title: how to move cursor in UITextField after setting its value
body: <p>can anybody help me with this: i need to implement <code>UITextField</code> for input number. This number should always be in decimal format with 4 places e.g. 12.3456 or 12.3400.
  So I created <code>NSNumberFormatter</code> that helps me with decimal places.</p>
  
  <p>I am setting the <code>UITextField</code> value in</p>
  
  <p><code>-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string</code>
   method. 
  I proccess input, use formatter and finally call <code>[textField setText: myFormattedValue];</code></p>
  
  <p>This works fine but this call also moves the cursor to the end of my field. That is unwanted. E.g. I have 12.3400 in my field and the cursor is located on the very beginning and user types number 1. The result value is 112.3400 but cursor is moved at the end. I want to end with cursor when the user expects (just after the number 1 recently added). There are some topics about setting cursor in <code>TextView</code> but this is <code>UITextField</code>. I also tried to catch <code>selectedTextRange</code> of the field, which saves the cursor position properly but after <code>setText</code> method call, this automatically changes and the origin <code>UITextRange</code> is lost (changed to current). hopefully my explanation is clear.</p>
  
  <p>Please, help me with this. thank you very much. </p>
  
  <p><strong>EDIT</strong> : Finally, i decided to switch the functionality to changing the format after whole editing and works good enough. I have done it by adding a selector <code>forControlEvents:UIControlEventEditingDidEnd</code>.</p>