Animating a UIButton fade in/out in a loop

[joec]

Hi

I am going to end up with an array of RSS feeds, and would like a button or some such to display them at the bottom of the view. I would like to animate through each feed in the array.

This is what i have so far to animate, which, works for the fade, but only animates the last item of the array.

feed = [[UIButton alloc] initWithFrame:CGRectMake(0,380,320,43)];
[self.view addSubview:feed];

feed.alpha=1;

NSArray *feeds = [NSArray arrayWithObjects:[NSString stringWithFormat:@"1234567"],
[NSString stringWithFormat:@"qwerty"],[NSString stringWithFormat:@"asdfgh"],nil];

for (NSString* f in feeds){

   [feed setTitle:f forState:UIControlStateNormal];

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
    [UIView setAnimationDuration:2.0f];
    feed.alpha=0;
    [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];
    [UIView commitAnimations];

}

Im sure its simple.

Thanks
Joe

[TUX2K]

feed = [[UIButton alloc] initWithFrame:CGRectMake(0,380,320,43)];
[self.view addSubview:feed];

feed.alpha=1;

NSArray *feeds = [NSArray arrayWithObjects:[NSString stringWithFormat:@"1234567"],
[NSString stringWithFormat:@"qwerty"],[NSString stringWithFormat:@"asdfgh"],nil];

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
[UIView setAnimationDuration:2.0f];
for (NSString* f in feeds){
   [feed setTitle:f forState:UIControlStateNormal];
   feed.alpha=0;
}    
[UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];
[UIView commitAnimations];

Try this.

[joec]

Thanks, I tried that, and it still seems to just animate the last item. Would i need an NSTimer as well?

[TUX2K]

It also looks like you just have one button called feed.
What you could do is in the animationDidStop set the next label via animantion.
And repeat until done.

This way you will not need a timer.

[joec]

I do have only one button called feed, i essentially just want to replace the title of the button, after fading the previous one out...

My animationDidStop method just looks like:

	[UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:2.0f];
	feed.alpha = 0;
	[UIView commitAnimations];

What would i need to change in this?

Thanks.

[TUX2K]

Create a property for feeds array and a property with the current index.

Start with position 0 in your first call and set the current index to 0 and start the first animation

Then in the animation did stop, check if the current index is large then the count of the array.
If not up the curentindex with one and do the animation again.

[joec]

I have done this now, and it animates the first item twice now :s

	if (!(currentIndex > [appDelegate.feeds count])) {
		[UIView beginAnimations:nil context:NULL];
		[UIView setAnimationCurve:UIViewAnimationOptionCurveEaseIn];
		[UIView setAnimationDuration:2.0f];
		[UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];

		Feed *f = [appDelegate.feeds objectAtIndex:currentIndex];
		[feed setTitle:f.author forState:UIControlStateNormal];
		[feed addTarget:self action:@selector(popUpModal:) forControlEvents:UIControlEventTouchUpInside];
		feed.alpha=1;
		
		[UIView commitAnimations];
		currentIndex++;
	}

What have i missed? It's very early here

[TUX2K]

Looks correct to me.

[joec]

Should it be an if or while?

[TUX2K]

If should be just fine, because you call the function every time the animation is stopped.

[joec]

I understand that it should work, but it is behaving weirdly... I've never done animation before, so i am possibly missing something, either in the initial animation call or the didStop method... where do i set currentIndex to 0, before or after the initial animation ?
Thanks

[joec]

OK, so now i have got it Looping through them all, but it still does the first one twice i assume because in the first call when the index is 0, its still matching the if condition...