Maintaining proportions when autorotating custom UIView

Question

This is probably either real easy, real dumb, or my google fu has taken a serious turn for the worse. Anyway, I'm implementing custom view for my app, which is using pure CGContext drawing, no subviews (for now at least). The thing is, I want it to autorotate, so I have shouldAutorotateToInterfaceOrientation return YES, and voila, the view rotates. But in doing so it's not actually redrawing the content (which I assume is rendered into a texture somewhere in the framework and splashed onto a rect, but that's not really relevant here), the rect is simply stretched, squishing the content. How can I get it to simply issue a draw of a bigger area while rotating? That is, my content is bigger than the screen, and I'd simply like the viewport to change during the rotation.

I've tried setting the view's contentMode to UIViewContentModeRedraw , but that didn't do anything, I've tried playing around with the autoresizeMask stuff, but didn't seem to help either. I've also tried inserting a setNeedsDisplay in willRotateToInterfaceOrientation , however that only caused it to redraw using the new bounds (ie squishing it first, and then stretching it out to the right size during the rotation), which is also not what I'd like to see.

Does anyone have any idea how I might go about getting this to work?

Answer 1

As it turns out, it's a mix of dumb and easy. I'm posting it here if anyone should care to read it someday. They way I managed to solve it was actually sandwiching a view between window and my view (I suppose you might be able to go to work on the window directly, but it felt more intuitive this way). That is, I added my view as a child view to that view, which I'll call the frame.

The frame is a resizing as normal, however, I turn OFF resizing of child views, and make my own view LARGER than the viewing area (square actually, 480x480, so it can cover the entire screen either way). Problem solved, basically.

Now I'm playing around with animating the offset of the view in the frame during willRotateToInterfaceOrientation , to have it appear to be rotating around the center, rather than the upper left corner, but that's a different question.