trouble with rotating view (and resizing elements within) in ipad application

Question

I'm having a nightmare with the rotation on iPad. I've searched all over the place for some tutorials, but nothing seems to really be for what I want. (Possibly not searching for the right thing?!)

I have a portrait view by default which is an image and a button inside the view. When I rotate, I detect this can work out if it's landscape. I then try to set the frame size of the uiview to fit nicely on the screen.

If I let it autoresize, it simply stretches and fills the screen. This I don't want. but the trouble is, when I resize, the button gets resized too, but not in the same ratio as the image.

My question is: What's the best way to resize the view. I wanted to simply reduce the uiview by say 60% and it resizes EVERYTHING in that view with the same 60%. The only way I see this is working at the moment is to create two views... but that's twice the work and maintenance!

I've tried messing with the autosizing arrows in Interface builder, but that again seems to screw things up more!

I'm completely lost here!! Thanks for any info

Answer 1

The problem you have there is that the view is automatically resized to the screen ratio. On an iPad in Portrait Orientation the screen size is 1024x768. After the rotation to Landscape the origin rotates too and your screen content is skewed or stretched to 768x1024.

What you need to do is to override the

-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation duration:(NSTimeInterval)duration

message of the UIViewController of the view which rotates. This message is called within the animation block of the rotation. You just set the framesize of your subviews (the button) to whatever is best for you. Once i had a problem with rotating an OpenGL view. The content of the view was stretched when rotating to landscape. Since it is not possible to alter any OpenGL matrices within the animation block the only solution i found was to make the view quadratic and to set the origin behind the bounds of the screen (in -x direction). You have to override the message also to reset the origin above the screen (in -y direction) bounds in landscape mode, to keep the viewport in the middle of the screen. That way the view kept its ratio. Whatever solution is best for you, overriding this message should work out.