Incremental number animation - ios

Question

I have a homepage that showing the value of incomes and expenses. Right now the values just appear on the the screen, however is was wondering whether i can make those number start from 0 and then have an animation to increment that value, like a stopwatch. Is it also possible to make the final number after the increment has finished to animate with a pulse". This is how i am making the label pulsate now but the label becomes bigger from the left had side and not from the center.
[self.view addSubview:_lblTotal];
CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
scaleAnimation.duration = 0.4;
scaleAnimation.repeatCount = HUGE_VAL;
scaleAnimation.autoreverses = YES;
scaleAnimation.fromValue = [NSNumber numberWithFloat:0.8];
scaleAnimation.toValue = [NSNumber numberWithFloat:1.0];
[_lblTotal.layer addAnimation:scaleAnimation forKey:#"scale"];

Answer 1

The following open source UILabel subclass does the scrolling numbers bit you are looking for.
https://github.com/dataxpress/UICountingLabel
Example of the type of usage is:
myLabel.method = UILabelCountingMethodLinear;
[myLabel countFrom:50 to:100 withDuration:5.0f];
I would look to see how that is done and then extend it to add the pulse at the end once the animation for the counting has completed.

Answer 2

yes this is possible.
add a variable with the number to increment
#property (nonatomic) double currentValue;
#property (nonatomic, retain) NSTimer *timer;
initialize it in viewDidLoad
_currentValue = 0.00;
write a function updateNumber
-(void)updateNumber {
_currentValue = _currentValue + 0.01;
[_label setText:[NSString stringWithFormat:#"%.2f", _currentValue]];
if(_currentValue >= 100.0) { //example to stop incrementation on 100
_timer = nil; // stop the timer
// do your animation
}
}
in your viewDidAppear() or whenever you want to start the counting like this
if(_timer == nil) {
_timer = [NSTimer scheduledTimerWithTimeInterval:1.0 //seconds
target:self
selector:#selector(updateNumber)
userInfo:nil
repeats:true];
}

Answer 3

You might want to separate the incrementing number and the pulse animation into two different questions.
On the question of the pulse, the code is correct but the reason it scales off-center is probably due to your view's frame which is bigger than its content, which appears to be right-aligned rather than centered.
If you make _lblTotal's frame fit the content, by calling [_lblTotal sizeToFit]; your pulse animation should work as expected. But then this assumes that you do the right-alignment yourself.

Answer 4

Here is an example code , which will surely help you but you have to customize the timing as it certainly suit my need:-
-(void)viewDidLoad
{
currentValueAmount=0; //provide initial value for your incremented label
targetFloatAmount=1300;//provide the target value up-to which the value will be incremented.
self.lblAmount.text=[NSString stringWithFormat:#"%.2f",currentValueAmount];
[self performSelector:#selector(animateIncrementLabel) withObject:nil afterDelay:0.5f]; // give some delay as per your choice as to load the whole UI first and then calling the method to increment.
}
-(void)animateIncrementLabel
{
self.lblAmount.transform=CGAffineTransformMakeScale(0.000f, 0.000f);
timer = [NSTimer scheduledTimerWithTimeInterval: 0.001 //calling timer , if the label value is very small then increase the no of Zero's for example 0.00001
target: self
selector: #selector(handleTimer:)
userInfo: nil
repeats: YES];
//animating the incremented text with some transform and bounce
[UIView animateWithDuration:2.1 delay:0.2f usingSpringWithDamping:0.4 initialSpringVelocity:0.3 options:0 animations:^{
self.lblAmount.transform=CGAffineTransformMakeScale(1.3, 1.3);
}];
}
- (void) handleTimer: (NSTimer *) timer
{
if(currentValueAmount>targetFloatAmount)
{
self.lblAmount.text=[NSString stringWithFormat:#"%.2f",targetFloatAmount];
[timer invalidate];
timer=nil;
[UIView animateWithDuration:0.5 delay:0.2f usingSpringWithDamping:0.4 initialSpringVelocity:0.3 options:0 animations:^{
self.lblAmount.transform=CGAffineTransformMakeScale(1.0, 1.0);
}];
}
else
{
currentValueAmount=currentValueAmount+0.0008;
self.lblAmount.text=[NSString stringWithFormat:#"%.2f",currentValueAmount];
}
}