UIScrollView with pages enabled and device rotation/orientation changes (MADNESS)

Question

I'm having a hard time getting this right.

I've got a UIScrollView, with paging enabled. It is managed by a view controller (MainViewController) and each page is managed by a PageViewController, its view added as a subview of the scrollView at the proper offset. Scrolling is left-right, for standard orientation iPhone app. Works well. Basically exactly like the sample provided by Apple and also like the Weather app provided with the iPhone.

However, when I try to support other orientations, things don't work very well. I've supported every orientation in both MainViewController and PageViewController with this method:

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
     return YES;
}

However, when I rotate the device, my pages become quite skewed, and there are lots of drawing glitches, especially if only some of the pages have been loaded, then I rotate, then scroll more, etc... Very messy.

I've told my views to support auto-resizing with

 theView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

But to no avail. It seems to just stretch and distort my views.

In my MainViewController, I added this line in an attempt to resize all my pages' views:

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * ([self.viewControllers count]), self.scrollView.frame.size.height);

    for (int i = 0; i < [self.viewControllers count]; i++) {
        PageViewController *controller = [self.viewControllers objectAtIndex:i];
        if ((NSNull *)controller == [NSNull null])
            continue;

        NSLog(@"Changing frame: %d", i);
        CGRect frame = self.scrollView.frame;
        frame.origin.x = frame.size.width * i;
        frame.origin.y = 0;
        controller.view.frame = frame;
    }
}

But it didn't help too much (because I lazily load the views, so not all of them are necessarily loaded when this executes).

Is there any way to solve this problem?

Answer 1

Is it necessary to have a separate UIViewController (PageViewController) for every page in your UIScrollView? Why not let your MainViewController take care of this.

Resizing your views (and your UI in general) after rotating the device is much easier when you build your UI in Interface Builder.