Added overload to support custom frame.

[krummler]

Custom frame enables easy use to display the scanner in a UIPopoverController instead of showing it full-screen. An example can be found in the zxing-ipad-example project.

[zxing]

This is a read-only mirror of zxing. Patches should be posted to the zxing google group. Thanks!

[krummler]

curl https://github.com/zxing/zxing/pull/5.patch

[smparkes]

Sure, I know how to get it, but it's more likely to get review if you add it as an issue at http://code.google.com/p/zxing/issues/list. That's the official issue list. (I maintain the gh mirror for benefit of myself and others, but it's not officially sanctioned by the project.)