Animating a border around UlLabel frame using Objective C in iOS - ios

Question

I am working on an iPhone application using Objective C, where I need to make a border animation to UILabel.
I tried below code using CABasicAnimation :
CABasicAnimation* borderAnimation = [CABasicAnimation animationWithKeyPath:#"borderWidth"];
[borderAnimation setFromValue:[NSNumber numberWithFloat:4.0f]];
[borderAnimation setToValue:[NSNumber numberWithFloat:0.0f]];
[borderAnimation setRepeatCount:1.0];
[borderAnimation setAutoreverses:NO];
[borderAnimation setDuration:0.7f];
[focusScannerView.layer addAnimation:borderAnimation forKey:#"animateBorder"];
But border animation is not working perfectly. Anybody have an idea of how would I do this? Thank you in Advance.

Answer 1

#import "ViewController.h"
#interface ViewController ()
{
UIBezierPath *path;
CAShapeLayer *shapeLayer;
int lineNo;
}
#property (nonatomic, weak) IBOutlet UILabel *textLabel;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
path = [UIBezierPath bezierPath];
shapeLayer = [CAShapeLayer layer];
shapeLayer.strokeColor = [[UIColor blueColor] CGColor];
shapeLayer.lineWidth = 3.0;
shapeLayer.fillColor = [[UIColor clearColor] CGColor];
[_textLabel addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(startAnimation)]];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)startAnimation{
lineNo = 0;
[self drawLine:lineNo];
}
-(void)drawLine:(int)line{
CGPoint startPoint;
CGPoint endPoint;
switch (line) {
case 0:
startPoint = CGPointMake(self.textLabel.frame.origin.x, self.textLabel.frame.origin.y);
endPoint = CGPointMake(CGRectGetMaxX(self.textLabel.frame), self.textLabel.frame.origin.y);
break;
case 1:
startPoint = CGPointMake(CGRectGetMaxX(self.textLabel.frame), self.textLabel.frame.origin.y);
endPoint = CGPointMake(CGRectGetMaxX(self.textLabel.frame), CGRectGetMaxY(self.textLabel.frame));
break;
case 2:
startPoint = CGPointMake(CGRectGetMaxX(self.textLabel.frame), CGRectGetMaxY(self.textLabel.frame));
endPoint = CGPointMake(self.textLabel.frame.origin.x, CGRectGetMaxY(self.textLabel.frame));
break;
case 3:
startPoint = CGPointMake(self.textLabel.frame.origin.x, CGRectGetMaxY(self.textLabel.frame));
endPoint = CGPointMake(self.textLabel.frame.origin.x, self.textLabel.frame.origin.y);
break;
default:
return;
}
[self animateStartPoint:startPoint andEndPoint:endPoint];
}
-(void)animateStartPoint:(CGPoint) startPoint andEndPoint:(CGPoint)endPoint{
[path moveToPoint:startPoint];
[path addLineToPoint:endPoint];
shapeLayer.path = [path CGPath];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.duration = 5;
animation.removedOnCompletion = NO;
animation.fromValue = #(0);
animation.toValue = #(1);
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
[shapeLayer addAnimation:animation forKey:#"drawLineAnimation"];
[self.view.layer addSublayer:shapeLayer];
lineNo++;
[self drawLine:lineNo];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end