Question

I’ve been adding support for rotation for an app recently and it has been a pain. One thing I’m finding that’s fairly consistently annoying is that one of my views shifts up by about 50 pixels or so everytime I rotate between my landscape and portrait mode.

My landscape mode is not actually the same view controller; I push a viewcontroller when I rotate. However, when I rotate back, I have to reset the portrait’s view.bounds or else my view ends up shifting upwards.

So in my rotation code, I have to do this:

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    UIInterfaceOrientation toOrientation = self.interfaceOrientation;

    if ( self.tabBarController.view.subviews.count >= 2 )
    {
        if(toOrientation == UIInterfaceOrientationPortrait)
        {
            self.tabBarController.tabBar.hidden = NO;
            self.navigationController.navigationBar.hidden = NO;
            CGFloat height = [[UIScreen mainScreen] bounds].size.height;
            CGFloat width = [[UIScreen mainScreen] bounds].size.width;
            self.view.bounds = CGRectMake(0, -55, width, height);
        }
    }
}

Surely this can’t be right. In my app, there is a navbar and the standard status bar (batt life, reception, etc) occupying the top of my app. But…it seems like my view is slipping too upwards unless I set the y coordinate origin to be negative (which makes no sense!).

What’s happening?

Answer 1

In my app, I hide the tabbar and navbar when I go to landscape mode. The statements to make the bars hidden are written into the portrait view’s viewcontroller’s code.

When I transition back from landscape mode to portrait mode, the landscape viewcontroller gets popped and I get the weird shifted views. Turns out this was caused by the order in which the tab/nav bar un-hiding statements.

My tab/nav bar un-hiding statements were in the portrait viewcontroller, so they were called too late. After moving the tab/nav un-hiding statements to the rotation code in the landscape viewcontroller (rather than the portrait’s viewcontroller), my problem disappeared.