External Bluetooth Keyboard integration in IOS 7

Question

I need to support external keyboard functionality in my app and need key combinations like Alt+Tab Tab to be detected in the app to trigger some event. In IOS 6 I had overridden the

- (void)sendEvent:(UIEvent *)anEvent;

function in the UIApplication subclass to get the key pressed combinations on external keyboard.

But now I am testing my app in IOS 7 and the sendEvent doesn't even seem to get called for any hardware key pressed event.

Any Solutions..?

Answer 1

There is a 100% supported way to handle keyboard shortcuts on a Bluetooth keyboard in iOS 7 using the new UIKeyCommand class and the UIResponder chain. I did blog about this, but here's the gist:

Somewhere in your Responder chain add a method for keyCommands that returns an array of UIKeyCommand objects:

- (NSArray *)keyCommands {
    UIKeyCommand *commandF = [UIKeyCommand keyCommandWithInput:@"f" modifierFlags:UIKeyModifierCommand action:@selector(handleCommandF:)];
    return @[commandF];
}

Then, when ⌘F is pressed (in a text input view) the Responder chain will look for that handleCommandF method. If there are multiple definitions, it'll use the most tightly scoped one (eg. the View itself takes precedence over a ViewController).

Do note that this will only work when an input (such as UITextField or UITextView) is the first responder. If you want 'global' shortcuts in your app you can do the trick where you hide a UITextField offscreen and focus on that.