Control cursor position in UITextField

Question

I have a UITextField that I\'m forcing formatting on by modifying the text inside the change notification handler. This works great (once I solved the reentranc

Answer 1

Controlling cursor position in a UITextField is complicated because so many abstractions are involved with input boxes and calculating positions. However, it's certainly possible. You can use the member function setSelectedTextRange:

[input setSelectedTextRange:[input textRangeFromPosition:start toPosition:end]];

Here's a function which takes a range and selects the texts in that range. If you just want to place the cursor at a certain index, just use a range with length 0:

+ (void)selectTextForInput:(UITextField *)input atRange:(NSRange)range {
    UITextPosition *start = [input positionFromPosition:[input beginningOfDocument] 
                                                 offset:range.location];
    UITextPosition *end = [input positionFromPosition:start
                                               offset:range.length];
    [input setSelectedTextRange:[input textRangeFromPosition:start toPosition:end]];
}

For example, to place the cursor at idx in the UITextField input:

    [Helpers selectTextForInput:input 
                        atRange:NSMakeRange(idx, 0)];