title: Focus on UITextField does not work
body: <p><br>
  In my iPhone application I have a UIScrollView with several UITextFields.<br>
  Using BSKeyboardControls I have added Prev/Next/Done buttons to move between the fields. However, the focus on the selected field is not working, meaning that the text field is actually still under the keyboard although selected.<br>
  <code>becomeFirstResponder</code> is activated but just don't set the focus.<br>
  Any ideas what might be wrong?<br>
  Thanks<br><br>
  In the H file</p>
  
  <pre><code>#import "BSKeyboardControls.h"
  ...
  @interface AddClientViewController : BaseViewController&lt;UIAlertViewDelegate, UIScrollViewDelegate, UIPickerViewDelegate, UIPickerViewDataSource, UITextFieldDelegate, UITextViewDelegate, BSKeyboardControlsDelegate&gt;
  ...
  @property (strong, nonatomic) IBOutlet UITextField *firstName;
  @property (strong, nonatomic) IBOutlet UITextField *lastName;
  @property (strong, nonatomic) IBOutlet UITextField *email;
  @property (strong, nonatomic) IBOutlet UITextField *mobile;
  @property (strong, nonatomic) IBOutlet UITextField *birthday;
  @property (strong, nonatomic) IBOutlet UITextField *anniversary;
  @property (strong, nonatomic) IBOutlet UITextField *street;
  @property (strong, nonatomic) IBOutlet UITextField *city;
  @property (strong, nonatomic) IBOutlet UITextField *state;
  @property (strong, nonatomic) IBOutlet UITextField *zip;
  @property (strong, nonatomic) IBOutlet UIScrollView *scrollView;
  
  @property (nonatomic, strong) BSKeyboardControls *keyboardControls;
  ....
  </code></pre>
  
  <p>In M file</p>
  
  <pre><code>- (void)viewDidLoad
  {
  ...
      NSArray *fields = @[ self.firstName, self.lastName,
      self.email, self.mobile,
      self.birthday, self.anniversary,
      self.street, self.city, self.state, self.zip];
  
      [self setKeyboardControls:[[BSKeyboardControls alloc] initWithFields:fields]];
      [self.keyboardControls setDelegate:self];
  }
  
  - (void)keyboardControlsDonePressed:(BSKeyboardControls *)keyboardControls
  {
      [keyboardControls.activeField resignFirstResponder];
  }
  - (void)keyboardControls:(BSKeyboardControls *)keyboardControls directionPressed:(BSKeyboardControlsDirection)direction
  {
      UIView *view = keyboardControls.activeField.superview.superview;
      [self.scrollView scrollRectToVisible:view.frame animated:YES];
  }
  - (void)keyboardControls:(BSKeyboardControls *)keyboardControls selectedField:(UIView *)field inDirection:(BSKeyboardControlsDirection)direction
  {
      UIView *view = keyboardControls.activeField.superview.superview;
      [self.scrollView scrollRectToVisible:view.frame animated:YES];
  }
  - (void)textFieldDidBeginEditing:(UITextField *)textField
  {
      [self.keyboardControls setActiveField:textField];
  }
  - (void)textViewDidBeginEditing:(UITextView *)textView
  {
      [self.keyboardControls setActiveField:textView];
  }
  </code></pre>
  
  <p>The setActiveField in BSKeyboardControls</p>
  
  <pre><code>- (void)setActiveField:(id)activeField
  {
      if (activeField != _activeField)
      {
          if ([self.fields containsObject:activeField])
          {
              _activeField = activeField;
  
              if (![activeField isFirstResponder])
              {
                  [activeField becomeFirstResponder];
              }
  
              [self updateSegmentedControlEnabledStates];
          }
      }
  }
  </code></pre>