Animate UIButton state change

Question

I\'m using a UIButton with images for normal and highlighted states. They work as expected but I want to have some fading/merging transition and not just a sudden swap.

Answer 1

To accomplish that I extended UIButton. added a new property called hilightedImage with the following code:

- (void)setHilightImage:(UIImageView *)_hilightImage
{
    if (hilightImage != _hilightImage) {
        [hilightImage release];
        hilightImage = [_hilightImage retain];
    }
    [hilightImage setAlpha:0];
    [self addSubview:hilightImage];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.14];
    if(hilightImage){
        [hilightImage setAlpha:1];
    }
    [UIView commitAnimations];
    [super touchesBegan:touches withEvent:event];
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    self.highlighted = FALSE;
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.14];
    if(hilightImage){
        [hilightImage setAlpha:0];
    }

    [UIView commitAnimations];
    [super touchesEnded:touches withEvent:event];
}