cocoa + what ui element should i use?

Question

hi guys

I am developing an app which has a text field box. so when i am entering text, it should search the database and give me suggestions just like google search. like if i have entered letter 'a', it should have a box like thing below text field with all names starting with letter 'a'. then if i have entered letter 'b', it should resize the box and give names that start with 'ab' and so on.

I was planning to use a table view below the text field which reloads itself as and when new thing is entered into text field. but i dont know how to resize the table view depending on number of suggestions. So is there any other ui element which suits this kind of situations?

Also how do i detect a new alphabet or number entered into text field so that i can filter out suggestions like is there any such notification? what i mean to say is say i entered letter 'a' so now the string value of text field is 'a' and now i entered say 'b'. so now the string value changed to 'ab'. how do i detect this? i think textDidChange notification will do this for me.

Thanks

Answer 1

You can use an NSComboBox for auto-completing lists like you describe. NSComboBox is a subclass of NSControl so you can use the -controlTextDidChange: delegate method to detect changes in the text that the user types. Make sure you set the control to "continuous" in Interface Builder or call [comboBox setContinuous:YES].

Answer 2

If, for whatever reason, you find that a combo box is inappropriate for your situation, you can implement the list of completions as a child window of the control's window, with a headerless table view in it. Then you would programmatically resize that window as the number of possible completions changes.