title: How does - (CGRect)convertRect:(CGRect)rect toView:(UIView *)view work
body: <p>I've been using that kind of methods on and off but never really understood how they behaved.</p>
  
  <p>Every time I try to use them, I find myself poking in the dark as I try different aspect and it never seem to do what I expect it to.</p>
  
  <p>For the sake of argument, I'm trying to convert the frame I get from UIKeyboard's notification.</p>
  
  <p>In landscape mode, I get this NSRect:</p>
  
  <pre><code>UIKeyboardFrameEndUserInfoKey = NSRect: {{406, 0}, {362, 1024}}
  </code></pre>
  
  <p>Now I want to convert it to the proper rect (swap x/y, width and height) so I do </p>
  
  <pre><code>CGRect compatibleRect = [self convertRect:[[[notif userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue] toView:nil];
  </code></pre>
  
  <p>But the rect becomes: </p>
  
  <pre><code>compatibleRect = CGRect: {{406,406}, {362, 1024}}
  </code></pre>
  
  <p>Any help would be appreciated :)</p>