Trying to find which text field is active ios

Question

I am trying to find which textfield is active for when the I move the view when the keyboard rises. I am trying to set a property in my viewcontroller from the subview of a

Answer 1

I first used Xilexio's solution but it was slow. I ended up using tags. Here is my code and set up as an example.

@property (nonatomic) NSInteger currentFormField;

typedef NS_ENUM(NSInteger, IOUFormField) {
    IOUFormFieldName,
    IOUFormFieldAmount,
    IOUFormFieldDescription,
    IOUFormFieldDate
};

...

self.nameField.tag = IOUFormFieldName;
self.amountField.tag = IOUFormFieldAmount;
self.descriptionField.tag = IOUFormFieldDescription;
self.dateField.tag = IOUFormFieldDate;

-(void)keyboardWillShow:(NSNotification *)notification {
    // Move the scroll view to a position where the user can see the top and bottom form fields
    // For example, if the user is on the description field, they should be able to see the date field and the amount field.

    // The keyboard rect value comes as a NSValue * (a wrapped NSRect) with origin and size.
    // The origin is using screen coordinates which is pixel based so don't use it.
    // Use the size. Seems like it is density based.
    CGFloat viewableScreenHeight = self.view.frame.size.height - keyboardFrameBeginRect.size.height;

    // When the user is on a form field, get the current form field y position to where the scroll view should move to
    CGFloat currentFormFieldYPosition = 0;
    switch (self.currentFormField) {
        case IOUFormFieldName:
        {
            currentFormFieldYPosition = self.nameField.frame.origin.y;

            // If the scroll view is at the bottom and the user taps on the name field, move the scroll view to the top.
            // This is so that users can see the give/get segments.
            [self.scrollView setContentOffset:CGPointMake(0, 0) animated:YES];

            break;
        }
        case IOUFormFieldAmount:
        {
            currentFormFieldYPosition = self.amountField.frame.origin.y;
            break;
        }
        case IOUFormFieldDescription:
        {
            currentFormFieldYPosition = self.descriptionField.frame.origin.y;
            break;
        }
        case IOUFormFieldDate:
        {
            currentFormFieldYPosition = self.dateField.frame.origin.y;
            break;
        }
        default:
            break;
    }

    // I want the current form field y position to be 100dp from the keyboard y position.
    // 50dp for the current form field to be visible and another 50dp for the next form field so users can see it.
    CGFloat leftoverTopHeight = viewableScreenHeight - 100;

    // If the current form field y position is greater than the left over top height, that means that the current form field is hidden
    // We make the calculations and then move the scroll view to the right position
    if (currentFormFieldYPosition > leftoverTopHeight) {
        CGFloat movedScreenPosition = currentFormFieldYPosition - leftoverTopHeight;
        [self.scrollView setContentOffset:CGPointMake(0, movedScreenPosition) animated:YES];
    }   
}

#pragma mark - UITextFieldDelegate

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
    switch (textField.tag) {
        case IOUFormFieldName:
            self.currentFormField = IOUFormFieldName;
            break;
        case IOUFormFieldAmount:
            self.currentFormField = IOUFormFieldAmount;
            break;
        case IOUFormFieldDescription:
            self.currentFormField = IOUFormFieldDescription;
            break;
        case IOUFormFieldDate:
            self.currentFormField = IOUFormFieldDate;
        default:
            break;
    }

    return true;
}

Let me know if you have any questions and I'll clarify. Note that the comments are for me. Also note that some code or omitted for brevity.