IOS animated pulsing circle like blue ball on maps

iosios6

I'd like to know how to implement the blue ball with the pulsating ring of current location in maps, but without a mapview.

Basically I'd like to know the best way to have a blue ball with a pulsating ring on a normal UIView (or my custom view) whenever the user touches the screen, with that touch being the center of the blue ball.

I have 2 ideas, first I could implement an animation, which I was not able to do, but it is probably possible.
Second I could get a sequence of images, like a gif, and display it wherever the user touches.

Which one is the best option? Or is there a better option?

Thank you.

Best Answer

Try this:

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(200, 200, 100, 100)];
view.backgroundColor = [UIColor blueColor];
view.layer.cornerRadius = 50;

[self.view addSubview:view];

CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
scaleAnimation.duration = 0.2;
scaleAnimation.repeatCount = HUGE_VAL;
scaleAnimation.autoreverses = YES;
scaleAnimation.fromValue = [NSNumber numberWithFloat:1.2];
scaleAnimation.toValue = [NSNumber numberWithFloat:0.8];

[view.layer addAnimation:scaleAnimation forKey:@"scale"];

Set the parameters as you like, to modify the effect.

Edit:

You have to add the QuartzCore framework, and include <QuartzCore/QuartzCore.h> for this to work.

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You will only need a ScrollView if the contents you have now do not fit in the iPhone screen. (If you are adding the ScrollView as the superview of the components just to make the TextField scroll up when keyboard comes up, then it's not needed.)
The standard way to prevent the TextFields from being covered by the keyboard is to move the view up/down whenever the keyboard is shown.

Here is some sample code:

#define kOFFSET_FOR_KEYBOARD 80.0

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-(void)textFieldDidBeginEditing:(UITextField *)sender
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IOS: Modal ViewController with transparent background

For those trying to get this to work in iOS 8, the "Apple-approved" way to display a transparent modal view controller is by setting modalPresentationStyle on the presented controller to UIModalPresentationOverCurrentContext.

This can be done in code, or by setting the properties of the segue in the storyboard.

From the UIViewController documentation:

UIModalPresentationOverCurrentContext

A presentation style where the content is displayed over only the parent view controller’s content. The views beneath the presented content are not removed from the view hierarchy when the presentation finishes. So if the presented view controller does not fill the screen with opaque content, the underlying content shows through.

When presenting a view controller in a popover, this presentation style is supported only if the transition style is UIModalTransitionStyleCoverVertical. Attempting to use a different transition style triggers an exception. However, you may use other transition styles (except the partial curl transition) if the parent view controller is not in a popover.

Available in iOS 8.0 and later.

https://developer.apple.com/documentation/uikit/uiviewcontroller

The 'View Controller Advancements in iOS 8' video from WWDC 2014 goes into this in some detail.

Note:

Be sure to give your presented view controller a clear background color, lest it not actually be see-through!
You have to set this before presenting ie setting this parameter in the viewDidLoad of the presentedViewController won't have any affect

Best Answer

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