Customized Application Loader

Introduction

A loader is something in a service based app for loading data from the server, it takes time to download heavy data such as audio, images and so on. For a better user experience developers show an activity view until the download completes.

The following is the procedure to create and use it in an application.

Step 1

Open XCode by double-clicking on it.

Step 2

Create a UIView class like the following.



Step 3

Take User Interface View like the following:



Step 4

Now here we will write the code in the UIView class Objective-C file.

BActivityIndicator.h

#import < UIKit / UIKit.h >

@interface BActivityIndicator: UIView {
    CGAffineTransform rotationTransform;
}@property(weak, nonatomic) IBOutlet UILabel * pleaseWaitLabel;@property(weak, nonatomic) IBOutlet UIImageView * spinningImage;

- (id) initWithView: (UIView * ) view;

+ (BActivityIndicator * ) showHUDAddedTo: (UIView * ) view animated: (BOOL) animated;

+ (BOOL) hideHUDForView: (UIView * ) view animated: (BOOL) animated;

@end

BActivityIndicator.m

#import "BActivityIndicator.h"

@implementation BActivityIndicator

- (id) initWithFrame: (CGRect) frame {
    self = [super initWithFrame: frame];
    if (self) {
        self = [
            [
                [NSBundle mainBundle] loadNibNamed: @
                "BActivityIndicator"
                owner: self
                options: nil] lastObject];
        self.frame = frame;
        [self rotateLayerInfinite];

        self.pleaseWaitLabel.font = [UIFont fontWithName: @
        "RobotoCondensed-Regular"
        size: 14.0f];
    }
    return self;
}

- (id) initWithView: (UIView * ) view {
    // Let's check if the view is nil (this is a common error when using the windw initializer above)
    if (!view) {
        [NSException raise: @
        "MBProgressHUDViewIsNillException"
        format: @
        "The view used in the MBProgressHUD initializer is nil."];
    }
    id me = [self initWithFrame: CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];
    // We need to take care of rotation ourselfs if we're adding the HUD to a window
    if ([view isKindOfClass: [UIWindow class]]) {
        [self setTransformForCurrentOrientation: NO];
    }
    [
        [NSNotificationCenter defaultCenter] addObserver: self selector: @selector(deviceOrientationDidChange: )
        name: UIDeviceOrientationDidChangeNotification object: nil];

    return me;
}


- (void) rotateLayerInfinite {
    CABasicAnimation * rotation;
    rotation = [CABasicAnimation animationWithKeyPath: @
    "transform.rotation"];
    rotation.fromValue = [NSNumber numberWithFloat: 0];
    rotation.toValue = [NSNumber numberWithFloat: (2 * M_PI)];
    rotation.duration = 1.5f;
    rotation.repeatCount = HUGE_VALF;
    [_spinningImage.layer removeAllAnimations];
    [_spinningImage.layer addAnimation: rotation forKey: @
    "Spin"];
}

#pragma mark - #pragma mark Manual oritentation change

#define RADIANS(degrees)((degrees * (float) M_PI) / 180.0f)

- (void) deviceOrientationDidChange: (NSNotification * ) notification {
    if (!self.superview) {
        return;
    }
    if ([self.superview isKindOfClass: [UIWindow class]]) {
        [self setTransformForCurrentOrientation: YES];
    }
}

- (void) setTransformForCurrentOrientation: (BOOL) animated {
    UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
    NSInteger degrees = 0;

    // Stay in sync with the superview
    if (self.superview) {
        self.bounds = self.superview.bounds;
        [self setNeedsDisplay];
    }

    if (UIInterfaceOrientationIsLandscape(orientation)) {
        if (orientation == UIInterfaceOrientationLandscapeLeft) {
            degrees = -90;
        } else {
            degrees = 90;
        }
        // Window coordinates differ!
        self.bounds = CGRectMake(0, 0, self.bounds.size.height, self.bounds.size.width);
    } else {
        if (orientation == UIInterfaceOrientationPortraitUpsideDown) {
            degrees = 180;
        } else {
            degrees = 0;
        }
    }

    rotationTransform = CGAffineTransformMakeRotation(RADIANS(degrees));

    if (animated) {
        [UIView beginAnimations: nil context: nil];
    }
    [self setTransform: rotationTransform];
    if (animated) {
        [UIView commitAnimations];
    }
}

+ (BActivityIndicator * ) showHUDAddedTo: (UIView * ) view animated: (BOOL) animated {
    BActivityIndicator * hud = [
        [BActivityIndicator alloc] initWithView: view];
    [view addSubview: hud];
    return hud;
}

+ (BOOL) hideHUDForView: (UIView * ) view animated: (BOOL) animated {
    UIView * viewToRemove = nil;
    for (UIView * v in [view subviews]) {
        if ([v isKindOfClass: [BActivityIndicator class]]) {
            viewToRemove = v;
        }
    }
    if (viewToRemove != nil) {
        [viewToRemove removeFromSuperview];
        return YES;
    } else {
        return NO;
    }
}

- (void) dealloc {
    [_spinningImage.layer removeAnimationForKey: @
    "Spin"];
}

@end

ViewController.Xib



Step 7

Now here I’ll explain how to call that class within a project.

In your common Utility Class you need to write these functions for calling it:

#pragma mark - Activity Indicator + (void) startActivityIndicatorInView: (UIView * ) aView withMessage: (NSString * ) aMessage {
    //    MBProgressHUD *_hud = [MBProgressHUD showHUDAddedTo:aView animated:YES];
    //    _hud.dimBackground  = YES;
    //    _hud.labelText      = aMessage;

    BActivityIndicator * _hud = [BActivityIndicator showHUDAddedTo: aView animated: YES];
    //    _hud.pleaseWaitLabel.text  = aMessage;

}

+ (void) stopActivityIndicatorInView: (UIView * ) aView {
    // [MBProgressHUD hideHUDForView:aView animated:YES];
    [BActivityIndicator hideHUDForView: aView animated: YES];
}

Output