iOS: Hidden parts of table view behind keyboard issue - ios

Question

I've been struggling with this for hours now and worked through a lot on stackoverflow and the docs. However I cannot get the apple code running properly in my app.
Here's the complete apple code and from there I afterwards I ask my questions:
// 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;
}
1.: Why do they adjust the insets here? I still don't get that:
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
2: I'm writing with this code a subclass of UITableView in order to use it in all my table views in my app. I never have just a plain table view, usually it's embedded in a superview. Or let's say I usually have a view at the top of my screen, one at the bottom and in the middle between I have my tableview. I want to move my table view up only if a textfield is hidden below the keyboard and only so much that this textfield is visible. I'm saying that because at least in one screen with the keyboard shown only about 2 cells at once are visible. And with the apple code the table view get's scrolled up waaaay to much. I've adjusted the code so far like this (my subclass of tableview has two properties, activeField and activeFieldOriginInSuperView (without that I think it's not possible?) But it's moving the table view still way too much up and the relevant textfield isn't visible anymore...any idea what's wrong?
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize keyBoardSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
CGRect tableFrame = self.frame;
tableFrame.size.height -= keyBoardSize.height;
CGPoint activeFieldOrigin = self.activeFieldOriginInSuperView;
activeFieldOrigin.y -= self.contentOffset.y;
CGPoint activeFieldLowerEnd = CGPointMake(activeFieldOrigin.x, activeFieldOrigin.y + self.activeField.frame.size.height + 5);
if (!CGRectContainsPoint(tableFrame, activeFieldLowerEnd) ) {
CGPoint scrollPoint = CGPointMake(0.0, activeFieldLowerEnd.y - tableFrame.size.height);
[self setContentOffset:scrollPoint animated:YES];
}
}

Answer 1

It will definitely work. It works for me for last 50 applications.
Try this
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardDidShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardDidHide:) name:UIKeyboardWillHideNotification object:nil];
- (void)keyboardDidShow: (NSNotification *) notif{
[UIView animateWithDuration:0.5f delay:0.0f options: UIViewAnimationOptionCurveEaseInOut animations:^{
_scrollView.contentOffset = CGPointMake(0, txtId_.frame.origin.y - 200);
} completion:^(BOOL finished){ }];
}
- (void)keyboardDidHide: (NSNotification *) notif{
[UIView animateWithDuration:0.5f delay:0.0f options: UIViewAnimationOptionCurveEaseInOut animations:^{
_scrollView.contentOffset = self.view.frame.origin;
} completion:^(BOOL finished){ }];
}