Custom iPhone Keyboard

Question

I need (i.e. a customer requirement) to provide a custom keyboard for the user to type text into both text fields and areas. I already have something that does the keyboard

Answer 1

You can do it with iOS 3.2 or later. Check the inputView property of UITextField for details.

Answer 2

Here's an idea: modify the existing keyboard to your own needs. First, register to be notified when it appears on screen:

[[NSNotificationCenter defaultCenter] addObserver:self 
                                      selector:@selector(modifyKeyboard:)
                                      name:UIKeyboardWillShowNotification
                                      object:nil];

Then, in your modifyKeyboard method:

- (void)modifyKeyboard:(NSNotification *)notification 
{
    UIView *firstResponder = [[[UIApplication sharedApplication] keyWindow] performSelector:@selector(firstResponder)];

    for (UIWindow *keyboardWindow in [[UIApplication sharedApplication] windows])
        for (UIView *keyboard in [keyboardWindow subviews])
            if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)
            {
                MyFancyKeyboardView *customKeyboard = [[MyFancyKeyboardView alloc] initWithFrame: CGRectMake(0, 0, keyboard.frame.size.width, keyboard.frame.size.height);
                [keyboard addSubview: customKeyboard];
                [customKeyboard release];
            }
}

This adds your view on top of the original keyboard, so make sure you make it opaque.

Answer 3

It depends how custom you want it. I personally wanted a numeric only keyboard, but didn't like the number pad, so I used the standard keyboard and added in a standard filter, which is part of the options, which rejects all the key presses that aren't numbers or space or delete.

I can't say whether Apple would like this though, and you're going to have a very hard time writing your own behavior that acts like the other keyboards. So much so, that it should be declared a bad idea.

update based on your comment it sounds more like you just need to create a view with a lot of buttons on it, and move this view around with the animate option turned on. It could then sort of slide up from the bottom like a keyboard and slide away again when dismissed.

Answer 4

As long as you're not submitting your app to the app store, you can use a technique called method swizzling to dynamically replace methods of core classes at runtime. For example:

@interface UIControl(CustomKeyboard)
- (BOOL)__my__becomeFirstResponder
@end

@implementation UIControl(CustomKeyboard)
- (BOOL)__my__becomeFirstResponder
{
    BOOL becameFirstResponder = [self __my__becomeFirstResponder];
    if ([self canBecomeFirstResponder]) {
        [MyKeyboard orderFront];
    }
    return becameFirstResponder;
}

+ (void)initialize
{
    Method old = class_getInstanceMethod(self, @selector(becomeFirstResponder));
    Method new = class_getInstanceMethod(self, @selector(__my__becomeFirstResponder));
    method_exchangeImplementations(old, new);
}
@end

Please don't use anything like this in any production code. Also, I haven't actually tested this, so YMMV.