How to change the space used by the battery icon on the iPhone?

Question

I noticed that this iPhone app Reeder has a special icon on top of the battery icon. How is this done? It even does animation in that corner so I assume you can just lay an UIView on top of the battery?

Also a side question, how do you overlay a texture on top of NavBar and the bottom Toolbar? Noticed how the bars are not exactly black, it has a texture on it.

alt text http://img689.imageshack.us/img689/1224/photofo.jpg

Answer 1

I would imagine that this app simply creates an UIWindow with it's windowLevel property set to some large value. By doing so, one can make a window appear to be part of the statusbar.

UIWindow *topWindow = [[UIWindow alloc] initWithFrame:CGRectMake(5.0f, 5.0f, 310.0f, 12.0f)];
[topWindow setBackgroundColor:[UIColor redColor]];
[topWindow setAlpha:0.5f];
[topWindow setWindowLevel:10000.0f];
[topWindow setHidden:NO];