scroll textfield covered by keyboard - iphone

Question

Im working on getting my UIscroll to scroll when ever a textfield is blocked by the keyboard by following this documentation
http://developer.apple.com/library/ios/#documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html#//apple_ref/doc/uid/TP40009542-CH5-SW7
However sadly...there is a variable mentioned, activeField and i cannot figure out how it is declared. I would really like if some probably advise how/where it is declared or even a solution to scrolling when the keyboard is activated will help.
Thank you

Answer 1

To answer your specific question, since the Apple Documentation is only ever using activeField for size data, you can simply declare it as a private global UIView *activeField and it will work for textFields, textViews, etc all the same.
However, their code actually doesn't work very well at all. I had to make some changes to their code to get mine to work correctly. This code is basically theirs with some minor tweaks to handle all of the cases listed below:
1) If you have a smaller scrollView nested inside of a view, not full screen scrollView and it still works.
2) If you want to move text fields down to the keyboard focus area as well as move them up from behind the keyboard.
3) Works on textViews and textFields of various sizes
4) If the keyboard is currently showing, it will move any newly tapped fields into the focus area
5) Works if you have your content already scrolled and invoke the keyboard
6) Works on all keyboard sizes for all devices (no hardcoded constants)
First off, create private variables for these:
UIView *_activeField;
CGFloat _keyboardHeight;
BOOL _isShowingKeyboard;
Next, just cut and paste this code into your ViewController (it looks like a lot but it's not that bad).
#pragma mark TextFieldKeyboardScrolling
- (void)registerForKeyboardNotifications {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWasShown:) name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillBeHidden:) name:UIKeyboardWillHideNotification object:nil];
}
- (void)adjustInputFieldsForKeyboard {
CGFloat keyBoardTopInScrollView = self.view.frame.size.height - _keyboardHeight - self.scrollView.frame.origin.y;
CGFloat inputFieldBottomInVisibleScrollView = _activeField.frame.origin.y - self.scrollView.contentOffset.y + 30 /* small buffer for cursor size */;
CGPoint scrollPoint;
if (keyBoardTopInScrollView > inputFieldBottomInVisibleScrollView) {
scrollPoint = CGPointMake(0.0, self.scrollView.contentOffset.y - (keyBoardTopInScrollView - inputFieldBottomInVisibleScrollView));
} else {
scrollPoint = CGPointMake(0.0, self.scrollView.contentOffset.y + (inputFieldBottomInVisibleScrollView - keyBoardTopInScrollView));
}
[self.scrollView setContentOffset:scrollPoint animated:YES];
}
- (void)keyboardWasShown:(NSNotification*)aNotification {
_isShowingKeyboard = YES;
NSDictionary* info = [aNotification userInfo];
_keyboardHeight = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size.height;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, _keyboardHeight, 0.0);
self.scrollView.contentInset = contentInsets;
self.scrollView.scrollIndicatorInsets = contentInsets;
[self adjustInputFieldsForKeyboard];
}
- (void)keyboardWillBeHidden:(NSNotification*)aNotification {
_isShowingKeyboard = NO;
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
self.scrollView.contentInset = contentInsets;
self.scrollView.scrollIndicatorInsets = contentInsets;
}
#pragma mark UITextFieldDelegate
- (void)textFieldDidBeginEditing:(UITextField *)textField {
_activeField = textField;
if (_isShowingKeyboard) {
[self adjustInputFieldsForKeyboard];
}
}
- (void)textFieldDidEndEditing:(UITextField *)textField {
_activeField = nil;
}
That's it, just call [self registerForKeyboardNotifications]; in your viewDidLoad method, hook up your scrollView outlet and textField/textView delegates in storyboard and you're all set.

Answer 2

The keyboard is only active when one of the texfields become active(Became first responder).So you should listen to UITextField delegate method to see when and which uitextfield became first responder.
- (void)textFieldDidBeginEditing:(UITextField *)textField
if you assign a tag to your textfield or make it ivar you can also understand which uitextfield has become active and also get its frame.

Answer 3

I don't use the scroll view or follow the above documentation.
Here is how without using the scroll view
In my
textFieldShouldBeginEditing
CGRect frame = self.view.frame;
frame.origin.y = <some negative value>;
self.view.frame = frame
and in my
textFieldShouldEndEditing
CGRect frame = self.view.frame;
frame.origin.y = <some positive value>; // absolute value of your above negative value
self.view.frame = frame
The above works for me. Remember these are the text field delegate methods. So you need to setup your delegate.