Trouble with controlling a ScrollView from a Popover - ios

Question

I'm a junior and I have been really struggling to get this to work, would really appreciate some help.
I am trying to build an App where you can scroll through different WebViews by selecting an item from a table in a popover (while the popover remains in place). Unfortunately, I can't get my scrollView to move when I select an item from the popover view.
I have set up a UIScrollView with page control in a main UIViewController. The scrollView is populated with (pageViewController) UIWebViews. The main UIViewController has a nav bar with a button, when the button is clicked it creates a Popover View. When I select an item from the table in the popover view I want my UIScrollView to scroll to a certain position (equates to a selected page), but the scrollView does not move.
The method below takes the value selected from the popover and uses the page number to determine where the scrollView should scroll to, but it doesn't work because at this point my scrollView is Null.
I can supply more code if needed.
main UIViewController.m code:
- (void)setDetailItem:(id)newDetailItem {
if (detailItem != newDetailItem) {
[detailItem release];
detailItem = [newDetailItem retain];
NSString *pgnum = [[NSString alloc] initWithString:[detailItem description]];
int pg;
if(pgnum == #"Page 1"){
pg =1;
}
if(pgnum == #"Page 2"){
pg =2;
}
if(pgnum == #"Page 3"){
pg =3;
}
[pgnum release];
pageControl.currentPage = pg;
[self loadScrollViewWithPage:pg - 1];
[self loadScrollViewWithPage:pg];
[self loadScrollViewWithPage:pg + 1];
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * pg;
frame.origin.y = 0;
[scrollView scrollRectToVisible:frame animated:YES];
pageControlUsed = YES;
}
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
}
This is how I triggered the popOverController
The infoButton is on the navbar.
The scrollView is NOT NULL in the infoButton
- (void)infoButton:(id)sender {
NSLog(#"Entering: infoButton");
// [self inspectView:self.view level:#""];
if (self.popoverController == nil) {
PopoverViewController *popoverViewController =
[[PopoverViewController alloc]
initWithNibName:#"PopoverViewController"
bundle:[NSBundle mainBundle]];
popoverViewController.navigationItem.title = #"Navigation";
UINavigationController *navController =
[[UINavigationController alloc]
initWithRootViewController:popoverViewController];
UIPopoverController *popover =
[[UIPopoverController alloc]
initWithContentViewController:navController];
popover.delegate = self;
[popoverViewController release];
[navController release];
self.popoverController = popover;
[popover release];
//NSLog(#"User pressed the info button");
}
[self.popoverController presentPopoverFromBarButtonItem:sender permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; }

Answer 1

UIPopover, being neither the most obvious class to use memory-management wise, nor the most stable, does not require you to release it before you present it. In fact, doing so causes it to throw a fatal exception! Popovers should be released after they are removed from the screen, and/or in -dealloc.