Core Animation Basic Example

gistfile1.m

- (void)viewDidLoad
{
    UIView* sampleView = [[UIView alloc] init];
    [self.view addSubview:sampleView];
    sampleView.backgroundColor = [UIColor redColor];
    
    
    // define center of view
    CGPoint currentCenterPoint = self.view.center;
    CGRect invisibleRect = CGRectMake(currentCenterPoint.x, currentCenterPoint.y, 0, 0);
    
    NSArray* randomValueArray = @[@276.23, @839.32, @894.3, @263.4];
    NSNumber* randomValue = [randomValueArray objectAtIndex:arc4random() % randomValueArray.count];
    NSNumber* randomValue2 = [randomValueArray objectAtIndex:arc4random() % randomValueArray.count];
    NSNumber* randomValue3 = [randomValueArray objectAtIndex:arc4random() % randomValueArray.count];
    NSNumber* randomValue4 = [randomValueArray objectAtIndex:arc4random() % randomValueArray.count];
    
    NSLog(@"randomValue = %@", randomValue);
    
    // origin x
    // centerX - finalWidth/2
    
    // origin y
    // centerY - finalHeight/2
    CGRect visibleRect = CGRectMake(currentCenterPoint.x - ([randomValue integerValue]/10)/2, currentCenterPoint.y - ([randomValue2 integerValue]/10)/2, [randomValue integerValue]/10, [randomValue2 integerValue]/10);
    CGRect visibleRect2 = CGRectMake(currentCenterPoint.x - ([randomValue3 integerValue]/10)/2, currentCenterPoint.y - ([randomValue4 integerValue]/10)/2, [randomValue3 integerValue]/10, [randomValue4 integerValue]/10);
    
    // 99% of animations are frame manipulations
    sampleView.frame = invisibleRect;
    
    double delayInSeconds = 2.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        
        
        
        [UIView animateWithDuration:0.3f animations:^{
            sampleView.bounds = visibleRect;
        } completion:^(BOOL finished) {
            [UIView animateWithDuration:0.3f animations:^{
                sampleView.bounds = invisibleRect;
            } completion:^(BOOL finished) {
                [UIView animateWithDuration:0.3f animations:^{
                    sampleView.bounds = visibleRect2;
                } completion:nil];
            }];
        }];
    });
    
}