Textfields under keyboard - ios

Question

In my app there are few forms. Sometimes keyboard hides fields so user can't see what he it typing. For that case I found way to move view or scrollview up so textfields stays above keyboard.
Problem is that on iPhone 5 I need to move view up for last 3 textfields but for iPhone 6 - only for the last textfield.
Of corse I can define all cases of fields and device screen height values.
But I want to find more elegant solution to detect is texfield is under the keyboard on current device and is it necessary to move view?

Answer 1

Use TPKeyboardAvoidingScrollView. Its easy to use
drop the TPKeyboardAvoidingScrollView.m and TPKeyboardAvoidingScrollView.h source files into your project, pop a UIScrollView into your view controller's xib, set the scroll view's class to TPKeyboardAvoidingScrollView, and put all your controls within that scroll view. You can also create it programmatically, without using a xib - just use the TPKeyboardAvoidingScrollView as your top-level view.

Answer 2

There is a great help guide by Apple here
You need to listen to keyboard notifications like
// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWillBeHidden:)
name:UIKeyboardWillHideNotification object:nil];
}
// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
// If active text field is hidden by keyboard, scroll it so it's visible
// Your app might not need or want this behavior.
CGRect aRect = self.view.frame;
aRect.size.height -= kbSize.height;
if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
[self.scrollView scrollRectToVisible:activeField.frame animated:YES];
}
}
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
}

Answer 3

You can detect which UITextField is the "Active" one by using its delegate method - (void)textFieldDidBeginEditing:(UITextField *)textField.
Use textField.frame to calculate the offset you need to set for scrollView.contentOffset.
In the - textFieldDidBeginEditing: method you can reset the contentOffset = CGPointZero