 100.0, 100.0);
}
return self;
}
- (void)startAnimation:(UIView *)view {
self.indicator.center = view.center;
self.indicator.hidden = NO;
[self.indicator startAnimating];
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 12 * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
if ([self.indicator isAnimating])
[self stopAnimation];
});
[view addSubview:self.indicator];
}
- (void)stopAnimation {
if ([self.indicator isAnimating]) {
[self.indicator stopAnimating];
[self.indicator removeFromSuperview];
}
}
#end
Please note I have added a rule that if the indicator didn't get triggered to stop in 12 seconds the class would stop the indicator by itself.
Now, all I have to do is to add this line in every place in my code where I would like to start the indicator:
[[ProgressView shared] startAnimation:self.view];
And to add this line to stop it:
[[ProgressView shared] stopAnimation];