Pop up tutorial page like Photosynth's - objective-c

Question

I want to create something that is basically a clone of what photosynth does for their tutorial page. A small "?" button pops up what looks like a new view in a frame that is slightly smaller than the first view, so that you can still see the first view around the edges.
It's a little tough to see from the pic above, but the part around the edges is the old view that the tutorial display popped up over.
My first guess is that I need to use a container view somehow, but I can't find anything on the web about exactly how to do this. I can currently create a container view, hook it up to a new view controller via a segue, and do whatever I want in that new view controller, but the container view is always visible on the view it is contained within. Any help?
BTW, I'm using storyboarding with ARC.

Answer 1

You can add a transparent view to the key window, add a tap gesture recognizer that would dismiss it and the subviews to show the content:
#define OVERLAY_TAG 997
-(void)showTutorial
{
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView *overlay = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];
overlay.backgroundColor = [UIColor clearColor];
overlay.userInteractionEnabled = YES;
[keyWindow addSubview:overlay];
UITapGestureRecognizer * tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(dismissTutorial)];
CGFloat border = 10;
CGRect frame = overlay.bounds;
// 20 is the status bar height (sorry for using the number)
frame = CGRectMake(border, border + 20, frame.size.width - border * 2, frame.size.height - border * 2 - 20);
// the black view in the example is probably a scroll view
UIView *blackView = [[UIView alloc] initWithFrame:frame];
blackView.backgroundColor = [UIColor blackColor];
blackView.alpha = 0.0;
[overlay addSubview:dimView];
// add all the subviews for your tutorial
// make it appear with an animation
[UIView animateWithDuration:0.3
animations:^{dimView.alpha = 1;}
completion:^(BOOL finished){[overlay addGestureRecognizer:tapRecognizer];}];
}
-(void)dismissTutorial
{
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView *overlay = [keyWindow viewWithTag:OVERLAY_TAG];
[UIView animateWithDuration:0.3
animations:^{
overlay.alpha = 0.0;
}
completion:^(BOOL finished){
[overlay removeFromSuperview];
}];
}
This way you would remove the tutorial with a simple tap but you can use a button for instance.