Fade in/out a view.

gistfile1.m

-(void) animateGridView:(BOOL)animateIn {

    CAMediaTimingFunction *timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
    CABasicAnimation *scaleAnim = [CABasicAnimation animationWithKeyPath:@"transform"];
    CABasicAnimation *opacityAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
    
    scaleAnim.timingFunction = opacityAnim.timingFunction = timingFunction;
    
    CATransform3D endTransform;
    CATransform3D fullScale = CATransform3DMakeScale(1, 1, 1);
    CATransform3D smallScale = CATransform3DMakeScale(0.75, 0.75, 1);
    float endOpacity;
    
    if(animateIn) {
        scaleAnim.fromValue = [NSValue valueWithCATransform3D:smallScale];
        endTransform = fullScale;
        opacityAnim.fromValue = [NSNumber numberWithFloat:0];
        endOpacity = 1.0;
    } else {
        scaleAnim.fromValue = [NSValue valueWithCATransform3D:fullScale];
        endTransform = smallScale;
        opacityAnim.fromValue = [NSNumber numberWithFloat:1];
        endOpacity = 0.0;
    }

    opacityAnim.toValue = [NSNumber numberWithFloat:endOpacity];
    scaleAnim.toValue = [NSValue valueWithCATransform3D:endTransform];
    
    // Necessary to retain transformed properties after animation completes.
    self.gridView.layer.transform = endTransform;
    self.gridView.layer.opacity = endOpacity;
    
    CAAnimationGroup *animGroup = [CAAnimationGroup animation];
    animGroup.animations = [NSArray arrayWithObjects:scaleAnim, opacityAnim, nil];
    animGroup.duration = 0.5;

    [self.gridView.layer addAnimation:animGroup forKey:nil];
}