Programmatically align a toolbar on top of the iPhone keyboard

Question

In several cases I want to add a toolbar to the top of the iPhone keyboard (as in iPhone Safari when you're navigating form elements, for example).

Currently I am specifying the toolbar's rectangle with constants but because other elements of the interface are in flux - toolbars and nav bars at the top of the screen - every time we make a minor interface change, the toolbar goes out of alignment.

Is there a way to programmatically determine the position of the keyboard in relation to the current view?

Solution 1

As of iOS 3.2 there's a new way to achieve this effect:

UITextFields and UITextViews have an inputAccessoryView property, which you can set to any view, that is automatically displayed above and animated with the keyboard.

Note that the view you use should neither be in the view hierarchy elsewhere, nor should you add it to some superview, this is done for you.

Solution 2

This is based on the existing answer from tonklon - I'm just adding a code snippet that shows a semi transparent black toolbar on top of the keyboard, together with a "done" button on the right:

UIToolbar *toolbar = [[[UIToolbar alloc] init] autorelease];
[toolbar setBarStyle:UIBarStyleBlackTranslucent];
[toolbar sizeToFit];

UIBarButtonItem *flexButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
UIBarButtonItem *doneButton =[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(resignKeyboard)];

NSArray *itemsArray = [NSArray arrayWithObjects:flexButton, doneButton, nil];

[flexButton release];
[doneButton release];
[toolbar setItems:itemsArray];

[aTextField setInputAccessoryView:toolbar];

and the -resignKeyboard looks like:

-(void)resignKeyboard {
  [aTextField resignFirstResponder];
}

Hope that helps someone.

Solution 3

If you register for keyboard notifications, ie UIKeyboardWillShowNotification UIKeyboardWillHideNotification, etc, the notification you receive will contain the bounds of the keyboard in the userInfo dict (UIKeyboardBoundsUserInfoKey).

See the UIWindow class reference.

Solution 4

In 3.0 and above you can get the animation duration and curve from the userInfo dictionary of the notifications.

for instance, to animate the size of the view to make room for the keyboard, register for the UIKeyboardWillShowNotification and do something like the following:

- (void)keyboardWillShow:(NSNotification *)notification
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationCurve:[[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
    [UIView setAnimationDuration:[[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];

    CGRect frame = self.view.frame;
    frame.size.height -= [[[notification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] CGRectValue].size.height;
    self.view.frame = frame;

    [UIView commitAnimations];
}

Do a similar animation for UIKeyboardWillHideNotification.

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