Find out UITextfield's end editing without resigning first responder

Question

When user is typing in UITextfield, and he stops for 2 seconds, the cursor is still on UITextfield, so how we can identify this event? i.e. I want to check the whether the editing is end or not without resigning the first responser from that UITextField. What is the way to do that?

Answer 1

Yes, we can check that! with UITextField delegate, - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

- (void) callMeAfterTwoSeconds {
    NSLog(@"I'll call after two seconds of inactivity!");
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    [NSRunLoop cancelPreviousPerformRequestsWithTarget:self];
    [self performSelector:@selector(callMeAfterTwoSeconds) withObject:nil afterDelay:2.0];

    return YES;
}

While you're typing (tapping keys from keyboard), it will cancel previous calls for the callMeAfterTwoSeconds function, once you stop, it sets it to call after 2 seconds delay, and yes, it will call after 2 seconds.

Update: Even you can pass that textfield as object to performSelector to know which textfield is inactive, for that your callMeAfterTwoSeconds function will be like,

- (void) callMeAfterTwoSeconds:(UITextField *)textfield {
    if(textfield == txtUserName) {
        NSLog(@"User textfield has NO activity from last two seconds!"); }
}

Answer 2

Go to the connections inspector of your UITextField and connect the "Editing Changed" from the Sent Events list to a predefined IBAction of your choice. Alternatively you can do it programmatically if you are not working with Storyboard.

[youTextField addTarget:self action:@selector(textFieldInputDidChange:) forControlEvents:UIControlEventEditingChanged];

Now the IBAction you've just connected will be fired every time the user changes a character in the UITextField. Create a timer as ivar. Now every time IBAction gets called, start the timer, if it will hit 2sec without being restarted by a new call you know the user hasn't entered/deleted values in the UITextField.

Answer 3

I did this for a searchBar, but I think it works for an UITextField too. The code is in Swift. :)

func searchBar(searchBar: UISearchBar, textDidChange searchText: String) {
    searchTimer?.invalidate()
    searchTimer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("search"), userInfo: nil, repeats: false)
}

func search() {
    println("search \(searchBar.text)")
}

Answer 4

I don't think that calling [NSRunLoop cancelPreviousPerformRequestsWithTarget:self] is a good practice.

Instead I would do:

[self.searchTextField addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
//or select the textfield in the storyboard, go to connections inspector and choose the target for 'Editing Changed'


- (IBAction)textFieldDidChange:(id)sender {
    [self performSelector:@selector(editingChanged:) withObject:self.searchTextField.text afterDelay:2.0]; 
}

- (void)editingChanged:(NSString *)text {
    if ([text isEqualToString:self.searchTextField.text]) {
        //do your thing
    }
}

this way the user can type and it will trigger a call to editingChanged:, then you can double check if the value changed meanwhile, and if it didn't then the user stopped typing for 2 seconds.