keyboard obeserver ios - objective-c

Question

I have a UIView and i'm trying to make it follow the keyboard when the user move the keyboard. imagine the user having a scrollview and a open keyboard, the user want to scroll down which makes the keyboard to close half way, the keyboard origin.y change. the problem is when the keyboard is open and moving no event is being called else you literally close the keyboard.
I tried using the keyboard delegate + textfield delegate which is:
* UIKeyboardWillShowNotification
* UIKeyboardDidShowNotification
* UIKeyboardWillHideNotification
* UIKeyboardDidHideNotification
* UIKeyboardWillChangeFrameNotification
* textFieldDidBeginEditing:
* textFieldShouldBeginEditing:
* textFieldDidEndEditing:
* textFieldShouldEndEditing:
All those methods are being called only when keyboard is about to open/dismiss and what is happening is that when the user is moving the keyboard the UIView wont move as it wait for one of those observers to be called.
What i am basically looking for is a way to observe the keyboard origin.y (shown height) whenever its value change

Answer 1

Put this code below
#import
static const CGFloat KEYBOARD_ANIMATION_DURATION = 0.3;
static const CGFloat MINIMUM_SCROLL_FRACTION = 0.2;
static const CGFloat MAXIMUM_SCROLL_FRACTION = 0.8;
static const CGFloat PORTRAIT_KEYBOARD_HEIGHT = 216;
static const CGFloat LANDSCAPE_KEYBOARD_HEIGHT = 140;
textfieldDelegate
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
CGRect viewRect = [self.view.window convertRect:self.view.bounds fromView:self.view];
CGFloat midline = textFieldRect.origin.y + 0.5 * textFieldRect.size.height;
CGFloat numerator = midline - viewRect.origin.y - MINIMUM_SCROLL_FRACTION * viewRect.size.height;
CGFloat denominator = (MAXIMUM_SCROLL_FRACTION - MINIMUM_SCROLL_FRACTION) * viewRect.size.height;
CGFloat heightFraction = numerator / denominator;
if (heightFraction < 0.0)
{
heightFraction = 0.0;
}
else if (heightFraction > 1.0)
{
heightFraction = 1.0;
}
UIInterfaceOrientation orientation =
[[UIApplication sharedApplication] statusBarOrientation];
if (orientation == UIInterfaceOrientationPortrait ||
orientation == UIInterfaceOrientationPortraitUpsideDown)
{
animatedDistance = floor(PORTRAIT_KEYBOARD_HEIGHT * heightFraction);
}
else
{
animatedDistance = floor(LANDSCAPE_KEYBOARD_HEIGHT * heightFraction);
}
CGRect viewFrame = self.view.frame;
viewFrame.origin.y -= animatedDistance;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrame];
[UIView commitAnimations];
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
CGRect viewFrame = self.view.frame;
viewFrame.origin.y += animatedDistance;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrame];
[UIView commitAnimations];
}
-(BOOL)textFieldShouldReturn:(UITextField*)textField
{
NSInteger nextTag = textField.tag + 1;
// Try to find next responder
UIResponder* nextResponder = [textField.superview viewWithTag:nextTag];
if (nextResponder)
{
// Found next responder, so set it.
[nextResponder becomeFirstResponder];
}
else
{
//Not found, so remove keyboard.
[textField resignFirstResponder];
}
return NO; // We // We do not want UITextField to insert line-breaks.
}